Autophagic activity of piperine on small intestine in dementia model mice with Parkinson's disease / 中国中药杂志

This article is to investigate the effect of piperine on the small intestine of mice with Parkinson's disease with dementia(PDD). Ninety-six C57 BL/6 mice of SPF grade were randomly divided into 8 groups(male, 12 in each group): normal group, model group, autophagy inhibitor group(6-amino-3-methylpurine, 3 MA, 30 mg·kg~(-1)), autophagy activator group(rapamycin, 1 mg·kg~(-1)), low, medium, and high dose piperine groups(10, 20, 40 mg·kg~(-1)), and medopar group(112.5 mg·kg~(-1)). Except for the normal group, mice in each group were injected subcutaneously with reserpine(0.1 mg·kg~(-1)) once every 48 hours for 40 days. In addition, on the 20 th day of administration, except for the normal group, the mice in the other groups were subjected to bilateral common carotid artery occlusion to finally prepare PDD models. At the same time, each group was given the corresponding drug treatment once a day for 40 days. After the last administration, the behavioral changes of mice were observed by autonomic activity experiment and hot plate experiment. The expression levels of α-synuclein(α-syn) and tyrosine hydroxylase(TH) in the small intestine were detected by immunohistochemistry. The expression levels of beclin-1, microtubule-associated protein 1 light chain 3 B(LC3 B) and p62 in the small intestine were detected by immunofluorescence assay. Hematoxylin-eosin staining was used to observe the pathological morphology of small intestine tissues in each group. Enzyme-linked immunosorbent assay was adopted for detection of β-amyloid precursor protein(APP), p-tau, acetylcholine transferase(ChAT), interleukin-6(IL-6) and tumor necrosis factor-α(TNF-α) in small intestine. Real-time fluorescent quantitative polymerase chain reaction was used to detect the expression of α-syn, TH, beclin-1, microtubule-associated protein 1 light chain 3(LC3), and p62 mRNA and mmu-miR-99 a-5 p in the small intestine. The results of this study showed that, as compared with the model group, the number of activities, the expression levels of ChAT, TH, and p62 were significantly increased in the 3 MA group, the various piperine dose groups, and the medopar group(P<0.05), and their first foot licking time was shortened; APP, p-tau, IL-6, TNF-α, α-syn, beclin-1, LC3 B and mmu-miR-99 a-5 p expression levels were significantly reduced(P<0.05). However, as compared with the model group, the number of activities, ChAT, TH, and p62 expression levels in the rapamycin group were significantly reduced(P<0.05), and the APP, p-tau, IL-6, TNF-α, α-syn, beclin-1, LC3 B and mmu-miR-99 a-5 p expression levels were significantly increased(P<0.05). As compared with the 3 MA group, the number of activities, ChAT, TH, and p62 expression levels were significantly reduced in the low and medium dose piperine groups and rapamycin group(P<0.05); howe-ver, their first foot licking time was significantly prolonged, APP, p-tau, IL-6, TNF-α, α-syn, beclin-1, LC3 B and mmu-miR-99 a-5 p expression levels were increased significantly(P<0.05). As compared with the medopar group, the number of activities, ChAT, TH, and p62 expression levels were significantly reduced in low dose piperine group and rapamycin group(P<0.05), but their first foot licking time was significantly extended, and APP, p-tau, IL-6, TNF-α, α-syn, beclin-1, LC3 B and mmu-miR-99 a-5 p expression levels were significantly increased(P<0.05). In addition, as compared with the normal group, the small intestinal epithelial cells of the model group and the rapamycin group were shed off a lot, with severe damages of intestinal mucosa as well as edema and shedding of the small intestine villi. After administration of the therapeutic interventions, the small intestinal epithelial cells of the 3 MA group, each dose group of piperine, and the medopa group were slightly damaged and the villi were slightly shed off. In summary, piperine has a protective effect on the small intestine of PDD model mice, showing reduced expression of mmu-miR-99 a-5 p, pro-inflammatory factors and autophagy factors, and the mechanism of slowing PDD pathological symptoms may be related to the inhibition of autophagy.

