Evaluation of In Vitro Antioxidant Activity of Stem-Bark and Stem-Wood of Premna serratifolia Lin., (Verbenaceae)

Premna serratifolia Lin., is widely used in Ayurvedic system medicine for the treatment of cardiovascular disorders, arthritis, inflammation etc. The stem-bark and stem-wood were extracted with 95% ethanol and double distilled water and these extracts were screened for their in-vitro antioxidant potential. Inhibition of oxygen-derived free radicals, viz., assays for free radical scavenging by DPPH, reducing power ability and nitric oxide scavenging were performed. All the antioxidant activities were compared with standard antioxidant such as ascorbic acid. Both the extracts of this plant showed effective free radical scavenging activity, reducing power and nitric oxide scavenging activity. All these antioxidant properties were concentration dependent. The highest antioxidant activity was observed with ethanol extracts. Preliminary phytochemical screening revealed the presence of flavonoids, steroids, alkaloids, glycosides and phenolic compounds in the extracts and the results obtained from the current study indicate that Premna serratifolia Lin., is a potential source of natural antioxidants and the extracts have constituents which were capable of showing anti-oxidant activity and the said in-vitro anti-oxidant activity may also be due to the presence of anti-oxidant principles present in the extracts like flavonoids and phenolic compounds. These findings confirm the great interest of the Premna serratifolia whose phytochemistry and phytopharmacology should be investigated further in order to detect possible phytotherapeutic uses in the prevention of ageing related diseases, cardiovascular disorders and Alzheimer disease.