Potential antiviral effects of some native Iranian medicinal plants extracts and fractions against influenza A virus.

BACKGROUND: Influenza A virus (IAV) infection is a continual threat to the health of animals and humans globally. Consumption of the conventional drugs has shown several side effects and drug resistance. This study was aimed to screen some Iranian medicinal plants extracts and their fractions against influenza A virus. METHODS: Glycyrrhiza glabra (rhizome), Myrtus commonis (leaves), Melissa officinalis (leaves), Hypericum perforatum (aerial parts), Tilia platyphyllos (flower), Salix alba (bark), and Camellia sinensis (green and fermented leaves) were extracted with 80% methanol and fractionated with chloroform and methanol, respectively. The cytotoxicity of the compounds were determined by MTT colorimetric assay on MDCK cells. The effective concentrations (EC50) of the compounds were calculated from the MTT results compared to the negative control with no significant effects on cell viability. The effects of EC50 of the compounds on viral surface glycoproteins and viral titer were tested by HI and HA virological assays, respectively and compared with oseltamivir and amantadine. Preliminary phytochemical analysis were done for promising anti-IAV extracts and fractions. RESULTS: The most effective samples against IAV titer (P ≤ 0.05) were crude extracts of G. glabra, M. officinalis and S. alba; methanol fractions of M. communis and M. officinalis; and chloroform fractions of M. communis and C. sinensis (fermented) mostly in co- and pre-penetration combined treatments. The potential extracts and fractions were rich in flavonoids, tannins, steroids and triterpenoids. CONCLUSION: The outcomes confirmed a scientific basis for anti-influenza A virus capacity of the extracts and fractions from the selected plants for the first time, and correlated their effects with their phytochemical constituents. It is worth focusing on elucidating pure compounds and identifying their mechanism(s) of action.

Evaluation of changes in cytochrome P450 2C19 activity in type 2 diabetic rats before and after treatment, by using isolated perfused liver model.

OBJECTIVES: Alteration in drug metabolism is very likely in diabetes mellitus. This study assessed changes in CYP2C19 enzymatic activity in the liver using omeprazole as a probe in the animal model of type II diabetes (T2DM) before and after treatment with metformin and cinnamon. MATERIALS AND METHODS: Twenty-eight male Wistar rats were randomly divided into seven groups. Fourteen days after induction of type 2 diabetic mellitus (T2DM), rats in the test group received metformin, cinnamon, and metformin plus cinnamon daily for 14 days. On day 28, rats were subjected to liver perfusion by Krebs-Henseleit buffer containing omeprazole as a CYP2C19 probe. Perfusate samples were analyzed by HPLC-UV to evaluate the activity of CYP2C19. RESULTS: Mean metabolic ratio of omeprazole was changed from 0.091±0.005 in the control group to 0.054±0.005 in the untreated-diabetic rats. This average was increased inordinately to 0.218±0.036 in the treated rats with metformin. Interestingly, the administration of cinnamon in combination with metformin in diabetic rats caused the enzyme activity to return to (0.085±0.002) approximately the observed levels in the control group (0.091±0.005). CONCLUSION: Results showed that despite the suppression of the CYP2C19 enzyme activity in T2DM rats, metformin treatment could increase the enzyme activity. Simultaneous application of cinnamon and metformin can modulate the function of CYP2C19 to the observed level in the control group and make it more predictable to treat diabetes mellitus and fate of drugs that are metabolized by this enzyme.