ObjectiveGiven the crucial role of the PI3K/Akt signaling pathway in chondrocyte survival and inflammation in osteoarthritis (OA), this study aimed to investigate the effects of Gu Bi Tang on chondrocyte proliferation, apoptosis, and inflammatory factor expression in a rat model of OA, with a focus on the PI3K/Akt signaling pathway.MethodsForty-five specific pathogen-free (SPF) C57 mice were randomly divided into three groups: the model group (Group A), the Gu Bi Tang group (Group B), and the Amfenac group (Group C), with 15 rats in each group. All 45 rats underwent anterior cruciate ligament transection (ACLT) surgery to establish an OA model. The ACLT procedure is a well-established method for inducing OA in rodents, as it leads to the destabilization of the knee joint and the development of degenerative changes characteristic of human OA. After 8 weeks of modeling, Group A rats received an equivalent volume of normal saline by gastric lavage, Group B rats were administered 13 mL/kg of Gu Bi Tang, and Group C rats received 19.5 mg/kg of Amfenac solution by gastric lavage. The dosages of Gu Bi Tang and Amfenac were selected based on previous studies examining the therapeutic effects of these interventions in rodent OA models. The gastric lavage frequency for all three groups was maintained at twice daily. The researchers analyzed cartilage morphological changes using toluidine blue staining, chondrocyte proliferation and apoptosis using the TUNEL method, and the expression of PI3K/AKT/mTOR proteins in chondrocytes using Western blotting. Additionally, the expression of inflammatory factors (TNF-α and IL-1β) in serum was measured using ELISA.ResultsStaining: Compared to the model group (Group A), both the Gu Bi Tang group (Group B) and the Amfenac group (Group C) showed significant improvement in cartilage tissue, with deeper toluidine blue staining. Toluidine blue staining is a marker of cartilage integrity and glycosaminoglycan content, indicating improved cartilage structure and composition in the treatment groups. Chondrocyte proliferation and apoptosis: Compared to the model group (Group A), both the Gu Bi Tang group (Group B) and the Amfenac group (Group C) significantly reduced chondrocyte apoptosis (P < .05). This reduction in chondrocyte death contributes to a healthier cartilage environment and helps prevent further cartilage degradation. Protein expression: In comparison to the model group (Group A), the expression of PI3K, AKT, and mTOR proteins in the joint cartilage of the Gu Bi Tang group (Group B) and the Amfenac group (Group C) significantly decreased, with the Amfenac group showing a greater reduction than the Gu Bi Tang group (P < .05). The inhibition of this detrimental PI3K/AKT/mTOR signaling pathway promotes chondrocyte survival and a more favorable cartilage homeostasis. Inflammatory factor expression: Prior to treatment, there was no significant difference in the expression levels of the inflammatory factors TNF-α and IL-1β in serum among the three groups (P > .05). However, after treatment, both the Gu Bi Tang group (Group B) and the Amfenac group (Group C) showed a significant reduction in the serum expression of TNF-α and IL-1β compared to the model group (Group A), with the Amfenac group showing a greater reduction than the Gu Bi Tang group (P < .05). This is important, as TNF-α and IL-1β are key pro-inflammatory cytokines that drive the destructive processes in osteoarthritis.ConclusionIn summary, this study demonstrates that Gu Bi Tang exerts protective effects on chondrocytes in a rat model of osteoarthritis. Specifically, Gu Bi Tang was shown to inhibit chondrocyte apoptosis, reduce the expression of key proteins in the PI3K/AKT/mTOR signaling pathway, and decrease the levels of the pro-inflammatory cytokines TNF-α and IL-1β. These findings suggest that Gu Bi Tang could offer a novel therapeutic approach for osteoarthritis by modulating key signaling pathways and inflammatory responses. The ability of Gu Bi Tang to preserve chondrocyte viability and maintain a more favorable cartilage homeostasis makes it a promising candidate for further investigation as a potential treatment for osteoarthritis. Future studies should explore the precise mechanisms by which Gu Bi Tang exerts its beneficial effects and evaluate its efficacy in additional animal models and clinical settings.
