Antioxidant and Anti-Inflammatory Properties of Anacardium occidentale Leaf Extract

Abstract

In tropical America, principally in Northeastern Brazil, the leaf extract of Anacardium occidentale is traditionally used for treatment of different diseases. However, chemical and biological properties and activities of Anacardium occidentale are poorly investigated and known. Here, we evaluated the antioxidant and anti-inflammatory activities "in vitro" of leaf extract from Anacardium occidentale. Our results show that leaf extract exhibits antioxidant activity when used to treat RAW 264.7 macrophage cells. Antioxidant effects were observed by decrease in oxidative damage in macrophage cells treated with 0.5 µg/mL and 5 µg/mL of leaf extract. Moreover, leaf extract reversed oxidative damage and inflammatory parameters induced in LPS-stimulated RAW 264.7 macrophage cells. Leaf extract at 0.5 µg/mL and 5 µg/mL was able to inhibit release of TNF-α and IL-1β in LPS-stimulated cells. Taken together, our results indicate antioxidant and anti-inflammatory effects of leaf extract from Anacardium occidentale and reveal the positive effects that intake of these products can mediate in biological system.

Figure 1

Parameters of cell viability and oxidative stress in RAW 264.7 cells treated with Anacardium occidentale leaf extract for 24 hours. RAW 264.7 cells were treated with leaf extract at different concentrations, 0.5, 5, and 500 µg/mL. Different assays were performed to evaluate cell viability after incubation; lipopolysaccharides LPS (1 µg/mL) was used as a positive control for loss of viability. (a) MTT assay and (b) SRB–incorporation assay. Control group is represented in all graphs by “Control.” Data represent mean ± SEM from three independent experiments (n = 6 per group). One-way ANOVA followed by the post hoc Tukey's test, ^∗p < 0.05 versus the control group.

Figure 2

Cells were treated with different concentrations of leaf extract for 1 hour and the total production of reactive species by living cells was evaluated by the real-time DCFH oxidation assay; LPS (1 µg/mL) was used as a positive control for reactive species production and fluorescence intensity was calculated relative to control cells. Control group is represented in all graphs by “Control.” Data represent mean ± SEM from three independent experiments (n = 6 per group). One-way ANOVA followed by the post hoc Tukey's test, ^∗p < 0.05 versus the control group; ^∗∗p < 0.05 versus treated group.

Figure 3

The levels of IL-1β (a) and TNF-α (b) in medium of incubation were measured. Detection of cytokines was performed by ELISA assays. Control group is represented in all graphs by “Control.” Data represent mean ± SEM from three independent experiments (n = 6 per group). One-way ANOVA followed by the post hoc Tukey's test, ^∗p < 0.05 versus the control group; ^∗∗p < 0.05 versus treated group.