# Anti-Inflammatory and Antioxidant Effects Induced by
## 3 Results and Discussion
### Toxicological and Pharmacological Studies
Accordingly, we previously reported that GWE exerted cardioprotective activities, by suppressing LPS-induced COX-2, IL-6, and NF-kB gene expression, as well as PGE\({}_{2}\) levels, in heart specimens. To this regard, we hypothesized that the suppression of NF-kB gene expression could be involved in modulating the inhibitory effects induced by GWE on COX-2 gene expression and PGE\({}_{2}\) production [22]. Accordingly, ethyl linoleate from garlic was reported to suppress LPS-induced COX-2 mRNA and protein expression as well as PGE\({}_{2}\) production in RAW264.7 cells, by suppressing NF-kB activation [57]. Actually, the anti-inflammatory effects exerted by GHE and GWE could be related, at least in part, to their phenol and flavonoid content [58; 59; 60; 61; 62; 63; 64; 65; 66; 67], with particular regards to catechin [58]. To this regard, catechin was suggested to act as a potential therapeutic agent in the prevention of inflammation. In particular, catechin exhibited anti-inflammatory properties by suppressing inducible nitric oxide synthase (iNOS), and COX-2 protein expression, as well as IL-6 and TNF-\(\alpha\) mRNA levels in LPS-treated RAW264.7 cells [68]. Interestingly, GHE was shown more effective than GWE in decreasing gene expression of COX-2, and IL-6 (Figure 7A,D), as well as PGE\({}_{2}\) levels (Figure 9) in isolated mouse colon specimens following LPS challenge. This finding could be related to its major content in catechin [69], resveratrol [70], naringenin [71], and hesperetin [72]. Accumulating evidence showed that 5-HT is a pro-inflammatory mediator critically involved in the pathogenesis of intestinal disorders, such as IBD [73; 74; 75], irritable bowel syndrome [73; 76; 77], as well as DSS-induced experimental colitis [78]. In the present study, we also investigated the effects of the garlic extracts on the LPS-induced 5 HIIA/5-HT ratio, which is known as a  
Figure 7: Effects of garlic hydroalcoholic extract (GHE) (1, 10, and 100 \(\upmu\)g/mL), garlic water extract (GWE) (1, 10, and 100 \(\upmu\)g/mL) and vehicle (RPMI) on LPS-induced cyclooxygenase (COX)-2 (**A**), tumor necrosis factor (TNF)-\(\alpha\) (**B**) nuclear factor-kB (NF-kB (**C**)), interleukin (IL)-6 (**D**), nuclear factor erythroid 2-related factor 2 (Nrf2) (**E**) gene expression (RQ, relative quantification) in mouse colon specimens. Data are displayed as the means \(\pm\) SEM. ANOVA, \(p<0.01\); \({}^{*}\)\(p<0.05\), \({}^{**}\)\(p<0.01\) vs. LPS, and \({}^{***}\)\(p<0.001\) vs. LPS; \({}^{\#}\)\(p<0.05\) vs. LPS+GWE 100 \(\upmu\)g/mL; \({}^{\#}\)\(p<0.01\) vs. GWE 10 \(\upmu\)g/mL. useful index of 5-HT turnover, in vivo [79; 80], deeply related to the activity of monoamine oxidase (MAO)-A [81]. Figure 8: Effects of garlic hydroalcoholic extract (GHE) (1, 10, and 100 \(\mathrm{\SIUnitSymbolMicro g}\)/mL), garlic water extract (GWE) (1, 10, and 100 \(\mathrm{\SIUnitSymbolMicro g}\)/mL) and vehicle (RPMI) on LPS-induced prostaglandin E\({}_{2}\) (PGE\({}_{2}\)) levels in mouse colon specimens. Data are shown as the means \(\pm\) SEM. ANOVA, \(p\) < 0.0001; \(\star\)\(p\) < 0.05, and \(\star\)\(p\) < 0.001 vs. LPS; \(\star\)\(p\) < 0.01, \(\star\)\(\star\)\(p\) < 0.001 vs. co-respective treatment with GWE. Figure 9: Effects of garlic hydroalcoholic extract (GHE) (1, 10, and 100 \(\mathrm{\SIUnitSymbolMicro g}\)/mL), garlic water extract (GWE) (1, 10, and 100 \(\mathrm{\SIUnitSymbolMicro g}\)/mL) and vehicle (RPMI) on the 5-HIIA/5-HT ratio in mouse colon specimens treated with vehicle. Data are displayed as the means \(\pm\) SEM. ANOVA, \(p\) < 0.0001; \(\star\)\(p\) < 0.05, and \(\star\)\(\star\)\(p\) < 0.001 vs. LPS; \(\star\)\(p\) < 0.001 vs. LPS + GWE 100 \(\mathrm{\SIUnitSymbolMicro g}\)/mL. Consistently with the literature data [33], we found that LPS reduced the 5 HIIA/5-HT ratio (Figure 9) in isolated mouse colon specimens. However, GHE and GWE (100 \(\upmu\)g/mL) prevented LPS-induced reduction in 5-HT turnover.