Eucalyptus Oils Phytochemical Composition in Correlation with Their Newly Explored Anti-SARS-CoV-2 Potential: in Vitro and in Silico Approaches.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the latest arisen contagious respiratory pathogen related to the global outbreak of atypical pneumonia pandemic (COVID-19). The essential oils (EOs) of Eucalyptus camaldulensis, E. ficifolia F. Muell., E. citriodora Hook, E. globulus Labill, E. sideroxylon Cunn. ex Woolls, and E. torquata Luehm. were investigated for its antiviral activity against SARS-CoV-2. The EOs phytochemical composition was determined using GC/MS analysis. Correlation with the explored antiviral activity was also studied using multi-variate data analysis and Pearson's correlation. The antiviral MTT and cytopathic effect inhibition assays revealed very potent and promising anti SARS-CoV-2 potential for E. citriodora EO (IC50 = 0.00019 µg/mL and SI = 26.27). The multivariate analysis revealed α-pinene, α-terpinyl acetate, globulol, γ -terpinene, and pinocarvone were the main biomarkers for E. citriodora oil. Pearson's correlation revealed that globulol is the top positively correlated compound in E. citriodora oil to its newly explored potent anti SARS-CoV-2 potential. A molecular simulation was performed on globulol via docking in the main active sites of both SARS-CoV-2 viral main protease (Mpro) and spike protein (S). In silico predictive ADMET study was also developed to investigate the pharmacokinetic profile and predict globulol toxicity. The obtained in silico, in vitro and Pearson's correlation results were aligned showing promising SARS-CoV-2 inhibitory activity of E. citriodora and globulol. This study is a first record for E. citriodora EO as a novel lead exhibiting potent in vitro, and in silico anti SARS-CoV-2 potential and suggesting its component globulol as a promising candidate for further extensive in silico, in vitro and in vivo anti-COVID studies.

Eucalyptus torquata L. flowers: a comprehensive study reporting their metabolites profiling and anti-gouty arthritis potential.

Gouty arthritis is one of the most common metabolic disorders affecting people. Plant based drugs can lower the risk of this health disorder. The anti-gouty potential of Eucalyptus torquata flowers methanol extract (ETME) was evaluated in vitro via measuring the inhibitory effects of five pro-inflammatory enzymes; xanthine oxidase (XO), hyaluronidase, lipoxygenase (5-LOX), cyclooxygenases COX-1, and COX-2, in addition to evaluating the inhibition of histamine release, albumin denaturation, membrane stabilization, tyrosinase, and protease inhibitory activities. Also, its antioxidant potential was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging assays and ferric reducing power assay (FRAP). HPLC-PDA-MS/MS was used to identify the metabolites in the tested extract. The latter exhibited substantial anti-arthritic properties in all assays with comparable potential to the corresponding reference drugs. HPLC-MS/MS analysis of this bioactive extract tentatively annotated 46 metabolites including phloroglucinols, gallic and ellagic acids derivatives, terpenes, flavonoids, fatty acids, and miscellaneous metabolites. Our study highlights the medicinal importance of E. torquata as an anti-gouty candidate and opens new avenues of gouty management.

Poly (ADP-ribose) polymerase pathway inhibitor (Olaparib) upregulates SERCA2a expression and attenuates doxorubicin-induced cardiomyopathy in mice.

The cardiotoxicity induced by doxorubicin is dose-dependent. The present study tested the potential cardioprotective effect of Poly ADP Ribose Polymerase (PARP) pathway inhibitor "olaparib" in a mouse model of doxorubicin-induced cardiomyopathy (DOX-CM). Seventy-two male BALB/c mice were randomized into six equal groups; control, DOX-CM, dexrazoxane-treated, and three olaparib-treated groups (5, 10, and 50 mg/kg/day). Cardiomyopathy was assessed by heart weight/Tibial length (HW/TL) ratio, cardiac fibrosis, oxidative stress, and electron microscope. Myocardial expression of SERCA2a mRNA and cleaved PARP-1 protein were also assessed. Similar to dexrazoxane, olaparib (10 mg/kg/day) significantly ameliorated oxidative stress, and preserved cardiac structure. It also suppressed myocardial PARP-1 protein expression and boosted SERCA2a mRNA expression. Olaparib (5 or 50 mg/kg/day) failed to show comparable effects. The current study detected the cardioprotective effect of olaparib at a dosage of 10 mg/kg/day. Also, the present study discovered a new cardioprotective mechanism of dexrazoxane by targeting PARP-1 in the heart.

