# Lycopene: A Natural Arsenal in the War against Oxidative Stress and Cardiovascular Diseases
## 3 Lycopene as an Antioxidant  
A stressor is any agent that induces stress [78; 79]. Stress is an organism's general response to negative stimuli. Stress affects the physiological balance by causing a biological  
Figure 4: A diagram depicting the digestion and absorption of lycopene. Food releases lycopene, which is then integrated into micelles containing bile salt, cholesterol, and fatty acids. The micelle approaches enterocytes, and lycopene diffuses over the apical membrane in a passive manner. Lycopene is packed with other dietary lipids inside the enterocyte to form chylomicrons, which are carried over the basolateral membrane, into the lymphatic system, and subsequently discharged into the blood. reaction to stimuli [80]. Oxidative stress, which is induced by highly reactive free radicals, is one of the primary causes of chronic illness [81; 82]. Antioxidants have been identified as a varied set of chemicals that inhibit oxidation in various ways [83; 84; 85; 86]. Only a few lipophilic natural oxidants exist, and lycopene is one of them. As a powerful singlet oxygen quencher, it can stop lipid oxidation in its early stages. Lycopene's ability to protect against oxidative stress has been established [87; 88]. Lycopene has been found to be more potent in this activity as compared to other carotenoids, such astocopherol, \(\beta\)-cryptoxanthin, caroten, lutein, and zeaxanthin [9]. B-carotene and a-tocopherol, two more lipophilic antioxidants, had double and 100-fold lower rates, respectively [89]. Lycopene's major biological purpose is to protect DNA from oxidative stress in order to prevent mutations that might lead to chronic diseases [90; 91; 92]. lycopene is the most potent free radical and single oxygen scavenger among 600 naturally occurring carotenoids because of its long chain with conjugated double bonds [93; 94]. It modulates phase I and II detoxifying enzymes, which affect cell proliferation, immunological response, and gene transcription [24]. It activates the antioxidant response element (ARE), which causes the cellular enzymes glutathione S-transferase (GST), superoxide dismutase (SOD), and quinone reductase to be synthesized [95; 96; 97; 98]. HO-1, GST, NQO1, and SOD are antioxidant and detoxifying enzymes that are sometimes referred to as phase II cytoprotective enzymes [99; 46]. ARE is located in the promoter regions of inducible genes that code for phase II enzymes, and it promotes overexpression of these genes when it binds to Nrf2. Lycopene inhibits Nrf2/Keapl binding in heat stressed birds, allowing Nrf2 to be transported to the nucleus and upregulate phase II enzyme synthesis [100]. The electrophile response element transcription system (EpRE) or antioxidant response element transcription system (ARE) are related to the cis-regulatory portions in the promoter region of detoxifying enzymes [26; 101]. By activating the ARE transcription pathway [26], lycopene can affect xenobiotic metabolism by disrupting the cytosolic linkages between the major ARE-activating Nrf2 and its inhibitor (Keap1) [26; 102]. Once liberated of Keap1, Nrf2 translocates to the nucleus, where it induces phase II enzyme expression [26; 103]. According to some research, overexpression of phase II detoxification enzymes, in addition to blocking phase I metabolism and metabolic activation of aflatoxin B1, enhances lycopene's anti-aflatoxin actions [104; 105]. Lycopene operates in three methods to produce reactive oxygen species (ROS): first, radical addition (adduct formation), then electron transfer to the radical, and finally, allylic hydrogen abstraction [106]. Two processes that contribute to lycopene's antioxidative impact are the formation of adducts and allylic hydrogen abstraction [107; 108]. The type of the reacting free radical, the structural characteristics of lycopene, and the positioning and direction of lycopene inside the membrane in biological systems are all elements that impact these potential interactions [109; 110; 111].