Role of phyto-stabilised silver nanoparticles in suppressing adjuvant induced arthritis in rats

•Silver nanoparticles synthesized using aqueous extract of Piper nigrum L has potential anti-arthritic effects•At low doses the phyto-stabilized silver nanoparticles reversed the articular damage and paw edema induced by CFA•Its anti arthritic effect is mediated by suppression of TNF-α and transcription factor NF-kβ p65.•The low toxicity of phytostabilised silver nanoparticles suggests a new therapeutic rationale for arthritis.

Aim of the studyThe present study was aimed to evaluate the anti-arthritic effects of silver nanoparticles synthesised using Piper nigrum extract and to further establish its mechanism of action in a rat model of adjuvant induced arthritis (AA).Materials and methodsAdjuvant arthritis was induced by injecting complete Freund's adjuvant (0.1 mL) into the left hind paw of 36 albino Wistar rats (n = 6). Silver nanoparticles stabilised with Piper nigrum extract (25 and 50 mg/kg). Commercial silver nanoparticles (50 mg/kg) and methotrexate (0.1 mg/kg) were administered by intraperitoneal route from day 11 to day 22 on alternate days.ResultsIt was found that treatment with silver nanoparticles stabilised with Piper nigrum (S-AgNPs) significantly reduced the paw edema and alleviated the histopathological changes of cell infiltration, synovial hyperplasia, bone and cartilage destruction. Furthermore, the phytostabilised silver nanoparticles (S-AgNPs) inhibited the protein expression of NF-kβ p65 and TNF-α as evidenced by immunohistochemistry analysis.ConclusionOur current findings suggest that silver nanoparticles stabilised with Piper nigrum extract (S-AgNPs) have potent anti-arthritic activity which is mediated by inhibition of TNF-α and suppression of pro-inflammatory cytokines that are secreted in response to activated transcription factors of NF-kβ.

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