Anti Inflammatory, Antinociceptive and Central Nervous System Depressant Activities of Marine Bacterial Extracts Introduction Marine microbes associated with macroalgae produce diverse secondary metabolites that include alkaloids, polypeptides, polyketides, etc. Some novel bioactive compounds of epiphytic origin exhibit anti-inflammatory activity against reactive oxygen species and other mediators that induce the inflammatory process in tissues. Their ability to suppress inflammatory factors indicates that they can inhibit oxidative damage and nociceptive sensitivity in vivo. Summary The study examined the pharmacological properties – anti-inflammatory, antinociceptive, and CNS depressant – of epiphytic bacteria associated with seaweeds and other marine organisms. The study involved the inoculation of ectosymbionts and endosymbionts isolated from three seaweeds (C . limonoids, U. Lactuca, and E. compressa ) growing on the Tuticorin coast, India, in seawater broth to grow bacterial cultures. Epiphytic bacteria associated with ascidians were also isolated. Crude extracts from the bacterial cultures were used in the pharmacological assays. The anti-inflammatory activity of the extracts was tested using model animals (rats) with edematous paws. The antinociceptive activity analysis involved comparing the reaction time of mice treated with the extracts and the controls. The CNS depressant activity test entailed measurement of locomotor activity of mice injected with diazepam and the extract. From the results of the anti-inflammatory test, extracts from seaweed ( C. compress ed) associated bacterial strains (EM13 and EM14) exhibited significant anti-inflammatory activity. The inhibitory effect was 20.4-59.5% at 200 mg/Kg dosage. The isolates significantly minimized paw edema through the bioactive compounds that mimic anti-inflammatory mediators and antioxidants. The bacterial extracts also lowered the locomotor activity and CNS depressant state in the mice. Strains EM13 and EM14 showed pharmacological potential as anti-oxidants for protecting tissues from factors that induce inflammation. The authors conclude that the isolation and characterization of the bioactive principles from the potent strains could yield pharmacological agents with antioxidant potential. Presence of Quorum-sensing Inhibitor-like Compounds from Bacteria Isolated from the Brown Alga Colpomenia sinuosa Introduction Marine bacterial quorum sensing (QS) antagonists are seen as potential pharmacological compounds with antioxidant activity. QS is a bacterial signaling mechanism that is mediated by autoinducers such as N-acyl homoserine lactone (AHL). Preexisting epiphytic bacteria produce QS antagonists that inhibit surface colonization by other competing strains through the disruption of QS signaling. The QS inhibitory effect of these molecules is attributed to the reduction of the signal mediators produced by epiphytes. Summary The study sought to screen for potent QS inhibitors produced by epiphytic bacteria using a protocol that was applied in isolating inhibitory pigments from indicator bacteria. In this study, the researchers inoculated agar plates with isolates of epibiotic bacteria attached to the surface of brown algae ( C. sinuosa ) growing on a Japanese Island. Selection based on colony morphology obtained 96 strains, which were cultured on agar plates. The indicator bacterial sp. – Serratia rubidaea – was also isola