Asian Journal of Biochemistry, Genetics and Molecular Biology

Osteoporosis is a significant public health concern, with over 200 million persons affected globally. In Africa, the burden of osteoporosis is rising due to increasing life expectancy and lifestyle changes. Osteoporosis in Nigeria remains underdiagnosed, yet hospital-based studies have constantly reported increasing prevalence rates among postmenopausal women due to hormonal changes, aging, and long-term corticosteroid use.

Aim: This study evaluated the biochemical markers of bone metabolism and liver function in dexamethasone-induced osteoporosis in female albino rats treated with compound marrow powder and alendronate.

Methodology: A total of thirty-five (35) female albino rats weighing between 180 to 200g were used for the study. The rats were weighed and grouped into 5 groups of 7 rats each, and osteoporosis was induced by intramuscular administration of dexamethasone (5 mg/kg). Treatments (drugs) were administered according to the groupings by means of oral gavage for 28 days (4 weeks). Osteocalcin and cathepsin K were quantitatively determined by a rat-specific sandwich-enzyme linked immunosorbent assay (ELISA) method. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were determined using the Reitman-Frankel method. Alkaline phosphatase (ALP) was determined using the colorimetric endpoint method. Quantitative determination of the phytochemicals in the polyherbal drug was done using spectrophotometric methods.

Results: Phytochemical analysis revealed the presence of flavonoids, phenols, saponins, tannins, alkaloids, polyphenols and anthraquinones in the herbal drug. The positive control had significantly higher (P<0.05) levels of osteocalcin and cathepsin K, compared to the negative control. Osteocalcin levels were significantly higher (P<0.05) in the group 3 administered compound marrow powder, compared to the negative control, but not significantly different (P>0.05) from the positive control group. Cathepsin K levels were significantly higher (P<0.05) in group 3, compared to the negative and positive controls. In group 4, administered alendronate, osteocalcin and cathepsin K levels were not significantly different (P>0.05) from the negative control. In group 5, administered the combination, osteocalcin was not significantly different (P>0.05) from the negative control, whereas cathepsin K levels were significantly higher (P<0.05) than the negative control, and not significantly different (P>0.05) from the positive control. Alanine aminotransferase (ALT), aspartate aminotransferase levels (AST) and alkaline phosphatase (ALP) levels were significantly elevated (P<0.05) in the positive control group, compared to the negative control. The treatment groups also had significantly elevated (P<0.05) liver enzyme levels. Alendronate administration however, reduced AST levels to negative control levels.

Conclusion: Dexamethasone-induced osteoporosis is characterised by elevated osteocalcin and cathepsin K levels, indicating increased bone turnover and resorption. Treatment with alendronate significantly improved the bone parameters, indicating its effectiveness in mitigating glucocorticoid-induced bone loss. Treatment with compound marrow powder and its combination with alendronate was not effective, as it did not improve the bone parameters. Neither of the treatments were hepatoprotective, as specific liver enzyme levels remained elevated after treatments. These findings support the continued use of alendronate as a standard therapeutic agent for osteoporosis and highlight the need for further research on the safety and mechanisms of herbal formulations, and their combination with orthodox drugs.