Natural compounds as possible anti-SARS-CoV-2 therapeutic agents: an in-vitro and in-silico study.

WHO declared severe acute respiratory syndrome coronavirus-2' (SARS-CoV-2) was global health emergency since 2020. In our study eighteen natural compounds were investigated for possible anti-SARS-CoV-2 potential, where the most potent natural compounds were ursolic acid and dioscin with IC50 value of 4.49 µg/mL and 7.11 µg/mL, respectively. Hesperidin, catechin, diosmin, isorhamnetin-3-O-glucoside and hyperoside showed medium antiviral activity with IC50 value of 20.87, 22.57, 38.92, 39.62 and 47.10 µg/mL, respectively. Molecular modelling studies including docking study and predictive ADME study were performed on all tested molecules. Their binding energies after docking were calculated and their orientations at the active sites of both SARS-CoV-2 main protease (Mpro) and spike (S) receptors were visualised and compared to the downloaded ligands. Also, the predictive ADME studies showed good pharmacokinetic properties of most of the tested compounds. The obtained in silico results obtained confirmed that many of the tested compounds are promising SARS-CoV-2 inhibitors.

CD4/CD8 Ratio could be predictor of burden hepatocellular carcinoma in Egyptian chronic hepatitis C after combined sofosbuvir and daclatasvir therapy.

Background: During the first years of the use of direct acting Hepatitis C antiviral drugs (DAAS), several studies reported a possible correlation between this new era of treatment and an increased risk of Hepatocellular carcinoma (HCC). Its development could possibly be favored by the changes in the immunological milieu and the different cellular behavior after eradication of HCV infection with them. For this reason, this study aimed to address the immunological effect of DAAS. Subject & methods: Prospective paired -sample design, carried out on 90 naïve chronically infected HCV patients before and after receiving a combination therapy of sofosbuvir; at a dose of 400 mg once daily and daclatasvir; at a dose of 60 mg once daily for 12 weeks and follow up for one year. immunological tests including: total T cell count, T helper cell count, T cytotoxic cell count and natural killer cell count in peripheral blood through (CD3, CD3/CD4, CD3/CD8 and CD56 respectively) by Fluorochrome monoclonal antibodies labelled with specific dyes through Multiparameter, FACSCanto ™ II flow cytometer (Becton Dickinson, USA). Result: Concerning the immunological changes, total T cells (CD3+), Natural killer cells showed non-significant decrease at end of therapy while significant decrease in T helper cells (CD3+CD4+) T cytotoxic cells (CD3+CD8+) compared to pre-treatment value. Long follow up revealed 26.6% developed focal HCC, in more addition, multivariate analysis show CD4/CD8 ratio could be predictor as well as sex for early development of HCC after combined DAAS therapy. Conclusion: HCV treatment by DAAS produces significant decrease in T helper, T cytotoxic cells in CHC patients at the end of therapy. 26.6% developed focal HCC with independent CD4/CD8 predictor for burden malignancy. Further large extended population study is needed for clarify this concern.

The comparative effectiveness of metformin and risperidone in a rat model of valproic acid-induced autism, Potential role for enhanced autophagy.

RATIONALE: Risperidone is the first antipsychotic to be approved by Food and Drug Administration (FDA) for treating autism spectrum disorder (ASD). The potential efficacy of metformin in preventing and/or controlling ASD behavioral deficits was also recently reported. Suppression of hippocampus autophagy was suggested as a potential pathologic mechanism in ASD. OBJECTIVES: Is metformin's ability to improve ASD clinical phenotype driven by its autophagy-enhancing properties? And does hippocampus autophagy enhancement underlie risperidone's efficacy as well? Both questions are yet to be answered. METHODS: The effectiveness of metformin on alleviation of ASD-like behavioral deficits in adolescent rats exposed prenatally to valproic acid (VPA) was compared to that of risperidone. The potential modulatory effects of risperidone on hippocampal autophagic activity were also assessed and compared to those of metformin. RESULTS: Male offspring exposed to VPA during gestation exhibited marked anxiety, social impairment and aggravation of stereotyped grooming; such deficits were efficiently rescued by postnatal risperidone or metformin therapy. This autistic phenotype was associated with suppressed hippocampal autophagy; as evidenced by reduced gene/dendritic protein expression of LC3B (microtubule-associated proteins 1 light chain 3B) and increased somatic P62 (Sequestosome 1) protein aggregates. Interestingly, compared to risperidone, the effectiveness of metformin in controlling ASD symptoms and improving hippocampal neuronal survival was well correlated to its ability to markedly induce pyramidal neuronal LC3B expression while lowering P62 accumulation. CONCLUSIONS: Our work highlights, for the first time, positive modulation of hippocampus autophagy as potential mechanism underlying improvements in autistic behaviors, observed with metformin, as well as risperidone, therapy.

