Antidiabetes constituents, cycloartenol and 24-methylenecycloartanol, from Ficus krishnae.

Ficus krishnae stem bark and leaves are used for diabetes treatment in traditional medicines. Stem bark of F. krishnae was sequentially extracted with hexane, methanol and water, and these extracts were tested for their antihyperglyceamic activity by oral glucose tolerance test (OGTT) in overnight fasted glucose loaded normal rats. Hexane extract showed significant glucose lowering activity in OGTT, and the triterpene alcohols (cycloartenol+24-methylenecycloartanol) (CA+24-MCA) were isolated together from it by activity guided isolation and characterized by NMR and mass spectroscopy. The ratio of the chemical constituents CA and 24-MCA in (CA+24-MCA) was determined as 2.27:1.00 by chemical derivatization and gas chromatographic quantification. (CA+24-MCA) in high fat diet-streptozotocin induced type II diabetic rats showed significant antidiabetes activity at 1 mg/kg and ameliorated derailed blood glucose and other serum biochemical parameters. Cytoprotective activity of (CA+24-MCA) from glucose toxicity was evaluated in cultured RIN-5F cells by MTT assay and fluorescent microscopy. (CA+24-MCA) in in vitro studies showed enhanced cell viability in RIN-5F cells and significant protection of beta cells from glucose toxicity. Both in in vivo and in vitro studies (CA+24-MCA) showed enhancement in insulin release from the beta cells. In short term toxicity studies in mice (CA+24-MCA) did not show any conspicuous toxic symptoms. The combination of the phytosterols (CA+24-MCA) obtained through activity guided isolation of the stem bark of F. krishnae showed significant activity, and therefore is a promising candidate for new generation antidiabetes drug development.

Protection of mouse brain from paracetamol-induced stress by Centella asiatica methanol extract.

ETHNOPHARMACOLOGICAL RELEVANCE: Centella asiatica (CA) is a medicinal herb traditionally used as a brain tonic in Ayurvedic medicine. Various ethnomedical leads revealed the effective use of CA in the treatment of symptoms associated to oxidative stress and inflammation. AIM OF THE STUDY: The aim of this study was to evaluate the therapeutic ability of CA methanol extract (CAM) in protecting mouse brain and astrocytes from oxidative stress and inflammation induced by Paracetamol, and thus to substantiate the allied traditional/ethnomedical claims of CA. MATERIALS AND METHODS: Chemical profiling of CAM and quantification of its major constituents were carried out by HPTLC-densitometry. Mice were administered with CAM and Paracetamol in various combinations, and oxidative stress parameters (lipid peroxidation, radical scavenging) as well as nitric oxide stress were estimated from isolated mouse brain. Cellular toxicity was investigated by apoptosis/necrosis in primary astrocytes isolated from brain tissues of mouse (which was challenged by CAM/Paracetamol) by flow cytometry and fluorescent microscopy. Expression of inflammatory cytokine mediators (monocyte chemo attractant protein 1, interleukin 1, interferon γ, tumor necrosis factor ß, interleukin 10 and mitogen activated protein kinase 14 gene) in CAM/Paracetamol administered mouse brain tissues was analyzed by real time PCR. Mouse brain tissues challenged by CAM/Paracetamol were also assessed for gross and histopathology. In addition, staining with acridine orange was carried out in C6 cell lines treated with CAM, and viewed under fluorescent microscopy. RESULTS: Paracetamol elicited reactive oxygen species generation was revealed through Ferric Reducing Antioxidant Power (FRAP) activity. CAM reversed the Paracetamol induced free radical and reactive nitrogen species production and increased the scavenging activity which was more pronounced at the higher dose (80 mg/kg b.wt). CAM negated the Paracetamol-induced damage by inhibiting expression of pro-inflammatory cytokines (MCP 1, IL 1, TNF ß), and increasing the expression of the anti-inflammatory cytokine (IL 10) profoundly. Interestingly, MAPK 14 gene expression was decreased gradually and became same as normal control with increase in the dose of CAM. Also, it was evident that CAM protected mouse primary astrocytes from Paracetamol by maintaining a normal morphology. Similarly, apoptosis of primary astrocytes (treated with Paracetamol/CAM) decreased with the increase in CAM dose (80 mg/kg b.wt.) which was evident from flow cytometric data. Severe brain damage in the form of lesions was apparent from the histology of Paracetamol alone treated mouse brain. Whereas, CAM treated together with Paracetamol upturned these lesions. Surprisingly, CAM alone proved to be cytotoxic to C6 Glioma cells. CONCLUSIONS: CAM showed antioxidant and anti-inflammatory effects (which were pronounced at higher doses) against Paracetamol-induced oxidative stress and associated inflammation in mouse brain. The underlying mechanisms may be mediated by inhibiting the pro-inflammatory cytokines TNF ß, IL 1 and MCP 1 via regulation of the antioxidant mediated INF γ and MAPK 14 gene signalling pathways. The major bioactive constituents in CAM are the triterpenoid saponins, asiaticoside and madecassoside. The present results provide pharmacological evidence that CAM acts as an antioxidant and anti-inflammatory agent. Furthermore, this study validates the use of CA as an antioxidant and anti-inflammatory agent in ethnomedicine.