1. Field
The present disclosure relates to a composition for preventing, improving, or treating osteoporosis (Type I osteoporosis) in postmenopausal women, the composition including, as an active ingredient, scopolin, a derivative thereof, or a pharmaceutically acceptable salt thereof.
2. Description of the Related Art
Estrogen which is a representative hormone that symbolizes women is an important female hormone that regulates a lifespan of women through menstruation, pregnancy, and menopause. Estrogen is a well-known female hormone that is mainly secreted from follicles and corpus luteum that are in female ovaries and from the placenta, and is a generic term for estrone (E1), estradiol (E2), and estriol (E3). Estrogen affects a wide range of tissues, and is especially needed to maintain flexibility and steady state of the uterus, urinary tract, breast, skin, bones, and blood vessels. In particular, estrogen acts on osteoblast involved in production of bones to maintain bone formation, and also acts on osteoclast involved in removal of bones to inhibit bone resorption, thereby maintaining homeostasis of bones (see FIG. 1). Thus, postmenopausal osteoporosis which is caused by reduced estrogen levels is one of the most serious diseases in postmenopausal women (see FIG. 2).
Osteoporosis is a condition where bone mass per unit volume is abnormally reduced compared to a normal level according to sex, age, and race of a normal person. Due to brittle bones that break easily by minor impacts such as bending the waist or sitting down, osteoporosis is characterized by fractures in the coxa, carpal, vertebrae, or the like. According to pathogenesis of osteoporosis, osteoporosis is divided into primary and secondary forms. Primary osteoporosis includes postmenopausal osteoporosis (Type I osteoporosis) and senile osteoporosis (Type II osteoporosis), and secondary osteoporosis is caused by drugs or the like (see FIG. 3).
Regarding postmenopausal osteoporosis (Type I osteoporosis) in women, when a deficiency of estrogen hormones appears after menopause, postmenopausal osteoporosis occurs as components of bones are absorbed into body tissues and calcium absorption through intestines is reduced (see FIG. 4). In addition, the reduction in estrogen hormones inhibits differentiation and proliferation of osteoblasts, resulting in inhibition of bone formation, and activation of osteoclasts leads to occur bone the resorption more frequently than the bone formation, resulting in an increase of bone loss and a decrease of bone mass (see FIG. 5). The above phenomenon may progress rapidly after menopause depending on a person.
Senile osteoporosis (Type II osteoporosis) is caused by bone loss with increasing age in both men and women. In particular, senile osteoporosis is characterized by a decrease in intestinal calcium absorption due to a reduction in active vitamin D in the body and by a decrease in the number of osteoblasts that newly produce osteocytes. Here, senile osteoporosis progresses relatively slowly herein.
Secondary osteoporosis is caused by various diseases or medications that affect functions related to bone cell production and maintenance of the human body. For example, such various diseases may include hyperthyroidism, hyperparathyroidism, Cushing's syndrome, rheumatoid arthritis, hyperprolactinemia, and the like, and in addition, steroid hormone preparations or thyroid hormone preparations may also cause secondary osteoporosis.
When the climacteric begins, female hormones secreted from the ovaries are reduced due to a decrease or an imbalance in ovarian functions, and accordingly a variety of symptoms may appear. Even after menopause, postmenopausal osteoporosis may occur due to a rapid decrease in bone density and a decrease of bone mass. Since postmenopausal osteoporosis may cause backache or other bone-related diseases, and bone fractures, postmenopausal osteoporosis is considered as a disease that significantly affects the quality of life. In particular, women undergoing premature menopause or having an ovariectomy before age of 50 may be more susceptible to postmenopausal osteoporosis.
As therapeutic agents for postmenopausal osteoporosis in women, incrementally modified composite drugs, such as Bonviva Plus (composition: bisphosphonate-based drugs) and Aclasta (composition: zoledronic acid injection 5 mg), may be used. However, due to side effects of the agents above, the demand for therapeutic agents derived from natural products or health functional foods is increasing. Calcium which is good for bone health, vitamin D, and health functional foods including isoflavones are widely used, but effects thereof are limited. Therefore, there is a need for the development of more effective pharmaceutical preparations or health functional foods for prevention, improvement, and treatment of postmenopausal osteoporosis in women.