Evaluation of antioxidant, anti-hemolytic, cytotoxic effects and anti-bacterial activity of selected mangrove plants ( Bruguiera gymnorrhiza and Heritiera littoralis ) in Bangladesh

Objectives In this present study, antioxidant, anti-hemolytic, cytotoxic and anti-bacterial activities derived from methanol extracts of Bruguiera gymnorrhiza and Heritiera littoralis were investigated in order to determine their medicinal activities. Materials and methods Folin-Ciocalteu reagent method and aluminum chloride methods were used to determine the mangroves’ total phenolics and total flavonoid content, respectively. Antioxidant capacity was assessed via the following methods: 1,1-diphenyl-2-picryl hydroxyl (DPPH), 43 mM H 2 O 2 , Fe 2+ quenching assay, and anti-hemolytic activity. Brine shrimp ( Artemia salina L.) lethality assay was also carried out to determine the cytotoxic potential of the mangroves along with anti-bacterial activity test using five Gram-negative and another two Gram-positive bacterial strains. Results The mangroves yielded 58.917 ± 0.601 and 36.625 ± 0.551 mg Gallic acid equivalent (GAE)/g sample and 76.417 ± 0.19 and 113.637 ± 0.17 mg quercetin equivalent (QE)/g sample in B. gymnorrhiza and H. littoralis , respectively. Methanol extracts of both mangroves exhibited high radical scavenging activity against DPPH, H 2 O 2 and Fe 2+ radicals. The reductive capacity of the extracts increased with increasing concentrations of samples, and the extracts inhibited H 2 O 2 induced hemolysis in human red blood cells (RBCs). Antioxidant properties were found to be moderately weaker than that of the reference standard, L-ascorbic acid (AA), and Gallic acid (GA). Further, brine shrimp ( Artemia salina L.) lethality assay revealed significant cytotoxicity (241.4 and 272.6 μg/mL, respectively). Methanol extracts could also inhibit the growth of pathogenic bacterial strains. Conclusion This study showed that the crude methanol extract of selected mangrove plants possesses free radical scavenging, anti-hemolytic, cytotoxic and anti-bacterial activity. The experimented plant has the potential to be used as a traditional medicine and replace synthetic drugs. Further studies are necessary to isolate active compounds responsible for the overall antioxidant activity of the crude extracts.