Effect of Piperine on the Inhibition of Nitric Oxide (NO) and TNF‐α Production

Abstract

Effect of piperine which is an alkaloid present in plants such as Piper nigrum and Piper longum on the production of nitric oxide (NO) and tumor necrosis factor‐α (TNF‐α) level was analyzed using in vitro as well as in vivo systems. The level of nitrite in the LPS stimulated Balb/C mice (95.3 µM) was reduced in the piperine treated animals (25 µM) significantly. Nitrite level in the Concanavalin‐A (Con‐A) treated control animals (83.1 µM) was also significantly reduced to 18.5 µM in the piperine treated mice. The drastically elevated levels of TNF‐α in the lipopolysaccharide (LPS) stimulated animals (625.8 pg/mL) was lowered in the piperine treated animals (105.8 pg/mL). Piperine also inhibited the Con‐A induced TNF‐α production. Piperine could inhibit the nitrite production by in vitro activated macrophages (116.25 µM) to the normal level (15.67 µM) at concentration of 5 µg/mL. In vitro L929 bioassay also revealed the inhibition of TNF‐α production by the piperine treatment.