In Vitro and In Vivo Antibiofilm Activity of Red Onion Scales: An Agro-Food Waste.

Red onion wastes (ROW) are valuable sources of bioactive metabolites with promising antimicrobial effects. Methicillin-resistant Staphylococcus aureus (MRSA) infections are a growing risk in hospitals and communities. This study aims to investigate the in vitro and in vivo antibiofilm activities of the acidified ethanolic extract of red onion scales (RO-T) and its fractions against an MRSA vaginal colonization model. The RO-T extract, as well as its anthocyanin-rich fraction (RO-P) and flavonoid-rich fraction (RO-S), recorded a promising antibacterial activity against highly virulent strains of bacteria (MRSA, Acinetobacter baumannii, Escherichia coli and Pseudomonas aeruginosa). RO-S showed the highest antibacterial activity (MBC of 0.33 ± 0.11 mg/mL) against MRSA USA300 and significantly eradicated its biofilm formation with an IC50 of 0.003. Using a rat model, in vivo assessment on all samples, which were formulated as a hydrogel, revealed a significant reduction of MRSA bacterial load recovered from an infected vagina compared to that of the negative control group (NCG). RO-T extract and vancomycin groups recorded the highest antibacterial activity with a bacterial load 2.998 and 3.358 logs lower than the NCG, respectively. The histopathological investigation confirmed our findings. RO-T and RO-S were standardized for their quercetin content. Finally, ROW offers a new potent antibiofilm agent mostly due to its high quercetin content.

Cardioprotective effect of abscisic acid in a rat model of type 3 cardio-renal syndrome: Role of NOX-4, P-53, and HSP-70.

Cardiorenal syndrome (CRS) is a complex heart and kidney pathophysiologic disorder that leads to a bidirectional interrelationship between them. Abscisic acid (ABA) is a phytohormone that is present in plants, and is known to regulate fundamental physiological functions. This study aimed to explore the efficacy of ABA in surgically induced-CRS type 3 rats. Rats were randomly and equally divided into four groups. Rats in Group 1 received saline (Sham group), Group 2 included control induced-CRS rats, Group 3 rats (CRS+ABA) included CRS rats treated with ABA and Group 4 (CRS + ABA + Verapamil + propofol) were CRS rats treated with Verapamil, propofol and ABA. The rats were treated with the drugs daily for four weeks. At the end of the study, relative heart weight corrected QT interval (QTc), mean blood pressure (MBP), kidney functions, oxidative stress, NADPH oxidase 4 (NOX4), protein 53 (P53), and heat shock proteins-70 (HSP-70) expression was assessed and recorded. ABA led to a significant shortening of the ventricular action potential duration indicated by QTc. Furthermore, it significantly lowered heart weight, MBP, serum creatinine, NOX-4, and P-53 expression and augmented HSP-70 expression. In contrast, adding calcium channel blockers (CCBs) to ABA mitigated this effect. The results suggested that ABA has a potential protective role in CRS-induced cardiac hypertrophy and arrhythmia that could be mediated through inhibition of P-53, NOX-4, and an increase in HSP-70 expression.

The Pattern of Antimicrobial Prescription at a Tertiary Health Center in Egypt: A Point Survey and Implications.

Background: The misuse of antimicrobials has major consequences, particularly antimicrobial resistance (AMR) and antimicrobials' related adverse effects. So, the WHO proposed antimicrobial surveillance to improve antimicrobials use. This point prevalence survey (PPS) was conducted to illustrate the prevalence of antimicrobial use at Mansoura University hospitals (MUH), Egypt. Methods: The survey process used was adapted from the European survey of antimicrobial resistance with modifications. The survey was conducted from 8 AM to 8 PM daily within 2 weeks. Results: A total of 300 patients received antimicrobials and the prevalence rate of antimicrobial prescription was 79.15%. The major indications of antimicrobials were surgical prophylaxis followed by the treatment of community-acquired infection. The most commonly prescribed initial antimicrobial group was Aminopenicillin ± ß-lactamase inhibitors. Although the purpose for antimicrobial administration was recorded in all cases, the stop/review history was recorded only in 19.6% and local guidelines were not available for 77.6% of antimicrobial prescriptions. The use of combined antimicrobials was common (46.6%), particularly in orthopedic and cardiothoracic surgery. Conclusion: The prevalence of antimicrobial prescription at MUH was high which requires serious actions including reviewing the antimicrobial indication, implementing local prescription guidelines, initiating an antimicrobial stewardship program (ASP), and optimizing infection control measures.

