# Old-Fashioned, but Still a Superfood--Red Beets as a Rich Source of Bioactive Compounds
## 2 Betalains
The first studies investigating the chemopreventive potential of beetroot extract were carried out in mice in 1996 [34]. This study proved that oral administration of beetroot extract contributed to the reduction of the number of skin papillomas. [PERSON] et al. also proved the chemopreventive effect of betanin in mice [35]. In their study, two carcinogenic substances, vinyl carbamate and benzopyrene, were used to induce lung tumours, and then an oral treatment with an aqueous solution of betanin was administered. As a result, a reduction of cancer cells was observed, explained by the increased expression of caspase-3, a proapoptotic enzyme belonging to the cysteine-protease group, which increases cell apoptosis levels. The anticancer properties of betalains in mice with xenografts from human lung tumour cells were also proved (A549) [36]. Figure 2: General chemical structures for betacyanins and betaxanthins. Reprinted with permission from [18]. According to [PERSON] et al., a more complex mechanism of betalain action is probably responsible for their antitumor effects [18]. The mechanism of action of _Beta vulgaris_ betanin on tumour cells is present in Figure 3. First, the antioxidant properties of betanin increase the activity of antioxidant enzymes that neutralize ROS produced by immune cells. Then, the red pigments, due to their anti-inflammatory capacity, are able to reduce the production of pro-inflammatory cytokines that increase the migration of leukocytes to the tumour area [37]. At the final stage, betanin causes the formation of blood vessels (angiogenesis) around the tumour area, while increasing levels of apoptosis. The anti-inflammatory properties of betalains are obvious from the use of _B. vulgaris_ betanin-rich pigments used as additives in the food industry. Several studies have attempted to explain the mechanism behind the mechanism of action of betalains [13; 38; 39]. The mechanism that could be responsible for observed anti-inflammatory effects may be the demonstrated in vitro inhibition that betalains exert on the enzymes lipoxygenase and cyclooxygenase, which are involved in the formation of the inflammation-mediating compounds leukotrienes and prostaglandamins. The cardioprotective effect of betalains was also proved. Consumption of betroot chips by rats resulted in a decrease in cholesterol and triglyceride levels in their blood [40]. Novel studies have evaluated the protective effect of betalain against heart failure [41], and the potential impacts of betalain supplementation on some atherosclerotic risk factors in coronary artery disease patients [42]. The effects of betalains on hyperglycemia in diabetic rats have also been reported [43; 44]. Even though the results of animal studies clearly show the health-promoting effect of betalains, only a few similar studies on humans have been described. These examined the impact of betalain intake on the body's efficiency and cardiovascular system [42] and the impact of beet juice supplementation in reducing muscle damage following eccentric exercises [45]. The intake of red beetroot improves glucose metabolism and can help in the treatment of people with type 2 diabetes [46].