Antioxidant and anti-inflammatory activities of selected medicinal plants containing phenolic and flavonoid compounds.
The antioxidant, anti-inflammatory, and cytotoxic activities of water and ethanol extracts of 14 Chinese medicinal plants were investigated and also their total phenolics and flavonoid contents measured. The antioxidant activity was evaluated in a biological assay using  Saccharomyces cerevisiae , whereas the radical scavenging activity was measured using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. Total phenolics and flavonoid contents were estimated by Folin-Ciocalteu and aluminum chloride methods, respectively. The anti-inflammatory activities of the plant extracts were determined by measuring the inhibition of production of nitric oxide (NO) and TNF-α in LPS and IFN-γ activated RAW 264.7 macrophages. Their cytotoxic activities against macrophages were determined by Alamar Blue assay. Four plants, namely,  Scutellaria baicalensis ,  Taxillus chinensis ,  Rheum officinale , and  Sophora japonica , showed significant antioxidant activity in both yeast model and also free radical scavenging methods. The ethanol extract of S. japonica showed highest levels of phenolics and flavonoids (91.33 GAE mg/g and 151.86 QE mg/g, respectively). A positive linear correlation between antioxidant activity and the total phenolics and flavonoid contents indicates that these compounds are likely to be the main antioxidants contributing to the observed activities. Five plant extracts (S. baicalensis, T. chinensis, S. japonica,  Mahonia fortunei , and  Sophora flavescens ) exhibited significant anti-inflammatory activity by in vitro inhibition of the production of NO and TNF-α with low IC(50) values. These findings suggest that some of the medicinal herbs studied in this paper are good sources of antioxidants.
School of Natural Sciences, University of Western Sydney, Locked Bag 1797, Penrith South DC, NSW 1797, Australia.
Lin
L
Zhang
Anjaneya S
AS
Ravipati
Sundar Rao
SR
Koyyalamudi
Sang Chul
SC
Jeong
Narsimha
N
Reddy
Paul T
PT
Smith
John
J
Bartlett
Kirubakaran
K
Shanmugam
Gerald
G
Münch
Ming Jie
MJ
Wu
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D000975:Antioxidants / Q000494:pharmacology*; D002460:Cell Line; D005419:Flavonoids / Q000032:analysis*; D008264:Macrophages / Q000187:drug effects; D051379:Mice; D010636:Phenols / Q000032:analysis*; D010936:Plant Extracts / Q000494:pharmacology*; D010946:Plants, Medicinal / Q000737:chemistry*
D000893:Anti-Inflammatory Agents; D000975:Antioxidants; D005419:Flavonoids; D010636:Phenols; D010936:Plant Extracts