Acceleration of Wound Repair and Regeneration by Nigella Sativa in the Deep Dermal Excision Wound of Mice Whole Body Exposed to Different Doses of γ-radiation

The effect of kalonji (Nigella sativa) extract (NSE) was studied on dermal excision wound of mice whole body exposed to different doses of γ-radiation. The optimum dose was selected by administering mice with different doses of NSE for five consecutive days before whole-body exposure to 6 Gy γ-radiation and creating a full thickness deep dermal wound of 15 mm diameter on the dorsum of mice after irradiation. The estimation of wound contraction and mean wound healing time showed that 150 mg/kg NSE was the optimum dose as it caused an early closure of the wound and reduced the mean wound healing time to a maximum extent than the other NSE doses. Irradiation of mice to 0, 2, 4, 6 and 8 Gy resulted in a dose dependent delay in the wound contraction and mean wound healing time, whereas administration of mice with 150 mg/kg b. wt. NSE before exposure to 0, 2, 4, 6 and 8 Gy γ-radiation, reduced the radiation induced delay in the wound contraction and mean healing time, significantly especially for 6 and 8 Gy irradiation. The estimation of total collagen and hexosamine contents at 3, 5, 10 and 15 days post-wounding in the granulation tissues of regenerating wounds, revealed that irradiation of mice to 6 Gy γ-radiation resulted in a significant decline in the collagen, and hexosamine contents at all post-irradiation times, whereas pre-treatment of mice with 150 mg/kg b. wt. NSE resulted in a significant elevation in the collagen and hexosamine synthesis when compared to the concurrent irradiation alone group. The irradiation caused a reduction in glutathione concentration in the granulation tissue at 6, 12, 48 and 72 h post-treatment, whereas glutathione peroxidase and superoxide dismutase activities increased at 6 h post-irradiation. NSE treatment arrested the decline in GSH concentration, and, further elevated glutathione peroxidase and superoxide dismutase activity. The irradiation resulted in a dose dependent elevation in lipid peroxidation and pretreatment of mice with NSE significantly reduced radiation induced lipid peroxidation. The NSE administration reduced the radiation induced delay in wound contraction and mean wound healing time, which may be due to enhanced synthesis of collagen and hexosamine and increased anti-oxidants and alleviation in the lipid peroxidation.