Effect of Euphorbia hirta plant leaf extract on immunostimulant response of Aeromonas hydrophila infected Cyprinus carpio.

The main objective of the present study is to improve the immune power of Cyprinus carpio by using Euphorbia hirta plant leaf extract as immunostimulants. The haematological, immunological and enzymatic studies were conducted on the medicated fish infected with Aeromonas hydrophila pathogen. The results obtained from the haematological studies show that the RBC count, WBC count and haemoglobin content were increased in the infected fish at higher concentration of leaf extract. The feeds with leaf extract of Euphorbia hirta were able to stimulate the specific immune response by increasing the titre value of antibody. It was able to stimulate the antibody production only up to the 5th day, when fed with higher concentrations of (25 g and 50 g) plant leaf extract. The plant extract showed non-specific immune responses such as lysozyme activity, phagocytic ratio, NBT assay, etc. at higher concentration (50 g) and in the same concentration (50 g), the leaf extract of Euphorbia hirta significantly eliminated the pathogen in blood and kidney. It was observed that fish have survival percentage significantly at higher concentration (50 g) of Euphorbia hirta, when compared with the control. The obtained results are statistically significant at P < 0.05 and P < 0.01 levels. This research work suggests that the plant Euphorbia hirta has immunostimulant activity by stimulating both specific and non-specific immunity at higher concentrations.

Immunopotentiation of hepatitis B vaccine using biodegradable polymers as an adjuvant.

BACKGROUND/PURPOSE: The purpose of this research was to develop an alternative adjuvant for hepatitis B vaccine (HBsAg) that elicits a long-lasting immune response after a single administration. In this study, the suitability of Poly (D, L)-lactide-co-glycolic acid (PLGA), Poly lactic acid (PLA) and Chitosan polymers as adjuvants for HBsAg were investigated. METHODS: We used solvent evaporation and emulsion cross-linking techniques to encapsulate HBsAg into the different polymeric systems. The newly developed microparticles were evaluated for vaccine content, particle size distribution, in vitro release and immunogenicity. RESULTS: HBsAg-encapsulated PLGA and PLA microparticles were smooth and spherical. However, Chitosan microparticles were homogeneous, and almost spherical, with rough surfaces. The vaccine loading and release patterns varied with the type of polymer used. In this study, Chitosan polymeric microparticles released antigen until day 63 post-injection; however, the release period of the PLGA and PLA systems was shorter. A significant increase in the level of antibodies to HBsAg was induced by all the polymeric microparticles. CONCLUSION: The results indicate that Chitosan microparticles are a more efficient adjuvant for HBsAg than PLGA and PLA polymeric microparticles.