The medicinal properties of curcumin obtained from Curcuma longa L. cannot be utilised because of poor bioavailability due to its rapid metabolism in the liver and intestinal wall. In this study, the effect of combining piperine, a known inhibitor of hepatic and intestinal glucuronidation, was evaluated on the bioavailability of curcumin in rats and healthy human volunteers. When curcumin was given alone, in the dose 2 g/kg to rats, moderate serum concentrations were achieved over a period of 4 h. Concomitant administration of piperine 20 mg/kg increased the serum concentration of curcumin for a short period of 1-2 h post drug. Time to maximum was significantly increased (P < 0.02) while elimination half life and clearance significantly decreased (P < 0.02), and the bioavailability was increased by 154%. On the other hand in humans after a dose of 2 g curcumin alone, serum levels were either undetectable or very low. Concomitant administration of piperine 20 mg produced much higher concentrations from 0.25 to 1 h post drug (P < 0.01 at 0.25 and 0.5 h; P < 0.001 at 1 h), the increase in bioavailability was 2000%. The study shows that in the dosages used, piperine enhances the serum concentration, extent of absorption and bioavailability of curcumin in both rats and humans with no adverse effects.

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Development of drug delivery system conjugated with doxorubicin (dox) on the surface of AuNPs with polyvinylpyrrolidone (Dox@PVP-AuNPs), we have demonstrated that human lung cancer cells can significantly overcome by the combination of highly effective cellular entry and responsive intracellular release of doxorubicin from Dox@PVP-AuNPs complex. Previously drug release from doxorubicin-conjugated AuNPs was confirmed by the recovered fluorescence of doxorubicin from quenching due to the nanosurface energy transfer between doxorubicinyl groups and AuNPs. Dox@PVP-AuNPs achieved enhanced inhibition of lung cancer cells growth than free Doxorubicin and PVP-AuNPs. The in vitro cytotoxic effect of PVP-AuNPs, free Dox and Dox@PVP-AuNPs inhibited the proliferation of human lung cancer cells with IC50 concentration. Compared with control cells, PVP-AuNPs and free Dox, Dox@PVP-AuNPs can increases ROS generation, sensitize mitochondrial membrane potential and induces both early and late apoptosis in lung cancer cells. Moreover, Dox@PVP-AuNPs highly upregulates the expression of tumor suppressor genes than free Dox and PVP-AuNPs and induces intrinsic apoptosis in lung cancer cells. From the results, Dox@PVP-AuNPs can be considered as an potential drug delivery system for effective treatment of human lung cancer.

BackgroundHibiscus sabdariffa is used regularly in folk medicine to treat various conditions.MethodsThe study was a double blind, placebo controlled, randomized trial. Sixty subjects with serum LDL values in the range of 130-190 mg/dl and with no history of coronary heart disease were randomized into experimental and placebo groups. The experimental group received 1 gm of the extract for 90 days while the placebo received a similar amount of maltodextrin in addition to dietary and physical activity advice for the control of their blood lipids. Anthropometry, blood biochemistry, dietary and physical activity were assessed at baseline, day 45 and day 90.ResultsWhile body weight, serum LDL cholesterol and triglyceride levels decreased in both groups, there were no significant differences between the experimental and placebo group.ConclusionsIt is likely that the observed effects were as a result of the patients following the standard dietary and physical activity advice. At a dose of 1 gm/day, hibiscus sabdariffa leaf extract did not appear to have a blood lipid lowering effect.Trial RegistrationREFCTRI2009000472