The crude alkaloidal extract of Picralima nitida seeds alleviates TNBS-induced inflammatory bowel disease through reduced serum expression of TNF-α, IL-1β and p38 MAPK

Picralima nitida possesses anti-inflammatory, antioxidant and antiulcerogenic properties, among others. The crude alkaloidal extract from the seeds of Picralima nitida (PNE) has been reported to exhibit anti-inflammatory effect in some rodent models. This study aims to investigate the intestinal anti-inflammatory effects of PNE in rats with bowel inflammation induced by trinitrobenzenesulfonic acid (TNBS) administration.

Rats were treated with PNE (30, 100, and 300 mg/kg) or sulphasalazine 500 mg/kg daily for 7 days after bowel inflammation induction with TNBS and euthanized 24 h following administration of the final doses of treatments. Blood samples were collected for haematological and biochemical investigations whereas colons were excised and inspected for tissue damage, both macroscopically and microscopically.

Macroscopic assessment showed that PNE reduced mucosal inflammation and ulceration. Histology showed preservation of normal mucosal architecture and goblet cells numbers, lowered inflammatory cell infiltration and decreased mucosal thickening. PNE treatment altered haematological markers and lowered serum levels of interleukin-1β (IL-1β), tumor necrosis factor alpha (TNF-α) and p38 mitogen-activated protein kinase (p38 MAPK). Moreover, PNE treatment increased glutathione (GSH) levels, inhibited nitric oxide (NO) production, and decreased myeloperoxidase (MPO) activity and malondialdehyde (MDA) production.

The results depict that PNE suppresses oxidative stress and inflammatory injuries in the intestines induced with TNBS, suggesting its potential benefits in intestinal inflammatory diseases.