Ginsenoside Rg1 promotes lymphatic drainage and improves chronic inflammatory arthritis

OBJECTIVE: The lymphatic system plays an important role in joint diseases. This study aimed to evaluate the effects of ginsenoside Rg1 on lymphatic drainage and accumulation of inflammatory products in the joints. METHODS: Two-month-old transgenic mice that overexpress tumor necrosis factor alpha (TNF-α; TNF-Tg) were used as the animal models. Ginsenoside Rg1 was administered for 12 weeks and the lymphatic drainage in the mice was evaluated using near infrared-indocyanine green (NIR-ICG) lymphatic imaging system. The clinical symptoms of arthritis were evaluated weekly. The ankle and knee joints were harvested for hematoxylin-eosin (HE), alcian blue/orange G (ABOG), and tartrate-resistant acid phosphatase (TRAP) staining, and the foot dorsal skin was used for whole-mount immuno-staining. Simultaneously, the serum levels of IL-6 and TNF-α were detected using enzyme-linked immunosorbent assay (ELISA). RESULTS: Ginsenoside Rg1 significantly improved the lymphatic drainage function, reduced synovial inflammation and bone erosion, decreased serum IL-6 and TNF-α concentration, and increased smooth muscle coverage on the collecting lymphatic vessels in the foot skin of the TNF-Tg mice. Furthermore, ginsenoside Rg1 treatment for 12 weeks did not cause any damage to the liver and kidney tissues. CONCLUSION: Ginsenoside Rg1 improves lymphatic drainage and joint inflammation in TNF-Tg mice. Therefore, ginsenoside Rg1 has the potential to be a candidate drug for the treatment of inflammatory arthritis.