Comparison of Nutritional Value and Bioactive Compounds in <I>Gymnema inodorum</I> Decne. Leaves

Abstract

Gymnema inodorum Decne. is indigenous plant distributed widely in the northern and northeastern regions of Thailand, also used for traditional Thai cuisines and healthy herbal product to prevent diabetics. Two groups of G. inodorum; broad and narrow leaves were found and two months of stem cuttings were planted in the natural condition at Huai Hong Khrai Royal Development Study Centre, Doi Saket, Chiang Mai province. After six months, the plants were harvested their leaves at positions 4 to 6 form the apex in the mature stages were collected for analysis. This research aims to compare the phenolic content using Folin-Ciocalteu colorimetric assay and active ingredient, gymnemic acid content by high performance liquid chromatography (HPLC) in G. inodorum. Results revealed that some nutritional values in G. inodorum leaves include protein, fat, and fiber contents were found and the value did not show significant differences between the two leaf types, whereas sugar content showed statistically significant difference (P<0.05) between broad and narrow leaves of 4.68 ± 0.28 and 6.70 ± 0.81%, respectively. Moreover, total phenolic content was found that both the narrow (18.18 ± 0.04 mg GAE/g DW) and board leaves (17.09 ± 0.77 mg GAE/g DW) showed similar values. While, gymnemic acid content of narrow leaves (2.50 ± 0.11 g/100g) and board leaves (2.44 ± 0.02 g/100g) were not significant different. Therefore, the leaves of two groups of G. inodorum showed phenolic content and some bioactive compound that can control blood sugar levels by gymnemic acid, and both of two groups can be developed as the healthy herbal products.