Identification of Tumor Necrosis Factor-α Inhibitors from Traditionally Used Medicinal Plants

Abstract

The inflammatory response protects our bodies from foreign pathogens. However, when inflammation is uncontrolled it can lead to inflammatory and autoimmune diseases. The drugs currently used as treatment for these diseases, such as non-steroidal anti-inflammatory drugs (NSAIDs), have very serious side effects. There is a need for less toxic, alternative treatments. Traditional Chinese Medicine is becoming more popular in the United States and many plants are being evaluated for their medicinal purposes. In this study, 12 subfractions of one primary extract from a particular Chinese plant, designated 25A, and 44 fractions of a local plant, Cichorium intybus (chicory), were screened for cytotoxicity to human macrophage-like cells and the non-toxic concentrations were then assayed for TNF-α inhibitory activity. Fraction 7 of 25A exhibited greater than 90% inhibition of TNF-α while simultaneously having lower than 10% toxicity to THP-1 human macrophage-like cells and was further separated into three pure fractions. 25A-7 F1 was the only fraction to show greater than 90% TNF-α inhibition. The same process was repeated with the 44 chicory samples from four sources: wild-type, hairy root, and callus cell culture with and without elicitors. The callus cell culture subfractions showed no inhibitory activity. The remaining two sources, wild-type and hairy root, had promising activity with various fractions producing TNF-α inhibition. This research provides potential anti-inflammatory treatment candidates from medicinal plants.