Phytochemical analysis, invitro antioxidant activity and GC-MS studies of crude extracts of Cissus populnea stem

Abstract

Uduak Aletan, Elijah Adetola, Ahmed Abudullahi, Olayinka Onifade, Hadiza Kwazo Adamu

The medicinal capabilities of plants has been attributed to the presents of phytochemicals and their antioxidant activities. In this study, five solvent extracts (aqueous, ethanol, butanol ethyl acetate, and n-hexane) of Cissus populnea stem were evaluated qualitatively and quantitatively for some phytoconstituents and in vitro antioxidant activities using three methods of antioxidant assessment. GC-MS analysis was also carried out on the aqueous extract for the identification of the bioactive compounds. The ethyl acetate extract revealed the presence of all the phytochemicals tested for in the qualitative phytochemical screening. The butanol extract indicated the highest quantity of alkaloids (91.90 ± 2.13 mg/100g), flavonoids (67.24 ± 1.56 mg/100g), and saponins (60.13 ± 1.41 mg/100g) while the highest level of tannins (65.25±0.14 mg/100g) and phenols (15.35±0.27 mg/100g) were recorded in the aqueous extract. The n-hexane extract recorded the least quantity of all the phytochemicals studied. In all three methods of in vitro antioxidant assessment used, antioxidant activity increased with increased concentration in all the extracts. For the percentage, DPPH and nitric acid inhibition methods all the extracts at 100 μg/ml showed antioxidant capacity up to 50% of that showed by the standard, ascorbic acid at the same concentration. The GC-MS analysis of the aqueous extract revealed the presence of 36 compounds belonging to 15 known classes of compounds while 2 of the compounds were unclassified. The major chemical constituents were 9, 12-Octadecadienoic acid (Z, Z)- (21.17%), n-Hexadecanoic acid (20.33%), Stigmastam-3, 5, 22-trien (7.78%) and 2',6'- Dihydroxyacetophenone (6.61%) . These data show that C. populnea stem is a potential source of bioactive compounds