Effects of Combination of Curcumin and Piperine Supplementation on Glycemic Profile in Patients with Prediabetes and Type 2 Diabetes Mellitus: A Systematic Review and Meta-analysis.

Objective: This study aimed to evaluate the effects of the combination of curcumin and piperine supplementation on Fasting Plasma Glucose (FPG), Homeostatic Model of Insulin Resistance (HOMA-IR), and Body Mass Index (BMI) in patients with prediabetes and type 2 Diabetes Mellitus (T2DM). This review was done to identify potential herbal remedies that may help improve glycemic parameters, leading to better health outcomes in combination with current antidiabetic treatment. Methodology: This systematic review was based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). It was conducted in 2023 with sources and databases from MEDLINE, EBSCO-Host, ScienceDirect and ProQuest. This paper included randomized-controlled trials exploring the effects of the combination of curcumin and piperine on patients with prediabetes and T2DM. Systematic reviews, observational studies, case reports, case series, conference abstracts, book sections, commentaries/editorials, non-human studies and articles with unavailable full-text and written in non-English language, were excluded. The key terms for the literature search were "curcumin," "piperine," "prediabetes" and "Type 2 Diabetes Mellitus." We use Cochrane Risk of Bias (RoB) 2 for quality assessment of the included studies and Review Manager (RevMan) 5.4 to do the meta-analysis. Results: A total of three studies were included in this systematic review. Two studies from Neta et al., and Cicero et al., showed no significant difference in HOMA-IR, BMI and FPG levels between the curcumin, piperine and placebo groups. One study from Panahi et al. demonstrated a significant difference in BMI levels between the curcumin and piperine and placebo groups (p <0.01). The meta-analysis showed that FPG levels, HOMA-IR and BMI improved among patients with diabetes given in curcumin and piperine with reported mean differences (MD) of = -7.61, 95% CI [-15.26, 0.03], p = 0.05, MD = -0.36, 95% CI [-0.77 to 0.05], p = 0.09, and MD = -0.41, 95% CI [-0.85 to 0.03], p = 0.07, respectively). Conclusions: The supplementation of curcumin and piperine showed a numerical reduction in FPG, HOMA-IR and BMI, but were not statistically significant. Further research is needed as there is a paucity of studies included in the review.

Curcumin, Piperine and Taurine Combination Enhances the Efficacy of Transarterial Chemoembolization Therapy in patients with Intermediate Stage Hepatocellular Carcinoma: A Pilot Study.

INTRODUCTION: Diagnosis of the majority of hepatocellular carcinoma (HCC) patients occurs at intermediate to advanced stages, with a few curative therapeutic options being available. It is therefore strongly urgent to discover additional adjuvant therapy for this lethal malignancy. This study aimed to assess the effectiveness of curcumin (C), piperine (P) and taurine (T) combination as adjuvant agents on serum levels of IFN-γ, immunophenotypic and molecular characterization of mononuclear leukocytes (MNLs) in HCC patients treated with Transarterial chemoembolization (TACE). PATIENTS AND METHODS: Serum and MNLs were collected from 20 TACE-treated HCC patients before (baseline-control samples) and after treatment with 5 g curcumin capsules , 10 mg piperine and 0.5 mg taurine taken daily for three consecutive months. Immunophenotypic and molecular characterization of MNLs were determined by flow cytometry and quantitative real time PCR, respectively. In addition, serum IFN-γ level was quantified by ELISA. RESULTS: After receiving treatment with CPT combination, there was a highly significant increase in IFN- γ levels in the sera of patients when compared to basal line control samples. Additionally, the group receiving combined therapy demonstrated a downregulation in the expression levels of PD-1, in MNLs as compared to controls. MNLs' immunophenotyping revealed a significant decline in CD4+CD25+cells (regulatory T lymphocytes). Furthermore, clinicopathological characteristics revealed a highly significant impact of CPT combination on aspartate aminotransferase (AST), lactate dehydrogenase (LDH) and alpha feto protein (AFP) levels. CONCLUSION: This study introduces a promising adjuvant CPT combined treatment as natural agents to enhance the management of HCC patients who are candidates to TACE treatment.

Formulation and evaluation of dissolving microneedle for transdermal delivery of piperine: the effect of polymers concentration.

