Evaluation of the In Vitro antidiabetic potential of Vitex Negundo L. and its fractions using 13C nuclear magnetic resonance phytochemical profiling

• Main Author: ZABALA, MYRNILLE JOY
• Format: text
• Published: Archīum Ateneo 2017
• Subjects: Vitex agnus-castus > Therapeutic use; Botanical chemistry; Herbs > Therapeutic use; Diabetes > Prevention; Nuclear magnetic resonance.
• Online Access: https://archium.ateneo.edu/theses-dissertations/97; http://rizalls.lib.admu.edu.ph/#section=resource&resourceid=1198431187&currentIndex=0&view=fullDetailsDetailsTab
• Institution: Ateneo De Manila University

Diabetes mellitus is a metabolic disorder of glucose metabolism. Plants are rich sources of potential hypoglycemic agents to control blood glucose. The objective of this study is to investigate the effect of crude methanol and ethanol extracts, and ethyl acetate, chloroform and aqueous fractions of Vitex negundo, L. on the diffusion of glucose through the intestinal lumen into the blood stream using an in vitro membrane model and to determine the phytochemical profile of the extracts and fractions using 13C nuclear magnetic resonance (NMR) spectroscopy. The diffusion of glucose (from 7, 10 and 15 mM concentrations) into the external solution through a dialysis membrane tubing was measured using the dinitrosalicylic acid method at time intervals. At 1% extract concentration, the chloroform-EtOH fraction showed the highest retardation activity compared to the control with mean glucose diffusion retardation index (%GDRI) values of 60% and 39% at 7 mM and 10 mM glucose, respectively. At 2% extract concentration, almost all extracts had negative GDRI values, except for ethyl acetate-MeOH and aqueous-MeOH at 10 mM and 15 mM glucose. The crude ethanol and methanol extracts retarded the diffusion in the starch-amylase system at both extract concentrations. Retardation of glucose diffusion suggests that V. negundo has the potential of lowering postprandial glucose in the blood. Correlation analysis of the 13C NMR profile with retardation activity suggests that compounds containing glycosidic residues may be responsible for the glucose retardation activity. This is the first example where activity has been correlated with specific structural features of compounds from a crude extract using 13C NMR chemical shifts to assist in the identification of active compounds.