Abstract: Objective To explore the therapeutic effects of aloe polysaccharides (APS) on osteoarthritis (OA) in rats through in vitro and in vivo experiments. Methods The articular chondrocytes of SD suckling mice were isolated in vitro and cultured to 2 generations. The concentration of APS in the experimental group was screened by CCK-8. The chondrocyte proliferation and matrix degradation were assessed by detecting DNA content and proteoglycan (GAG) secretion. The realtime fluorescent quantitative PCR was used to detect osteoarthritis-related gene expression, and enzyme-linked immunosorbent assay (ELISA) method was used to detect inflammatory factor levels. Hematoxylin -Eosin (HE) staining, Safranin O and immunofluorescence staining were used to observe the anti-inflammatory and cartilage protection effects of APS. Its effects on osteoarthritis were further explored in SD rat model. Results The APS concentrations of 5 g/L, 10 g/L and 20 g/L were selected by CCK-8 as the low, medium and high dose experimental groups. It was found that DNA contents were significantly higher in each experimental group than those of the model group (P＜0.05). The detection showed that of GAG secretion was significantly higher in the high-dose experimental group than that of the model group (P＜0.05). PCR results showed that the expression levels of aggrecan (ACAN) and type Ⅱ collagen (COL2A1) were significantly up-regulated in the high-dose experimental group compared with those of the model group (P＜0.05), while tumor necrosis factor (TNF)- α, interleukin (IL)-6, the expression of matrix metalloproteinase (MMP)-3 and MMP-13 were significantly down-regulated (P＜0.05). The secretion levels of TNF-α and IL-6 were significantly lower in the high-dose experimental group than those of the model group (P＜0.05). HE and Safranin O staining also showed that the cell morphology was better in the APS experimental group than that of the model group. The immunofluorescence assay showed that the expression level of MMP- 13 was significantly lower in the high-dose experimental group than that of the model group (P＜0.05). In vivo articular cartilage tissue Safranin O staining and the International Osteoarthritis Research Society (OARSI) cartilage damage score also showed that the cartilage damage was significantly lower in the experimental group than that in the model group (P＜ 0.05). Conclusion APS has certain anti-inflammatory and cartilage protective effects on OA.

Key words: polysaccharides, aloe, osteoarthritis, cartilage, articular, cells, cultured, glycosaminoglycans, aloe polysaccharide