Antioxidant and anti-inflammatory activities of several commonly used spices

Antioxidant and anti-inflammatory activities are extensively used to screen chemopreventive foods. Five well-known anticancer spices, ginger, red pepper, garlic, green onion, and leek, were selected and assessed in this study. Antioxidant function was evaluated based on the scavenging ability of the cation radical ABTS⁺. Moreover, anti-inflammatory activity was determined based on the inhibitory effect of nitric oxide (NO) production by lipopolysaccharide (LPS)-activated macrophages. The antioxidant activity of the 5 spices followed this order: ginger > red pepper > leek > green onion and garlic. All of these spices had a strict inhibitory effect on NO production. The anti-inflammatory activity could be ranked based on the IC₅₀ of the spices, as garlic > ginger > green onion > leek and red pepper. Additionally, a significant correlation existed between antioxidant activity and total phenolics content. Obviously, total phenolics content was a crucial determinant of the antioxidant but not the anti-inflammatory activity of foods. The compounds responsible for the anti-inflammatory activity should differ from those responsible for the antioxidant activity.