Bioavailability enhancers of herbal origin: an overview

Recently, the use of herbal medicines has been increased all over the world due to their therapeutic effects and fewer adverse effects as compared to the modern medicines. However, many herbal drugs and herbal extracts despite of their impressive in-vitro findings demonstrates less or negligible in-vivo activity due to their poor lipid solubility or improper molecular size, resulting in poor absorption and hence poor bioavailability. Nowadays with the advancement in the technology, novel drug delivery systems open the door towards the development of enhancing bioavailability of herbal drug delivery systems. For last one decade many novel carriers such as liposomes, microspheres, nanoparticles, transferosomes, ethosomes, lipid based systems etc. have been reported for successful modified delivery of various herbal drugs. Many herbal compounds including quercetin, genistein, naringin, sinomenine, piperine, glycyrrhizin and nitrile glycoside have demonstrated capability to enhance the bioavailability. The objective of this review is to summarize various available novel drug delivery technologies which have been developed for delivery of drugs (herbal), and to achieve better therapeutic response. An attempt has also been made to compile a profile on bioavailability enhancers of herbal origin with the mechanism of action (wherever reported) and studies on improvement in drug bioavailability, exhibited particularly by natural compounds.

Anti-hyperglycemic activity of leaves extract of Hyptis suaveolens L. Poit in streptozotocin induced diabetic rats

OBJECTIVE@#To evaluate the antihyperglycemic activity of leaves of Hyptis suaveolens using streptozotocin model.@*METHODS@#Hyptis suaveolens extract (HSE) 250 and 500 mg/kg body weight was administered orally to streptozotocin induced diabetes, once daily for 21 days.@*RESULTS@#A significant reduction in blood glucose was observed in diabetic animals treated with HSE at different doses when compared with diabetic rats. Levels of triglyceride, total cholesterol, low density lipoprotein, very low density lipoprotein were decreased while administering HSE at different doses, compared with their control values in diabetic animals.@*CONCLUSIONS@#Our results show that HSE possesses significant antihyperglycemic activity which might be attributed to stimulating effects on glucose utilization and antioxidant enzyme.