Abstract
Abstract: Methotrexate (MTX) is widely-utilized as an anticancer and immunosuppressive agent; however, its therapeutic use is limited by gastrointestinal toxicity, including duodenal mucositis. Inflammation contributes substantially to MTX-induced mucosal injury through increased production of pro-inflammatory cytokines, including interleukin-1 beta (IL-1β) and interleukin-6 (IL-6), upregulation of cyclooxygenase-2 (COX-2), and disruption of anti-inflammatory regulation. Perillic acid is a naturally occurring monoterpenoid metabolite of D-limonene with potential antioxidant and anti-inflammatory properties, while vitamin E is an established antioxidant with anti-inflammatory activity.
Objective: This study investigated the protective effects of two doses of perillic acid and vitamin E against MTX-induced duodenal mucositis in rats by evaluating inflammatory markers, COX-2 gene expression, and histopathological changes.
Methods: Forty-two adult male Sprague–Dawley rats were randomly-allocated into six groups of seven rats each: negative control, MTX, perillic acid 30mg/kg alone, perillic acid 15mg/kg plus MTX, perillic acid 30mg/kg plus MTX, and vitamin E plus MTX. Perillic acid and vitamin E each were administered orally once daily for 14 consecutive days. MTX was administered as a single intraperitoneal dose of 20mg/kg on day 14. Serum IL-1β, IL-6, and GSH concentrations were measured using enzyme-linked immunosorbent assays. Duodenal COX-2 gene expression was assessed using quantitative real-time polymerase chain reaction, and duodenal tissues were examined histopathologically.
Results: MTX induces a marked inflammatory response that characterized by increased serum IL-1β and IL-6 levels, GSH decreased, marked upregulation of duodenal COX-2 gene expression, and severe histopathological injury. The observed lesions included villous destruction, epithelial desquamation, leukocyte infiltration, glandular degeneration, mucosal edema, and epithelial hyperplasia. Perillic acid at 15mg/kg produced limited protection, as inflammatory markers remained substantially-altered and severe enteritis persisted. In contrast, perillic acid at 30mg/kg markedly reduces IL-1β, IL-6, and COX-2 expression, restored GSH toward the control level, and preserves the duodenal mucosal architecture. Vitamin E produced a comparable protective effect, and preserving villi, enterocytes, goblet cells, and intestinal glands.
Conclusion: Perillic acid exerts a dose-dependent protective effect against MTX-induced duodenal mucositis. The 30mg/kg dose is more effective than the 15mg/kg dose in modulating inflammatory markers, suppressing COX-2 gene expression, and reducing histopathological injury. Vitamin E also demonstrated substantial anti-inflammatory and histological protection.
| Has the manuscript been published | not published |
|---|---|
| Intend to be published in the IJPS ? | Yes |
