Phytochemical screening, TLC profile and antioxidant activity of hydromethanolic extract of Centaurothamnus maximus leaves

The species Centaurothamnus maximus (Forssk.) Wagenitz & Dittrich is grown in different places in Yemen and is used to treat many diseases. The aim of this research was to investigate the phytochemicals and the antioxidant activity of hydromethanolic extract obtained from this plant. For preliminary phytochemical analysis, standard procedures were applied. The Folin–Ciocalteu method was used to evaluate the total phenolic acid content of the plant extract, while the total flavonoid content was determined using the aluminum chloride colorimetric assay. The antioxidant activities were assessed using the 1,1-diphenyl-2-picrylhydrazyl. Chemical analysis revealed the presence of carbohydrates, saponins, polyphenols, flavonoids, triterpenes, sterols, tannins and alkaloid. The total content of phenols was 43.04±3.30 mg gallic acid equivalent per gram dry extract, while the total flavonoid content was 36.60±2.86 mg rutin equivalent per gram dry extract. With TLC and specific reagents, flavonoid and phenolic substances were identified. The hydromethanolic extract and its fractions showed a dose dependent scavenging activity, we found that the ethyl acetate fraction has high inhibitory percentages equivalent to IC50 40.86±0.001 for DPPH. These results indicate that the leaves of Centaurothamnus maximus are rich in secondary metabolites, and may be used as a natural anti-oxidant source. Extensive chemical and pharmacological studies should be carried out