Effect of Aegle marmelos Extract-Phospholipid Complexes in Dextran Sulfate Sodium-Induced Ulcerative Colitis in Rats

Ayurvedic texts mention the use of Aegle marmelos fruit in colitis and other gastrointestinal ailments. The polyphenolic contents of the fruit, however, have poor bioavailability, limiting their therapeutic use. The study aimed to develop and optimise the A. marmelos fruit extract-phospholipid (AMEP) complex to improve the oral bioavailability of the A. marmelos extract (AME), and compare the in vivo effect of AME and AMEP in dextran sulfate sodium (DSS)-induced ulcerative colitis in rats.

The research work is the first of its kind to use a hydroalcoholic extract of A. marmelos fruit in the preparation of phospholipid complexes for ameliorating UC. The complexes were prepared using the solvent evaporation method and optimised by Box-Behnken design. The work compares the in vivo activity of plain AME, its phospholipid complexes, and the standard drug (mesalamine) in the alleviation of chemical-induced colitis in rats. AMEP was optimised using response surface methodology by Box-Behnken design. AMEP was characterised using scanning electron microscopy, Fourier transform infrared spectroscopy, differential scanning calorimetry, zeta analysis, and particle size analysis. A DSS-induced rat model was used in vivo studies to mimic ulcerative colitis. The pathogenesis of the disease was assessed by evaluating the levels of oxidative stress markers [nitric oxide (NO), malondialdehyde (MDA), and superoxide dismutase (SOD) activity], cytokines [tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6)], disease activity index, colon length, and histopathology.

The characterization confirmed the formation of AMEP, having a particle size of 673.6±4.30 nm, polydispersity index of 0.224±0.010, and zeta potential of -42.6 mV±0.51. The NO, MDA, TNF-α, and IL-6 levels were significantly reduced (p<0.0001, p<0.005, p<0.0001, p<0.01), and the SOD level was significantly increased (p<0.05) in AMEP-treated groups compared to the AME-treated groups.

These findings suggessts that AMEP has a powerful potential to reduce the levels of oxidative markers and inflammatory cytokines, making it a promising treatment for ulcerative colitis.