Biomedicine: 2023; 43(2): 595-602 March-April 2023 DOI: https://doi.org/10.51248/.v43i02.1961 Biomedicine- Vol. 43 No. 2: 2023 Research article Evaluation of Semecarpus kurzii Engler from Bay Islands for oxidative DNA damage protective activity and in vitro antioxidant potential Sonali Das 1 , Raghavendra L.S. Hallur 1 , Asit B. Mandal 2 1 Centre for Biotechnology, Pravara Institute of Medical Sciences-DU, Loni (Bk), 413736, Taluk Rahata, District Ahmednagar, Maharashtra, India 2 Division of Crop Improvement, Central Research Institute for Jute & Allied Fibres (ICAR), Barrackpore, Kolkata, 700 120, West Bengal, India (Received: July 2022 Revised: January 2023 Accepted: April 2023) Corresponding author: Sonali Das. Email: sonali.d@rediffmail.com ABSTRACT Introduction and Aim: Harnessing traditional knowledge of medicinal plants is important for the betterment of mankind. We must safeguard traditional knowledge from misuse by miscreants living in modern societies and knowledge must be available in the public domain for use in drug designing in the healthcare system. Since the beginning of recorded history, Indians have used plants as a source of medicine, and their cultural past is incredibly rich. This study was conducted to evaluate the oxidative stress-induced DNA damage prevention and antioxidant potential of Semecarpus kurzii found in the Bay Islands. Materials and Methods: The scavenging of superoxide, hydroxyl radicals, nitric oxide (NO), 2,2-diphenyl-2- picrylhydrazyl hydrate (DPPH) radicals, ferric reducing power (FRAP), and lipid peroxidation inhibition activity were tested to determine antioxidant activity. DNA damage inhibition test was used to evaluate the protection against oxidative DNA damage. Results: The S. kurzii extract showed dose-dependent scavenging of DPPH, superoxide anion, nitric oxide, hydroxyl radical and reducing power evaluated by comparing with standard antioxidants (ascorbic acid, α- tocopherol and BHT). However, the nitric oxide scavenging (IC50 =186.47 μg/mL) and superoxide scavenging (IC50 = 678.32 μg/mL) was more than that of DPPH (IC50 =28.03 μg/mL) and Hydroxyl radical (IC50 =89.10 μg/mL) scavenging capacity. In addition, S. kurzii extract and ascorbic acid showed lipid peroxidation inhibition activity. The extract also exhibited DNA protection which was confirmed by the DNA damage inhibition assay. Conclusion: Our results corroborated that, the methanolic extract of S. kurzii bark has substantial antioxidant activity and DNA damage inhibition. The potential antioxidant and oxidative DNA damage preventive activity could be due to the existence of polyphenolic compounds in the S. kurzii bark. Keywords: Bay Islands; antioxidant; DNA damage assay; ethnomedicine; Semecarpus kurzii. INTRODUCTION ndaman and Nicobar Islands is a group of islands popularly known as Bay Islands with 2500 angiosperm species distributed across the island territory among which 45 species are traditionally used as medicine by tribals and aboriginals (Great Andamanese, Onges, Shompens and Nicobarese) (1). About 223 species of medicinal plants are endemic to these islands, which are found to be more effective for diseases like the common cold to some life-threatening diseases (2, 3). Several ethnobotanical studies have been carried out on the Great Andamanese, Onges, and Jarawas tribes but detailed information is not available on the folklore medicines of these Negrito tribes (4,5). Plants are potent biochemical reactors that have proved to be a good source of phytochemicals with potent medicinal properties since time immemorial. All plant parts, including the leaves, bark, roots, flowers, fruits, and seeds, contain natural antioxidants that guard the human body against many diseases (6, 7). The combined actions of secondary metabolites in a specific plant that is distinct in a taxonomic sense determine the synergistic effects of medicinal plants, which are unique to plant species or groupings (8). For the prevention and treatment of complicated illnesses including cancer, Alzheimer's disease, atherosclerosis, stroke, and diabetes, antioxidant-based drugs and formulations have been created in the last three decades (9,10). By forming covalent bonds with enzymes, superoxide anions (O2), nitric oxide (NO), and hydroxyl radicals (OH-) render them inactive (11). The oxidative stress is caused due to the increased production of toxic oxygen derivatives. Plants and other organisms can synthesize a variety of antioxidant molecules thereby evolving a wide range of mechanisms to avert different disease conditions. In the modern food industry, synthetic antioxidants are commonly used, and it has been suggested that their indirect inclusion in the human diet may have cancer-causing consequences (12). In addition to their ability to scavenge free radicals, natural antioxidants are preferred over synthetic antioxidants because they are safer and healthier. This has led to an increased A 595