A Comparative Study of the Effect of Melatonin Versus Vitamin C on Aged Labial Tissues in Albino Rats

Abstract

Background: Structural changes occur with aging, associated with fibrosis and inflammation in body tissues. Aging of oral mucosa causes alterations in oral epithelium and sub-epithelial tissues, due to reduction in certain growth factors, endogenous anti-oxidant enzymes, or both. Aim: to assess anti-aging potential of melatonin & vitamin C on albino rats’ lips.Materials and Methods: 28 male albino rats were used, divided into: Group I: 7 rats aged 6 months (18 years in humans), Group II: 21 rats aged 24 months (72 years in humans), were equally subdivided into 3 subgroups 7 rats each as follows: Subgroup IIA: positive control for other subgroups; Subgroup IIB: received melatonin via gastric gavage (10mg/kg/day) for six consecutive weeks; Subgroup IIC: received vitamin C via gastric gavage (2mg/ml/day) for six consecutive weeks. At the end of the experiment, rats were sacrificed by a high dose of anesthesia. The lips were excised. Specimens were processed for histological examination, stained by H&E, Masson’s Trichrome& Anti-VEGF, examined by light microscope.Results: Subgroup IIA showed statistically significant increase in number of vacuolated epithelial cells, statistically significant reduction in VEGF positive cells, apparent decrease in epithelial thickness, statistically significant reduction in immature collagen fibers’ percentage within connective tissue (CT). Subgroups IIB & IIC, showed significant reduction in number of vacuolated epithelial cells and significant increase in VEGF positive cells and area percentage of immature collagen fibers in CT. However, subgroup IIB’s epithelial structure showed better image and subgroup IIC’s CT structure presented better image.Conclusion: Aging showed structural changes in skin & mucous membrane sides of rat lips, observed within both epithelium and CT. Melatonin & vit. C exhibited efficiency in counteracting these effects. Melatonin presented superior effect on keratinocytes, vit. C showed superiority in repairing senile CT components.