Antioxidant and Antitumorigenic Activities of the Standardized Water Extract From Fruit of Terminalia chebula Retz. var. chebula

Abstract

Background: Terminalia chebula Retz. var. chebula (T chebula) has been traditionally used as a crude drug for treating various diseases, including skin disorders. This study aimed to investigate the potential antioxidant effects and antitumorigenic activity of an aqueous extract from the fruit of T chebula. Methods: The extract's total phenolic content and antioxidant activity were measured using Folin-Ciocalteu, 1,1-diphenyl-2-picrylhydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) tests, respectively. The 2 ´,7 ´-dichlorodihydrofluorescin diacetate assay was employed to evaluate the extract's ability to reduce intracellular reactive oxygen species (ROS) in U-937 human monocytic cell lines which had been treated with hydrogen peroxide for 30 min. Male ICR mice (n = 30, 5 groups) were used to investigate the influence of T chebula extract on dimethylbenz[a]anthracene (DMBA)/12-O-tetradecanoylphorbol 13-acetate (TPA)-induced carcinogenesis. After 20 weeks of treatment with T chebula extract, tumor incidence, size, and number were assessed. The major phenolic compounds in the extract were determined using high-performance liquid chromatography. Statistical analysis was performed using ANOVA followed by post hoc least significant difference test. Results: T chebula extract effectively reduced intracellular ROS and scavenged antioxidants in vitro. The IC50 values of the extract as measured by DPPH and FRAP assays were 109.0 ± 14.5 μg/mL and 2.39 ± 0.17 μg/mL, respectively. Moreover, 4 mg of T chebula extract significantly decreased the incidence, volume, and number of tumors in DMBA/TPA-induced skin tumorigenesis in mice. Conclusion: T chebula extract effectively reduced intracellular ROS, and significantly decreased the incidence, volume, and number of tumors in DMBA/TPA-induced skin tumorigenesis in mice. These findings suggest that T chebula extract could be a promising therapeutic agent for skin tumors and other oxidative stress-related diseases.