Abstract
Osteoporosis represents an imbalance between bone formation and bone resorption. As a result of low estrogen levels, it is markedly prevalent during menopause, thus making such patients susceptible to fractures. Both bone formation and resorption are modulated by nitric oxide (NO). Currently, there are no risk-free pharmaceutical prevention therapies for osteoporosis. COMB-4, a nutraceutical combination of Paullinia cupana, Muira puama, ginger, and L-citrulline, known to activate the NO-cGMP pathway, was reported to accelerate fracture healing in the rat. To determine whether COMB-4 could be effective in preventing menopausal osteoporosis, it was compared to estradiol (E2) in an ovariectomized (OVX) rat osteoporosis model. Nine-month-old female Sprague Dawley rats were divided into SHAM, OVX, OVX+E2, and OVX+COMB-4. After 100 days of treatment, bone mineral density (BMD) and bone mineral content (BMC) were measured by DXA scan. TRAP staining was performed in the femur and lumbar vertebrae. TRACP 5b and osteocalcin levels were assayed in the serum. MC3T3-E1 cells were differentiated into osteoblasts and treated with COMB-4 for one week in order to evaluate calcium deposition by Alizarin staining, cGMP production by ELISA, and upregulation of the nitric oxide synthase (NOS) enzymes by RT-PCR. OVX resulted in a decrease in BMD, BMC, and serum osteocalcin and an increase in serum TRACP 5b. Except for an increase in BMC with COMB-4, both E2 and COMB-4 reverted all bone and serum markers, as well as the number of osteoclasts in the vertebrae, to SHAM levels. Incubation of MC3T3-E1 cells with COMB-4 demonstrated an increase in the three NOS isoforms, cGMP, and calcium deposition. COMB-4 increased BMD in OVX rats by inhibiting bone resorption and increasing calcium deposition presumably via activation of the NO-cGMP pathway. It remains to be determined whether COMB-4 could be a potential nutraceutical therapy for the prevention of premenopausal bone loss.
Highlights
Osteoporosis, defined as a reduction in bone mass and a disruption of bone architecture, results in a decrease in bone integrity and an increase in fractures
When bone mineral density (BMD) was normalized to the fat mass due to interference of fat in the BMD measurements [27, 28], a more pronounced increase in BMD was observed in the COMB-4 and E2 treated groups, in contrast with the decrease in BMD observed in the OVX group (Figure 2(b))
This study in the adult ovariectomized and presumably estrogen deficient rat demonstrates that the daily treatment with the nutraceutical combination, COMB-4, replicates the same effects that exogenous estrogen has on this animal model
Summary
Osteoporosis, defined as a reduction in bone mass and a disruption of bone architecture, results in a decrease in bone integrity and an increase in fractures. One in every two women and one in every four men over age 50 will have an osteoporosis related fracture in their lifetime [2]. The major sites for such fractures are the vertebrae, hip, and wrist [3]. For those with hip fractures, there is an overall mortality of up to 33% [4,5,6,7,8], many are unable to walk independently at one year [9], more than half require assistance with daily living [9, 10], nearly 20% will require care in a long-term facility [4], and up to 42% fracture again within five years [11].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
