Objective: To investigate the crude extract of marine actinomycetes with adverse effect locally on the adult Wister albino rats or systematically in the blood circulation. Methods: Acute toxicity, sub acute toxicity, biochemical and histopathological were tested. Results: In the results acute toxicity (LD50=2 500 μg/kg bw), sub acute toxicity study (2 500 μg/kg bw) were significant at 5% level of each experimental groups compared to the control group. Biochemical and histopathological study also showed better as compared with control group Conclusion:This crude microbial extract from Streptomyces sp. RSAUT 20 and Streptomyces scabiei (S. scabiei) RSAUK 49 is potential source for novel antimicrobial compounds. The crude extract of Streptomyces sp. RSAUT 20 and S. scabiei RSAUK 49 were tested for in vivo toxicity study.

Objective: To identify the possible antiplasmodial compounds from Achyranthes aspera (A. aspera), Acalypha indica (A. indica), Jatropha glandulifera (J. glandulifera) and Phyllanthusamarus (P. amarus). Methods: The A. aspera, A. indica, J. glandulifera and P. amarus were collected along Palk Strait and the extraction was carried out in ethanol. The filter sterilized extracts (100, 50, 25, 12.5, 6.25 and 3.125 μg/mL) of leaf, stem, root and flower extracts of A. aspera, A. indica, J. glandulifera and P. amarus were tested for antiplasmodial activity against Plasmodiumfalciparum. The potential extracts were also tested for their phytochemical constituents. Results:Of the selected plants species parts, the stem extract of A. indica showed excellent antiplasmodial activity (IC50= 43.81μg/mL) followed by stem extract of J. glandulifera (IC50= 49.14μg/mL). The stem extract of A. aspera, leaf and root extracts of A. indica, leaf, root and seed extracts of J.glandulifera and leaf and stem extracts of P. amarus showed IC 50 values between 50 and 100 μg/mL. Statistical analysis revealed that, significant antiplasmodial activity (P<0.01) was observed between the concentrations and time of exposure. The chemical injury to erythrocytes was also carried out and it showed that there were no morphological changes in erythrocytes by the ethanolic extract of all the tested plant extracts. The in vitro antiplasmodial activity might be due to the presence of alkaloids, glycosides, flavonoids, phenols, saponins, triterpenoids, proteins, and tannins in the ethanolic extracts of tested plants. Conclusions: The ethanolic stem extracts of P. amarus and J. glandulifera possess lead compounds for the development of antiplasmodial drugs.