The muscle mass in all people decreases by about 10-15% in 50-70 years of age and 30% or more in 70-80 years of age, resulting in decreases in muscle strength and function. This is called sarcopenia. Sarcopenia, a muscular disease that occurs in most elderly individuals, presents with the decrease in muscle mass with aging. When this senile sarcopenia is not treated, it causes a painful old age life due to a discomfort performance of physical function and can also cause various age-related diseases, including diabetes, obesity, cardiovascular diseases, osteoporosis and the like.
Various studies on the efficient control of sarcopenia have been conducted. It was found that treatment with, for example, growth hormone (GH), can increase muscle mass. However, this treatment is very expensive and cause some undesired side effects such as shortening average life expectancy. As one of the most efficient methods for delaying the progression of sarcopenia, exercise has been recommended, but it is very unsuitable for elderly or sickbed patients. Thus, there is an urgent need to develop a drug and technology for treating sarcopenia, which can induce the regeneration and differentiation of muscle.
Meanwhile, it was reported that diaminodiphenylsulfone (Dapsone; DDS) well-known as an antibiotic increases the life span of Caenorhabditis elegans by 20-30%. DDS is a substance synthesized one century ago, is well known as a therapeutic agent for leprosy and is used as an important drug for many other skin diseases.