Investigating the Anti-Inflammatory, Analgesic, and Chondroprotective Effects of Gynostemma pentaphyllum (Thunb.) Makino in Osteoarthritis: An In Vitro and In Vivo Study

Abstract

Osteoarthritis (OA) is an age-related disease characterized by inflammation, pain, articular cartilage damage, synovitis, and irreversible disability. Gynostemma pentaphyllum (Thunb.) Makino (GP), a herbal medicine traditionally used in East Asia for its anti-inflammatory properties, was investigated for its potential to modulate OA pathology and symptoms. This study evaluated GP's efficacy in inhibiting pain, functional decline, and cartilage destruction in monosodium iodoacetate-induced OA and acetic acid-induced writhing models. Additionally, the effects of GP on OA-related inflammatory targets were assessed via mRNA and protein expression in rat knee cartilage and lipopolysaccharide-induced RAW 264.7 cells. The GP group demonstrated significant pain relief, functional improvement, and cartilage protection. Notably, GP inhibited key inflammatory mediators, including interleukin (IL)-1β, IL-6, matrix metalloproteinases (MMP)-3 and MMP-13, cyclooxygenase-2, and prostaglandin E receptor 2, surpassing the effects of active controls. These findings suggest that GP is a promising candidate for disease-modifying OA drugs and warrants further comprehensive studies.

Keywords: Gynostemma pentaphyllum (Thunb.) Makino; analgesic; anti-inflammatory; chondroprotective; herbal medicine; osteoarthritis.

Figure 1

HPLC chromatogram of the GP extract at 203 nm: rutin and gypenoside III retention time = 5.00 min and 13.235 min. The x-axis shown the retention time; the y-axis shown the absorbance unit; the z-axis indicates the absorbance unit. HPLC: high-performance liquid chromatography, GP: Gynostemma pentaphyllum (Thunb.).

Figure 2

Number of writhing responses in AAW ICR mice. After 30 min of sample treatment, groups were treated with 0.7% acetic acid (i.p.) before 10 min measuring. *** p < 0.001 vs. CON using one-way ANOVA, Dunnett’s test. AAW: acetic acid-induced writhing, CON: control, GP: Gynostemma pentaphyllum, IBU 200: ibuprofen 200 mg/kg.

Figure 3

The effects of GP on weight-bearing of hind limb in MIA-induced OA model. (A) Weight-bearing distribution of MIA rats on 0–24 days with GP 300 or INDO 3 treatment and (B) AUC were analyzed by incapacitance meter tester. ^### p < 0.001 vs. sham, *** p < 0.001 vs. CON. AUC: area under the curve, GP: Gynostemma pentaphyllum, INDO 3: indomethacin 3 mg/kg, MIA: monosodium iodoacetate.

Figure 4

Photographs of the knee joint cartilages of OA rats. OA rats were administrated INDO 3 and GP 300. (A) Representative photo in knee joint cartilage of OA rat. The arrows signed the cartilage erosion point. (B) The scoring of macroscopic. ^### p < 0.001 vs. sham, *** p < 0.001 vs. CON by a one-way analysis, Dunnett’s test. GP: Gynostemma pentaphyllum, INDO 3: indomethacin 3 mg/kg, MIA: monosodium iodoacetate.

Figure 5

Expression levels of (A) IL-1β and (B) IL-6 levels in serum from OA rats. Rats were treated with INDO 3 and GP 300 for 24 d. ^### p < 0.001 vs. sham, *** p < 0.001 vs. CON by one-way ANOVA, Dunnett’s test. GP: Gynostemma pentaphyllum, INDO 3: indomethacin 3 mg/kg, MIA: monosodium iodoacetate.

Figure 6

Evaluation of cytokine level in cartilage tissue in experimental groups. (A–H) mRNA expression of IL-1β, IL-6, NOS2, Ptger2, MMP-1, MMP-3, MMP-8, and MMP-13 measured using qRT-PCR. (I–P) Protein expression of IL-1β, IL-6, NOS2, Ptger2, MMP-3, MMP-8, and MMP-13 measured with western blot analysis. * p < 0.05 vs. CON, ** p < 0.01 vs. CON, *** p < 0.001 vs. CON, ^### p < 0.001 vs. sham by one-way ANOVA, Dunnett’s test. GP: Gynostemma pentaphyllum, INDO 3: indomethacin 3 mg/kg, MIA: monosodium iodoacetate.

