Antimicrobial and immunomodulating activities of hesperidin and ellagic acid against diarrheic Aeromonas hydrophila in a murine model.

AIMS: The present study is designed to evaluate the in vitro and in vivo bactericidal and immunomodulating activities of hesperidin (HES) and ellagic acid (EA) against Aeromonas hydrophila. A hydrophila, an uncommon human pathogen, can cause invasive infections in immunocompromised individuals and common clinical presentations in acute gastrointestinal illness, soft-tissue infections and sepsis. The antimicrobial activities of medicinal plants against A. hydrophila have received only cursory attention. METHODS: We examined the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values in vitro. Moreover, the effects of HES and EA against bacterial colonization were studied in vivo. Also, humoral immune response was tested against A. hydrophila-LPS or A. hydrophila-ECP antigen preparations and the intestinal histopathological alterations were studied. RESULTS: Data revealed that the treatments with HES and EA each had antimicrobial activities against A. hydrophila. Both HES and EA treatments significantly increased anti-LPS IgM levels and reduced anti-LPS and anti-ECP IgA levels to their normal values in comparison to the infected group, which recorded significantly elevated levels two week post-infection. In conclusion, the present data suggest that HES and EA have antimicrobial and immunomodulating activities against murine A. hydrophila infections. SIGNIFICANT: These data warrant clinical studies to delineate HES and EA roles in human infectious diseases.

Immunomodulatory effects of curcumin treatment on murine schistosomiasis mansoni.

Curcumin is a polyphenol derived from the dietary spice turmeric. It has been shown to regulate numerous transcription factors, cytokines, adhesion molecules, and enzymes that have been linked to inflammation. In addition to inhibiting the growth of a variety of pathogens, curcumin has been shown to have nematocidal activity. The present study was designed to evaluate the schistosomicidal activity of curcumin in vivo as well as immunomodulation of granulomatous inflammation and liver pathology in acute schistosomiasis mansoni. Mice were infected each with 80 Schistosoma (S.) mansoni cercariae and injected intraperitoneally with curcumin at a total dose of 400mg/kg body weight. Curcumin was effective in reducing worm and tissue-egg burdens, hepatic granuloma volume and liver collagen content by 44.4%, 30.9%, 79%, and 38.6%, respectively. Curcumin treatment restored hepatic enzymes activities to the normal levels and enhanced catalase activity in the liver tissue of infected mice. Moreover, hepato-spleenomegaly and eosinophilia induced by S. mansoni infection were largely improved with curcumin treatment. Infected mice treated with curcumin showed low serum level of both interleukin (IL)-12 and tumor necrosis factor alpha (TNF-alpha), but IL-10 level was not significantly altered. Specific IgG and IgG1 responses against both soluble worm antigen (SWAP) and soluble egg antigen (SEA) were augmented with curcumin treatment, but IgM and IgG2a responses were not significantly changed. In conclusion, curcumin treatment modulates cellular and humoral immune responses of infected mice and lead to a significant reduction of parasite burden and liver pathology in acute murine schistosomiasis mansoni.