Melatonin: Effects on Cartilage Homeostasis and Therapeutic Prospects in Cartilage-related Diseases.

Cartilage is a relatively simple connective tissue that plays a variety of roles in the human body, including joint support and protection, load bearing of the intervertebral discs, joint lubrication, formation of the external structure of the ears and nose and support of the trachea. The maintenance of cartilage homeostasis is therefore crucial. Cartilage-related diseases are difficult to diagnose and treat because their molecular and pathological mechanisms are not fully understood. Melatonin, which has a wide range of physiological effects, is an endocrine hormone mainly secreted by the pineal gland. Its biological effects include its antioxidant, antiaging, analgesic, and hypnotic effects and its ability to stabilize the circadian rhythm. In recent years, research on cartilage homeostasis and melatonin has been increasing, and melatonin has gradually been used in the treatment of cartilage-related diseases. Therefore, this article will briefly review the role of melatonin in cartilage homeostasis, including its anti-inflammatory effects and effects in protecting cartilage from damage by other factors and promoting chondrocyte growth and the expression of cartilage-related genes. Based on the above, the current status and future developmental direction of melatonin in the treatment of cartilage-related diseases are also discussed, demonstrating the broad prospects of melatonin in maintaining cartilage homeostasis and treating cartilage injury-related diseases.

Caloric restriction: implications for sarcopenia and potential mechanisms.

Sarcopenia is a potential risk factor for weakness, disability and death in elderly individuals. Therefore, seeking effective methods to delay and treat sarcopenia and to improve the quality of life of elderly individuals is a trending topic in geriatrics. Caloric restriction (CR) is currently recognized as an effective means to extend the lifespan and delay the decline in organ function caused by aging. In this review, we describe the effects of CR on improving muscle protein synthesis, delaying muscle atrophy, regulating muscle mitochondrial function, maintaining muscle strength, promoting muscle stem cell (MuSC) regeneration and differentiation, and thus protecting against sarcopenia. We also summarize the possible cellular mechanisms by which CR delays sarcopenia. CR can delay sarcopenia by reducing the generation of oxygen free radicals, reducing oxidative stress damage, enhancing mitochondrial function, improving protein homeostasis, reducing iron overload, increasing autophagy and apoptosis, and reducing inflammation. However, the relationships between CR and genetics, sex, animal strain, regimen duration and energy intake level are complex. Therefore, further study of the proper timing and application method of CR to prevent sarcopenia is highly important for the aging population.

Possible sarcopenia: early screening and intervention-narrative review.

Sarcopenia is a new geriatric syndrome that has become a heavily researched topic, and it is a potential risk factor for weakness, disability, and death in elderly people. As the world's population ages, the incidence of sarcopenia has also increased, which has resulted in a series of health problems and in large medical costs. Although there are generally accepted diagnostic criteria for sarcopenia, the existing criteria require a comprehensive evaluation of muscle quality, muscle strength and muscle function. Most of these evaluations are time-consuming, labourious, difficult to implement, and unsuitable for large-scale population surveys. Moreover, the abilities of the elderly to undertake daily-life activities are often affected when they are diagnosed with sarcopenia. Therefore, if individuals who are likely to suffer from sarcopenia could be identified by screening at an early stage and then comprehensively evaluated, time and labour would be saved, and the detection rate would be improved. Timely intervention can be undertaken in possible sarcopenia to prevent further development of sarcopenia and strongly improve the quality of life of individuals. This study reviews the early screening and intervention of the possible sarcopenia, analyses its advantages and disadvantages and attempt to identify reliable and practical methods to reduce adverse consequences and the extent of harm.