**1.12 Lycopene**

*Strawberry - Pre- and Post-Harvest Management Techniques for Higher Fruit Quality*

[62] showed that naringenin can reduce Fe3+ and Cu2+

inhibits Cyp2e1 in liver microsomal assay done on rats [86].

tolerated by patients and beneficial for treating cirrhosis.

reported that naringenin did not cause any harmful effects in beagle dogs, the maximum time of exposure being 180 days and with doses varying of 20, 100, or 500 mg/kg body weight per day. Naringenin has many pharmacological properties. It acts as a hypolipidemic, antihypertensive, anti-inflammatory, antioxidant, and antifibrotic agent [81]. The metabolism of naringenin takes place in small intestine where glycoside form of naringenin gets cleaved, resulting in sulfate and glucuronide metabolites in the small intestine wall; then, it gets absorbed [77]. Mira et al.

quercetin. Chtourou et al. [83] found that naringenin averts depletion of SOD, CAT, GPx, and GSH. On the other hand, naringenin also prevents an increase in lipid peroxidation, and it also prevents increase of enzymes ALT and AST [78]. Yen et al. [84] also obtained similar results on liver enzymes and prevention of lipid peroxidation when they used naringenin alone and also naringenin-loaded nanoparticle system (NARN). In both treatments, naringenin exhibited antioxidant and hepatoprotective activities. In these experiments, treatment with naringenin also inhibited the activation of caspases 3 and 8. However, NARN was found to have better hepatoprotective and antioxidant effects than free naringenin, and it was also shown to inhibit caspase 9 during CC14-induced hepatotoxicity in rats. Han et al. [64] reported that a pretreatment with naringenin-7-O-glucoside increases NQO1 and ERK phosphorylation and translocation of Nrf2 to the nucleus in H9c2 cardiomyocytes. It also upregulated the mRNA expression of GCLC and GCL modifier [64]. Similar findings have been reported by Esmaeili et al. [85] who showed that naringenin attenuates CC14 induced liver injury by downregulating TNF-α, INOS, and cyclooxigenase-2 and also by increasing Nfr2 and HO-1 expressions. Motawi et al. [86] showed that naringenin

*Camellia sinensis* or green tea is a widely consumed beverage across the globe and it has antioxidant, anti-inflammatory, antiarthritic, and antiangiogenic effects. It is a mixture of polyphenols (the major class of active compounds) including catechins (also known as flavan-3-ols) which constitute about 30% (mass fraction) of green tea leaves. The major catechins in green tea are (+) -catechin, (−) -epicatechin, (−) -epigallocatechin, (−) -epicatechin-3-gallate, (−) -gallocatechin, (−) -gallocatechin gallate, and (−) -epigallocatechin-3-gallate (EGCG). EGCG is the most abundant catechin accounting for 50% of total polyphenols; thus, it is the main biological active compound of green tea [87]. However, polyphenols are not the only compounds that green tea exerts its antioxidant activity with through. The amino acid, L-theanine, in green tea accounts for 1–2% of the leaf dry weight that is synthetized in the roots of green tea and is concentrated in the leaves. Studies have reported that L-theanine protects the cell by maintaining its GSH levels in cancer and neurotoxic diseases [88]. The intake of green tea can be considered safe unless its consumption exceeds 1–2 cups a day. And higher consumption such as in attempts to lose weight resulted in hepatotoxicity [87]. At normal doses, Pérez-Vargas et al. [88] found that the main amino acid of green tea, L-theanine, reduced expression of NF-kB and downregulated IL-1β and IL-6 and the cytokines TGF-β and CTGF. Halegoua-De Marzio et al. [89] tested a single high dose of green tea (400 mg), in patients with HCV-induced cirrhosis and found that it is well

L-Carnitine (LC), B-hydroxy-y-trimethylaminobutyric acid, is a water-soluble

molecule important in mitochondrial oxidation of fatty acids in mammalian

ions but it is less potent than

**132**

**1.11 L-Carnitine**

**1.10 Green tea**

Lycopene (LYC) is an acyclic isomer of beta-carotene which has great antioxidant activities. It is synthesized by plants or autotrophic bacteria but not by animals. Red fruits and vegetables, such as tomatoes, watermelons, pink grapefruits, apricots, pink guavas, and papaya, contain LYC. Studies show that LYC consumption not only reduces the risk of cancer of many organs but also retards the growth of tumors. LYC has been shown to have protective effects on other pathologies such as cardiovascular diseases, osteoporosis, male infertility, and this action is mainly mediated by LC's ability to inhibit other toxic agents (**Figure 5**). Numerous *in vitro*

#### **Figure 4.**

*The mitochondrial carnitine system. Abbreviations: CPT I, carnitine-palmitoyl transferase I; CACT, carnitine acyl carnitine transferase; CPT II, carnitine-palmitoyl transferase II; CAT, carnitine acyl transferase; CoA, coenzyme A [90].*

and *in vivo* studies showed that LYC could provide protection against ionizing radiation. Therefore, supplementation of LYC might be protective against damaging effects of radiotherapy in cancer treatments and it can also be protective against accidental radiation exposure [94].

