LAUSR

The present study was conducted to investigate the existence of phytochemical constituents and antioxidant activity of medicinally important plants such as Eremostachys thyrsiflora, Cousinia stocksii and Gaillonia macrantha found in the north of Quetta, Balochistan. Phytochemical analysis of selected plants showed the presence of phenolics, alkaloids, steroids, flavonoids, saponins, terpenoids and tannins. The total alkaloids, phenolics, flavonoids and saponins found in the crude methanolic extracts of Eremostachys thyrsiflora were 8%, 3.2%, 5.9% and 1.5%, while in Cousinia stocksii the proportions were 7%, 2.2%, 6.8%, 1% and in Gaillonia macrantha these phytochemicals were found to be 8%, 2.8%, 0% and 0.5% respectively. In-Vitro antioxidant activities were studied spectrophotometrically by using total antioxidant activity, free radical scavenging power (DPPH) assay, ferric reducing antioxidant power assay and reducing power assays. The total antioxidant capacity of the E. thyrsiflora, C. stocksii and G. macrantha were determined and found to be 2.31, 5.44 and 9.15 mg ascorbic acid equivalent/ gram of plant extract respectively. The crude methanolic extracts of all these plants revealed antibacterial activity against S. typhi, E. coli, K. pneumonia and S. aureus and antifungal activity against S. cerevisiae. These results indicated that the crude methanolic extracts of the selected plants contained medicinally bioactive constituents which could be used for the treatment of different diseases and could also be used to reduce the oxidative stress.