Enhancement of oral bioavailability and immune response of Ginsenoside Rh2 by co-administration with piperine / 中国天然药物

Ginsenoside Rh2 (Rh2) is one of the major bioactive ginsenosides in Panax ginseng. However, the oral bioavailability of Rh2 is low, with P-glycoprotein (P-gp) and CYP3A4 being reported to be the main factors. The purpose of the present study was to determine the enhancing effect of piperine on the oral bioavailability as well as bioactivity of Rh2. The inhibitory effect of piperine on P-gp and CYP3A4 was determined using a Caco-2 monolayer model and a recombinant CYP3A4 metabolic system, respectively. The pharmacokinetics of oral Rh2 (10 mg·kg) administered alone or in combination with piperine (10 and 20 mg·kg) was performed in rats. The immune boosting effect of Rh2 was assessed in rats by measuring IL-12 level after treated by Rh2 alone or co-administered with piperine. The results indicated that piperine significantly increased the permeability of Rh2 and inhibited the metabolism of Rh2. The pharmacokinetic study results showed that the AUC of Rh2 was significantly increased in combination with piperine at high dose (20 mg·kg) when compared to the control group, with relative bioavailability of 196.8%. The increase of Rh2 exposure led to increased serum levels of IL-12. In conclusion, piperine may be used as a bioenhancer to improve pharmacological effect of Rh2 when given orally.

Effects of six compounds with different chemical structures on melanogenesis / 中国天然药物

Several chemical compounds can restore pigmentation in vitiligo through mechanisms that vary according to disease etiology. In the present study, we investigated the melanogenic activity of six structurally distinct compounds, namely, scopoletin, kaempferol, chrysin, vitamin D, piperine, and 6-benzylaminopurine. We determined their effectiveness, toxicity, and mechanism of action for stimulating pigmentation in B16F10 melanoma cells and in a zebrafish model. The melanogenic activity of 6-benzylaminopurine, the compound identified as the most potent, was further verified by measuring green fluorescent protein concentration in tyrp1 a: eGFP (tyrosinase-related protein 1) zebrafish and mitfa: eGFP (microphthalmia associated transcription factor) zebrafish and antioxidative activity. All the tested compounds were found to enhance melanogenesis responses both in vivo and in vitro at their respective optimal concentration by increasing melanin content and expression of TYR and MITF. 6-Benzyamino-purine showed the strongest re-pigmentation action at a concentration of 20 μmol·Lin vivo and 100 μmol·Lin vitro, and up-regulated the strong fluorescence expression of green fluorescent protein in tyrp1a: eGFP and mitfa: eGFP zebrafish in vitro. However, its relative anti-oxidative activity was found to be very low. Overall, our results indicated that 6-benzylaminopurine stimulated pigmentation through a direct mechanism, by increasing melanin content via positive regulation of tyrosinase activity in vitro, as well as up-regulating the expression of the green fluorescent protein in transgenic zebrafish in vivo.

Enhancement of oral bioavailability and immune response of Ginsenoside Rh2 by co-administration with piperine / 中国天然药物

Ginsenoside Rh2 (Rh2) is one of the major bioactive ginsenosides in Panax ginseng. However, the oral bioavailability of Rh2 is low, with P-glycoprotein (P-gp) and CYP3A4 being reported to be the main factors. The purpose of the present study was to determine the enhancing effect of piperine on the oral bioavailability as well as bioactivity of Rh2. The inhibitory effect of piperine on P-gp and CYP3A4 was determined using a Caco-2 monolayer model and a recombinant CYP3A4 metabolic system, respectively. The pharmacokinetics of oral Rh2 (10 mg·kg) administered alone or in combination with piperine (10 and 20 mg·kg) was performed in rats. The immune boosting effect of Rh2 was assessed in rats by measuring IL-12 level after treated by Rh2 alone or co-administered with piperine. The results indicated that piperine significantly increased the permeability of Rh2 and inhibited the metabolism of Rh2. The pharmacokinetic study results showed that the AUC of Rh2 was significantly increased in combination with piperine at high dose (20 mg·kg) when compared to the control group, with relative bioavailability of 196.8%. The increase of Rh2 exposure led to increased serum levels of IL-12. In conclusion, piperine may be used as a bioenhancer to improve pharmacological effect of Rh2 when given orally.

