Evaluation of in vitro anti-inflammatory activity of five selected marine sponges against denaturation of protein-A pilot study

Background: Marine sponges are well renowned for producing bioactive secondary metabolites with drug leads. Screening of anti-inflammatory compounds from marine sponges is highly appreciated in the field of marine pharmacognosy due to their effectiveness and specificity over the most of synthetic non-steroidal anti-inflammatory drugs. In vitro models to test anti-inflammatory activity are considered obligatory prior to pre-clinical studies. Objective: To evaluate in vitro anti-inflammatory effect of crude extracts of five marine sponge samples (N=5), collected from Dehiwala, Colombo, Sri Lanka. Methodology: Identification of sponge species were based on morphology, spicule and skeleton analysis, using light microscopy. Each sponge crude extract (SCE) was tested for selected zoo-chemicals and against the denaturation of albumin to assess the anti-inflammatory activity. Diclofenac sodium was used as the reference drug. Results: Sponge samples were identified as 1) Stylissa sp, 2) Stylissa carteri, 3) Axinella sp., 4) Phakellia sp. and 5) Family Axinellidae. Zoo-chemical analysis indicated the presence of alkaloids, saponins, terpenoids, and sterols in sponge extracts in varying degree. Heat induced egg albumin denaturation was inhibited by 4 SCEs specifying marked anti-inflammatory activity. Accordingly, the 3 sponge crude extracts were more potent (IC50 = 22.74 for Sp. 02, 3.98 for Sp. 03 and 63.665µgmL -1for Sp. 05) than the of standard reference drug, Diclofinac sodium (IC50=147.02 µg/mL). Conclusions: Thus, the present study for the first time investigated in vitro anti-inflammatory activity of crude extract of 5 selected marine sponge species from Sri Lanka, out of which 3 were more potent than the reference diclofenac sodium. Therefore, isolation and characterization of bioactive compounds which are responsible for anti- inflammatory activity will lead to discover novel marine derived anti-inflammatory drugs in the future.