Morphological alterations in the jejunal mucosa of aged rats and the possible protective role of green tea

Abstract

introduction. Gastrointestinal disorders become more prevalent with ageing. This study is aimed to describe morphological changes that occur in the jejunal mucosa of male albino rats as a result of ageing and the protective effect of green tea (GT) extract. Material and methods. The experiment was performed on sixty rats: thirty young-adult (6-month old, body mass 200-220 g) and thirty old (24-month-old, body mass 220-260 g) animals. Each group was further divided into two subgroups (n = 15 each): control rats and GT-treated rats that received 1.5 mL (300 mg/kg/day) of GT extract for 14 weeks by oral gavage. Sections of the jejunum were stained with hematoxylin and eosin, periodic acid Schiff, toluidine blue and Mallory trichrome methods. The presence of proliferating cell nuclear antigen (PCNA)-and CD68-positive cells was evaluated by immunohistochemical staining. Ultrathin sections were prepared and examined by a transmission electron microscope (TEM). results. Jejunal sections of the old control rats showed distortion of submucosa and attenuated muscularis externa with decreased height of intestinal villi. The villi also showed partial loss of acidophilic brush border with wide spaces between enterocytes. Swollen, short, blunt or broad villi with abundant mononuclear cell infiltration of lamina propria and congested blood vessels were evident both by light and electron microscopy. The number of PCNA-and CD68-positive cells in jejunal mucosa of old rats was higher than in young rats. The activity of glutathione peroxidase (GPX) and total antioxidant capacity (TAC) in the mucosa of old control rats were lower, whereas malondialdehyde (MDA) levels were higher in the jejunal homogenates of old rats as compared to young control rats. Administration of GT extract protected the jejunal mucosa from age-related changes by restoring its histological structure. The treatment of old rats with GT extract significantly decreased MDA levels in the jejunum and increased TAC and GPX activity. Conclusions. The age-related changes of the morphology of rat jejunum could be ameliorated by prolonged supplementation of the green tea extract.

A comparison of intestinal integrity, digestive function, and egg quality in laying hens with different ages

“…In an experiment performed on the mice at 3 different ages (3-mo-old, 12-mo-old, and 24-mo-old), it has been identified that thinner mucosal muscularis, shortened and scattered villus, and reduced villus density can be observed from the ileal histological structure in the aging mice, which may be related to the mucosal atrophy, increased bacteria counts, and decreased expression of epithelial tight junction proteins ( Ren et al., 2014 ). Similarly, another report has also demonstrated that 24-mo-old rats exhibit the distorted and destructed state of jejunum, as well as the disrupted mucosal antioxidant defense system ( Hassan et al., 2017 ), suggesting the negative effects of aging on gut function. In humans, a literature has summarized that aging is accompanied by the continuous damage to morphology and function of gastrointestinal tract, which would impair the nutrient absorption and protection against ingested pathogens ( Soenen et al., 2016 ).…”

The Aged Intestine: Performance and Rejuvenation

“…Morphological changes in aged mouse and rat models have been described as thicker muscular layers, distorted villi, more secretory Paneth and goblet cells, and impaired junctions between adjacent enterocytes [ 18 - 24 ]. Mice have wider and higher villi with increasing age [ 22 ], while rats have wider and shorter ones [ 23 ]. Furthermore, rats have darkly stained nuclei in their aged intestines [ 23 ].…”

“…Mice have wider and higher villi with increasing age [ 22 ], while rats have wider and shorter ones [ 23 ]. Furthermore, rats have darkly stained nuclei in their aged intestines [ 23 ]. Human studies showed no significant changes in the duodenum [ 25 ].…”

Effects of Oral Exposure to Mn-Doped ZnS Quantum Dots on Intestinal Tract and Gut Microbiota in Mice

“…The intestinal tract comprises structurally and functionally distinct regions, including digestive, absorptive, secretory, and protective functions ( Bergin and Witzmann, 2013 ; Hassan et al, 2017 ). More than 100 trillion bacteria live in human digestive tracts and we collectively call them the gut microbiota ( van den Brule et al, 2016 ; Li et al, 2018a ).…”