Carbohydrate-Rich Fraction of Aloe vera (L.) Burm.f. Extract Mitigates Bone Loss and Improves Metabolic Disturbance in Estrogen-Deficient Rats

Abstract

Aloe vera (L.) Burm.f., (AE) herb has been shown to have osteogenic, anti-diabetic, and prebiotic activities in animal and human studies. Postmenopausal women generally exhibit massive bone loss, impaired intestinal calcium absorption, obesity-related insulin resistance, and fat accumulation in the liver. It was possible that the AE herb may have a potential as a remedy for bone and metabolic disturbances associated with estrogen deficiency. Sham and ovariectomized rats were divided into 2 subgroups, that is, receiving daily administration of distilled water or 50 or 100 mg/kg of AE via either oral administration (p.o.) or intraperitoneal injection (i.p.) for 8 and 12 weeks. Nine weeks after ovariectomy, rats developed metabolic disturbances, as evidenced by obesity, impaired glucose tolerance, and high serum cholesterol levels. AE supplementation, either by p.o. or i.p., alleviated metabolic aberrations by improving glucose tolerance, reducing body weight, and decreasing fat deposition by increasing serum insulin levels. Furthermore, AE supplementation restored ovariectomy-associated calcium malabsorption to that of sham. At week 12 post-ovariectomy, massive bone loss was observed at trabecular-rich regions. Daily AE supplementation at 50 mg/kg for 12 weeks, but not 8 weeks, significantly increased BMD and BMC compared with those of sham. Additionally, AE enhanced bone formation and suppressed bone resorption, as shown by bone histomorphometry and serum bone turnover markers. These findings clearly demonstrated the anti-diabetic and osteogenic properties of Aloe vera extract in ovariectomized rats. Thus, Aloe vera had a potential as a nutraceutical candidate for the treatment of osteoporosis and metabolic disturbances associated with estrogen deficiency.