Evaluation of the healing activity of Cucurbita spp. leaf and seed extracts on experimental thermal burns

Abstract

Burns are the most common skin injuries associated with many complications and high incidences of wound infections. Many compounds of plant products have been assessed to accelerate wound healing or reduce contamination. The possible healing effect of two Cucurbita spp. in skin burns was investigated. Cucurbita maxima and Cucurbita pepo leaves and seeds were extracted using ethanol and analyzed by gas chromatography-mass spectrometry. Second-degree burn wounds were made on laboratory rats, and the burn wounds were applied topically with extracts for 14 days and silver sulfadiazine (SS) for comparison. Serum vascular endothelial growth factor (VEGF) was analyzed posttreatment. Hydroxyproline content and histopathological changes were evaluated in skin biopsy. Phytochemical analysis displayed that C. maxima leaf extracts contain linolenic acid (21.94%), phytol (6.45%), and ascorbic acid (9.09%), and they were characterized by glucopyranoside (8.49%) and limonene (5.39%) compounds. The C. pepo leaves were characterized by palmitic acid (48.04%) and alkaloid (tetratriacontane: 13.11%). The seeds extracts of both Cucurbita spp. revealed a high ratio of linoleic acid, palmitic acid, and ascorbic acid. The leaf extracts accelerated wound contraction by 100%, with normal skin appearance, due to their more structural tissue layers, regular collagen fibers, ability to reduce inflammation, and high hydroxyproline content compared to the seed extracts and SS group. The bioactivity of unsaturated fatty acids, ascorbic acid, monoterpene, glycosides, and alkaloids provided the therapeutic property of these extracts. Serum VEGF was significantly reduced in the groups treated with extracts compared with those treated by the SS group. The leaf extracts of both Cucurbita species exhibited a healing efficiency on burn wounds, which were more effective than the seed extracts. Thus, they can be used as a promising plant derivative in burn treatments.