Bioassay-guided Isolation and Identification of Antidiabetic Compounds from Naregamia alata

Abstract

Background: Naregamia alata is an endemic herb of Western Ghats with traditional medicinal uses and pharmacological activities, viz. anti-inflammatory, antioxidant, antipyretic, hepatoprotective and antidiabetic effects. However, no information is available on the phyto-constituents of N. alata responsible for antidiabetic activities. Objective: Isolation and identification of compound/s from the dichloromethane fraction of methanol extract of N. alata and to confirm the antidiabetic activity using streptozotocin induced diabetic rat models. Methods: The DCM fraction obtained from the methanol extract of N. alata was fractionated using column chromatography. The fractions with in vivo antidiabetic activity were characterised chemically using GCMS, FTIR, and 1H NMR to identify the phytochemicals responsible for the antidiabetic activities. Results: The study showed the antidiabetic effect of DCM fraction with the regulation of serum biochemical parameters. The chemical characterisation of the fractions responsible for the in vivo antidiabetic effect revealed the presence of hexadecanoic acid methyl ester and 13-docosenamide as two major compounds in one of the fractions (Fraction 1) and citronellol in another fraction (Fraction 2.2.1). Conclusion: The study highlights the role of hexadecanoic acid methyl ester, 13-docosenamide and citronellol in a reversal of serum biochemical parameters along with body weight in streptozotocin-induced diabetic rats to near normal suggesting the potential antidiabetic properties of these compounds.