Sacubitril/valsartan combination enhanced cardiac glycophagy and prevented the progression of murine diabetic cardiomyopathy.

BACKGROUND: Diabetic cardiomyopathy (DCM) is linked to disturbance in cardiac glucose handling and increased cardiac glycogen storage. This study tested the potential role of sacubitril/valsartan on the progression of DCM in high fat diet (HFD)/streptozotocin (STZ)-induced type 2 diabetic rats compared to valsartan alone, including their effects on the cardiac glycophagy process. MATERIALS AND METHODS: Rats were fed on HFD for 6 weeks followed by single low-dose STZ (35 mg/kg). After confirming hyperglycemia, diabetic rats were continued on HFD and divided into three subgroups: Untreated-diabetic, Valsartan-treated diabetic and Sacubitril/valsartan-treated diabetic groups; in addition to a control group. Changes in ECG, blood glucose, serum insulin, lipid profile, and Homeostasis model of assessment of insulin resistance (HOMA-IR) were assessed and the degree of cardiac fibrosis was examined. Cardiac glycogen content and glycophagy process were evaluated. RESULTS: Sacubitril/valsartan administration to diabetic rats resulted in improvement of metabolic changes more than valsartan alone. Also, sacubitril/valsartan effectively prevented diabetes-associated cardiac hypertrophy, QTc prolongation, and fibrosis. Finally, cardiac glycogen concentrations in diabetic rats were decreased by sacubitril/valsartan combination, coupled with significant induction of glycophagy process in the diabetic rats' heart. CONCLUSION: Sacubitril/valsartan therapy provides a more favorable metabolic and cardioprotective response compared to valsartan alone in a rat model of DCM. These findings may be due to a direct cardioprotective impact of sacubitril/valsartan and secondary beneficial effects of improved hyperglycemia and dyslipidemia. In addition, these beneficial cardiac effects could be attributed to the induction of the glycophagy process and alleviating cardiac glycogen overload.

Pentosan polysulfate exerts anti-inflammatory effect and halts albuminuria progression in diabetic nephropathy: Role of combined losartan.

Pentosan polysulfate sodium (PPS) is a polysulfated glycosaminoglycan approved for the treatment of interstitial cystitis. It also showed renoprotective effects in chronic kidney injury models, for example, 5/6 nephrectomy and diabetic nephropathy (DN). In the present study, we addressed to evaluate the therapeutic value of PPS in DN of rats in combination with losartan (LSR). Sixty male Sprague-Dawley rats were randomly divided into six groups: control group, untreated diabetic groups (8 and 16 weeks after diabetes induction by streptozotocin "STZ", 60 mg/kg, intraperitoneal [I.P.]), LSR-treated diabetic group (10 mg/kg/day, P.O.), PPS-treated diabetic group (25 mg/kg/day, P.O.), and combination-treated diabetic group. Drug treatment was started 8 weeks after induction of diabetes and continued for a further 8 weeks. Renal functions, albuminuria, renal IL-6, oxidative stress, and renal histopathology were evaluated. STZ-treated diabetic rats developed progressive albuminuria, renal dysfunction, and significant glomerular change 16 weeks after induction of diabetes. Administration of PPS, alone or in combination with LSR, showed some beneficial effects on DN evolution and significantly decreased renal inflammation as detected by IL-6 level. The best beneficial effect on DN evolution was obtained by PPS sole therapy based on albuminuria evaluation and renal histopathology. However, the combination of PPS and LSR did not show additive benefits. This study reported that the renoprotection of PPS in the setting of DN is evident by exerting anti-inflammatory and antioxidant effects, but this effect could be masked when combined with an angiotensin receptor blocker.

Pentosan Polysulfate Sodium augments the therapeutic effect of 5-Aminosalicylic Acid in DSS colitis model; the role of IL-35 expression.