Effects of six compounds with different chemical structures on melanogenesis / 中国天然药物

Several chemical compounds can restore pigmentation in vitiligo through mechanisms that vary according to disease etiology. In the present study, we investigated the melanogenic activity of six structurally distinct compounds, namely, scopoletin, kaempferol, chrysin, vitamin D, piperine, and 6-benzylaminopurine. We determined their effectiveness, toxicity, and mechanism of action for stimulating pigmentation in B16F10 melanoma cells and in a zebrafish model. The melanogenic activity of 6-benzylaminopurine, the compound identified as the most potent, was further verified by measuring green fluorescent protein concentration in tyrp1 a: eGFP (tyrosinase-related protein 1) zebrafish and mitfa: eGFP (microphthalmia associated transcription factor) zebrafish and antioxidative activity. All the tested compounds were found to enhance melanogenesis responses both in vivo and in vitro at their respective optimal concentration by increasing melanin content and expression of TYR and MITF. 6-Benzyamino-purine showed the strongest re-pigmentation action at a concentration of 20 μmol·Lin vivo and 100 μmol·Lin vitro, and up-regulated the strong fluorescence expression of green fluorescent protein in tyrp1a: eGFP and mitfa: eGFP zebrafish in vitro. However, its relative anti-oxidative activity was found to be very low. Overall, our results indicated that 6-benzylaminopurine stimulated pigmentation through a direct mechanism, by increasing melanin content via positive regulation of tyrosinase activity in vitro, as well as up-regulating the expression of the green fluorescent protein in transgenic zebrafish in vivo.

Optimization and characterization of curcumin-piperine dual drug loaded self-microemulsifying drug delivery system by simplex lattice design / 中国中药杂志

The objective of the study was to prepare and evaluate the quality of curcumin-piperinedual drug loaded self-microemulsifying drug delivery system(Cur-PIP-SMEDDS). Simplex lattice design was constructed using optimal oil phase, surfactant and co-surfactant concentration as independent variables, and the curcumin and piperine were used as model drugs to optimize Cur-PIP-SMEDDS formulation. In the present study, the drug loadings of curcumin and piperine, mean particle size of Cur-PIP-SMEDDS were made as indicators, and the experiment design, model building and response surface analysis were established using Design Expert 8. 06 software to optimize and verify the composition of SMEDDS formulation. The quality of Cur-PIP-SMEDDS was evaluated by observing the appearance status, transmission electron microscope micrographs and determining particle diameter, electric potential, drug entrapment efficiency and drug loading of it. As a result, the optimal formulation of SMEDDS was CapryoL 90-Cremophor RH40-TranscutoL HP (10:60:30). The appearance of Cur-PIP-SMEDDS remained clarified and transparent, and the microemulsion droplets appeared spherical without aggregation with uniform particle size distribution. The mean size of microemulsion droplet formed from Cur-PIP-SMEDDS was 15.33 nm, the drug loading of SMEDDS for Cur and PIP were 40.90 mg · g(-1) and 0.97 mg · g(-1), respectively, the drug entrapment efficiency were 94.98% and 90.96%, respectively. The results show that Cur-PIP-SMEDDS can increase the solubility and stability of curcumin significantly, in the expectation of enhancing the bioavailability of it. Taken together, these findings can provide the reference to a preferable choice of the Cur formulation and contribute to therapeutic application in clinical research.

Studies of effective part group of piperine to regulating lipid / 中国中药杂志

The effects of effective part group on hyperlipidemia in animal were studied. The SD rats, hamsters and Kunming mouse were divided into blank group, model group. The positive control group and test group were fed with normal diet, blank and other groups were fed with high fat diet (mouse only a single intraperitoneal injection of egg yolk ). The corresponding concentration of solvent, simvastatin, effective part group of emulsion were given gavage once daily. The animal serum total cholesterol (TC) , triglyceride (TG) , low density lipoprotein (LDL) , high density lipoprotein (HDL) and liver TC, TG contents were determined to observe the effects of the effective fractions on blood lipid regulating function. Comparing with control group, the animial hyperlipidemia models of the SD rat (TC increase), mouse (TC, TG, LDL increase), hamsters ( TC, TG, LDL increase, HDL decrease) (P <0. 05, P < 0. 001) were successfully established. Piper longum effective part group could decrease the serum TC, TG, LDL (P <0.05, P < 0. 001) and liver TC, TG content, and elevate serum HDL levels (P <0.05, P <0.001). The golden hamster is ideal for hyperlipidemia model.