This research aims to develop the formulation of Dissolving Microneedle Piperine (DMNs PIP) and evaluate the effect of polymer concentration on characterisation and permeation testing results in ex vivo. DMNs PIP were prepared from varying concentrations of piperine (PIP) (10, 15, and 20% w/w) and polymers of polyvinyl alcohol (PVA): Polyvinyl pyrrolidone (30:60 and 60:25), respectively. Then the morphological evaluation of the formula was carried out, followed by mechanical strength testing. Furthermore, the density, LOD, and weight percentage of piperine in the dried microneedle were calculated and the determination of volume, needle weight and piperine weight and analysed. Ex vivo testing, X-Ray Diffraction, FTIR and hemolysis tests were carried out. PIP with PVA and PVP (F1) polymers produced DMN with mechanical strength (8.35 ± 0.11%) and good penetration ability. In vitro tests showed that the F1 polymer mixture gave good penetration (95.02 ± 1.42 µg/cm2), significantly higher than the F2, F3, F4, and F5 polymer mixtures. The DMNs PIP characterisation results through XRD analysis showed a distinctive peak in the 20-30 region, indicating the presence of crystals. The FTIR study showed that the characteristics of piperine found in DMNs PIP indicated that piperine did not undergo interactions with polymers. The results of the ex vivo study through DMNs PIP hemolytic testing showed no hemolysis occurred, with the hemolysis index below the 5% threshold reported in the literature. These findings indicate that DMNs PIP is non-toxic and safe to use as alternative for treating inflammation.

The attenuation effect of low piperine Piper nigrum extract on doxorubicin-induced toxicity of blood chemical and immunological properties in mammary tumour rats.

CONTEXT: Many natural extracts have been shown to minimize the toxicity of doxorubicin (Dox). Low piperine Piper nigrum L. (Piperaceae) extract (PFPE) is a natural extract containing many types of antioxidants that may reduce Dox toxicities. OBJECTIVE: To evaluate the effect of PFPE in attenuating the side effects of Dox. MATERIALS AND METHODS: Tumour-bearing Sprague Dawley rats were divided into five groups including normal, vehicle, 100 mg/kg BW of PFPE plus 2 mg/kg BW of Dox (P100 + Dox), 100 mg/kg BW of PFPE plus 2 mg/kg BW of Dox (P200 + Dox) and Dox. Rats were treated with Dox and/or PFPE three times/week for 4 weeks. Tumour burden, blood parameters, weight of internal organs and immunological data were investigated. RESULTS: The addition of 200 mg/kg PFPE significantly restored the levels of AST from 174.60 ± 45.67 U/L in the Dox group near to normal levels at 109.80 ± 4.99 U/L. The combination of PFPE and Dox also decreased the levels of CXCL7, TIMP-1, sICAM-1 and l-selectin about 1.4-1.6-fold compared to Dox group. Feeding rats with 200 mg/kg BW of PFPE combination with Dox slightly increased Th1 from 161.67 ± 14.28 cells in Dox group to 200.75 ± 5.8 cells meanwhile suppressed Treg from 3088 ± 78 cells in Dox to 2561 ± 71 cells. DISCUSSION AND CONCLUSIONS: This study showed that PFPE ameliorated Dox toxicity in many aspects indicating the role of antioxidant and other substances in the extract on toxicity attenuation. This suggested the using of PFPE may be valuable for Dox treated patients.

Antioxidant effects of piperine on steroid-induced hepatotoxicity.

OBJECTIVE: Glucocorticoids (GCs) are steroids that play an essential role in physiological processes and are valuable therapeutic agents against various diseases. The aim of our study was to evaluate the antioxidant effects of piperine (PIP) on steroid-induced oxidative stress in liver tissue. MATERIALS AND METHODS: We used 36 fertilized specific-pathogen-free (SPF) chicken eggs that were divided into the following 6 groups: group 1 (n=6), phosphate buffered saline (PBS) (pH 7.4 saline solution [0.9%] isotonic); group 2 (n=6), 0.50 µmol hydrocortisone succinate sodium (HC); group 3 (n=6), 0.50 µmol HC and 100 mg/kg piperine (PIP); group 4 (n=6), 0.50 µmol HC and 50 mg/kg PIP; group 5 (n=6), 0.50 µmol HC and 25 mg/kg PIP; and group 6 (n=6), 0.50 µmol HC and 10 mg/kg PIP. Chick embryos were removed from the eggs and the livers dissected from the embryos. The total antioxidant status (TAS), total oxidant status (TOS), reduced glutathione (GSH), and lipid peroxidation (malondialdehyde [MDA]) levels were measured. RESULTS: The highest levels of GSH and TAS in the liver tissues were observed in group 3, with a significant difference from those in group 2 (p <0.001 and p =0.006, respectively). The lowest levels of MDA and TOS in the liver tissues were observed in group 3, with a significant difference from those in group 2 (p <0.001 and p =0.021, respectively). CONCLUSIONS: The antioxidant and hepatoprotective properties of PIP were observed only at high doses.

