Phytochemical screening and antioxidant activity of Uncaria tomentosa extract: In vitro and in vivo studies

Background: Uncaria tomentosa is a traditional medicinal herb with antiviral, antioxidant, immunostimulating, anti-inflammatory, and anticancer effects. Objective: The present study was conducted to evaluate the antioxidant capacity in vitro and in vivo and the phytochemical analysis of Uncaria tomentosa. Materials and Methods: The plant extract was screened for phytochemical compounds and antioxidant capacity in vitro using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method and in vivo using acetic acid-induced colitis. Colitis was induced in rats by transrectal administration (5 mL/kg) of 4% (v/v) acetic acid. Forty adult albino rats were divided into four groups: control group, acetic acid group, acetic acid + sulfasalazine (100 mg/kg/day) group, and acetic acid + Uncaria tomentosa extract (250 mg/kg/day) group. After inducing colitis, sulfasalazine and Uncaria tomentosa extract were given orally for 10 days. Data were statistically analyzed, and P < 0.05 was considered statistically significant throughout the study. Results: Preliminary phytochemical study showed that Uncaria tomentosa extract contains flavonoids, phenols alkaloids, saponin, and terpenoids. In the DPPH assay, the extract exhibited considerable antioxidant capacity in a dose-dependent manner. Also, Uncaria tomentosa extract dramatically decreased oxidative stress parameters, such as myeloperoxidase enzyme activity and malondialdehyde in colonic tissue. Moreover, Uncaria tomentosa treatment attenuated macroscopic colonic scores and histopathological changes induced by acetic acid. Conclusion: The findings of this study show that Uncaria tomentosa extract could be a source of natural antioxidants and may have a therapeutic effect on ulcerative colitis.