Objective: To observe the effects of Qishe Pill, a compound traditional Chinese herbal medicine, on lumbar vertebral bone formation induced by long-time upright posture in rats and to investigate the potential mechanism.
Methods: Thirty SD rats were randomly divided into normal control group, untreated group and Qishe Pill group. The rats in normal control group received no treatment and were raised in normal cages. The rats in untreated group and Qishe Pill group were cut off forelimbs by operation so as to be forced to adopt an upright posture for 8 months to induce hyperostosis. Rats in the Qishe Pill group were intragastrically administered with Qishe Pill at a dose of 5 g/(kg x d) for 1 month. All rats were sacrificed at the 9th month after surgery and all lumbar vertebrae were harvested for detection. Safranin O/fast green staining and picrosirius red staining were used to observe pathological changes. Expressions of type I collagen (ColI), type X collagen (ColX), vascular endothelial growth factor (VEGF) and transforming growth factor beta1 (TGF-beta1) in the 5th lumbar vertebra (L(5)) were detected by immunohistochemical method. Expressions of type I collagen alpha2 (Col1alpha2), type X collagen alpha1 (Col10alpha1), TGF-beta1, and VEGF and runt-related transcription factor 2 (Runx2) mRNAs in L(1)-L(3) were detected by real-time fluorescent quantitation reverse transcription-polymerase chain reaction.
Results: Safranin O/fast green staining showed that in the untreated group, non-matrix components increased at marginal lumbar vertebra and intervertebral disc junction, and hyperostosis appeared. However, no obvious change was observed in the normal control group. Non-matrix components decreased at the same location in Qishe Pill group as compared with the untreated group. Picrosirius red staining showed compact collagens at marginal lumbar vertebra and intervertebral disc junction in the normal control group, however, Col I and ColX increased at the same location in the untreated group. In the Qishe Pill group, it showed more compact collagens, especially ColI. Compared with normal control group, expressions of ColX, VEGF and TGF-beta1 were increased at marginal lumbar vertebra and intervertebral disc junction in the untreated group. ColX and VEGF expressions decreased in the Qishe Pill group as compared with the untreated group. Col10alpha1 and Runx2 mRNA expressions were down-regulated by Qishe Pill (P<0.01).
Conclusion: Qishe Pill may delay hyperostosis at marginal lumbar vertebra and intervertebral disc junction, which may be related to reducing type X collagen and Runx2 expressions.