**4.4 Effects of anthocyanins in preventing cardiovascular diseases**

In recent years, cardiovascular diseases have become the common diseases that endanger human health. With the deepening of the research on oxygen free radicals in diseases, a large number of data have confirmed that the oxidative reactions mediated by free radicals and their products play an important role in the occurrence and development of cardiovascular diseases. As people age, the elastic fibers of arteries harden as they are oxidized, and the change is a major cause of cardiovascular disease in aging people. Proanthocyanidins mainly play an important role in preventing cardiovascular diseases by inhibiting the formation of artery atherosclerotic plaque and reducing the damage of free radicals induced by myocardial ischemia for protecting myocardial cell activity. Proanthocyanidins can protect blood vessels and reduce capillary permeability, and its function of preventing cardiovascular diseases is closely related to its antioxidative stress. Some results indicated that grape seed proanthocyanidins can effectively reduce the levels of LDL and cholesterol and the generation of MDA [28]. In addition, GSPE can protect vascular substances by capturing ROS and regulating enzyme activity [29]. Anthocyanins extracted from red wine can effectively remove superoxide free radicals and hydroxyl free radicals. The in vitro experiments indicated that anthocyanins can significantly inhibit the oxidation of LDL and the aggregation of platelets [30]. The animal and clinical studies have also found that proanthocyanidins can reduce blood pressure by lowering cholesterol level, reducing cholesterol deposition on blood vessel walls and improving vascular elasticity [31]. Some studies showed that *Nelumbo nucifera* Gaertn proanthocyanidins can increase the SOD activity of myocardial cells during ischemia reperfusion and reduce the production of MDA, thereby inhibiting apoptosis and protecting myocardial ischemia reperfusion [32]. Studies by Suda I et al. showed that anthocyanins from *Solanum tuberosum* can be absorbed by rats, enhance the antioxidant capacity of plasma, and play an important role in protecting cardiovascular system [33].

#### **4.5 Protective effects of anthocyanins on liver and kidney**

Studies have shown that gluttony can harm gastrointestinal tract, liver, and kidney as large amounts of free radicals are produced. Removing these deteriorated free radicals timely can protect liver cells and improve liver function. When fatty liver occurs, free fatty acids, oxidative stress, and free radicals are increased, which lead to the degeneration of proteins, DNA, and lipid in liver cells and lower the immunity. *Solanum tuberosum* anthocyanins were proven to alleviate liver injury caused by dimethylnitrosamine (DMN), protect the liver function, and resist

*Anthocyanins: Novel Antioxidants in Diseases Prevention and Human Health DOI: http://dx.doi.org/10.5772/intechopen.89746*

liver fibrosis [34]. In addition, *Solanum tuberosum* anthocyanins can also activate adenosine monophosphate to sensitize the protein kinase and inhibit liver fatty accumulation [35]. The results by Zhang et al. were also reported that anthocyanins from *Solanum tuberosum* can alleviate insulin resistance in liver caused by high-fat diet, and the effective mechanism is that anthocyanins can block oxidative and endoplasmic reticulum stress [36]. Studies showed that anthocyanins of *Solanum tuberosum* can inhibit oxidative stress in the kidney, and the molecular mechanism was to inhibit the activation of NLRP3 signaling pathway of inflammasome [37]. Studies by Sun et al. reported that *Solanum tuberosum* anthocyanins have a preventive effect on acute and subacute alcoholic liver injury and indicated that *Solanum tuberosum* anthocyanins have a certain antialcoholic effect [38].
