Effect of green tea on aged rat skeletal muscle: a light and electron microscopic study

ABSTRACT

Age-related sarcopenia represents a powerful risk factor for the loss of independence and physical disability in the elderly. Green tea contains a series of polyphenols called catechins and has been applied for disease prevention and treatment. To determine the effects of the intake of green tea on age-related changes in skeletal muscle. Thirty female albino rats were divided into three equal groups group I [control adults] included 6-month-old rats, group II [aged]included 18-month-old rats, and group III [green tea treated] included 12-month-old rats that received green tea at a dose of 300mg/kg body weight in 1.5ml distilled water orally daily by a gastric tube for 6 months. Quadriceps muscle was dissected bilaterally and prepared for light and electron microscopical examination. Morphometric and statistical studies of the mean cross-sectional area of myofibers were carried out in the three studied groups. With increasing age, there were focal degeneration and atrophy, and significant decrease in the mean cross-sectional area of myofibers. The connective tissue framework showed increased collagen fiber deposition and deficient reticular fibers. Ultrathin sections showed areas of myofibrillar loss and mitochondria with destroyed cristae. Dense shrunken nuclei of satellite cells were observed. After treatment with green tea, normal-appearing myofibers, except for centrally located nuclei, were observed. The mean cross-sectional area of myofibers increased significantly compared with the aged group. Collagen and reticular fibers were relatively similar to those of the control. Proliferation of satellite cells was observed with restoration of normal myofiber ultrastructure. Good regenerative outcome was observed in aged skeletal muscle after the intake of green tea