A review on the bioavailability, bio-efficacies and novel delivery systems for piperine.

As the major naturally occurring alkaloid in pepper with a pungent taste, piperine is known for its beneficial biological functions and therapeutic effects. In this work, the bioavailability and biological activities of piperine were presented and discussed. Novel delivery systems for enhancing the bioavailability of piperine were also reviewed. This study could provide a better understanding of the physiological and biochemical aspects of piperine to be further developed in the food and nutraceutical industries.

Quercetin and piperine enriched nanostructured lipid carriers (NLCs) to improve apoptosis in oral squamous cellular carcinoma (FaDu cells) with improved biodistribution profile.

Oral squamous cellular carcinoma (OSCC) is considered a life-threatening disease with detection in late stages, which forces us to opt for dangerous treatment with a combination of chemotherapy and radiotherapy. Herbal components such as piperine and quercetin are derived from edible sources, proving their anticancer potential against oral cancer cells in vitro. Encapsulation into lipid matrix-mediated nanostructured lipid carriers (NLCs) can make both drugs bio-accessible. NLCs were synthesised using the high shear homogenisation method and characterised for their physicochemical properties, followed by in vitro cellular evaluation in FaDu oral cancer cells. NLCs showed negatively charged particles smaller than 180 nm with a polydispersity index (PDI) of <0.3. Both drugs were found to encapsulate sufficiently, with >85% entrapment efficiency and an improved drug release profile compared to their pristine counterparts. Differential scanning calorimetry (DSC) thermograms showed conversion into an amorphous matrix in lyophilized NLCs, which was supported by X-ray diffraction (XRD) analysis. The cytotoxicity assay showed the IC50 concentration for dual drug-loaded NLCs, which was more effective than the pure drug solution. NLCs were found to be internalised in cells in a short time with an almost 95% co-localization rate. Dual drug-loaded NLCs showed maximum depolarisation of the mitochondrial membrane along with more apoptotic changes. Improved apoptosis was confirmed in NLCs using flow cytometry. The in vivo biodistribution of Coumarin-6 labelled NLCs in rats confirmed their efficient distribution in various parts of the oral cavity through oral administration. Optimised dual drug-loaded NLCs provide a better option for delivering both drugs through a single lipid matrix against oral cancer.

Anti-inflammatory and antioxidant effects of nanoformulations composed of metal-organic frameworks delivering rutin and/or piperine natural agents.

Plant-derived natural medicines have been extensively studied for anti-inflammatory or antioxidant properties, but challenges to their clinical use include low bioavailability, poor solubility in water, and difficult-to-control release kinetics. Nanomedicine may offer innovative solutions that can enhance the therapeutic activity and control release kinetics of these agents, opening the way to translating them into the clinic. Two agents of particular interest are rutin (Ru), a flavonoid, and piperine (Pip), an alkaloid, which exhibit a range of pharmacological activities that include antioxidant and anti-inflammatory effects. In this work, nanoformulations were developed consisting of two metal-organic frameworks (MOFs) with surface modifications, Ti-MOF and Zr-MOF, each of them loaded with Ru and/or Pip. Both MOFs and nanoformulations were characterized and evaluated in vivo for anti-inflammatory and antioxidant effects. Loadings of ∼17 wt.% for a single pro-drug and ∼27 wt.% for dual loading were achieved. The release patterns for Ru and or Pip followed two stages: a zero-order for the first 12-hour stage, and a second stage of stable sustained release. At pH 7.4, the release patterns best fit to zero-order and Korsmeyer-Peppas kinetic models. The nanoformulations had enhanced anti-inflammatory and antioxidant effects than any of their elements singly, and those with Ru or Pip alone showed stronger effects than those with both agents. Results of assays using a paw edema model, leukocyte migration, and plasma antioxidant capacity were in agreement. Our preliminary findings indicate that nanoformulations with these agents exert better anti-inflammatory and antioxidant effects than the agents in their free form.

Statistical optimization of bile salt deployed nanovesicles as a potential platform for oral delivery of piperine: accentuated antiviral and anti-inflammatory activity in MERS-CoV challenged mice.