Ulcerative colitis (UC) primarily affects the mucosa of the distal colon. Dysregulated immune response in genetically-prone persons is claimed to be responsible for chronic intestinal inflammation. This study aimed to explore the efficacy and the hematological effects of pentosan polysulfate sodium (PPS) in a dextran sulfate sodium (DSS)-induced colitis model. Forty C57BL/6 female mice were equally divided into five groups: control group, DSS-colitis group, DSS-colitis treated with 5-aminosalicylic acid, DSS-colitis treated with PPS, and DSS-colitis treated with both drugs. Disease activity index (DAI) and colon length were calculated. Colonic IL-6 and IL-35 levels were assayed by ELISA. IL-35 gene expression was evaluated by qRT-PCR. Colon tissue samples were examined by H&E stain and immunohistochemistry (IHC) of Ki67. The colitis group subjected to combined treatment showed the best outcome with significant improvement of DAI and increased colon length. Colonic IL-6 was significantly lower in both PPS- and combination-treated groups accompanied by a significantly higher IL-35 level and its EBI3 subunit mRNA expression. However, the PPS-treated colitis group showed higher gene expression of IL-35 EBI3 subunit by 1.5-fold compared with the combined group. The colon mucosa and crypts were significantly preserved in mice treated with both drugs with the best Ki67 positive cell density. PPS is a safe and promising drug in the treatment of UC as it exerted the best positive effect on the anti-inflammatory IL-35 level and gene expression. However, superior improvement of DAI was seen when PPS was added to ASA with a greater mucosal proliferation and repair.

The phloroglucinol calcitrinone A, a novel mitochondria-targeting agent, induces cell death in breast cancer cells.

Breast cancer is the most common cancer and the leading cause of cancer-related mortality among females worldwide. From the leaves of Callistemon citrinus, we have isolated a novel phloroglucinol dimer, calcitrinone A, and analyzed its potential anticancer activity using the triple-negative breast cancer cell line MDA-MB-231. Calcitrinone A decreased the total intracellular ATP levels, inhibited proliferation, and induced apoptosis in MDA-MB-231 cells, but was less toxic to peripheral blood mononuclear cells. The antiproliferative and apoptosis-inducing effects of calcitrinone A were confirmed in vivo using breast cancer xenografts grown on chick chorioallantoic membranes. Mechanistic analysis showed mitochondrial membrane-potential dissipation and interference with energy-yielding processes resulting in cell accumulation in the S phase of the cell cycle. Seahorse assay analysis revealed an early inhibition of mitochondrial oxidative phosphorylation (OXPHOS). At the molecular level, calcitrinone A inhibited activity of the succinate-coenzyme Q reductase (SQR) (mitochondrial complex II). In silico docking identified the coenzyme Q binding pocket as a possible high affinity binding site for calcitrinone A in SQR. Inhibition of complex II was accompanied by strong elevation of mitochondrial superoxide and cytoplasmic ROS. Calcitrinone A might be a promising anticancer lead compound acting through the interference with the mitochondrial complex II activity.

Exploring the Antivirulence Activity of Pulverulentone A, a Phloroglucinol-Derivative from Callistemon citrinus Leaf Extract, against Multi-Drug Resistant Pseudomonas aeruginosa.

(1) Background: Bacterial resistance to antibiotics is a global life-threatening issue. Antivirulence therapy is a promising approach to combat bacterial infections as it disarms the bacteria from their virulence factors with reduced selective pressure and a lower chance of resistance. (2) Methods: Callistemon citrinus leaf extract and its major constituent, Pulverulentone A, were tested for their ability to inhibit biofilm, exopolysaccharides, pyocyanin and proteases produced by MDR P. aeruginosa. In addition, a Galleria mellonella larvae model was employed to evaluate the in vivo cytotoxicity of Pulverulentone A and its ability to combat Pseudomonas infection. Docking study was further performed to investigate Pulverulentone A druggability against main quorum sensing (QS) targets expressed by P. aeruginosa; (3) Results: Both C. citrinus extract and the isolated compound could inhibit biofilm formation, extracellular polymeric substances (EPS) and pigment production by the tested isolates. Unexpectedly, no significant inhibition was observed on proteases production. The in silico docking analysis revealed good interactions of Pulverulentone A with all QS targets examined (LasR, MyfR/PqsR, QscR). Pulverulentone A was safe up to 400 µg·mL-1 in Galleria caterpillars. Moreover, pre-treatment of P. aeruginosa with Pulverulentone A slightly enhanced the survival of the infected larvae. (4) Conclusions: The present study proves Pulverulentone A safety with significant in vitro and in silico antivirulence potential against P. aeruginosa.

