## 4 Discussion
In this study, GPI and GPS showed relatively high DPPH radical scavenging capacities of 522.83 \(\pm\) 26.00 mg VCE/100 g and 518.67 \(\pm\) 7.21 mg VCE/100 g, respectively and the ABTS radical scavenging capacity of 1941.91 mg VCE /100 g and 1902.77 mg VCE /100 g, respectively. Because piperise is a major component of pepper [44], we predicted that the higher antioxidant activity of green pepper, as compared to that of black pepper, may be correlated with the piperine content. Interestingly, although BPS had the lowest DPPH and ABTS scavenging capacities, its piperine content (7388.50 \(\pm\) 37.00 mg/100 g) was similar to that of GPI (8613.27 \(\pm\) 45.86 mg/100 g), which had the strongest DPPH and ABTS radical scavenging capacities (Table 2). A previous study using supercritical extraction with carbon dioxide and gas chromatography with flame ionization detection (GC-FID) and gas chromatography and mass spectrometry (GC-MS) analysis showed that _P. nigrum_ contains \(\beta\)-caryophyllene, limonene, sabinene, 3-carene, \(\beta\)-pinene, and \(\alpha\)-pinene [43]. [PERSON] et al. showed that after extraction of _P. nigrum_ with the Clevenger and Soxhlet apparatus, GC-MS revealed that piperine, \(\beta\)-caryophyllene, limonene, \(\beta\)-pinene, and sabinene were the components present in _P. nigrum_[44]. These studies suggest that various compounds besides piperine may contribute to the antioxidant activity of green pepper. Therefore, other components present in green pepper should be identified and quantified by liquid chromatography-MS analysis in future studies. Inflammation is the major cause of various metabolic diseases such as diabetes, cardiovascular diseases, and brain disease; therefore, inflamed tissues are the major therapeutic target for functional foods as well as medication [9; 45; 46; 47]. Because green pepper was found to have higher antioxidant activity than black pepper, we further evaluated the anti-inflammatory efficacy and the mechanism of action of GPEs in this study. GPS and GPI inhibited LPS-induced nitrite production by suppressing iNOS expression in RAW 264.7 cells. Abnormal production of NO and expression of iNOS as a response to LPS are considered as an inflammatory phenomenon in mammals. Thus, it can be assumed that green pepper is a promising anti-inflammatory nutraceutical for the treatment of various inflammatory diseases. As the central mediator in LPS-induced iNOS expression and subsequent NO production, pepper extracts were evaluated for their effects on the phosphorylation of p65, the catalytic subunit of NF-kB. Interestingly, p65 phosphorylation was not affected by GPS and GPI. Since MAPKs are also a major factor affecting the NF-kB signaling pathways and iNOS expression, we evaluated the effects of GPS and GPI on LPS-induced phosphorylation of MAPKs. GPS and GPI suppressed the LPS-induced phosphorylation of JNK1/2 and p38, while the GPEs only slightly suppressed the phosphorylation of ERK1/2 in RAW 264.7 cells. In fact, NF-kB plays a critical role in LPS-mediated iNOS expression and NO production. In a previous study, we found that seaweed extracts affect the phosphorylation of MAPKs, but not NF-kB signaling pathways by using SR2001, a specific AP-1 inhibitor [48]. We demonstrated that only AP-1 can regulate LPS-induced iNOS expression and NO production in RAW 264.7 cells. Therefore, we further evaluated the effect of GPS and GPI on LPS-induced phosphorylation of c-Jun, a down-stream signaling molecule of JNK, and c-Jun translocation from the cytosol to the nucleus. Western blot assay and immunofluorescence analysis results showed that GPI suppressed the phosphorylation of c-Jun and c-Jun translocation (Figure 4). These results indicate that the inhibitory effect of GPS and GPI on LPS-induced iNOS expression and NO production results from the inhibition of phosphorylation of MAPKs and c-Jun and translocation of c-Jun from the cytosol to the nucleus.