The objective of this paper is to confine piperine, a poor oral bioavailable herbal drug into bile salt based nano vesicles for improving its aqueous solubility, hence, its therapeutic activity. Piperine-loaded bilosomes were fabricated adopting thin film hydration technique according to 32.21 full factorial design to investigate the impact of different formulation variables on the characters of bilosomes: entrapment efficiency (EE%), particle size, and % of drug released post 8 h (Q8hr). The selected optimum formula was F2 (enclosing 1% bile salt, brij72 as a surfactant, and ratio of surfactant:cholesterol was 9:1) with desirability value 0.801, exhibiting high EE% (97.2 ± 0.8%) nanosized spherical vesicles (220.2 ± 20.5 nm) and Q8hr (88.2%±5.6). The superiority of the optimized formula (F2) over the drug suspension was revealed via ex vivo permeation study, also pharmacokinetic study denoted to the boosted oral bioavailability of piperine-loaded bilosome compared to piperine suspension. Moreover, antiviral activity and safety margin of F2 was significantly higher than that of the drug suspension. The ability of piperine to interact with the key amino acids in the receptor binding domain 4L3N as indicated by its docking configuration, rationalized its observed activity. Furthermore, F2 significantly reduce oxidant markers, inflammatory cytokines in MERS-CoV-infected mice. Hence, bilosomes can be considered as a carrier of choice for piperine with potential antiviral and anti-inflammatory activities.

Zanthoxylum alkylamides ameliorate protein metabolism in type 2 diabetes mellitus rats by regulating multiple signaling pathways.

Type 2 diabetes mellitus (T2DM) can easily induce insulin resistance (IR) in skeletal muscle, causing protein metabolism disorder and inflammation. The present study aimed to investigate whether Zanthoxylum alkylamides (ZA) could ameliorate T2DM through regulating protein metabolism disorder by using a rat model of T2DM. The predominant bioactive constituents found in ZA were hydroxyl-α-sanshool, hydroxyl-ß-sanshool and hydroxyl-γ-sanshool. The results showed that ZA improved a series of biochemical indices associated with protein metabolism and inflammation in T2DM rats. Our mechanistic finding indicated that ZA promoted protein anabolism in T2DM rats by up-regulating the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway. ZA also promoted glucose transportation in skeletal muscle to ameliorate skeletal muscle IR and energy metabolism through regulating the AMP-activated protein kinase (AMPK) signaling pathway. Moreover, ZA inhibited protein degradation and improved protein catabolism disorder in T2DM rats by down-regulating the PI3K/Akt/forkhead box O (FoxO) signaling pathway, and ZA further ameliorated inflammation to inhibit protein catabolism via regulating the tumor necrosis factor α (TNF-α)/nuclear factor κB (NF-κB) pathway in the skeletal muscle of T2DM rats. Collectively, the ameliorating effect of ZA on protein metabolism disorder in T2DM rats was the common result of regulating multiple signaling pathways. ZA decreased skeletal muscle IR to promote protein anabolism and inhibit protein catabolism for improving protein metabolism disorder, thus ultimately ameliorating T2DM. In sum, our findings demonstrated that ZA treatment could effectively ameliorate T2DM through improving protein metabolism, providing a new treatment target for T2DM.

Cannabinoid Receptor-2 Activation in Keratinocytes Contributes to Elevated Peripheral ß-Endorphin Levels in Patients With Obstructive Jaundice.

BACKGROUND: Cholestatic diseases are often accompanied by elevated plasma levels of endogenous opioid peptides, but it is still unclear whether central or peripheral mechanisms are involved in this process, and little is known about the change of pain threshold in these patients. The purpose of this study was to determine the preoperative pain threshold, postoperative morphine consumption, and central and peripheral ß-endorphin levels in patients with obstructive jaundice. This study also tests the hypothesis that activation of the cannabinoid receptor-2 (CB2R) in skin keratinocytes by endocannabinoids is the mechanism underlying circulating ß-endorphin elevation in patients with obstructive jaundice. METHODS: The electrical pain thresholds, 48-hour postoperative morphine consumption, concentrations of ß-endorphin in plasma and cerebrospinal fluid, skin and liver ß-endorphin expression, and plasma levels of endocannabinoids were measured in jaundiced (n = 32) and control (n = 32) patients. Male Sprague-Dawley rats and human keratinocytes (human immortalized keratinocyte cell line [HaCaT]) were used for the in vivo and in vitro experiments, respectively. Mechanical and thermal withdrawal latency, plasma level, and skin expression of ß-endorphin were measured in CB2R-antagonist-treated and control bile duct-ligated (BDL) rats. In cultured keratinocytes, the effect of CB2R agonist AM1241-induced ß-endorphin expression was observed and the phosphorylation of extracellular-regulated protein kinases 1/2, p38, and signal transducer and activator of transcription (STAT) pathways were investigated. RESULTS: This study found (1) the plasma level of ß-endorphin (mean ± standard error of the mean [SEM]) was 193.9 ± 9.6 pg/mL in control patients, while it was significantly increased in jaundiced patients (286.6 ± 14.5 pg/mL); (2) the electrical pain perception threshold and the electrical pain tolerance threshold were higher in patients with obstructive jaundice compared with controls, while the 48-hour postoperative morphine consumption was lower in the jaundiced patients; (3) there was no correlation between plasma ß-endorphin levels, electrical pain thresholds, and 48-hour postoperative morphine consumption in patients with obstructive jaundice; (4) the plasma level of the endogenous cannabinoid anandamide was increased in the jaundiced patients; (5) CB2R antagonist treatment of the BDL rats reduced ß-endorphin levels in plasma and skin keratinocytes, while it did not alter the nociceptive thresholds in BDL and control rats; (6) the endocannabinoid anandamide-induced ß-endorphin synthesis and release via CB2R in cultured keratinocytes; and (7) phosphorylation of extracellular-regulated protein kinases 1/2 is involved in the CB2R-agonist-induced ß-endorphin expression in keratinocytes. CONCLUSIONS: CB2R activation in keratinocytes by the endocannabinoid anandamide may play an important role in the peripheral elevation of ß-endorphin during obstructive jaundice.

