Protective Effects of Peucedanum japonicum Extract against Osteoarthritis in an Animal Model Using a Combined Systems Approach for Compound-Target Prediction

Abstract

Peucedanum japonicum Thunberg is an herbal medicine used to treat neuralgia, rheumatoid arthritis, and inflammatory-related diseases. However, its effects on osteoarthritis (OA) and its regulatory mechanisms have not been investigated by network analysis. Here, we investigated the pharmacological effects of Peucedanum japonicum extract (PJE) on OA, by combining in vivo effective verification and network pharmacology prediction. Rats in which OA was induced by monosodium iodoacetate (MIA) were treated with PJE (200 mg/kg), and histopathological parameters, weight bearing distribution and inflammatory factors in serum and joint tissue were measured after 28 days of treatment. Additionally, in silico network analysis was used to predict holistic OA regulatory mechanisms of PJE. The results showed that PJE exerted potential protective effects by recovering hind paw weight bearing distribution, alleviating histopathological features of cartilage and inhibiting inflammatory mediator levels in the OA rat model. Furthermore, network analysis identified caspase-3 (CASP3), caspase-7 (CASP7), and cytochrome P450 2D6 (CYP2D6) as potential target genes; in addition, the TNF (Tumor necrosis factor) signaling pathway was linked to OA therapeutic action. Our combined animal OA model and network analysis confirmed the therapeutic effects of PJE against OA and identified intracellular signaling pathways, active compounds and target genes linked to its therapeutic action.

Keywords: Peucedanum japonicum; compound-target gene network; inflammatory mediator; monosodium iodoacetate; network pharmacology; osteoarthritis.

Figure 1

The experimental scheme and the effects of Peucedanum japonicum extract (PJE) on the hind paw weight bearing distribution in monosodium iodoacetate (MIA)-induced osteoarthritis (OA) model rats. (A) Experimental protocol used to induce osteoarthritis, followed by administration of PJE. I.A., intra-articular injection. (B) Body weights and (C) weight bearing distribution were measured (once per week for 21 days after injection of MIA) using an incapacitance tester. ### p < 0.001 vs. saline controls; * p < 0.05 vs. the MIA group.

Figure 2

Histopathological features of knee joint tissue of MIA-induced OA model rats. Representative photographs of knee joint tissues stained with (A) hematoxylin and eosin, and (B) safranin O-fast green (×100 magnification). Scale bars = 500 μm.

Figure 3

Effects of PJE on serum levels of cytokines and inflammatory mediators in MIA-induced OA model rats. Levels of (A) TNF-α: Tumor necrosis factor alpha, (B) IL-6: Interleukin 6, (C) LTB4: Leukotriene B4, and (D) 5-LOX: 5-lipoxygenase in serum measured by ELISA. # p < 0.05, ## p < 0.01, and ### p < 0.001 vs. saline controls; * p < 0.05 and *** p < 0.001 vs. the MIA group.

Figure 4

Effects of PJE on the expression of cytokines and inflammatory mediators in the knee joint of MIA-induced OA model rats. Expression of IL-1β, IL-6, TNF-α, COX-2 and iNOS mRNA levels determined by real-time PCR. # p < 0.05, ## p < 0.01 and ### p < 0.001 vs. saline controls; * p < 0.05 and ** p < 0.01 vs. the MIA group. COX-2, iNOS. IL-1β: Interleukin 1 beta; IL-6: Interleukin 6; TNF-α: Tumor necrosis factor alpha; COX-2: Cyclooxygenase-2; iNOS: Inducible nitric oxide synthases.

Figure 5

Compound-target gene network linking the protective effects of PJE against OA to potential target genes and signaling pathways. Compounds derived from PJE are indicated by pink rectangles, target genes are represented by green ovals, and gray lines represent compound-target gene interactions. PJE: Peucedanum japonicum extract; OA: Osteoarthritis.