Phytochemical profiling, antioxidant and anticancer activities of Gastrocotyle hispida growing in Saudi Arabia

The present study aimed at isolation the phytocompounds from the aerial parts of Gastrocotyle hispida and to evaluate its antioxidant and anticancer potential using in vitro assay. Gastrocotyle hispida is belonging to the family Boraginaceae used as a refreshing drink like tea. The decoction of the leaves is diuretic and is used in the treatment of rheumatism. Phytochemical study of a methanol extract yielded five known compounds viz: β-sitosterol (GH-1), β-sitosterol 3-glucoside (GH-2), 1-O-β-glucopyranosyl-1,4-dihydroxy-2-prenylbenzene (GH-3), 6-Hydroxy-2,2-dimethyl-3-chrom (GH-4) and rosmarinic acid (GH-5). Total phenolic and flavonoid contents were calculated for the extract and fractions, the methanolic extract contained the highest content of total flavonoids (178 mg/g, expressed as quercetin equivalents) and total polyphenol (98.4 mg/g, expressed as gallic acid equivalent). Compounds were isolated by using column chromatography. In vitro, antioxidant activity of the extract and isolated compounds was investigated by DPPH and ABTS radical scavenging assays. The four different cell lines HepG2 (Liver), HEK-293 (Kidney) MCF-7 (Breast) and MDA-MB 231 (Breast) were used against the compounds. The isolated compounds showed dose-dependent free radical scavenging property in all tested models with the IC₅₀ values of 10.2 μg/mL rosmarinic acid (GH-5), 52.1 μg/mL β-sitosterol (GH-1) and 85 μg/mL for β-sitosterol 3-glucoside (GH-2). The β-sitosterol (GH-1) showed significant activity against HepG2 and HEK 293 cell lines. Rosmarinic acid (GH-5) possesses potent anticancer activity against breast cancer cells (MCF7) with the IC₅₀ value of 4.2 μg/mL. It can be concluded that Gastrocotyle hispida has potential antioxidant, anticancer activities and further used as an anticancer agent.