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Because of the practical importance of acute radiation exposure associated with combined injuries, it is imperative to investigate the efficacy of cost-effective nutritional factors in the reconstruction of irradiated wounds. Therefore, effect of pretreatment of ascorbic acid was studied on the healing of excised wounds in mice exposed to 2, 4, 6 and 8 Gy whole body gamma-radiation. A full-thickness wound was created on the dorsum of the irradiated mice and the progression of wound contraction was monitored by capturing video images of the wound at various varying days after irradiation. Irradiation caused a dose dependent delay in wound contraction and wound healing time, while ascorbic acid pretreatment resulted in a significant acceleration in the rate of wound contraction and a decrease in the mean wound healing time. To understand the mechanism of healing, collagen, hexosamine, DNA, nitrite and nitrate contents were measured in the granulation tissue of wounded mice treated with ascorbic acid before exposure to 6 Gy gamma-radiation. Ascorbic acid treatment prior to irradiation enhanced the synthesis of collagen, hexosamine, DNA, nitrite and nitrate contents. The histological assessment of wound biopsy revealed an improved collagen deposition, and increase in fibroblast and vascular densities. The present study demonstrates that ascorbic acid pretreatment has a beneficial effect on the irradiated wound and could be a substantial therapeutic strategy to accelerate wound repair in irradiated wounds and in the cases of combined injury situations.

The healing of irradiated wounds has always been a central consideration in medical practice because radiation disrupts normal response to injury, leading to a protracted recovery period. The quest for clinically effective wound healing agents is important in the medical management of irradiated wounds. Therefore, the present study was conceptualized to investigate the effect of curcumin (natural yellow, diferuloylmethane), a major yellow pigment and an active component of turmeric on wound healing in mice exposed to whole-body gamma-radiation. A full-thickness wound was created on the dorsum of mice whole-body irradiated to 2, 4, 6, or 8 Gy. The progression of wound contraction was monitored periodically by capturing video images of the wound. The collagen, hexosamine, DNA, nitric oxide, and histological profiles were evaluated at various postirradiation days in mice treated and not treated with curcumin before exposure to 0 or 6 Gy. The whole-body exposure resulted in a dose-dependent delay in wound contraction and prolongation of wound healing time. Irradiation caused a significant reduction in collagen, hexosamine, DNA, and nitric oxide synthesis. Pretreatment with curcumin significantly enhanced the rate of wound contraction, decreased mean wound healing time, increased synthesis of collagen, hexosamine, DNA, and nitric oxide and improved fibroblast and vascular densities. This study demonstrates that curcumin pretreatment has a conducive effect on the irradiated wound and could be a substantial therapeutic strategy in initiating and supporting the cascade of tissue repair processes in irradiated wounds.

Purpose: Because of the crucial practical importance of acute radiation exposure associated with combined injuries, the study was undertaken to investigate the effect of various doses of ascorbic acid on the survival and healing of wounds in mice exposed to whole-body gamma-radiation., Materials and Methods: Animals were given double-distilled water or different doses of ascorbic acid by intraperitoneal injection before exposure to 0 or 10 Gy whole-body gamma-radiation to evaluate the effect of ascorbic acid on radiation-induced mortality. The animals were monitored daily for the symptoms of radiation sickness and mortality. In a separate experiment, animals were administered with either double-distilled water or different doses of ascorbic acid before exposure to 0 or 6 Gy whole-body gamma-radiation to investigate the effect of ascorbic acid on the irradiated wound. A full-thickness skin wound was created on the dorsum of the irradiated mice and the progression of wound contraction was monitored by capturing video images of the wound at various post-irradiation periods., Result: Treatment of mice with various doses of ascorbic acid elevated survival of mice and a highest number of survivors (67 and 33% for 10 and 30 days post-irradiation) was observed for 250 mg kg(-1) (p<0.002 and<0.02 for 10- and 30-day survival, respectively). Ascorbic acid treatment caused a dose-dependent elevation in the wound contraction and highest contraction was observed for 250 mg kg(-1). The wound contraction was significantly greater at 3 (p<0.005), 6 (<0.05) and 9 (<0.05) days post-irradiation with 250 mg kg(-1) ascorbic acid. The complete healing of the wound was effected by day 22.8 post-irradiation in the ascorbic acid-treated irradiation group., Conclusion: Administration of ascorbic acid protected mice against radiation-induced sickness, mortality and improved healing of wounds after exposure to whole-body gamma-radiation. Additional studies will be directed toward analysing the role of successive administration of ascorbic acid to protect non-target tissues during radiotherapy and in initiating and supporting the cascade of tissue repair processes in radiotherapy delayed wounds.

Objective: To study the effect on wound contraction of pretreatment with various doses of curcumin (the most important active ingredient of the spice turmeric) in mice exposed to 6 Gy whole-body gamma radiation., Method: A full-thickness skin wound was produced on the dorsum of Swiss albino mice treated with and without 25, 50, 100, 150 or 200 mg/kg body weight of curcumin before exposure to 6 Gy gamma radiation. Progression of wound contraction was monitored using video images of the wound at various days post-irradiation until full healing occurred. Mean wound healing times were also calculated., Results: Irradiation caused significant delay in wound contraction and healing times. However, treatment with curcumin resulted in a dose-dependent increase in contraction when compared with a control. Greatest contraction was observed for 100 mg/kg curcumin, with statistically significant results at days three (p < 0.009), six (p < 0.05) and nine (p < 0.05) post-irradiation for this dose. Complete healing was achieved by day 23 post-irradiation in the curcumin-treated irradiation group., Conclusion: Pretreatment with curcumin has a conductive effect on irradiated wounds. It could be a substantial therapeutic agent for ameliorating radiation-induced delay in wound repair in cases of combined injuries.

Alteration of the radiation-induced changes in wound contraction, collagen synthesis and wound histology by ascorbic acid was studied in mice exposed to 10, 16 and 20 Gy of fractionated (2 Gy/fraction) gamma radiation. The animals were given double-distilled water or ascorbic acid daily before exposure to 2 Gy/day of fractionated irradiation. A full-thickness skin wound was created on the dorsum of the irradiated mice, and the progression of wound contraction and collagen synthesis were examined and histological evaluations were carried out at various times after wounding. Irradiation caused a dose-dependent delay in wound contraction, and pretreatment with ascorbic acid resulted in a significant increase in wound contraction. The greatest increase in wound contraction was observed 6 and 9 days after wounding in both groups. Pretreatment with ascorbic acid augmented the synthesis of collagen significantly as revealed by an increase in hydroxyproline content. The collagen deposition and fibroblast and vasculature densities declined in a dose-dependent manner in groups receiving radiation alone as indicated by histological evaluation. Pretreatment with ascorbic acid ameliorated the observed effect significantly. These studies demonstrate that pretreatment with ascorbic acid resulted in a significant reduction of radiation-induced delay in wound healing as shown by earlier wound closure and increased collagen content and fibroblast and vascular densities., (Copyright 2003 by Radiation Research Society)