Identification of anti-inflammatory constituents in Phellodendri Cortex and Coptidis Rhizoma by monitoring the suppression of nitric oxide production

AbstractPhellodendri Cortex (Obaku in Japanese) and Coptidis Rhizoma (Oren), both of which contain berberine, have been used to prepare the kampo formulaorengedokuto to treat inflammatory diseases, including dermatitis, gastric ulcers, and gastritis. These drugs are blended differently in other formulas, such as the use of Phellodendri Cortex inshichimotsukokato to treat hypertension and Coptidis Rhizoma inhangeshashinto to treat diarrhea and stomatitis. However, the differences in their medicinal properties are not well characterized. We prepared extracts fromPhellodendron amurense bark (PAB) andCoptis chinensis rhizome (CCR) and separated them into alkaloid and non-alkaloid fractions. Anti-inflammatory effects were examined by monitoring the production of nitric oxide (NO), which is a pro-inflammatory mediator. A non-alkaloid fraction of the PAB extract suppressed NO production in hepatocytes more efficiently than that of the CCR extract. When each non-alkaloid fraction of the PAB and CCR extracts was administered to mice, the fractions of both extracts decreased the levels of mRNAs encoding inducible NO synthase and molecules in the interleukin-1 β signaling pathway. Limonin and obakunone identified in the PAB non-alkaloid fraction suppressed NO production, exhibiting IC50 values of 16 and 2.6  μM, respectively, whereas berberine and coptisine displayed IC50 values of 12 and 14  μM, respectively. Limonin and obakunone reduced the expression of theiNOS gene, probably t...
Source: Journal of Natural Medicines - Category: Drugs & Pharmacology Source Type: research