Fractionation and bioassay-guided isolation of antihypertensive components of Senecio serratuloides

Abstract

Senecio serratuloides commonly referred to as "two day cure" is used in folk medicine for treating hypertension and wounds in South Africa. This study was aimed at isolating and testing the antihypertensive effects of bioactive compounds from S. serratuloides. Senecio serratuloides was serially extracted using solvents of increasing polarity. Phytochemical analysis, antioxidant capacity and antihypertensive properties of fractions were investigated. Bioactive compounds were isolated from ethyl acetate and methanol fractions, their antihypertensive effects and effect on urine norepinephrine concentration were determined. Ethyl acetate and methanol fractions had all eight phytochemicals tested, better antioxidant capacity and significantly (p < 0.001) prevented the increase in blood pressure induced by N ω -Nitro-L-arginine methyl ester hydrochloride. The isolated bioactive compounds were phytosteroids and Estran-3-one, 17-(acetyloxy)-2-methyl-, (2à,5à,17á)which was isolated from methanol fraction had significantly (p < 0.001) better antihypertensive effects through the 4-h period of the study. Senecio serratuloides may be a potential source of antihypertensive lead compounds.

Toxicological, Bioassay-Guided Fractionation and Antibacterial Activity of Methanol Stem Extract of Terminalia microptera on Oral Bacteria Pathogens

“…Ethyl acetate is a secondary polar solvent and its extract has been reported to contain phytochemicals majorly alkaloids, saponins and some classes of phenols that play important roles as antibacterial agents and maybe the rationale behind the observed level of activity in TME fraction. This observation supports the findings of Tata et al 59, and Sakar et al 43 who reported similar observation in their respective studies. The variation in the zones of inhibition between the crude (Table 6), partitioned fraction (Table 8), and fractions obtained from the column (Table 10) may be due to a decrease in the concentration of the phytochemical constituents' present in these fractions as the purification processes progress.…”