The present study aimed to investigate the efficacy of flavonoids isolated from the fruit of Terminalia chebula against the hydrogen peroxide-induced DNA damage. Five fractions were screened and were compared for their in vitro antioxidant activity by DPPH method and DNA protection activity by DNA nicking assay. All the extracts showed excellent antioxidant activity with IC 50 values ranging from 11.23 ± 0.18 to 36.70 ± 0.12 µg/ml. The band intensity of supercoiled, circular and linear DNA was measured in DNA nicking assay and it is very clear that the addition of extract significantly inhibited the formation of circular and linear forms of DNA. Methanol-Water 1:1 fraction which showed the highest activity in antioxidant and DNA protection was subjected to structural characterization using different spectroscopic techniques. The structure of the compound was identified as a derivative of luteolin. The result presented in this work strongly supports the hypothesis that DNA protection activities were positively associated with the antioxidant property.

Background: DNA in a human cell is subjected to constant assault from both environmental factors and normal metabolic processes. Accumulation of DNA damage drives the progression of many health disorders like aging, cancer, diabetes, and neurodegenerative disorders. Results: The present study focuses on the isolation of phenolic compound from the fruit of Terminalia chebula and its protective role on induced DNA damage. Diethyl ether and ethyl acetate extract of Terminalia chebula fruit were subjected to column chromatographic purification, and the fractions obtained were tested for the presence of phenolics. Fraction-12 isolated from diethyl ether extract was identified as gallic acid, which is used for cytotoxic and DNA damage protection activity assays. To select a non-toxic concentration of isolated compound, cytotoxicity was assessed by MTT assay. Gallic acid showed moderate toxicity at the highest concentration tested (i.e., percentage cell viability at 100 μg/ml is 40.51 ± 1.31). Antigenotoxic effect of gallic acid on HeLa cells was carried by alkaline comet assay. The compound showed significant protective abilities against hydrogen peroxide-induced DNA damage in HeLa cells. Conclusion: These results show the importance of gallic acid isolated from Terminalia chebula fruit, as protector of oxidative stress-induced DNA damage.

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Background Hyperglycemia is the hallmark of diabetes, and the associated oxidative stress is a major concern that invites an array of diabetic complications. The traditional practices of medicare are of great, current interest due to the high cost and side effects of conventional diabetic medications. The present in vitro study focuses on evaluating the potential of various A. occidentale root extracts for their antihyperglycemic and antioxidant potentials. Materials and methods The four different solvent extracts petroleum ether (PEAO), chloroform (CHAO), ethyl acetate (EAAO), and 80 % methanol (80 % MAO) of A. occidentale roots were evaluated for their total phenolic, flavonoid, and antioxidant capacity. Using MIN6 pancreatic β-cells, the cytotoxicity of the extracts was evaluated by MTT assay and the antidiabetic potential by quantifying the insulin levels by ELISA at a higher concentration of glucose. The effect of 80 % MAO on INS gene expression was determined by qRT PCR analysis. Results Among the four different solvent extracts of A. occidentale roots, 80 % MAO showed the highest concentration of phenolics (437.33 ± 0.03 µg GAE/mg), CHAO to be a rich source of flavonoids (46.04 ± 0.1 µg QE/mg) and with the highest total antioxidant capacity (1865.33 ± 0.09 µg AAE/ mg). Evaluation of the free radical scavenging and reducing properties of the extracts indicated 80 % MAO to exhibit the highest activity. The MTT assay revealed the least cytotoxicity of all four extracts. 80 % MAO enhanced INS up-regulation as well as insulin secretion even under high glucose concentration (27mM). Conclusions The present study demonstrated that the A. occidentale root extracts have effective antihyperglycemic and antioxidative properties, together with the potential of normalizing the insulin secretory system of β-cells. Above mentioned properties have to be studied further by identifying the active principles of A. occidentale root extracts and in vivo effects. The prospect of the present study is identifying drug leads for better management of diabetes from the A. occidentale root extracts. Graphical abstract