The marine environment having vast resources of natural products with potential bioactivities. Among the marine natural products, fatty acids obtained from marine mollusks have broad range of biological activities including antimicrobial and antitumor activities. The present study aims to characterize the fatty acid derivatives from the Sydney rock oyster Saccostrea glomerata and its pharmacological activities. S. glomerata fleshes were serially extracted with hexane, ethyl acetate and methanol and studied the antimicrobial activities against pathogenic bacteria, fungi and virus. Based on the better result, the ethyl acetate extract was selected and purified through silica column chromatography and screened the fractions for antimicrobial and antitumor activities. Also the best active fraction (FV) was functionally and structurally characterized. The ethyl acetate extract of S. glomerata effectively controlled the bacterial pathogens and formed of more than 15 mm of zone of inhibition and also effectively suppressed the fungal growth and inhibit the shrimp white spot syndrome virus (WSSV). The secondary screening results revealed that, the fraction (FV) had potential antimicrobial and antitumor activities. The FV concentration (100 μg/ml) effectively suppressed the tumor mammary epithelial carcinoma cell of 14.45%. The GC–MS analysis revealed that, eleven compounds including N-hexadecanoic acid, L-(+)-ascorbic acid 2,6-dihexadecanoate and 6-Octadecenoic acid were characterized. The fatty acid derivatives isolated and characterized from S. glomerata extracts had the potent antimicrobial and antitumor activities. This basic research can help to develop the antimicrobial and anticancer drugs from the nutraceuticals in future.

Maintaining genomic stability is inevitable for organism survival and it is challenged by mutagenic agents, which include ultraviolet (UV) radiation. Whenever DNA damage occurs, it is sensed by DNA-repairing proteins and thereby performing the DNA-repair mechanism. Specifically, in response to DNA damage, H2AX is a key protein involved in initiating the DNA-repair processes. In this present study, we investigate the effect of UV-C on earthworm, Perionyx excavatus and analyzed the DNA-damage response. Briefly, we expose the worms to different doses of UV-C and find that worms are highly sensitive to UV-C. As a primary response, earthworms produce coelomic fluid followed by autotomy. However, tissue inflammation followed by death is observed when we expose worm to increased doses of UV-C. In particular, UV-C promotes damages in skin layers and on the contrary, it mediates the chloragogen and epithelial outgrowth in intestinal tissues. Furthermore, UV-C promotes DNA damages followed by upregulation of H2AX on dose-dependent manner. Our finding confirms DNA damage caused by UV-C is directly proportional to the expression of H2AX. In short, we conclude that H2AX is present in the invertebrate earthworm, which plays an evolutionarily conserved role in DNA damage event as like that in higher animals.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.