Anti inflammatory and immunomodulatory activity of some cucurbits in vitro and in vivo

Abstract

Interaction between host and enteric biota has a great role in our well-being and prebiotics can substantially improve this. The present study unraveled the effect of pH on the growth, biofilm formation and antimicrobial activity of Lactobacillus rhamnosus (L rh) and also the antioxidant and anti-inflammatory activities of cucurbits (Lagenaria siceraria; L.s, Luffa cylindrica; L.c and Cucurbita pepo; C.p) as prebiotics . The pH of 8.5 and above was not conducive for growth of L. rh while pH of 5.5 to 7.5 maximally supported the growth of L. rh. At pH 6.5, L.c, L.s and C.p correspondingly enhanced the biofilm density (peg method) by 33, 30 and 13% over the control. Bacteriocin or Nisin in broth (1/8: 1, v/v) inhibited the growth of E. coli by 86% of the control. Menthol, Thymol and Camphor (1:1:1, w/w) inhibited microbial population by 68%; it s combination with bacteriocin manifested 90% inhibition. Anti-inflammatory properties of cucurbits with respect to cyclooxygenase (COX)-1 and 2 were studied in vitro and interleukin (IL)-1and#946; and tumor necrosis factor (TNF)-and#945; in serum samples of lipopolysaccharide (LPS)-inflamed mice. The inhibition rate of superoxide radicals by Ls, Cp and Lc was 40, 36 and 31%, respectively, at a concentration of 0.08 mg/ml. With respect to COX-1 inhibition, IC50 for indomethacin, Cp, Lc and Ls were estimated to be 0.0154, 0.026, 0.0337 and 0.0335 mg/µl; and IC50 against COX-2 were 0.0427, 0.023, 0.0183 and 0.0150 mg/µl, respectively. In vivo study revealed that Ls, Lc, indomethacin and Cp correspondingly downregulated the expression of IL-1and#946; by 52, 68, 75 and 126 pg/100 µl, significantly less than control (260 pg/100 µl). TNF-and#945; was also reduced significantly more by Ls, Lc, indomethacin and Cp by 12, 16, 20 and 26 pg/100 µl, respectively, than control (46 pg/100 µl). The effect of different prebiotics varies considerably under different conditions. The cucurbits may be used as non-toxic therapeutic agents against gut ailments. newline