Poly-γ-glutamic acid attenuates angiogenesis and inflammation in experimental colitis

Area of Science:

• Microbiology
• Immunology
• Gastroenterology

Background:

• Inflammatory bowel disease (IBD) involves chronic inflammation sustained by angiogenesis.
• Poly-γ-glutamic acid (γ-PGA), produced by Bacillus, exhibits anti-inflammatory properties.
• The role of γ-PGA in IBD-related angiogenesis and inflammation is not well understood.

Purpose of the Study:

• To investigate the effects of γ-PGA on angiogenesis and inflammation in a dextran sulfate sodium (DSS)-induced mouse colitis model.
• To determine if γ-PGA can mitigate the pathological features of DSS-induced colitis.

Main Methods:

• Experimental colitis was induced in mice using 3% DSS.
• Mice received varying doses of γ-PGA (50 mg/kg or 200 mg/kg) daily.
• Evaluated disease activity index (DAI), histopathology, microvascular density, myeloperoxidase activity, and VEGF-A/VEGFR2 expression.

Main Results:

• γ-PGA significantly reduced weight loss, DAI, and colon shortening in DSS-treated mice.
• Histopathological scores and microvascular density were significantly decreased by γ-PGA treatment.
• γ-PGA attenuated DSS-induced expression of VEGF-A and VEGFR2, and reduced leukocyte recruitment.

Conclusions:

• γ-PGA demonstrates significant anti-inflammatory and anti-angiogenic effects in a mouse model of colitis.
• These findings suggest γ-PGA has potential therapeutic applications for inflammatory conditions characterized by angiogenesis and mucosal inflammation.