**7. Vegetable supplementation against oxidative stress**

Oxidative stress can lead to many health complications such as cancer, inflammatory diseases, cardiovascular diseases, neurodegenerative diseases, and aging [107]. As vegetables' secondary metabolites act as natural antioxidants, dietary supplementation of vegetable products can help reduce oxidative stress. The following section addresses the effect of vegetable supplementation on oxidative stress. A study on Wister rats under cadmium-induced oxidative stress has indicated that five days of intake of carrot juice as drinking water before stress induction can lower cadmium concentration in both liver and kidney along with the oxidative stress as determined by a lower concentration of malondialdehyde (MDA) (see **Table 5**) in pretreated rats [108]. Similar results, i.e., malondialdehyde reduction, were seen with beetroot juice and radish supplementation, proving the positive effect of raw consumed root vegetables on oxidative stress management [110, 112]. A study has shown betanin, a major


#### **Table 5.**

*Carrot, beetroot and radish supplementation effect on oxidative stress as determined by malondialdehyde (MDA) level.*

beetroot compound, as an efficient antioxidant against oxidative stress in rats with acute kidney damage [115]. In hepatotoxic conditions, the oxidative stress on the cells increases; however, black radish extract treatment to human hepatocyte carcinoma (HepG2) cells and rats with liver injury has indicated a dose-dependent increase in hepatic proteins expressions along with radical scavenging by 3-(E)-(methylthio) methylene-2-pyrrolidinethione, a compound isolated from black radish and lipid accumulation prevention which collectively produce a hepatoprotective effect [116]. Commercially available purple sweet potato pigments are also suitable for lowering oxidative stress resulting from hepatic injury in mice [117]. Antioxidants such as vitamin E and anthocyanins of purple carrots act as oxidative damage protectors in rat organs, and when provided in a combination, MDA level drops significantly [118]. A study has indicated 2, 4-di-tert-butylphenol as a prominent antioxidant of sweet potato, lowing oxidative stress in neuronal cell damage in mice [119]. Leave supplementation also effectively reduces oxidative stress in a dose-dependent manner. A study on rats (fed on a cholesterol-rich diet) has indicated an improvement in cholesterol profile along with lower MDA levels upon turnip leaves supplementation, compared to positive control [120]. A similar kind of study on cholesterol-fed hamsters has also shown a reduction in oxidative stress upon supplementing sweet potato leaves [121]. Yams extract has also shown a reduced hyperhomocysteinemic-induced oxidative stress in rats [114].
