In vitro antioxidant activities and screening of phytochemicals from methanolic and ethyl acetate extracts of Calligonum comosum L’Her

Calligonum comosum L’Her (Family: Polygonaceae) are perennial shrub plants growing in the United Arab Emirates, and are being used in traditional medicinal system of UAE. The aim of the proposed study was to evaluate the phytochemicals and in vitro antioxidant activities of the aerial parts of C. comosum. Further, the plant extract was tested for the free radical scavenging activity such as 2, 2′-azinobis- (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS^●+) radical decolorization, DPPH (2, 2-diphenyl, 2-picryl hydrazyl), hydroxyl and nitric oxide radical. The obtained results from phytochemical screening of the plant extracts showed the presence of flavonoid, tannin, carbohydrates, alkaloid, protein, steroids, terpenoids, saponin, phenols and phlobatannin. The plant leaves did not contain cardiacglycoside, anthraquinines and volatile oils. Furthermore, total phenolics content of C. comosum methanolic extract (CCME) and C. comosum Ethyl acetate extract (CCEAE) was 8.15, 4.53 mg/g of extract calculated as quercetin equivalent and the flavonoid was 2.13, 1.67 mg/g of extract calculated as gallic acid equivalent, respectively. The results exhibited a positive linear correlation between these phytochemicals and the free radical scavenging activities. Our findings provide evidence that the CCME and CCEAE posses a potential antioxidants and this justifies its use in folkloric medicines. Thus, a scientific validation of traditional knowledge been achieved in a preliminary level. The plant revealed promising antioxidant activity, and require further studies to throw light on their chemical composition.