Central nervous system, peripheral and hemodynamic effects of nanoformulated anandamide in hypertension.

PURPOSE: Hypertensive lesions induce alterations at hemodynamic, peripheral, and central levels. Anandamide (N-arachidonoylethanolamine; AEA) protects neurons from inflammatory damage, but its free administration may cause central adverse effects. AEA controlled release by nanoformulations could reduce/eliminate its side effects. The present study aimed to evaluate the effects of nanoformulated AEA (nf-AEA) on systolic blood pressure (SBP), behavior, and central/peripheral inflammatory, oxidative, and apoptotic state in spontaneously hypertensive rats (SHR). MATERIALS/METHODS: Male rats were used, both Wistar Kyoto (WKY) and SHR (n â€‹= â€‹10 per group), with/without treatment with nf-AEA (obtained by electrospraying) at a weekly dose of 5 â€‹mg/kg IP for 4 weeks. SBP was measured and behavioral tests were performed. Inflammatory/oxidative markers were quantified at the central (brain cortex) and peripheral (serum) level. RESULTS: SHR showed hyperactivity, low anxiety, and high concentrations of central/peripheral inflammatory/oxidative markers, also higher apoptosis of brain cortical cells compared to WKY. As opposed to this group, treatment with nf-AEA in SHR significantly reduced SBP, peripheral/central inflammatory/oxidative makers, and central apoptosis. Nf-AEA also increased neuroprotective mechanisms mediated by intracellular heat shock protein 70 (Hsp70), which were attenuated in untreated SHR. Additionally, nf-AEA reversed the abnormal behaviors observed in SHR without producing central adverse effects. CONCLUSIONS: Our results suggest protective properties of nf-AEA, both peripherally and centrally, through a signaling pathway that would involve the type I angiotensin II receptor, Wilms tumor transcription factor 1, Hsp70, and iNOS. Considering non-nf-AEA limitations, this nanoformulation could contribute to the development of new antihypertensive and behavioral disorder treatments associated with neuroinflammation.

The functional effects of piperine and piperine plus donepezil on hippocampal synaptic plasticity impairment in rat model of Alzheimer's disease.

AIMS: The modulatory effects of piperine on drug metabolizing enzymes play an important role in the control of pharmacokinetic and the bioavailability properties of the administered drugs. The present study investigated the effect of piperine and piperine-donepezil co-administration on cognitive functions and synaptic plasticity at hippocampal perforant pathway (PP) to dentate gyrus (DG) synapses in an experimental model of Alzheimer's disease (AD). MATERIALS AND METHODS: Intracerebroventricularly (ICV) streptozotocin (STZ) injected rats were treated once daily with piperine, donepezil and piperine combined with donepezil for 4 weeks. Cognitive performance was evaluated using passive avoidance and Morris water maze performance tasks. Analysis of evoked field potentials was done to explore possible effects on input/output response, paired-pulse facilitation and long-term synaptic plasticity (LTP) at PP to DG synapses of hippocampus. KEY FINDINGS: Rats subjected to ICV injection of STZ exhibited cognitive deficit associated with a hippocampal oxidative stress, effects that were reversed by chronic treatment with piperine or donepezil and or piperine combined with donepezil. Chronic treatment with piperine or donepezil restored the disruptive effects of STZ on LTP without altering basal synaptic transmission. SIGNIFICANCE: We found that optimal hippocampal function is dependent on tissue redox homeostasis. Piperine might reduce the synaptotoxic effects of STZ on hippocampal synaptic neurotransmission and correspondently is a good potential for neuroprotection against oxidative damage from ICV injection of STZ. These results suggest that piperine or donepezil significantly ameliorate cognitive deficit and LTP induction by attenuating oxidative status.