Inhibitory effects of endocannabinoid on the action potential of pacemaker cells in sinoatrial nodes of rabbits / 生理学报

Endocannabinoid anandamide (AEA) has protective effect on the heart against ischemia/reperfusion injury and arrhythmia, but the electrophysiological mechanism is unclear yet. In this study, the sinoatrial node (SAN) samples from New Zealand rabbits were prepared, and intracellular recording technique was used to elucidate the effect of AEA on the action potential (AP) of SAN pacemaker cells of rabbits and the mechanism. Different concentrations of AEA (1, 10, 100, 200, 500 nmol/L) were applied cumulatively. For some SAN samples, cannabinoid type 1 (CB1) receptor antagonist AM251, cannabinoid type 2 (CB2) receptor antagonist AM630, potassium channel blocker tetraethylammonium (TEA) and nitric oxide (NO) synthase inhibitor L-nitro-arginine methylester (L-NAME) were used before AEA treatment, respectively. We found that: (1) AEA (100, 200 and 500 nmol/L) not only shortened AP duration (APD), but also decreased AP amplitude (APA) (P < 0.05). (2) AM251, but not AM630, abolished the effect of AEA on APD shortening. (3) TEA and L-NAME had no influence on the AEA effect. These findings suggest that anandamide can decrease APA and shorten APD in SAN pacemaker cells of rabbits, which may be mediated by activation of CB1 receptors, and is related to blockade of calcium channels but not potassium channels and NO.

Amaranthus roxburghianus root extract in combination with piperine as a potential treatment of ulcerative colitis in mice / 中西医结合学报

<p><b>OBJECTIVE</b>The present work was undertaken to determine the effects of Amaranthus roxburghianus Nevski. (Amaranthaceae) root alone and in combination with piperine in treating ulcerative colitis (UC) in mice.</p><p><b>METHODS</b>Swiss albino mice were divided into seven groups (n = 6). Standard group received prednisolone (5 mg/kg, intraperitoneally). Treatment groups received hydroalcoholic extract of roots of A. roxburghianus (50 and 100 mg/kg, per oral) and a combination of hydroalcoholic extract of roots of A. roxburghianus (50 and 100 mg/kg, per oral) and piperine (5 mg/kg, per oral). Ulcer index, colitis severity, myeloperoxidase (MPO), malondialdehyde and glutathione were estimated from blood and tissue. Column chromatography of the extract was done and purified fractions were analyzed by gas chromatography-mass spectroscopy (GC-MS).</p><p><b>RESULTS</b>Treatment with the combination of hydroalcoholic extract of A. roxburghianus and piperine showed minimal ulceration, hemorrhage, necrosis and leucocyte infiltration by histopathological observation. Acetic acid increased MPO levels in blood and colon tissue to 355 U/mL and 385 U/mg, respectively. The combination of hydroalcoholic extract of A. roxburghianus (100 mg/kg) and piperine (5 mg/kg) significantly decreased MPO in blood and tissue to 182 U/mL and 193 U/mg, respectively (P < 0.05). Similarly, this combination significantly reduced malondialdehyde levels and increased glutathione levels in blood and tissue. Various phytoconstituents were detected by GC-MS.</p><p><b>CONCLUSION</b>The combination of hydroalcoholic extract of A. roxburghianus and piperine is effective in the treatment of UC and the effects are comparable with the standard drug prednisolone. 4H-pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl, eugenol and benzene, and 1-(1,5-dimethyl-4-hexenyl)-4-methyl are reported having analgesic, anti-inflammatory, and antioxidant properties; they may play a role in the biological activity of A. roxburghianus root.</p>

Effect of piperine on 5-HT and synaptophysin expression of rats with irritable bowel syndrome / 药学学报

This study is to explore the amelioration of piperine on chronic acute combining stress rat with depression-like behavior, visceral sensitivity, and its effect on the expression of serotonin (5-HT) and synaptophysin. Forty two SD rats were divided into seven groups: blank group, model group, piperine (12.5, 25, 50 and 100 mgkg-1, ig) and imipramine (10 mgkg-1, ip) groups. The rat model of irritable bowel syndrome was established by chronic acute combining stress, and then to evaluate depression-like behavior and visceral sensitivity. The expressions of 5-HT and synaptophysin in the hippocampus and colon were determined by high performance liquid chromatography (HPLC) and Western blotting, respectively. The duration of immobility of IBS rat in the forced swimming test had been significantly increased, the sucrose consumption of IBS rat had been reduced and visceral sensitivity was obviously elevated in the IBS model group as compared with those in the normal control group (P<0.05, P<0.01). As compared with those in the normal control group, the expression of 5-HT significantly decreased, 5-HIAA/5-HT ratio significantly increased in the hippocampus of IBS model group (P<0.05), but opposite presentations were noted in the colon (P<0.05). As compared with that in the normal control group, the synaptophysin expression in the hippocampus decreased significantly but obviously increased in the colon (P<0.05). Piperine improved the behavior of IBS rats, and reversed the levels of 5-HT and 5-HIAA, and 5-HIAA/5-HT proportion in the hippocampus and colon (P<0.05); besides, they significantly reverse the synaptophysin level in the hippocampus and colon (P<0.05). The presence of depression and visceral sensitivity had been changed in IBS rats, with abnormal expression of 5-HT and synaptophysin in the brain-gut system. Piperine can ameliorate the changes of the behavior and regulation of serotonin and synaptophysin expression in IBS rat model.

