In-vitro screening of DPPH free radical scavenging activity of freeze-dried extract of Crateva adansonii DC. stem bark decoction (Lunuwarana pothu kalan 12 Kashaya)

Nallaperuma D.M.* and Jayasiri A.P.A.

Abstract

Normal cellular metabolism in body produces highly reactive molecules called Reactive Oxygen Species (ROS). Excessive production of ROS can lead to oxidative stress causing damage to cells of body. Anti-oxidants are compounds that neutralize ROS and protect cells from oxidative damage. Natural anti-oxidants derived from plants are important due to their potential health benefits and minimal side effects. Crateva adansonii DC is an evergreen tree which is in family Capparidaceae. Ayurveda authentic texts have indicated the stem bark decoction of this plant (Lunuwarana pothu kalan 12 kashaya) for treatment of Mutra ashmari (urinary calculi). The objective of this study is in-vitro screening of the antioxidant activity of freeze-dried extract of Crateva adansonii DC stem bark decoction through DPPH free radical scavenging assay. The free radical used in this assay is 2, 2-diphenyl-1-picryl-hydrazyl (DPPH) and Trolox was used as the standard. The results revealed that the extract was capable of neutralizing the DPPH free radicals by 8.06±0.39%, 12.59±0.86%, 21.69±0.17%, 35.21±0.88% and 56.73±0.35% at concentrations of 78.13, 156.25, 321.5, 625 and 1250µg/ml. IC50 was found to be 1161.51±18.12µg/ml (Trolox IC50 10.06±0.10µg/ml) for the extract. According to the previous studies the stem bark of this plant was positive for alkaloids, tannins, saponins flavonoids, steroids, terpenoides, glycosides and proteins. It has been proven that presence of phytochemicals like flavonoids, terpenoides, saponins and phenols can contribute towards the anti-oxidant activity. So, this DPPH free radical scavenging activity could be due to the presence of such phytochemicals in this plant. Therefore, it can be concluded that the therapeutic effect of this decoction could be due to its DPPH free radical scavenging property.