Optimized piperine-phospholipid complex with enhanced bioavailability and hepatoprotective activity.

Piper species is one of the most widely consumed spices for culinary purposes. Piperine (PIP) present in Piper species has a wide range of therapeutic activity including hepatoprotection. However, the major biological limitation of PIP is its low bioavailability after oral administration. Purpose of the study was to prepare an optimized and adequately characterized PIP-phospholipid complex (PPC) as a delivery system to overcome these limitations and to investigate the pharmacokinetics and hepato-protectivity of the formulation in the animal model. Response surface methodology was adopted to optimize the process parameters for PPC preparation. FT-IR, DTA, PXRD, SEM, molecular docking etc. were used for characterization. Solubility, log P, dissolution efficiency and in vivo pharmacokinetics were also investigated. PPC showed enhanced hepatoprotective potential as compared to pure PIP at the same dose level (25 and 50 mg/kg). PPC restored the levels of serum marker and antioxidant enzymes. PPC also increased the bioavailability of PIP in rat serum by 10.40-fold in comparison with pure PIP at the same dose level and enhanced the elimination half-life (t1/2 el) from 0.477 ± 1.76 to 9.80 ± 1.98 h. Results concluded that PPC enhanced the hepatoprotection of PIP which may be due to the improved bioavailability and pharmacokinetics of PIP in rats.

Effects of systemic endocannabinoid manipulation on social and exploratory behavior in prairie voles (Microtus ochrogaster).

RATIONALE: Anandamide is an endocannabinoid that contributes to certain aspects of social behavior, like play and reward, by binding to cannabinoid receptor type 1 (CB1). Most interesting is the recent discovery that anandamide may be mobilized by oxytocin receptor activation under certain contexts, particularly in the nucleus accumbens. OBJECTIVES: Given the established role of oxytocin and the nucleus accumbens in the neurobiology of pair-bonding, we investigated whether systemic administration of brain-permeable modulators of the endocannabinoid system could alter preferential partner contact in both male and female prairie voles. METHODS: Specifically, we tested whether intraperitoneal administration of the neutral CB1 antagonist AM4113 (4.0-16.0 mg/kg) or the anandamide hydrolysis inhibitor URB597 (5.0-20.0 mg/kg) could prevent or facilitate partner preference formation, respectively. To further investigate the specificity of effects on partner preference, we repeated our URB597 dosing regimen on an additional group of females and tested their anxiety-related behavior in both an elevated-plus maze and a light/dark test. RESULTS: AM4113 administration had no effect on partner preference. But while URB597 also had no effect on partner preference, low-dose females did increase absolute preferential contact with either the partner or the stranger; individual females spent significant contact time with either the partner or the stranger. None of our outcome measures in either anxiety test showed significant effects of treatment. CONCLUSIONS: Our results reveal that experimentally increasing anandamide levels in female prairie voles can increase social contact with both a familiar and novel male via unknown mechanisms that are likely separate from anxiety reduction.

Effects of curcumin-piperine co-supplementation on clinical signs, duration, severity, and inflammatory factors in patients with COVID-19: a structured summary of a study protocol for a randomised controlled trial.