Fine-tuning of defensive behaviors in the dorsal periaqueductal gray by atypical neurotransmitters

This paper presents an up-to-date review of the evidence indicating that atypical neurotransmitters such as nitric oxide (NO) and endocannabinoids (eCBs) play an important role in the regulation of aversive responses in the periaqueductal gray (PAG). Among the results supporting this role, several studies have shown that inhibitors of neuronal NO synthase or cannabinoid receptor type 1 (CB1) receptor agonists cause clear anxiolytic responses when injected into this region. The nitrergic and eCB systems can regulate the activity of classical neurotransmitters such as glutamate and γ-aminobutyric acid (GABA) that control PAG activity. We propose that they exert a ‘fine-tuning’ regulatory control of defensive responses in this area. This control, however, is probably complex, which may explain the usually bell-shaped dose-response curves observed with drugs that act on NO- or CB1-mediated neurotransmission. Even if the mechanisms responsible for this complex interaction are still poorly understood, they are beginning to be recognized. For example, activation of transient receptor potential vanilloid type-1 channel (TRPV1) receptors by anandamide seems to counteract the anxiolytic effects induced by CB1 receptor activation caused by this compound. Further studies, however, are needed to identify other mechanisms responsible for this fine-tuning effect.

Anandamide inhibits the growth of colorectal cancer cells through CB1 and lipid rafts / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the influences of endocannabinoid-anandamide (AEA) on the proliferation and apoptosis of the colorectal cancer cell line (CaCo-2) and to elucidate the effects of CB1 and lipid rafts, and to further elucidate the molecular mechanism and the effect of AEA on the generation and development of colorectal cancer.</p><p><b>METHODS</b>Human colorectal cancer cell line CaCo-2 was cultured in RPMI 1640 medium supplemented with 10% fetal bovine serum in 5% CO(2) atmosphere at 37°C. CaCo-2 cells were divided into different groups and treated with different concentrations of AEA, AEA + SR141716A, AEA + AM630 and AEA + methyl-β-cyclodextrin (MCD). MTT assay was used to determine the effects of AEA, its putative CB1, CB2 receptor antagonists (SR141716A and AM630) and MCD on the proliferation of CaCo-2 cells. Annexin V-PE/7AAD binding assay was used to detect apoptosis in the CaCo-2 cells. Western-blot was applied to check the expressions of CB1, CB2, p-AKT and caspase-3 proteins in different groups of CaCo-2 cells.</p><p><b>RESULTS</b>AEA inhibited the proliferation of CaCo-2 cells in a concentration-dependent manner and the effect could be antagonized by SR141716A and MCD. The inhibiting rates were (21.52 ± 0.45)%, (42.16 ± 0.21)%, (73.64 ± 0.73)% and (83.28 ± 0.71)%, respectively, at different concentrations of AEA (5, 10, 20 and 40 µmol/L). The three groups (20 µmol/L AEA, 20 µmol/L AEA + 10 µmol/L SR141716A and 20 µmol/L AEA + 1 mmol/L MCD) showed different inhibiting rates [(73.64 ± 0.73)%, (16.15 ± 0.75)% and (12.58 ± 0.63)%], respectively. Annexin V-PE/7AAD binding assay showed that AEA induced apoptosis in the CaCo-2 cells and MCD could antagonize this effect. The apoptosis rates of the three groups (control, 20 µmol/L AEA and 20 µmol/L AEA + 1 mmol/L MCD) were (2.95 ± 0.73)%, (39.61 ± 0.73)% and (14.10 ± 0.64)%, respectively. The expressions of CB1, CB2, p-AKT and Caspase-3 proteins were all observed in the CaCo-2 cells. AEA inhibited p-AKT protein expression and induced caspase-3 protein expression. The two actions were also antagonized by MCD.</p><p><b>CONCLUSIONS</b>AEA can strongly suppress the proliferation of colorectal cancer CaCo-2 cells via the CB1 receptor and membrane cholesterol-LRs and induce apoptosis via lipid rafts. Anandamide plays a very important role in the carcinogenesis and development of colorectal cancer. MCD is a critical member in this system.</p>

