Catalpol ameliorates CFA-induced inflammatory pain by targeting spinal cord and peripheral inflammation

Abstract

Chronic, inflammatory pain is an international health concern that severely diminishes individuals’ quality of life. Catalpol is an iridoid glycoside derived from the roots of Rehmannia glutinosa that possesses anti-inflammatory, antioxidant, and neuroprotective properties for the treating multiple kinds of disorders. Nevertheless, catalpol’s impacts on inflammatory pain and its potential methods of action are still unclear. The purpose of this investigation is to determine the mechanism of catalpol to reduce the inflammatory pain behaviors in a rat model with complete Freund’s adjuvant (CFA). Catwalk, Von-Frey, and open field testing were performed for behavioral assessment. Western blot analysis and real-time quantitative PCR (RT-PCR) were employed to identify variations in molecular expression, while immunofluorescence was utilized to identify cellular localization. Catalpol effectively reduced CFA-induced mechanical allodynia and thermal hyperalgesia when injected intrathecally. Moreover, catalpol can regulate the HDAC4/PPAR-γ-signaling pathway in CFA rat spinal cord neurons. Meanwhile catalpol significantly decreased the expression of the NF-κB/NLRP3 inflammatory axis in the spinal cord of CFA rats. In addition, both in vivo and in vitro research revealed that catalpol treatment inhibited astrocyte activation and increase inflammatory factor expression. Interestingly, we also found that catalpol could alleviate peripheral pain by inhibiting tissue inflammation. Taken together, the findings declared that catalpol may inhibit inflammatory pain in CFA rats by targeting spinal cord and peripheral inflammation.

Clinical study of Tongdu Shujin decoction in the treatment of ankylosing spondylitis with cold-dampness obstruction type: Study protocol for a randomized controlled trial

“…[21] The anti-inflammatory effect of rehmannia glutinosa is also particularly obvious, and its active ingredient catalpol can significantly decreased the expression of NF- κ B/NLRP3 inflammatory axis and inflammatory factors, inhibit tissue inflammation and relieve pain. [22] Meanwhile, its active ingredient aucubin also has anti-inflammatory and antioxidant pharmacological effects. [23] Pyrola extract inhibits phosphorylation of p38 MAPK and NF- κ B, inhibits the expression of inducible nitric oxide synthase inducible nitric oxide synthase, iNOS and exerts anti-inflammatory effects.…”

Anti‐inflammatory effect and mechanism of catalpol in various inflammatory diseases

“…Catalpol can be effective for the relief of chronic inflammatory pain. Zhao et al found cytotoxicity at catalpol concentrations of 1000 μM, while subcutaneous administration of catalpol (2.5 and 10 mg/kg) reduced peripheral pain by inhibiting tissue inflammation in a dose-dependent manner (Zhao et al, 2022).…”

“…Catalpol is an iridoid glucoside extracted from the rhizome of rehmanniae , with molecular formula, C 15 H 22 O 10 (Figure 1) (Bhattamisra et al, 2020). Studies have shown that catalpol has various biological activities, such as anti‐inflammatory, antitumor, neuroprotective, and anti‐glycemic (Liu, Du, et al, 2022; Yap et al, 2020; Zhao et al, 2022). The anti‐inflammatory activity of catalpol has been widely studied.…”