Antidiabetic and antioxidant activities of Nypa fruticans Wurmb. vinegar sample from Malaysia

Objective: To study the antidiabetic and antioxidant activities of nipa palm vinegar(NPV) used in traditional Malay medicine for treating diabetes. Methods: NPV was extracted using liquid-liquid extraction method and the obtained samples were subjected to antidiabetic studies using normal and streptozotocin-induced diabetic rat models whereas antidoxidant activities were investigated via in vitro antioxidant tests namely 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azinobis-3-ethylbenzothiozoline-6-sulfonic acid free radicals scavenging activities and the reducing power assay. Results: Single administration of NPV and its extracts were not effective in both normal and diabetic rats. In intraperitoneal glucose tolerance test, NPV and its aqueous extract showed significant blood glucose lowering effect. In the sub-acute study, compared with the diabetic control, aqueous extract of NPV showed the most notable blood glucose lowering effect(56.6%) and a significant improvement in serum insulin levels(79.8%, P<0.05). To assess NPV's antioxidant activity, three in vitro antioxidant tests were employed: 2,2-diphenyl-1-picryhydrazyl and 2,2'-azinobis-3-ethylbenzothiozoline-6-sulfonic acid free radical-scavenging assays, and the reducing power assay. Ethyl acetate extract had the greatest antioxidant potential and content of phenolic and flavonoid compounds. A linear positive correlation between the antioxidant parameters was observed. Chemical profiling analysis of aqueous extract of NPV revealed the presence of acetic acid(35.25%), the main active constituent which significantly contributed to the observed antidiabetic activity. Conclusions: Aqueous extract of NPV possesses antihyperglycaemic activities comparable to the metformin, while the ethyl acetate extract precipitated significant antioxidant effects attributable to its high phenolic content. These findings suggest that antioxidant compounds of NPV do not contribute much towards the overall observed antidiabetic effect.

Decomposition and Reformulation of Banxia Baizhu Tianma Decoction:A Vasodilatory Approach

Objective To decompose and reformulate Banxia Baizhu Tianma Decoction（BBT） in order to optimize its ratio for vasodilatory effect.The fingerprints of these six component herbs were also studied via Tri-step FTIR analysis.Methods The herbal components of BBT were extracted separately with different solvents,such as 95%ethanol,50%ethanol,and distilled water.The vasodilatory effect of the extracts was studied using the in vitro pre-contracted aortic ring model.Among these extracts,the water extracts of Pinellia ternata[PT（W）]and Citri reticulatae[CR（W）],50%ethanol extracts of Castrodia elata[GE（50）]and Clycyrrhiza uralensis[GU（50）],and 95%ethanol extracts of Atractylodes macrocephala[AM（E）],and Poria cocos[PC（E）]were selected for the orthogonal stimulus-response compatibility group study due to their high effectiveness in vasodilation.Results The best combination ratio（G2） was GE（50）,GU（50）,AM（E）,PC（E）,CR（W）,and PT（W） at EC0,EC5,EC5,EC5,EC5,and EC5,with EC50 of（0.06 ± 0.01） mg/mL.Comparison between the vasodilatory effects of extracts derived from G2 and BBT were also studied.From the results,the 50%ethanol extract following G2 ratio was found to be most potent extract with the highest vasodilatory effect compared with other extracts derived from G2 or BBT,with EC50 of（0.05 ±0.005） mg/mL.Conclusion The optimum ratio and appropriate extraction method for the new BBT formulae are obtained.G2 is determined as the best formulae with the highest potency in producing the vasodilatory effect on isolated rat aortic rings.The results obtained suggest that 50%ethanol is found to be the best solvent to extract the vasoactive compounds of G2 in order to exhibit the highest efficacy of vasodilatory effect.