HPLC determination of four components in Tibetan medicine Dangzuo of different Tibetan regions / 中国中药杂志

<p><b>OBJECTIVE</b>To develop an HPLC method for determination of gallic acid, hydroxysafflor yellow A, cinnamic aldehyde and piperine in Tibetan medicine Dangzuo, and to compare the content of four active components in Dangzuo of different Tibetan regions.</p><p><b>METHOD</b>The separation was carried out on a Waters XTerra RP-C18 column ( 4.6 mm x 250 mm, 5 microm). The mobile phases were methanol and water, all contained 0.1% glacial acetic acid, for gradient elution. The gradient program was as follows: 0-22.5 min, methanol was changed from 5% to 50%; 22.5-40 min, changed to 80% 80:20. The flow rate was 1.0 mL x min(-1). The detection wavelength was 270 nm. The reference wavelength was 500 nm.</p><p><b>RESULT</b>The linear ranges of gallic acid, hydroxysafflor yellow A, cinnamic aldehyde and piperine were 0.040-0.640 microg (r = 0.999 8), 0.090-1.440 microg (r = 0.999 9), 0.031-0.500 microg (r = 0.999 9 ) and 0.092-41.477 microg (r = 0.998 9), respectively. The average recoveries (n = 6) were 97.42% (RSD 1.9%), 97.55% (RSD 2.9%), 98.69% (RSD 0.96%) and 96.72% (RSD 4.0%), respectively. The content ranges of gallic acid, hydroxysafflor yellow A, cinnamic aldehyde and piperine in Dangzuo samples of different Tibetan regions were 0.11341.69 mg x g(-1), 0.889-1.51 mg x g(-1), 0.000-40.606 mg x g(-1) and 1.96-2.73 mg x g(-1), respectively.</p><p><b>CONCLUSION</b>The method is a simple and effective for quality control of Tibetan medicine Dangzuo.</p>

Tissue distribution & elimination of capsaicin, piperine & curcumin following oral intake in rats.

Background & objectives: Curcumin, capsaicin and piperine - the bioactive compounds present in spices-turmeric (Curcuma longa), red pepper (Capsicum annuum) and black pepper (Piper nigrum) respectively, have a considerable portion of structural homology. Tissue distribution and elimination of these three structurally similar bioactive compounds was examined following their oral intake in rats. Methods: Separate sets of animals (150 - 160 g) were orally administered the three spice principles at dosages of 30 mg (capsaicin), 170 mg (piperine) and 500 mg (curcumin) / kg body weight. The tissue concentrations of administered spice compounds were determined by HPLC. Results: Maximum distribution of 24.4 per cent of administered capsaicin was seen at 1 h, while no intact capsaicin was detectable after 4 days. Absorption of capsaicin was about 94 per cent and very rapid relative to other two compounds. A maximum of 10.8 per cent of administered piperine was seen in tissues at 6 h. Absorption of the administered piperine was about 96 per cent. Curcumin concentration was maximum in the intestine at 1 h; maximum in blood at 6 h and remained at significantly higher level even at 24 h. About 63.5 per cent of the curcumin dose was absorbed. Only a small portion of the administered dose of capsaicin (< 0.1%) and curcumin (0.173 %) was excreted in urine, whereas piperine was not detectable in urine. Enhanced bioavailability of curcumin was evidenced when the same was orally administered concomitant with piperine. Intestinal absorption of curcumin was relatively higher when administered concomitantly with piperine, and it stayed significantly longer in the body tissues. Intact curcumin was detected in brain at 24, 48 and 96 h with a maximum at 48 h. Conclusions: Considerable difference exists in the bioavailability of the three test compounds. Curcumin could be traced in the brain following its administration. Bioavailability of curcumin can be improved by co-administration with piperine.