HPLC-PDA-ESI-MS/MS Profiling and Anti-Biofilm Potential of Eucalyptussideroxylon Flowers.

The development of multidrug-resistant bacterial strains is a worldwide emerging problem that needs a global solution. Exploring new natural antibiofilm agents is one of the most important alternative therapies in combating bacterial infections. This study aimed at testing the antimicrobial potential of Eucalyptus sideroxylon flowers extract (ESFE) against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans prior to testing the antibiofilm activity against S. aureus, P. aeruginosa and C. albicans. ESFE demonstrated antimicrobial activity and promising inhibition activity against methicillin-resistant S. aureus (MRSA) biofilm formation up to 95.9% (p < 0.05) at a concentration of 0.05 mg/mL and eradicated C. albicans biofilm formation up to 71.2% (p < 0.05) at a concentration of 0.7 mg/mL. LC-MS analysis allowed the tentative identification of eighty-three secondary metabolites: 21 phloroglucinol, 18 terpenes, 16 flavonoids, 7 oleuropeic acid derivatives, 7 ellagic acid derivatives, 6 gallic acid derivatives, 3 phenolic acids, 3 fatty acids and 2 miscellaneous. In conclusion, E. sideroxylon is a rich source of effective constituents that promote its valorization as a promising candidate in the management of multidrug-resistant bacterial infections.

Phytochemical profile, enzyme inhibition activity and molecular docking analysis of Feijoa sellowiana O. Berg.

Feijoa sellowiana leaves and fruits have been investigated as a source of diverse bioactive metabolites. Extract and eight metabolites isolated from F. sellowiana leaves were evaluated for their enzymatic inhibitory activity against α-glucosidase, amylase, tyrosinase, acetylcholinestrerase and butyrylcholinesterase both in vitro and in silico. Feijoa leaves' extract showed strong antioxidant activity and variable levels of inhibitions against target enzymes with a strong anti-tyrosinase activity (115.85 mg Kojic acid equivalent/g). Additionally, α-tocopherol emerged as a potent inhibitor of AChE and BChE (5.40 & 10.38 mmol galantamine equivalent/g, respectively). Which was further investigated through molecular docking and found to develop key enzymatic interactions in AChE and BChE active sites. Also, primetin showed good anti BChE (11.70 mmol galantamine equivalent/g) and anti-tyrosinase inhibition (90.06 mmol Kojic acid equivalent/g) which was also investigated by molecular docking studies. Highlights Isolation of eight bioactive constituents from Feijoa sellowiana leaves. In vitro assays using different enzymatic drug targets were investigated. In silico study was performed to define compound interactions with target proteins. Feijoa leaf is an excellent source of anti-AChE and antityrosinase bioactives.

Novel Antiviral and Antibacterial Activities of Hibiscus schizopetalus.

Hibiscus schizopetalus (Dyer) Hook.f. (Malvaceae) is an ornamental plant. The aim was to investigate its antimicrobial and antioxidant activities. In vitro antiviral, antibacterial, and antioxidant activities of the 70% ethanolic extract (Et-E) of the aerial parts of the plant were determined. The Dichloromethane Fraction (DCM-F) and the n-Butanol Fraction (Bu-F) were assessed using Liquid chromatography-mass spectrometry (LC-MS). The DCM-F showed higher antiviral activities against Coxsackie B4 (CoxB4) viruses (IC50 = 64.13 µg/mL) and adenoviruses (IC50 = 54.88 µg/mL) than acyclovir (IC50 = 72.79 µg/mL for CoxB4 viruses; IC50 = 91.92 µg/mL for adenoviruses). The DCM-F showed higher anti-helicobacter pylori activity (MIC = 3.9 µg/mL) than clarithromycin (MIC = 1.95 µg/mL). The DCM-F inhibited Herpes Simplex Virus (HSV) Type I (IC50 = 29.85 µg/mL) and HSV Type II (IC50 = 74.17 µg/mL). The Bu-F showed higher anti-mycobacterial activity (MIC = 7.81 µg/mL) than isoniazid (MIC = 0.24 µg/mL) and higher antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA)(MIC = 7.81 µg/mL) than vancomycin (MIC = 3.9 µg/mL). Antioxidant assays included total antioxidant capacity (TAC), 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS), 2,2-diphenyl-1-picryl-hydrazyl (DPPH), and iron reducing power. The Bu-F showed the highest antioxidant activity. Chemical profiles were analyzed using HPLC-HR-ESI-MS to identify the metabolites responsible for these biological activities. We identified more than 60 metabolites that belong to anthocyanins, flavonoids, phenolics, terpenes, sterols, and fatty acids. In conclusion, Hibiscusschizopetalus is endowed with metabolites that could be used against viruses and antibiotic-resistant bacteria. They can also be potent antioxidants.

