ANTIOXIDANT ACTIVITY ASSESSMENT OF CAMELLIA SINENSIS LEAVES EXTRACT IN GUINEA PIG PLASMA

This study planned to screen preliminary phytoconstituents, total phenolic- flavonoids content and in-vitro, in-vivo antioxidant activities of aqueous crude extract of Camellia sinensis leaves. We assessed phytochemical constituents in extract using previously reported methods for tannins, phenols, flavonoids, glycosides, alkaloids and saponins. Quantitative estimation of flavonoids and phenolic compounds was carried out by aluminium chloride and Folin Ciocalteu method. ABTS, DPPH and FRAP  methods are used for in-vitro assessment of antioxidant potential; meanwhile extract was tested for antioxidant capacity in Guinea pig plasma using ORAC, MDA and GSH assay in dose dependent manner. Total phenolic and flavonoid content of the extract was found to be 251.77 ± 6.59 µg/mg and 246.56 ± 2.58 µg/mg respectively. Extract shown 93.76 ± 12% antioxidant activity with ABTS and 95.13 ± 17.89% when tested with DPPH hydrogen reacting radicals. While, it was calculated 92.82 ± 8.72% for FRAP assay. The extract shows dose dependent decrease in MDA level (P<0.05, ANOVA) in plasma. Although, the extract produced dose depended increase in GSH value 20.97 ± 2.541 µg/mg protein and ORAC antioxidant potential 23.771 ± 1.926 mM Trolox Eq/L, when compared to control group. Our findings suggest that, extract contain phenolic and flavonoids content and showed in-vitro free radical scavenging activity. In-vivo results of selected biochemical parameters of oxidative stress in Guinea pig plasma, will serve as a benchmark for further pharmacological screening of Camellia sinensis constituents, which makes this as a therapeutic adjuvant agent against free radicals mediated diseases.