Curcumin reduces inflammation in knee osteoarthritis rats through blocking TLR4 /MyD88/NF‐κB signal pathway

Abstract

Preclinical Research & Development Curcumin has been shown to possess a series of beneficial effects, such as antiinflammatory, antioxidant, analgesic, and promoting healing. However, the effect and relative mechanism of curcumin on knee osteoarthritis (OA) have not been elucidated. The aim of this study is to explore the protective effect of curcumin on monosodium iodoacetate (MIA)‐induced OA. Forty‐eight rats were randomized into four experimental groups: control group, OA group, OA + PBS group, and OA + curcumin group, respectively. A single intraarticular injection of MIA was applied to establish the rat model of knee OA. Hematoxylin–eosin staining was used to evaluate histological changes of knee joint. The paw withdrawal threshold was collected and the expression of synovial fluid cytokine levels was measured by ELISA. The protein expression of TRL‐4, MyD88, p‐IκBα, NF‐κB, TNF‐α, IL‐1β, and IL6 was measured by western blot. Treating with curcumin can significantly reduce joint diameter and Mankin's score, and increase the paw withdrawal threshold. The expression of synovial fluid inflammatory biomarkers, IL‐6, IL‐1β, and TNF‐α in the OA + curcumin group were lower than that in OA and OA + PBS group. The protein expression of the TLR4 receptor was increased in the OA, OA + PBS, and OA + curcumin group compared to the control group. However, curcumin treatment can significantly decrease the expression of MyD88, p‐IκBα, NF‐κB, TNF‐α, IL‐1β, and IL6 in OA + curcumin group. These findings may indicate that curcumin could block TLR4/NF‐κB signal pathway, and reduce inflammation level to prevent knee wound in OA rats. Curcumin may be a feasible kind of medicament in the treatment of knee OA.

LncRNA FOXD2-AS1 induces chondrocyte proliferation through sponging miR-27a-3p in osteoarthritis

“…Ding et al found that miR-93 inhibited chondrocyte apoptosis and inflammation in OA by targeting the TLR4/NF-jB signaling pathway [25]. Zhang et al suggested that curcumin reduced inflammation in knee OA rats through blocking [26]. In the present study, we found that TLR4 acted as a target of miR-27a-3p.…”

Anti-allodynic effect induced by curcumin in neuropathic rat is mediated through the NO-cyclic-GMP-ATP sensitive K+ channels pathway

“…Its wide spectrum of biological activities including antiviral [5], antioxidant [6], neuroprotective [7], antidepressant [8], and anti-inflammatory effects [9]. In addition, curcumin has shown an anti-nociceptive effect in different types of pain, such as inflammatory pain [4,7,10], visceral pain [11], musculoskeletal pain [12], burning pain [13], and neuropathic pain [14][15][16][17]. Curcumin may alleviate neuropathic pain through inhibiting the expression of CX3CR1 by the activation of NF-κβ p65 in the dorsal horn of the spinal cord and dorsal root ganglion (DRG) [16].…”

Gastrodin improves preeclampsia‐induced cell apoptosis by regulation of TLR4/NF‐κB in rats

“…When inflammatory factors increase, the secretion of vasoactive diastolic factors such as NO and prostacyclin decreases and the vasoconstrictor factor thromboxane A2 increases, leading to the occurrence of preeclampsia (Perucci, Corrêa, and Dusse ()). Related studies have shown that activation of the MyD88/NF‐κB signaling pathway contributes to inflammatory response (Wang, Dong, & Wang, ; Zhang & Zeng, ) and cell apoptosis (Li et al, ; Zheng, Shen, & Ye, ). The results of the present study showed that preeclampsia‐induced apoptosis of placental cells was effectively inhibited after Gas treatment, and the underlying mechanism may involve downregulated activity of MyD88/NF‐κB signaling pathway.…”