Effect of Aging on the Cornea of Male Albino Rat and Possible Therapeutic Role of Royal Jelly

Abstract

Abstract Introduction Nowadays interest in aging has greatly increased, Aging is a complex natural process involving every molecule, cell, and organ in the body that is associated with tissue dysfunction in many organs. Aging of the cornea causes major eye effects and leads to substantial cost in medical and social terms. These effects include the highly prevalent dry eye disease (DED) that affects both visual function and quality of life in elderly. Symptoms of (DED) include, ocular pain, visual disturbances, and increase lacrimation. Functional foods such as Royal jelly (RJ) have a growing attention because of consumers increasing concerns about their health. Its importance not only for its nutritional properties but also for its functional and biological properties such as antioxidant, anti-inflammatory, antibacterial, antiviral, and anti-ulcerous activities. It is used as a cheap natural source in daily life and medicine. (RJ) is a complex substance composed of proteins, sugars, lipids, amino acids, vitamins, and minerals. Aim The present study aimed to investigate the histological effect of aging on the cornea of male albino rat and possible therapeutic role of (RJ) on senile group. Materials and Methods Twenty-four male albino rats were used in this study divided into Group I: consisted of 6 adult male rats aged 3- 6 months. Group II: consisted of 18 senile male rats aged 18-24 months, were further subdivided into three subgroups as follows: Group II A: (n = 6) negative control senile rats, not subjected to any procedure for 4 weeks. Group II B: (n = 6) control senile rats and were given distilled water by oral gavage once daily for 4 weeks. Group II C: (n = 6) senile rats were given (RJ) by oral gavage dissolved in distilled water once daily for 4 weeks. At the end of the experiment, rats were sacrificed after being deeply anesthetized with ether according to the protocol of the Committee of Animal Research Ethics (CARE). The cornea of each animal was carefully dissected out after death and immediately fixed in 10% formalin for preparation of paraffin blocks 5 micrometer thickness. Sections were stained with hematoxylin and eosin (I-I&E), Masson's trichrome and periodic acid-Schiff (PAS). Statistical analysis and quantitative morphometric study were done. Results Light microscopic examination of corneas of senile rats revealed different pathological changes included irregularity in the surface epithelium as well as surface erosions and cytoplasmic vacuolations. The stroma showed widely separated collagen fibers with decreased keratocyte density. It was concluded that (RJ) supplementation to senile rats obviously unproved all layers of the cornea histologically.