Evaluation of Long-Time Decoction-Detoxicated (Processed Debeaux Lateral Root With Peel) for Its Acute Toxicity and Therapeutic Effect on Mono-Iodoacetate Induced Osteoarthritis.

Background: As a degenerative joint disease with severe cartilage destruction and pain, osteoarthritis (OA) has no satisfactory therapy to date. In traditional Chinese medicine (TCM), Debeaux derived () has been developed for joint pain treatment. However, it causes adverse events in OA patients. Long-time decoction has been traditionally applied to reduce the aconite toxicity of and other aconite herbs, but its detoxifying effect is uncertain.

Methods: was extracted with dilute decoction times (30, 60, and 120 min) and evaluated by toxicological, chemical, pharmacological assays. Acute toxicity assay and chemical analysis were employed to determine the toxicity and chemoprofile of extracts, respectively. Since the detoxified (d) was defined, its therapeutic effect was evaluated by using an OA rat model induced by monosodium iodoacetate. d at 14 g/kg was orally administered for 28 days, and the pain assessments (mechanical withdrawal threshold and thermal withdrawal latency) and histopathological analyses (HE and safranin-O staining) were performed. Real-time PCR (qPCR) was applied to determine the molecular actions of d on cartilage tissue and on chondrocytes. MTT assay was conducted to evaluate the effect of d on the cell viability of chondrocytes. The cellular and molecular assays were also conducted to analyze the functions of chemical components in d.

Results: The chemoprofile result showed that the contents of toxic alkaloids (aconitine, mesaconitine, and hypaconitine) were decreased but that of non-toxic alkaloids (benzoylaconitine, benzoylmesaconitine, and benzoylhypaconitine) were increased with increasing decoction time. Acute toxicity assay showed that only extract with 120 min decoction was non-toxic within the therapeutic dose range. Thus, it was defined as d for further experiment. In OA experiment, d significantly attenuated joint pain and prevented articular degeneration from MIA attack. qPCR data showed that d restored the abnormal expressions of , , , , and up-regulated expression in rat cartilage. , dcontaining serum significantly proliferated rat chondrocytes and regulated the gene expressions of , , , and in a similar way as the data. Moreover, aconitine, mesaconitine, and hypaconitine exerted cytotoxic effects on chondrocytes, while benzoylaconitine and benzoylhypaconitine except benzoylmesaconitine exhibited similar molecular actions to d, indicating contributions of benzoylaconitine and benzoylhypaconitine to d.

Conclusions: This study defined d and demonstrated d as a potential analgesic and disease modifying agent against OA with molecular actions on the suppression of chondrocyte hypertrophy and extracellular matrix degradation, providing a promising TCM candidate for OA therapy.