**4. Summary**

synthase, and activation of arginase [9, 58, 59]. Furthermore, high blood cholesterol levels increase endogenous L‐arginine analogues that are able to inhibit nitric oxide synthesis. In particular, asymmetric dimethylarginine competes with L‐arginine at the catalytic site of nitric oxide synthase, and symmetric dimethylarginine blocks the transport of L‐arginine into the cells via the transporter for cationic amino acids [9, 58, 59]. In hypercholesterolemia, erythro‐ cytes and endothelial cells float in cholesterol‐enriched media. This results in a decrease of nitric oxide production and endothelial dysfunction [9, 58, 59]. On the contrary, L‐arginine supplementation restores nitric oxide levels and reduces vascular oxidative damage in hypercholesterolemic conditions [57]. It has been reported that L‐arginine–enriched foods lower LDL levels; this indicates positive health benefits associated with L‐arginine on cardio‐ vascular system [60]. Moreover, dietary supplementation with L‐arginine stimulates nitric oxide biosynthetic pathway. In addition, polyphenolic compound mediates L‐arginine transport into cells and enhances nitric oxide production [60, 61]. L‐arginine–enriched foods include dairy products, poultry, seafood, wheat germ, lupine, granola, oatmeal, peanuts, nuts, pumpkin seed, and chickpeas. The risk of hypotension must be considered during intake of L‐arginine as a cholesterol‐lowering agent. **Figure 3** shows role of cholesterol busters in

**Figure 3.** Mechanisms of action of cholesterol busters in prevention hypercholesterolemia induced endothelial dys‐

function. Green color indicates the site of action of therapeutic agent.

prevention hypercholesterolemia induced endothelial dysfunction.

10 Cholesterol Lowering Therapies and Drugs

Healthy diet and exercise can successfully manage blood cholesterol levels, besides supple‐ mentation of natural cholesterol busters. Natural cholesterol busters not only decrease cholesterol absorption, but also increase cholesterol metabolism and elimination. The inter‐ vention of natural cholesterol busters is the safest strategy in the prevention and treatment of hypercholesterolemia. The hypocholesterolemic properties of natural cholesterol busters have been proved; however, further studies are required to address general recommendations considering human variability in response to dietary regimen. The natural cholesterol busters are found in cereals, oatmeal, fruits, vegetables, and legumes. In case of failure of natural cholesterol busters as first choice cholesterol‐lowering option, the cholesterol‐lowering drugs are recommended with natural cholesterol busters. Take care that high intake of antinutrients may be associated with serious health problems due to the presence of phytate, oxalate, cyanogenic glycoside, and other toxic antinutrients.
