The preventive effects of diosmin alone or combined with irinotecan on 1,2-dimethylhydrazine-induced colon cancer in rats.

Objective: Colorectal cancer, one of the most frequently diagnosed cancers worldwide, has a high mortality rate. Thus, our research aims to examine the preventive effects of diosmin (DIO) alone and in conjunction with the anti-cancer drug irinotecan (camptothecin-11, CPT-11), on 1,2-dimethylhydrazine (DMH)-induced colon cancer (CC) in male Wistar rats.

Materials and methods: Fifty adult male Wistar rats were categorized into five groups. Group I (Normal) received saline 0.9 orally % as a vehicle once a week for 14 weeks. Group II (DMH) received DMH (20 mg/kg/week) orally dissolved in 0.9% saline for 14 weeks and 1% carboxymethylcellulose (CMC) every other day for the final 10 weeks. Group III (DMH+DIO) received DMH orally for 14 weeks and DIO (10 mg/kg, suspended in 1% CMC) every other day for the final 10 weeks. Group IV (DMH+CPT-11) received DMH orally for 14 weeks and intraperitoneal injection of CPT-11 (3 mg/kg) twice a week for the final 10 weeks. Group V (DMH+DIO+CPT-11) orally received DMH for 14 weeks and both DIO and CPT-11.

Results: All treated groups showed a significant reduction (p<0.05) in their elevated serum malondialdehyde levels and significant amelioration (p<0.05) of their lowered activities of colon glutathione-S-transferase (GST) and glutathione reductase (GR) as well as serum glutathione level (GSH). In addition, simultaneous treatment with DIO and CPT-11 led to a significant decrease (p<0.05) in the elevated serum levels of carcinoembryonic antigen (CEA) in rats administered with DMH, as well as a reduction in the colon expression levels of the inflammatory mediator (NF-κB), cell proliferator protein (Ki-67), and proapoptotic protein (p53).

Conclusions: These findings suggest DIO, CPT-11, and their combination have anticarcinogenic effects against DMH-induced CC by suppressing oxidative stress, simulating the antioxidant defense system, attenuating the inflammatory effects, and reducing cell proliferation.