Membrane cholesterol mediates the endocannabinoids-anandamide affection on HepG2 cells / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To study the effect of anandamide (AEA) on necrosis in HepG2 cells and to explore the role of AEA in progression of liver cancer.</p><p><b>METHODS</b>Localization of the fatty acid hydrolytic enzyme (FAAH), cannabinoid receptors 1(CB1) and cannabinoid receptors 2 (CB2) proteins was detected in L02 and HepG2 cells using immunofluorescence. L02 and HepG2 cells were treated with different concentrations of AEA and methyl-beta-cyclodextrin, and the rates of cells necrosis were examined by PI stain. Meanwhile, the expression levels of FAAH, CB1 and CB2 receptor proteins, as well as P38 mitogen-activated protein kinase (p-P38 MAPK) and c-Jun-NH2-terminal kinase (p-JNK) proteins, were analyzed by Western blot.</p><p><b>RESULTS</b>The FAAH, CB1 and CB2 receptor proteins were observed both in cytoplasm and on membrane in L02 and HepG2 cells. The expression level of FAAH protein was higher in HepG2 than in L02 cells. The expression level of CB1 receptor protein was very low in both L02 and HepG2 cells. The expression level of CB2 receptor protein was high in both L02 and HepG2 cells. AEA treatment induced necrosis in HepG2 cells but not in L02 cells. Methyl-beta-cyclodextrin treatment prevented necrosis in HepG2 cells (t = 3.702; 5.274; 3.503, P less than 0.05). The expression patterns of FAAH, CB1 and CB2 receptor protein in L02 and HepG2 cells were confirmed by western blot, which were consistent with the immunofluorescence results. AEA treatment increased the levels of p-P38MAPK and p-JNK proteins in a dose-dependent manner in HepG2 cells (F = 11.908; 26.054, P less than 0.05) and the increase can be partially by prevented by MCD (t = 2.801; t = 12.829, P less than 0.05).</p><p><b>CONCLUSION</b>AEA treatment induces necrosis in HepG2 cells via CB1 and CB2 receptors and lipid rafts.</p>

Study on transdermal absorption of piperine in Erxiekang plaster / 中国中药杂志

<p><b>OBJECTIVE</b>To research the absorbed character of piperine in Erxiekang plaster, and piperine by transdermal absorption was determined.</p><p><b>METHOD</b>The percutaneous absorption of piperine in vitro at different times was conducted by Franz osmosis and diffusion apparatus as well as high-performance liquid chromatography.</p><p><b>RESULT</b>It showed that the piperine through skins of mice gradually increased within the experiment time. After 52 h, the penetration of piperine was 78.51%, and remained basically unchanged.</p><p><b>CONCLUSION</b>The method is reliable, and can be used for Erxiekang plaster of determination of transdermal absorption.</p>

Dose-response effects of systemic anandamide administration in mice sequentially submitted to the open field and elevated plus-maze tests

The endocannabinoid system is involved in the control of many physiological functions, including the control of emotional states. In rodents, previous exposure to an open field increases the anxiety-like behavior in the elevated plus-maze. Anxiolytic-like effects of pharmacological compounds that increase endocannabinoid levels have been well documented. However, these effects are more evident in animals with high anxiety levels. Several studies have described characteristic inverted U-shaped dose-response effects of drugs that modulate the endocannabinoid levels. However, there are no studies showing the effects of different doses of exogenous anandamide, an endocannabinoid, in animal models of anxiety. Thus, in the present study, we determined the dose-response effects of exogenous anandamide at doses of 0.01, 0.1, and 1.0 mg/kg in C57BL/6 mice (N = 10/group) sequentially submitted to the open field and elevated plus-maze. Anandamide was diluted in 0.9 percent saline, ethyl alcohol, Emulphor® (18:1:1) and administered ip (0.1 mL/10 g body weight); control animals received the same volume of anandamide vehicle. Anandamide at the dose of 0.1 mg/kg (but not of 0.01 or 1 mg/kg) increased (P < 0.05) the time spent and the distance covered in the central zone of the open field, as well as the exploration of the open arms of the elevated plus-maze. Thus, exogenous anandamide, like pharmacological compounds that increase endocannabinoid levels, promoted a characteristic inverted U-shaped dose-response effect in animal models of anxiety. Furthermore, anandamide (0.1 mg/kg) induced an anxiolytic-like effect in the elevated plus-maze (P < 0.05) after exposing the animals to the open field test.

