LC-MSn analysis, antioxidant activity and in-vivo toxicology of methanolic extract of aerial parts from Calendula aegyptiaca.

Antioxidant activity of several organ and total aerial part extracts from Calendula aegyptiaca was investigated. Flavonoids and total phenol contents as well as ferric reducing power assay (FRAP), total antioxidant capacity (TAC), 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay revealed that methanolic extracts were richer in phenolics and flavonoids than Dichloromethane (DCM) and n-hexane extracts. The methanolic extract of the plant's aerial part (MEAP) was found to have the highest phenolic content (385.06 ± 0.92 mg of Gallic acid equivalent/g of dried extract). The chemical profile of MEAP was explored through high-performance liquid chromatography combined with negative electrospray ionisation mass spectrometry (HPLC-HESI-MS). Twenty-nine compounds were identified, mostly composed of flavonoids (32.4%), phenolic acids (10.5%), and saponins (46.8%). By administering the MEAP to Wistar female rats in drinking water, its subacute toxicity was examined. Hematological, biochemical, histological and oxidative stress parameters were evaluated. Doses of 0.125, 0.250, 0.500, and 1.000 g of plant per kg of body weight did not cause damage in rats receiving this treatment. Nevertheless, a decrease in serum uric acid level was observed following extract administration. So, this extract may have antihyperuricemic activity which should be confirmed by using an animal model of hyperuricaemia.