OBJECTIVES: This study aims to investigate the efficacy of curcumin-piperine co-supplementation on disease duration, severity and clinical symptoms, and inflammatory mediators in patients with coronavirus (COVID-19). TRIAL DESIGN: This is a randomized, placebo-controlled, double-blind, parallel arm clinical trial. PARTICIPANTS: All patients aged 20-75 years with the diagnosis of Covid-19 based on the PCR test. The exclusion criteria will include an age less than 20 and more than 75 years, current use of warfarin or other anticoagulant drugs, and the presence of sensitivity to herbal products such as turmeric and pepper. This study will be conducted in academic hospitals affiliated to Isfahan University of Medical Sciences, Isfahan, Iran. INTERVENTION AND COMPARATOR: Fifty outpatients will be randomly allocated in a ratio of 1:1 to receive a capsule of curcumin-piperine containing 500 mg curcumin plus 5 mg piperine or matching placebo containing 505 mg maltodextrin twice a daily, after lunch and dinner, over a period of 2 weeks. Similarly, 50 inpatients who are admitted to hospital wards excluding intensive care unit (ICU) will be randomly assigned in a ratio of 1:1 to receive a capsule curcumin-piperine or matching placebo (provided by the Sami Labs company) twice a daily, after lunch and dinner, over a period of 2 weeks. MAIN OUTCOMES: The main outcomes of this study are the efficacy of curcumin-piperine on coronavirus disease's clinical symptoms, duration, severity, and inflammatory mediators after 2 weeks of curcumin-piperine co-supplementation. RANDOMISATION: Randomization sequences will be generated with the use of a random-number table with a permuted block design (block size of 4) and stratification according to the gender variable (male vs. female). These sequences will be prepared by an independent statistician and will be kept in opaque, sealed, numbered envelopes which will be opened only at the time of enrollment. The allocation ratio in intervention and control groups is 1:1. Researchers and all patients will be unaware of the study-group assignment until the completion of data analyses. BLINDING (MASKING): This study is a double-blind clinical trial (participant, researcher). The curcumin-piperine and placebo supplements are packaged in similar numbered drug containers, and the researcher and all patients will be unaware of the study assignment until the end of the study. NUMBERS TO BE RANDOMISED (SAMPLE SIZE): The calculated total sample size is 100 patients, with 25 patients in each group. TRIAL STATUS: The protocol is Version 2.0, May 24, 2020. Recruitment began May 4, 2020, and is anticipated to be completed by April 19, 2021. TRIAL REGISTRATION: This trial has been registered by the title of "Effect of curcumin-piperine co-supplementation on disease duration, severity and clinical signs, and inflammatory factors in patients with coronavirus (COVID-19): A randomized, double-blind, placebo-controlled clinical trial study" in the Iranian Registry of Clinical Trials (IRCT) with code "IRCT20121216011763N46", https://www.irct.ir/trial/47529 . The registration date is May 4, 2020. FULL PROTOCOL: The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.

Pharmaco-molecular assessment of the effects of anandamide and its antagonists on hippocampal tissue in Wistar albino rats.

OBJECTIVE: The members of the matrix metalloproteinase (MMP) family and cannabinoids (CBs) are reportedly associated with hippocampus-dependent memory functions. However, the effects of endogenously formed CBs on hippocampal long-term potentiation remain unknown. The present study aimed to investigate the changes in the gene and protein expression levels of matrix metallopeptidase 9 (MMP-9), phosphatase and tensin homolog (PTEN), and NOTCH receptor 1 (NOTCH1) in rat hippocampal tissues treated with anandamide (AEA), AM251, 6-iodopravadolin (AM630), and N-[4-{[(3,4-Dimethyl-5-isoxazolyl)amino]sulfonyl}phenyl] (ML193). MATERIALS AND METHODS: The subjects were divided into 10 groups (n = five per group). The pharmaceuticals were administered via intraperitoneal injection once a day for seven days, except for the control group. The resected hippocampal tissues were then evaluated using a quantitative real-time polymerase chain reaction (RT-qPCR) and Western blot analysis. The data obtained were statistically analyzed, and p < 0.01 was considered statistically significant. RESULTS: Contrary to the literature, the changes in MMP-9 expression were not statistically significant, but the changes in PTEN and NOTCH1 were. The findings of this in vivo experimental study revealed that the agonists and antagonists acting on the CB system have significant molecular effects on hippocampal tissue. CONCLUSIONS: The changes in gene and protein expressions may be one of the reasons for the neurodegenerative processes observed in patients using these agonists and antagonists, whose effects on the CB system have not been fully explained yet. Our study can contribute to the literature as it is the first study investigating the MMP-9, PTEN and NOTCH1 gene and protein expression.

Supplementation with Resveratrol, Piperine and Alpha-Tocopherol Decreases Chronic Inflammation in a Cluster of Older Adults with Metabolic Syndrome.

Metabolic Syndrome (MetS) is increasing worldwide regardless of culture, genetic, gender, and geographic differences. While multiple individual risk factors, such as obesity, hypertension, diabetes, and hyperlipidemia, can cause cardiovascular disease (CVD), it is the intercurrence of these risk factors that defines MetS as a cluster that creates an environment for atherosclerosis and other manifestations of CVD. Despite the advances in the knowledge and management of each of the components of MetS, there are two molecular biology processes, chronic inflammation and oxidative stress, which are still underdiagnosed and undertreated. In order to assess the effect of a dietary supplement on chronic inflammation in MetS, we conducted a clinical trial with volunteers receiving a formula composed of resveratrol, piperine and alpha tocopherol (FRAMINTROL®), together with their habitual treatment, for three months. The inflammatory state was evaluated by ultrasensitive C reactive protein (US CRP) and ferritin in plasma, and oxygen consumption and chemiluminescence in neutrophils. The results showed that ferritin decreased by 10% (p < 0.05), US-CRP by 33% (p < 0.0001), oxygen consumption by 55% (p < 0.0001), and spontaneous chemiluminiscence was by 25% (p < 0.005) after treatment. As far as we know, this is the first study showing a chronic inflammation decrease in MetS patients due to the administration of a biopower Resveratrol-piperine and alpha tocopherol dietary supplement together with conventional therapy.

