When frostbite thaws, reperfusion injury has a crucial impact on tissue injury, and production of free radicals induces further tissue damage. This study examined whether extract of Ginkgo biloba 761 could ameliorate frostbite injury as a free radical scavenger.
Seventy-five Fisher 344 rats were divided into five groups of 15, and frostbite injury was created in each animal by sandwiching the left hind foot between a frozen magnet (−78.5°C) and a room-temperature magnet. Group I received saline; groups II, III, and IV received extract of Ginkgo biloba 761 (200, 100, and 50 mg/kg, respectively); and group V received superoxide dismutase (12 mg/kg). All drugs were injected intraperitoneally three times at 24-hour intervals. The wound surface area was measured throughout the wound healing period. Wounds were also harvested at various times to count cells stained by monoclonal antibodies for 4-hydroxy-2-nonenal and 8-hydroxy-2′-deoxyguanosine.
Compared to group I, the wound surface area was significantly smaller in groups II and III on days 1 and 3 after wound creation. Histologic examination revealed significantly more 4-hydroxy-2-nonenal–stained cells and 8-hydroxy-2′-deoxyguanosine–stained cells in group I compared to other groups on day 1. However, there was no difference in the total healing period among the groups. A higher dose test of extract of Ginkgo biloba 761 (300 mg/kg daily) induced animal death, probably because of toxicity.
Extract of Ginkgo biloba 761 demonstrated a protective effect against frostbite in the present model and probably alleviated reperfusion injury by reducing tissue peroxidation.
Tokorozawa, Saitama, Japan
From the Department of Plastic and Reconstructive Surgery, National Defense Medical College.
Received for publication November 9, 2017; accepted October 15, 2018.
Disclosure:The authors have no financial interest to declare in relation to the content of this article. There was no funding for this study.
Tetsushi Aizawa, M.D., 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan, firstname.lastname@example.org