Figure 6

Evaluation of cytokine level in cartilage tissue in experimental groups. (A–H) mRNA expression of IL-1β, IL-6, NOS2, Ptger2, MMP-1, MMP-3, MMP-8, and MMP-13 measured using qRT-PCR. (I–P) Protein expression of IL-1β, IL-6, NOS2, Ptger2, MMP-3, MMP-8, and MMP-13 measured with western blot analysis. * p < 0.05 vs. CON, ** p < 0.01 vs. CON, *** p < 0.001 vs. CON, ^### p < 0.001 vs. sham by one-way ANOVA, Dunnett’s test. GP: Gynostemma pentaphyllum, INDO 3: indomethacin 3 mg/kg, MIA: monosodium iodoacetate.

Figure 6

Evaluation of cytokine level in cartilage tissue in experimental groups. (A–H) mRNA expression of IL-1β, IL-6, NOS2, Ptger2, MMP-1, MMP-3, MMP-8, and MMP-13 measured using qRT-PCR. (I–P) Protein expression of IL-1β, IL-6, NOS2, Ptger2, MMP-3, MMP-8, and MMP-13 measured with western blot analysis. * p < 0.05 vs. CON, ** p < 0.01 vs. CON, *** p < 0.001 vs. CON, ^### p < 0.001 vs. sham by one-way ANOVA, Dunnett’s test. GP: Gynostemma pentaphyllum, INDO 3: indomethacin 3 mg/kg, MIA: monosodium iodoacetate.

Figure 7

Effects of GP on (A) cell viability and (B) NO generation in LPS-treated RAW264.7 cells, the mRNA expression level of (C–J) IL-1β, IL-6, NOS2, Ptger2, COX-2, TNF-α, MMP-3, and MMP-13 and the protein expression level of (K–P) IL-1β, IL-6, NOS2, MMP-3, and MMP-13 in RAW264.7 cells. Cell were treated with GP (30, 100, and 300 µg/mL) and 500 ng/mL LPS during 24 h. ^### p < 0.001 vs. sham, ** p < 0.01 vs. CON, *** p < 0.001 vs. CON by one-way ANOVA, Dunnett’s test. CON: control, DEX 1: dexamethasone 1 µg/mL, GP: Gynostemma pentaphyllum, LPS: lipopolysaccharide, NT: non-treated.

Figure 7

Effects of GP on (A) cell viability and (B) NO generation in LPS-treated RAW264.7 cells, the mRNA expression level of (C–J) IL-1β, IL-6, NOS2, Ptger2, COX-2, TNF-α, MMP-3, and MMP-13 and the protein expression level of (K–P) IL-1β, IL-6, NOS2, MMP-3, and MMP-13 in RAW264.7 cells. Cell were treated with GP (30, 100, and 300 µg/mL) and 500 ng/mL LPS during 24 h. ^### p < 0.001 vs. sham, ** p < 0.01 vs. CON, *** p < 0.001 vs. CON by one-way ANOVA, Dunnett’s test. CON: control, DEX 1: dexamethasone 1 µg/mL, GP: Gynostemma pentaphyllum, LPS: lipopolysaccharide, NT: non-treated.

Figure 7

Effects of GP on (A) cell viability and (B) NO generation in LPS-treated RAW264.7 cells, the mRNA expression level of (C–J) IL-1β, IL-6, NOS2, Ptger2, COX-2, TNF-α, MMP-3, and MMP-13 and the protein expression level of (K–P) IL-1β, IL-6, NOS2, MMP-3, and MMP-13 in RAW264.7 cells. Cell were treated with GP (30, 100, and 300 µg/mL) and 500 ng/mL LPS during 24 h. ^### p < 0.001 vs. sham, ** p < 0.01 vs. CON, *** p < 0.001 vs. CON by one-way ANOVA, Dunnett’s test. CON: control, DEX 1: dexamethasone 1 µg/mL, GP: Gynostemma pentaphyllum, LPS: lipopolysaccharide, NT: non-treated.