Antioxidant Compounds

*Antioxidants - Benefits, Sources, Mechanisms of Action*

[53] Yeh, J.; Bowman, M.J.;

84(2):1109-1113.

Browne, R.W. and Chen, N. 2005. Reproductive aging results in a reconfigured ovarian antioxidant defense profile in rats. Fertil. Steril. J.;

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**Chapter 11**

**Abstract**

carotenoids

**1. Introduction**

Lung Diseases

The Role of Lycopene in Chronic

*Emilio Balbuena, Junrui Cheng and Abdulkerim Eroglu*

Lycopene, a naturally occurring non-provitamin A carotenoid pigment, is responsible for the red to pink colors in tomato, watermelon, red bell peppers, and pink guava. There are many health benefits attributed to lycopene including but not limited to its antioxidant activity. According to the American Lung Association's State of Lung Cancer, lung cancer is still the leading cause of cancer death in the United States. Other chronic lung diseases such as asthma, emphysema, and chronic obstructive pulmonary disease are high prevalence. This chapter summarizes lycopene's protective role against lung diseases in both *in vitro* and *in vivo* studies. While it has been demonstrated that circulating lycopene can be used as a biomarker for several lung diseases, further studies are warranted to establish that. We aim to provide insights into how lycopene can remedy for lung diseases, including lung cancer.

**Keywords:** lycopene, lung diseases, oxidative stress, lung cancer, antioxidants,

Lycopene, a major dietary carotenoid pigment responsible for the red color, is synthesized by plants and microorganisms [1]. It is mostly found in tomatoes and tomato products, albeit there is a small amount of lycopene in few other fruits, including watermelon, papaya, guava, and pink grapefruit [2]. Lycopene is one of the six most abundant carotenoids (others being α-carotene, β-carotene, β-cryptoxanthin, lutein, and zeaxanthin) in circulation in humans [3]. It has been shown that lycopene exerts cancer-preventive or chemopreventive properties against several cancer types, including prostate, lung, and colon cancers [4]. Lycopene has a chemical formula of C40H56, tetraterpene comprised of eight isoprene units that are purely containing carbon and hydrogen [5]. Lycopene can undergo isomerization from *trans* to *cis* by heat, light, and chemical reactions,

Lycopene can be cleaved via two pathways (**Figure 1**). It can be metabolized by central cleavage, catalyzed by beta-carotene-15,15′-oxygenase (BCO1), yielding apo-15′-lycopenal [7]. It also can be metabolized by eccentric cleavage, catalyzed by beta-carotene-9′,10′-oxygenase (BCO2) yielding apo-10′-lycopenal, which can be either further oxidized into apo-10′-lycopenoic acid or reduced to apo-10′ lycopenol [8]. It has also been shown apo-lycopenals at various chain lengths can also be derived from the absorption of apo-lycopenals directly from food [9].

although the all-*trans* isomeric form is the main isomer in nature [6].

**1.1 Lycopene: chemical definition and metabolism**

## **Chapter 11**
