Dietary Phytochemicals: As a Natural Source of Antioxidants

Abstract

Since time immemorial, plants are used as the source of food and medicine. It can be traced back to the start of humanity. Bringing plant-based food, such as fruits, vegetables, and whole grains, rich in phytochemicals, with beneficial nutrients, opens the door for healthy living. The health benefits are partly attributed to the compounds which possess antioxidants. Several epidemiological observations have shown an opposite relationship between consumption of plant-based foods, rich in phytochemicals, and many diseases including cancer. The majority of the ailments are related to oxidative stress induced by free radicals. Free radicals are extremely unstable with a very short half-life, highly reactive molecule which leads to oxidative damage to macromolecules such as proteins, DNA, and lipids. Free radical induced cellular inflammation appears to be a major contributing factor to cause aging, and degenerative diseases such as cancer, cardiovascular diseases, diabetes, hepatic diseases, renal ailments, and brain dysfunction. Free radicals have been caught up in the pathogenesis of several diseases. Providentially, free radical formation is controlled naturally by phytochemicals, through their antioxidant potential which plays a key role in preventing many diseases including cancer by suppressing oxidative stress-induced DNA damage. Keeping these facts in mind, an attempt has been made to highlight the oxidative stress, enzymatic and non-enzymatic antioxidant, dietary phytochemicals and their role of in disease prevention and cure.

Pytochemical profile of Aloe ferox Mill. across different regions within South Africa

“…Agati et al (2020) alluded that flavonoids help the human body to function more efficiently while protecting against toxins and stressors. Makhaik, Shakya and Kale (2021) pointed out that flavonoids are powerful antioxidant agents with free radical scavenging capacity, coronary heart disease prevention, hepatoprotective, anti-inflammatory and anticancer activities. Literature reports that some flavonoids in plants do exhibit potential antiviral activities (Wang et al 2020).…”

PHYSIOLOGICAL ASPECTS OF PHYTOCHEMICALS AS ANTIOXIDANTS ON POULTRY: (Article Review)

“…c-Essential amino acids, such as methionine, which contain sulfur (Kim et al, 2020) d-Phytochemicals: These are non-vitamin and non-mineral polyphenolic substances as food ingredients of plant origin (medicinal plants) (Engwa, 2018). Phenolic compounds (the major dietary phenolic types are flavonoids, phenolic acids, and polyphenols) and carotenoids are the most typical kinds of phytochemicals (Makhaik et al, 2021). There are hundreds of carotenoids and thousands of flavonoids (Weng and Yen, 2012) responsible for giving fruits, vegetables, teas, and herbs their beautiful colors such as red, orange, yellow, and purple (Benzie, 2005).…”

“…As mentioned earlier, phytochemicals (plant chemicals) or phytonutrients are natural polyphenolic compounds found in plant diets (medicinal plants) (Shahidi and Ambigaipalan, 2015), as non-vitamin and non-mineral nutritional supplements (Engwa, 2018), must be supplemented in the diet because the body cannot produce them (Makhaik et al, 2021). Their phytochemical compounds may be existing in plant-based foods like vegetables, fruits, whole cereals, nuts, herbs, leaves, roots, legumes, seeds, and spices (Makhaik et al, 2021), which could contain several compounds, including flavonoids, polyphenols, stilbenes, carotenoids, and anthocyanins (Kamboh et al, 2015;Engwa, 2018).…”

“…Phytochemicals are bioactive plant molecules composed of thousands of chemicals, pigments, and natural antioxidants that are physiologically active in the body (Makhaik et al, 2021). Polyphenols and carotenoids are the most important phytochemicals (Weng and Yen, 2012), that act by inhibiting the free radical chain (Shahidi and Ambigaipalan, 2015), and provide the initial defense mechanism for cells against excessive ROS generation (Lipinski et al, 2017;Zhong and Zhou, 2013).…”

Flavonoids Biosynthesis in Plants as a Defense Mechanism: Role and Function Concerning Pharmacodynamics and Pharmacokinetic Properties

“…Due to their antioxidant, anti-inflammatory, antibacterial, and affinity/inhibitory properties toward inflammatory enzymes, plant extract rich in flavonoids are employed in dermatology and cosmetics. As dietary components, algal flavonoids may protect against several human diseases (Figure 1 and Table 1) [20].…”