### **1.13 Piperine**

Piperine [1-[5-(1,3-benzodioxol-5-yl)-1-oxo-2,4, pentadienyl] piperidine] is the major pungent alkaloid present in the fruits of *Piper nigrum* L*.* [95]. Piperine at low concentrations acts as a hydroxyl radical scavenger, but at higher concentrations, it activates the Fenton reaction, resulting in increased generation of hydroxyl radicals. Piperine has hepatoprotective effects and it was shown to inhibit lipid peroxidation in the rat liver microsomes at a concentration of 600 μM [96].

#### **1.14 Capsaicin**

Capsaicin (trans-8-methyl-N-vanillyl-6-nonenamide) is the major strong and irritating ingredient of red pepper. It may inhibit copper ion-induced lipid peroxidation of human LDL, which suggests that it is an effective antioxidant offering protection against oxidation of human LDL [97].

#### **Figure 5.**

*General mechanisms of action of lycopene. The proposed mechanisms of action of lycopene (oxidative and nonoxidative) that decreases the risk of oxidative stress-mediated diseases. Lycopene most likely acts via the oxidative mechanism of action to prevent oxidative stress and its detrimental effects on male infertility. ROS: reactive oxygen species [93].*

**135**

*Dietary Antioxidants in Experimental Models of Liver Diseases*

Diallyl sulfides and diallyl disulfides, the active components of garlic, have anti-inflammatory and antimutagenic activities. Onion is a major source of flavonoids, especially the two quercetin glycosides, quercetin 4-*o*-*β*-glucoside and quercetin 3,4-*o*-*β*-diglucosides, which are recognized as bioactive substances. In order to show the antioxidant properties and protective effects of garlic and onion, a study was carried out on rats. Animals were treated with 0.6 mg nicotine/kg and also given 100 mg garlic or onion oils/kg for 21 days. Nicotine increased concentrations of thiobarbituric acid, conjugated dienes, and hydroperoxides in the tissues. Supplementation with both the garlic oil and onion oil increased resistance not only to lipid peroxidation but they also increased levels of antioxidant enzymes and glutathione. These conclusions state that oils of garlic and onion are effective

antioxidants against nicotine-related oxidative stress and damage [98].

Vitamin C, substrate for ascorbate peroxidase, is not only a highly effective antioxidant but also an essential component of a healthy diet. Vitamin E, the major antioxidant found in lipid composition of membranes, is a fat-soluble antioxidant. During fat oxidization, vitamin E helps to inhibit formation of ROS [99]. Several studies showed that vitamin E serum levels are significantly reduced in alcoholic liver disease [100]. It is also shown that vitamin E levels are inversely proportional to formation of oxidative stress products that correlate with the extent of liver damage [101]. For this reason, maintenance of normal concentrations of vitamin E appears to be necessary for preventing lipid peroxidation due to alcohol consumption. Works from several laboratories have so far indicated that mitochondrial damage may present a common early event in cell injury [102]. It is possible to prevent mitochondrial damage through vitamin E [103]. Vitamin E or C alone, or in combination, can ease scavenging free radicals that are generated in the liver tissue [104]. In the mouse model, vitamin E supplementation restores alcohol-induced redox status, reduces apoptosis, and prevents oxidative stress [105]. What is more, vitamin E is effective in doses of 600 mg daily when it comes to suppressing HBV replication and normalizing ALT in a significant proportion of chronically infected patients with CLD [106].

Trace minerals act as a cofactor of antioxidant enzymes thus enabling the antioxidant activities to take place. These trace minerals include selenium (Se), zinc

nated by the enzyme Cu-Zn-SOD and Cu and Zn are the co-factors for the enzyme. One of the enzymes responsible for H2O2 clearance from the cells is CAT and Fe is the essential cofactor of this enzyme. Levels of ferritin may decline with exercise and increasing dietary or supplemental Fe can improve performance. It was shown that moderate-level supplementation of Fe to competitive swimmers increased their performance and helped to maintain normal ferritin levels [107]. Selenium (Se) is a cofactor for the antioxidant enzyme GPx, which is like the enzyme CAT, responsible for removing H2O2 and other organic H2O2 from the cell. A study by Akil et al. [108] showed in rats, that upon acute swimming exercise, lipid peroxidation in the brain was increased and Se supplementation to these rats increased antioxidant activity resulting in inhibition of the free radical production [108]. Manganese (Mn) is a

<sup>−</sup> radicals are elimi-

<sup>−</sup> radicals produced during oxida-

(Zn), manganese (Mn), iron (Fe), and copper (Cu) [103]. O2

cofactor for the enzyme Mn-SOD. It eliminates O2

tive phosphorylation [109].

*DOI: http://dx.doi.org/10.5772/intechopen.83485*

**1.15 Garlic and onion**

**1.16 Vitamins C and E**

**1.17 Trace minerals**
