Role of chrysin on expression of insulin signaling molecules.

BACKGROUND: Currently available drugs are unsuccessful for the treatment of tye-2 diabetes due to their adverseside-effects. Hence, a search for novel drugs, especially ofplant origin, continues. Chrysin (5,7-dihydroxyflavone) is a flavonoid, natural component of traditional medicinal herbs, present in honey, propolis and many plant extracts that hasbeen used in traditional medicine around the world to treat numerous ailments. OBJECTIVE: The present study was aimed to identify the protective role of chrysin on the expression of insulin-signaling molecules in the skeletal muscle of high fat and sucrose-induced type-2 diabetic adult male rats. MATERIALS AND METHODS: The oral effective dose of chrysin (100 mg/kg body weight) was given once a day until the end of the study (30 days post-induction of diabetes) to high fat diet-induced diabetic rats. At the end of the experimental period, fasting blood glucose, oral glucose tolerance, serum lipid profile, lipid peroxidation (LPO) and free radical generation, as well as the levels of insulin signaling molecules and tissue glycogen in the gastrocnemius muscle were assessed. RESULTS: Diabetic rats showed impaired glucose tolerance and impairment in insulin signaling molecules (IR, IRS-1, p-IRS-1Tyr(632), p- Akt(Thr308)), glucose transporter subtype 4 [GLUT4] proteins and glycogen concentration. Serum insulin, lipid profile, LPO and free radical generation were found to be increased in diabetic control rats. The treatment with chrysin normalized the altered levels of blood glucose, serum insulin, lipid profile, LPO and insulin signaling molecules as well as GLUT4 proteins. CONCLUSION: Our present findings indicate that chrysin improves glycemic control through activation of insulin signal transduction in the gastrocnemius muscle of high fat and sucrose-induced type-2 diabetic male rats.

Extensively drug resistant tuberculosis (XDR-TB): A potential threat.

Emergence of extensively drug resistant tuberculosis (XDR-TB) has been reported by more than 55 countries. XDR-TB is considered as untreatable and highly fatal disease. In developing countries like India, number of cases of multi-drug resistant tuberculosis (MDR-TB) and XDR-TB are increasing. Emergence of resistance to Isoniazid and Rifampicin, the two most effective and well tolerated agents, coupled with resistance to second line agents pose limited treatment options for XDR-TB. The present minireview provides information about the seriousness of XDR-TB and the drugs available for its treatment. Although considered a fatal disorder, judicious use of combination of drugs, retaining their antimycobacterial activity, can improve the clinical outcome of XDR-TB. Only such an approach can provide some hope for the patients of XDR-TB.