Analgesic, anti-inflammatory and NF-κB inhibitory activity of aerial parts of Cestrum diurnum

Abstract

Abstract Background Cestrum diurnum L. (Solanaceae), locally known as buno-Hasnahena, is widely used in different traditional medicinal practices to treat pain, burn, swelling and related disorders. Adequate evidence is not available to support its medicinal properties for further use and drug development. Present study was designed to evaluate its traditional use in pain and inflammation with further characterisation of its chemical constituents through liquid chromatography-mass spectroscopic (LC-MS) analysis. Methods Antinociceptive and analgesic potential of methanol extract of the aerial parts of C. diurnum was carried out using carrageenan induced paw oedema and formalin induced paw licking test in mice at the oral doses of 150 and 300 mg/kg body weight. Inhibition of the inflammatory mediator nuclear factor kappa B (NF-κB) was evaluated by tumour necrosis factor α (TNF-α) induced NF-κB activation assay in macrophage cells at the concentration of 100 μg/ml. LC-MS analysis of the extract was performed to characterise the active component responsible for bioactivities. Results The extract significantly inhibited (p < 0.05) carrageenan induced paw oedema at both doses tested and the effect persisted throughout the entire experimental period of 3 h with the highest activity (50% inhibition) observed at 3rd h. Further, the extract significantly inhibited (p < 0.05) formalin induced paw licking both in the early and late phase at the aforementioned dose levels. The extract also downregulated the expression of NF-κB p65 protein in the TNF-α induced NF-κB activation assay. LC-MS analysis of the extract indicated the presence of some important secondary metabolites including nicotine, nornicotine, ursolic acid, vitamin D3 and its derivatives. Conclusions The results of this study supported the folkloric uses of the plant in pain and inflammations. The insights and observations suggest the action might involve downregulation of NF-κB p65 protein expression and/or inhibition of autacoids (histamine, serotonin, prostaglandin).

Keywords

• Carrageenan induced paw oedema
• Formalin induced paw licking
• NF-κB downregulation
• LC-MS