Antioxidant and anti-inflammatory effects of piperine on UV-B-irradiated human HaCaT keratinocyte cells.

The increase in intracellular reactive oxygen and nitrogen species plays a key role in ultraviolet B (UV-B)-induced inflammatory responses in the human skin. Piperine exhibits many pharmacological benefits. In the present study, the photoprotective effects and the possible underlying mechanisms of the anti-inflammatory effects of piperine on UV-B-irradiated keratinocytes were investigated. Piperine exerted strong, direct scavenging effects on DPPH radicals and exhibited free radical scavenging capabilities as demonstrated by the DCFH-DA and Griess assays. Consistent with these results, 10, 20, and 40 µM piperine pretreatments attenuated UV-B irradiation-induced keratinocyte cytotoxicity as reported by the resazurin assay. The highest concentration of piperine inhibited UV-B irradiation-induced cell apoptosis, as revealed by Hoechst 33342 staining. Moreover, we demonstrated the anti-inflammatory effects of piperine using western blot analysis, real-time PCR, and ELISA. Pretreatment with piperine suppressed the activation of phosphorylated p38, JNK, and AP-1 as well as the levels of COX-2/PGE2 and iNOS synthesis, while UV-B-irradiated cells triggered the induction of these signaling molecules. These results indicated that the inhibition of these inflammatory signaling pathways might play a key role in the regulation of the anti-inflammatory effects of piperine. In addition, piperine showed stronger anti-inflammatory effects than celecoxib which served as a positive control at the same concentration. All these results suggested that the anti-inflammatory properties of piperine protected keratinocytes from UV-B-induced damage, which might be due to its antioxidant properties. Therefore, piperine may be an effective therapeutic candidate compound for the treatment of UV irradiation-induced skin inflammation.

Triple Strategies to Improve Oral Bioavailability by Fabricating Coamorphous Forms of Ursolic Acid with Piperine: Enhancing Water-Solubility, Permeability, and Inhibiting Cytochrome P450 Isozymes.

As a BCS IV drug, ursolic acid (UA) has low oral bioavailability mainly because of its poor aqueous solubility/dissolution, poor permeability, and metabolism by cytochrome P450 (CYP) isozymes, such as CYP3A4. Most UA preparations demonstrated a much higher dissolution than that of its crystalline form yet a low drug concentration in plasma due to their lower consideration or evaluation for the permeability and metabolism issues. In the current study, a supramolecular coamorphous system of UA with piperine (PIP) was prepared and characterized by powder X-ray diffraction, differential scanning calorimetry, and scanning electron microscopy. In comparison to crystalline UA and UA in physical mixture, such coamorphous system enhanced solubility (5.3-7-fold in the physiological solution) and dissolution (7-8-fold in the physiological solution within 2 h) of UA and exhibited excellent physical stability under 90-day storage conditions. More importantly, the pharmacokinetic study of coamorphous UA in rats exhibited 5.8-fold and 2.47-fold improvement in AUC0-∞ value, respectively, compared with its free and mixed crystalline counterparts. In order to further explore the mechanism of such improvement, the molecular interactions of a coamorphous system in the solid state were investigated. Fourier transform infrared spectroscopy, solid-state 13C nuclear magnetic resonance spectroscopy, and density functional theory modeling suggested that intermolecular hydrogen bonds with strong interactions newly formed between UA and PIP after coamorphization. The in vitro permeability studies across Caco-2 cell monolayer and metabolism studies by rat hepatic microsomes indicated that free PIP significantly increased the permeability of UA and inhibited the enzymatic metabolism of UA by CYP3A4. However, PIP in the coamorphous combination exhibited a much lower level in the bioenhancing than its free form arising from the synchronized dissolution characteristic of the preparation (only 60% of PIP released in comparison to its free counterpart in 2 h). The in situ loop study in rats proposed that the acid-sensitive dissolution in the stomach of the coamorphous preparation helped to improve the effective free drug concentration, thereby facilitating PIP to play its role in bioenhancing. The current study offers an exploratory strategy to overcome poor solubility/dissolution, poor permeability, and metabolism by cytochrome P450 isozymes of the BCS IV drug to improve its oral bioavailability.