A feasible method for isolation of pongamol from karanja (Pongamia pinnata) seed and its anti-inflammatory activity

Abstract

Pongamol a major bioactive compound present in karanja (Pongamia pinnata) seed oil, is a polyphenolic chalcone belonging to the flavonoid family. It is attributed to having several medicinal and therapeutic properties. This study reports a feasible technique to efficiently extract pongamol from karanja seed oil by treating with boron trifluoride etherate (BF3·OEt2) and its anti-inflammatory activity. This method affords 64 % recovery of pongamol with >95 % purity (HPLC) and it is characterized by FTIR and NMR spectroscopy. The IC50 value for soy lipoxygenase-1 (LOX-1) inhibitory activity was found to be 72.2 μM. Interaction of pongamol with soy LOX-1 by Fluorescence revealed that a quenching maximum of 50.25 % with the binding constant of 0.75×105M-1 . In silico studies revealed that pongamol could bind with soy LOX-1 with least binding energy of −5.79 kcal/mol by forming two hydrogen bonds. Pongamol exhibited antioxidant activity with an IC50 value of 12.2 μg/mL. In this investigation, semi-synthesis of dihydropongamol (DHP), a new molecule and its acute anti-inflammatory property is reported. Edema was induced in paw and ear of Wistar rats using Carrageenan and xylene. Pongamol of 50 ppm body weight reduced the edema by 55 % in the paw and 74 % in the ear within 3 h of its administration. The rat groups fed with dihydropongamol also exhibited similar anti-inflammatory activities. Primarily, this investigation reports a practical approach to pongamol isolation and also for the first time its feasibility as a potent anti-inflammatory agent.