Exploration of acute toxicity, analgesic, anti-inflammatory, and anti-pyretic activities of the black tunicate, Phallusia nigra (Savigny, 1816) using mice model

Among marine animals, ascidians represent the most highly evolved group for marine natural products having rich source of bioactive secondary metabolites with promising potential biomedical applications. In this study, an analgesic, anti-inflammatory, and anti-pyretic activities of Phallusia nigra were performed. The acute toxicity (LD₅₀) was calculated, and the intraperitoneal route was estimated to be 235.09, 252.90, and 295.59 mg/kg with 95% confidence limits for methanolic extract (ME), acetonitrile extract (ANE), and acetone extract (AE) respectively. Histopathological observations revealed the toxic effects of different crude extracts of P. nigra, which were more analogous on the organs such as the lungs, liver, and kidneys of the test animals. Analgesic response of acetonitrile fraction II (ANF2) was higher than all the crude extracts as well as the fractions tested, and it was very low in acetone fraction I (AF1). In addition to that, different extracts and their fractions obtained from P. nigra was potential to reduce the edema induced by carrageenan (500 μg/paw) in a duration dependent manner. Our study again proves that compounds isolated from lower forms (ascidians) showed tremendous effects in mice without any deleterious effect generally provoked during chemical drug treatments.