Abstract

Polyscias scutellaria (Burm.f) Fosberg has traditionally been used to treat various diseases. However, the study of its in vivo anti-inflammatory effects, mechanism of action, and metabolite profile is limited. This study aimed to investigate the free radical scavenging activity and the anti-inflammatory property of P. scutellaria leaves extract and study its mechanism of action on pro-inflammatory cytokines [tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and interleukin-6 (IL-6)]. The leaves of P. scutellaria were macerated in ethanol (90%) to yield ethanol extract of P. scutellaria leaves (EEPS). The rats were divided into 5 groups (n = 5): solvent group, sodium diclofenac group (13.65 mg/kg), and EEPS at the dose of 100, 200, and 400 mg/kg). The rats were pretreated with EEPS and the oedema were induced by carrageenan (1%). The oedema volume (inflammation) was measured and the expression of pro-inflammatory cytokines was assessed using an enzyme-linked immunosorbent assay. In addition, the chemical constituent of EEPS was analyzed using liquid chromatography-orbitrap high-resolution mass spectrometry (LC-HRMS). EEPS at doses of 200 and 400 mg/kg inhibited inflammation in carrageenan-induced rat paw oedema. The same effect was also observed in rats treated with sodium diclofenac. EEPS also significantly decreased the levels of TNF-α and IL-1β, but not IL-6. Phytochemical analysis using LC-HRMS revealed that the extract contains known antioxidant or anti-inflammatory compounds, such as ursolic acid and chlorogenic acid. EEPS demonstrated anti-inflammatory activity in carrageenan-induced paw oedema by suppressing the level of pro-inflammatory cytokines TNF-α and IL-1β.

Key words: Polyscias scutellaria, herbal medicine, inflammation, mass spectroscopy, TNF-α, IL-1β, IL-6