Abstract: Previous studies have shown that Lactobacillus plantarum AR495 has good anti-inflammatory and anti-osteoporosis effects. In order to further explore the effect and mechanism of AR495 in alleviating osteoporosis (OA), a rat model of OA was established to investigate the effects of AR495 on OA markers, inflammatory factor levels and oxidative stress injury in OA rats and to verify the recovery of cartilage matrix and bone by pathological staining of joints and microtomography (micro-CT) imaging. The results showed that AR495 could significantly alleviate excessive body mass gain caused by decreased physical activity in OA rats (P < 0.05). Pathological analysis showed that AR495 could significantly reduce the level of tumor necrosis factor-α (TNF-α) in the joint tissue of OA rats, inhibit the production of matrix metalloproteinase-13 (MMP-13) and the production of C-telopeptide of type II collagen (CTX-II) as a degradation product of cartilage matrix, thereby alleviating the degradation of articular cartilage matrix in rats. Micro-CT imaging showed that AR495 could significantly alleviate bone loss in the joint of OA rats and effectively protect the integrity of cartilage and synovium of rats. In addition, AR495 could significantly increase the activity of superoxide dismutase (SOD) and reduce the concentration of malondialdehyde (MDA) in peripheral blood (P < 0.05). Quantitative real-time polymerase chain reaction (qPCR) analysis showed that AR495 could stimulate the expression of the mucin-2 (MUC-2) and occludin-1 genes in intestinal goblet cells and repair the intestinal barrier function. It can be seen that AR495 can alleviate OA inflammation level and create a beneficial internal environment for chondrocytes to exert their functions and produce collagen matrix, thereby alleviating and restoring joint injury and improving OA symptoms.

Key words: osteoarthritis; Lactobacillus plantarum AR495; inflammatory factors; cartilage matrix; bone density