Organ specific differences in alteration of aquaporin expression in rats treated with sennoside A,senna anthraquinones and rhubarb anthraquinones

OBJECTIVE Senna and rhubarb are classified as stimulative laxatives,and known to have similar effective constituents,the anthraquinones.Being protected by theβ-glucoside bond,the anthraquinones can reach the intestines where they are degraded into complex metabolites by enzymes secreted from the intestinal microbiome.It is these complex metabolites that produce the laxative effects.Then the similarities and differences of action between the anthraquinones require further elucidation.METHODS Here,we studied metabolites of senna anthraquinones(SAQ),rhubarb anthraquinones(RAQ)and their chemical marker,sennoside A(SA),in a rat diarrhea model.In the in vitro biotransformation experiments,SAQ,RAQ and SA were incubated with rat fecal flora solution and the metabolites produced were analyzed using HPLC.In the in vivo studies,the same compounds were investigated for purgation induction,with measurement of histopathology and multiple aquaporins(Aqps)gene expression in six organs.RESULTS SAQ and RAQ had similar principal constituents but could be degraded into different metabolites.A similar profile of Aqps down-regulation for all compounds was seen in the colon,suggesting a similar mechanism of action for purgation.However,in the kidneys and livers of the diarrhea-rats,down-regulation of Aqps was found in the RAQ-rats whereas up-regulation of Aqps was seen in the SAQ-rats.Furthermore,the RAQ-rats showed lower aquaporin 2(Aqp2)protein expression in the kidneys,whilst the SA-rats and SAQ-rats had higher Aqp2 protein expression in the kidneys.This may have implications for side effects of SAQ or RAQ in patients with chronic kidney or liver diseases.CONCLUSION SAQ and RAQ showed similar laxative actions with a similar mechanism,they could display different actions in rat kidneys and livers.We suggest that the clinical usage of senna or rhubarb products should be clarified for patients having chronic kidney or liver diseases.

Regulation of microbiota–GLP1 axis by sennoside A in diet-induced obese mice

Sennoside A(SA) is a bioactive component of Chinese herbal medicines with an activity of irritant laxative, which is often used in the treatment of constipation and obesity. However, its activity remains unknown in the regulation of insulin sensitivity. In this study, the impact of SA on insulin sensitivity was tested in high fat diet(HFD)-induced obese mice through dietary supplementation. At a dosage of 30 mg/kg/day, SA improved insulin sensitivity in the mice after 8-week treatment as indicated by HOMA-IR(homeostatic model assessment for insulin resistance) and glucose tolerance test(GTT). SA restored plasma level of glucagon-like peptide 1(GLP1) by 90% and mRNA expression of Glp1 by 80% in the large intestine of HFD mice. In the mechanism, SA restored the gut microbiota profile, short chain fatty acids(SCFAs), and mucosal structure in the colon. A mitochondrial stress was observed in the enterocytes of HFD mice with ATP elevation, structural damage, and complex dysfunction. The mitochondrial response was induced in enterocytes by the dietary fat as the same responses were induced by palmitic acid in the cell culture. The mitochondrial response was inhibited in HFD mice by SA treatment. These data suggest that SA may restore the function of microbiota–GLP1 axis to improve glucose metabolism in the obese mice.

Effects of rhubarb and the active ingredients of rhubarb on the cytoplasmic free calcium in INTMNC of rabbits

INTRODUCTIONThe recent studies have shown that rhubarb has notonly the effect of removing stasis by purgation,butalso intestinal barrier effects.In order tofurther clarify the intestinal barrier mechanism ofrhubarb,we studied the effects of rhubarbdecoction and the active ingredients of rhubarb onthe cytoplasmic free calcium in isolated intestinalmononuclear ceils (INT-MNC).

Salvianolic acid B promotes the invasion and migration of H_(2)O_(2)-induced HTR-8/Svneo trophoblast cells by upregulating matrix metalloproteinase-9 via the phosphatidylinositol-4,5-bisphosphate 3-kinase/protein kinase B pathway

OBJECTIVE:To elucidate the regulatory effects of salvianolic acid B(Sal B)on trophoblast cells in preeclampsia(PE).METHODS:3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide(MTT)assays were used to detect the viability of human extravillous trophoblast HTR-8/Svneo cells induced by H_(2)O_(2)following treatment with different concentrations of Sal B.The levels of oxidative stressrelated molecules,including superoxide dismutase,glutathione-Px and malondialdehyde were detected using corresponding kits.Cell apoptosis was detected using a Terminal deoxynucleotidyl transferase(Td T)d UTP NickEnd Labeling(TUNEL)assay,and the expression of apoptosis-related proteins was detected using western blot analysis.In the present study,wound healing and Transwell assays were performed to measure the levels of cell invasion and migration.Western blot analysis was also used to detect the expression levels of epithelialmesenchymal transition-related proteins.The mechanisms underlying Sal B were further investigated using reverse transcription-quantitative real-time polymerase chain reaction(RT-q PCR)and western blot analysis,to determine the expression levels of matrix metallopeptidase 9(MMP-9)and phosphatidylinositol-4,5-bisphosphate 3-kinase(PI3K)/protein kinase B(Akt).RESULTS:Sal B increased the activity of HTR-8/Svneo cells,inhibited oxidative damage and promoted the invasion and migration of trophoblast cells induced by H_(2)O_(2).Furthermore,the expression levels of MMP-9 and members of the PI3K/Akt signaling pathway were significantly decreased.The pathway agonist,LY294002,and MMP-9 inhibitor,GM6001,reversed the effects of Sal B on H_(2)O_(2)-induced cells.CONCLUSIONS:Sal B promoted the invasion and migration of H_(2)O_(2)-induced HTR-8/Svneo trophoblast cells by upregulating MMP-9 via the PI3K/Akt signaling pathway.

Evaluation of diuretic and laxative activity of hydro-alcoholic extract of Desmostachya bipinnata(L.) Stapf in rats

OBJECTIVE： In continuation to the growing evidence for therapeutical potential of Desmostachya bipinnata （Linn） Stapf, the current pharmacological study was carried out to evaluate the diuretic and laxative activity of its hydro-alcoholic extract in rats. METHODS： The hydro-alcoholic extract of D. bipinnata whole plant was prepared by using Sox- hlet extractor and subjected to analysis by standard preliminary phytochemical tests. Evaluation of both diuretic and laxative activity was carried out using standard methods as reported earlier. Frusemide （20 mg/kg） was served as positive control for diuretic activity and sennosides （10 mg/kg） served as negative control for laxative activity. RESULTS： The hydro-alcoholic extract showed significant diuretic activity and was found to be the most potent in increasing the urinary output at 500 mg/kg when the effect was compared with that of the standard frusemide （P〈0.01）. Moreover, this extract was found to be most effective in increasing urinary electrolyte concentration （Na＋, K＋, and Cl-） at both doses tested. Whereas the results for laxative activity showed minimal increase of feces output at the dose of 500 mg/kg and the increase was negligible when compared with that of the standard drug sennosides. CONCLUSION： Altogether, the above significant findings validate and support its folkloric diuretic use and lend pharmacological credence to the ethno-medical use of this plant in traditional system of medicine, which demands further studies to investigate its active constituents, as well as its use and safety.