Hibiscus sabdariffa L.: A potent natural neuroprotective agent for the prevention of streptozotocin-induced Alzheimer's disease in mice.

Hibiscus sabdariffa L. (Malvaceae) is one of the well-known traditionally used remedy worldwide. It exhibited numerous pharmacological properties including antioxidant, antidepressant, sedative, anti-inflammatory, antiproliferative, antimicrobial and neuroprotective activities. The aim of this study is to highlight the mechanisms underlying the neuroprotective effects of anthocyanin-enriched extracts of two Hibiscus varieties (white and red calyces) in the management of Alzheimer's disease (AD) in addition to their metabolic profiling. The anthocyanin contents were determined quantitatively using the pH-differential technique and qualitatively by LC/MS/MS. The extracts were tested in vitro for their antioxidant potential as well as acetylcholinesterase inhibition activity and both showed promising activities. The LC/MS/MS analysis allowed the tentative identification of 26 and 24 metabolites in red and white calyces, respectively, represented by anthocyanins, flavonoids, aliphatic and phenolic acids. In vivo, streptozotocin induced AD in mice model was established and Hibiscus extracts were tested at a dose of 200 mg kg-1 compared to celecoxib (30 mg/kg). Histopathology of cerebral cortex and hippocampus, immunohistochemistry for tau- protein and caspase-3 with behavioral tests and measurement of several biochemical parameters were done. Hibiscus prevented memory impairment, and this could be attributed to the amelioration of STZ-induced neuroinflammation and amyloidogenesis. Consequently, Hibiscus represents a promising safe agent that can be repurposed for AD through exerting anti-inflammatory, anti-acetylcholinesterase, antioxidant, and anti-amyloidogenic activities.

Clopidogrel combats neuroinflammation and enhances learning behavior and memory in a rat model of Alzheimer's disease.

BACKGROUND AND AIM: Alzheimer's disease (AD) is a progressive neurodegenerative disease. Multiple molecular mechanisms have been employed in its pathogenesis such as Amyloid ß (Aß) formation, tau protein hyperphosphorylation, reduced acetylcholine (ACh) level, and neuroinflammation. This study aimed to assess the possible neuroprotective effect of clopidogrel in AD model induced by aluminum chloride (AlCl3) in rats. METHODS: Sixty adult male Sprague-Dawley rats were divided into four different groups: Control, AlCl3, AlCl3 + donepezil, and AlCl3 + Clopidogrel. AlCl3 and the drugs were given orally once/day for 42 days. The spatial learning and memory and recognition memory were evaluated using Morris Water Maze (MWM) and Novel Object Recognition (NOR) tests, respectively. After euthanasia, hippocampal acetylcholinesterase (AChE) activity, tumor necrosis factor-alpha (TNF-α), and interleukin-1ß (IL-1ß) levels were biochemically assessed. Moreover, amyloid precursor protein (APP) mRNA gene expression was analyzed in the hippocampi of all rats. Histopathology for amyloid plaques was done. RESULTS: Clopidogrel co-treatment significantly ameliorated the cognitive deficits induced by AlCl3 in rats. Besides, clopidogrel significantly reduced AChE activity, TNF-α and IL-1ß concentrations, and APP mRNA gene expression in the hippocampi of rats compared to AlCl3 rats. The decrease of hippocampal TNF-α and IL-1ß concentrations by clopidogrel was significant compared to donepezil co-treated rats. Clopidogrel co-treatment lessened amyloid plaque deposition in the hippocampal tissues of rats compared to AlCl3 rats. CONCLUSION: These findings demonstrate that clopidogrel could alleviate learning and memory deficit induced by AlCl3 in rats and significantly reduced AChE activity. The neuroprotective outcome of clopidogrel might be assigned to its anti-inflammatory effect.