Anandamide injected into the lateral ventricle of the brain inhibits submandibular salivary secretion by attenuating parasympathetic neurotransmission

Our objective was to determine the effect of arachidonylethanolamide (anandamide, AEA) injected intracerebroventricularly (icv) into the lateral ventricle of the rat brain on submandibular gland (SMG) salivary secretion. Parasympathetic decentralization (PSD) produced by cutting the chorda tympani nerve strongly inhibited methacholine (MC)-induced salivary secretion while sympathetic denervation (SD) produced by removing the superior cervical ganglia reduced it slightly. Also, AEA (50 ng/5 µL, icv) significantly decreased MC-induced salivary secretion in intact rats (MC 1 µg/kg: control (C), 5.3 ± 0.6 vs AEA, 2.7 ± 0.6 mg; MC 3 µg/kg: C, 17.6 ± 1.0 vs AEA, 8.7 ± 0.9 mg; MC 10 µg/kg: C, 37.4 ± 1.2 vs AEA, 22.9 ± 2.6 mg). However, AEA did not alter the significantly reduced salivary secretion in rats with PSD, but decreased the slightly reduced salivary secretion in rats with SD (MC 1 µg/kg: C, 3.8 ± 0.8 vs AEA, 1.4 ± 0.6 mg; MC 3 µg/kg: C, 14.7 ± 2.4 vs AEA, 6.9 ± 1.2 mg; P < 0.05; MC 10 µg/kg: C, 39.5 ± 1.0 vs AEA, 22.3 ± 0.5 mg; P < 0.001). We showed that the inhibitory effect of AEA is mediated by cannabinoid type 1 CB1 receptors and involves GABAergic neurotransmission, since it was blocked by previous injection of the CB1 receptor antagonist AM251 (500 ng/5 µL, icv) or of the GABA A receptor antagonist, bicuculline (25 ng/5 µL, icv). Our results suggest that parasympathetic neurotransmission from the central nervous system to the SMG can be inhibited by endocannabinoid and GABAergic systems.

Endocannabinoids anandamide and its cannabinoid receptors in liver fibrosis after murine schistosomiasis / 华中科技大学学报（医学）（英德文版）

This study examined endogenous cannabinoid (ECB)-anandamide (AEA) and its cannabinoid receptors (CBR) in mice liver with the development of schistosoma japonicum. Mice were infected with schistosoma by means of pasting the cercaria onto their abdomens. Liver fibrosis was pathologically confirmed nine weeks after the infection. High performance liquid chromatography (HPLC) was employed to determine the concentration of AEA in the plasma of mice. Immunofluorescence was used to detect the expression of CBR1 and CBR2 in liver tissue. Morphological examination showed typical pathological changes, with worm tubercles of schistosoma deposited in the liver tissue, fibrosis around the worm tubercles and infiltration or soakage of inflammatory cells. Also, CBR1 and CBR2 were present in hepatocytes and hepatic sinusoids of the two groups, but they were obviously enhanced in the schistosoma-infected mice. However, the average optical density of CBR1 in the negative control and fibrosis group was 13.28+/-7.32 and 30.55+/-7.78, and CBR2 were 28.13+/-6.42 and 52.29+/-4.24 (P<0.05). The levels of AEA in the fibrosis group were significantly increased as compared with those of the control group. The concentrations of AEA were (0.37+/-0.07) and (5.67+/-1.34) ng/mL (P<0.05). It is concluded that the expression of endocannabinoids AEA and its cannabinoid receptor CBR were significantly increased in schistosoma-infected mice. Endogenous endocannabinoids may be involved in the development of schistosoma-induced liver fibrosis.

Antidepressant-like effects of piperine and its neuroprotective mechanism / 中国中药杂志

<p><b>OBJECTIVE</b>To observe the antidepressant effect of piperine and its neuroprotective mechanism.</p><p><b>METHOD</b>The behavioral studies were performed in forced swimming test (FST) and tail suspension test (TST). To further explore the mechanisms underlying their antidepressant-like activities, CORT-induced neuroblastoma SH-SY5Y cells and isolated and cultured neural progenitor cells. By using MTT assay, the effect of piperine on neural cells proliferation was observed.</p><p><b>RESULT</b>The research results indicated that after a week of administration, piperine (10, 20 mg x kg(-1)) could significantly reduce the duration of immobility in both FST and TST. Piperine has the protective effect on neuroblastoma cells and increased proliferation of hippocampus neural progenitor cells.</p><p><b>CONCLUSION</b>In the present study, we demonstrated that the antidepressant-like effects of piperine and its mechanisms might be involved by up-regulation of the progenitor cell proliferation of hippocampus and cytoprotective activity.</p>