Antioxidant and Cytotoxic Effect of Barringtonia racemosa and Hibiscus sabdariffa Fruit Extracts in MCF-7 Human Breast Cancer Cell Line

Background: The fruits of Barringtonia racemosa and Hibiscus sabdariffa have been used in the treatment of abscess, ulcer, cough, asthma, and diarrhea as traditional remedy. Objective: This study aims to evaluate cytotoxic effect of B. racemosa and H. sabdariffa methanol fruit extracts toward human breast cancer cell lines (MCF‑7) and its antioxidant activities. Materials and Methods: Total antioxidant activities of extracts were assayed using 2,2’‑diphenyl‑1‑picrylhydrazyl radical (DPPH) and β‑carotene bleaching assay. Content of phytochemicals, total flavonoid content (TFC), and total phenolic content (TPC) were determined using aluminum chloride colorimetric method and Folin–Ciocalteu’s reagent, respectively. Cytotoxic activity in vitro was investigated through 3‑(4, 5‑dimethylthiazol‑2‑yl)‑2, 5‑diphenyl tetrazolium bromide (MTT) assay. Results: B. racemosa extract exhibited high antioxidant activities compared to H. sabdariffa methanol fruit extracts in DPPH radical scavenging assay (inhibitory concentration [IC₅₀] 15.26 ± 1.25 μg/mL) and ß‑carotene bleaching assay (I% 98.13 ± 1.83%). B. racemosa also showed higher TPC (14.70 ± 1.05 mg gallic acid equivalents [GAE]/g) and TFC (130 ± 1.18 mg quercetin equivalents [QE]/g) compared to H. sabdariffa (3.80 ± 2.13 mg GAE/g and 40.75 ± 1.15 mg QE/g, respectively). In MTT assay, B. racemosa extract also showed a higher cytotoxic activity (IC₅₀ 57.61 ± 2.24 μg/mL) compared to H. sabdariffa. Conclusion: The present study indicated that phenolic and flavonoid compounds known for oxidizing activities indicated an important role among the contents of these plants extract. B. racemosa methanol extract have shown potent cytotoxic activity toward MCF‑7. Following these promising results, further fractionation of the plant extract is underway to identify important phytochemical bioactives for the development of potential nutraceutical and pharmaceutical use.