Quantitative Phytochemical Screening and In-vitro Antioxidant Activities of Jatropha gossypifolia L. Leaf Extracts Aiming Antimicrobial and Therapeutical Applications

Total phenolic (polyphenols, flavonoids, and condensed tannins) contents and antioxidant property (DPPH, ABTS, FRAP) were evaluated in hexane (HE), acetone (AC), ethanol (ET), 70% (v/v) ethanol/water (EW), and powder extracts of Jatropha gossypifolia leaves using spectrophotometric methods. The lowest and highest contents of polyphenols (10.27 ± 0.36 and 21.23 ± 0.95 mg GAE/g), flavonoids (4.83 ±0.42 and 12.53 ±0.58 mg QE/g), and condensed tannins (3.03 ± 0.18 and 7.13 ± 0.12 mg CE/g) were recorded in powder and EW, respectively. EW exhibited the highest scavenging activities displayed by the lowest IC50 values (0.23±0.01 mg/mL DPPH and 0.2±0.03 mg/mL ABTS). Moreover, it recorded the highest reducing power (92.85±1.25 mg AAE/g), followed by HE (72.73±1.99 mg AAE/g) and AC (41.84±0.47 mg AAE/g). Relevant correlations were found between the polyphenols, flavonoids, condensed tannins and reducing antioxidant power (r = 0.986, p < 0.01; r = 0.958, p < 0.01; r =0.950, p < 0.05; respectively). Based on their phytochemical and antioxidant properties, PCA classified the five extracts into three distinct clusters. The results of this study indicate that EW contains powerful bioactive molecules with noteworthy antiradical and electron donating properties. Therefore, it may be a promising candidate in the search for natural compounds with therapeutic and food/crop preservative applications.