Probiotic bacteria and hypocholesterolemia peptides in camel milk prevent cholesterol reabsorption from the intestine by deconjugating bile salts, reducing cholesterol’s micellar solubility, and inhibiting cholesterol absorption.
What is Mechanism?
In rats, fermented camel milk had hypocholesterolemic effects. But maybe the interaction between the bioactive peptides in camel milk and cholesterol decreases cholesterol. According to other research, orotic acid produced from nucleic acid metabolism is responsible for lowering cholesterol in rats and humans who consume camel milk.
The administration of camel milk for five weeks showed a significant decrease in total cholesterol from 6.17 to 4.35 mmol. l-1. Researchers concluded that camel milk for 45 days significantly decreased hyperlipidemia, total cholesterol, triacylglycerol, free fatty acid, LDL, and VLDL in plasma, liver, heart, and kidney to normal levels. Also, after the consumption of camel milk, the content of HDL significantly improved. Other researchers recently reported the hypocholesterolemic effect of fermented camel milk or Garissa. After consuming camel milk for six months, the amounts of LDL and triacylglycerol reduced in type 1 diabetic cases.
According to researches, 1 % reduction in serum cholesterol leads to a 2 to 3 % reduction in the risk of cardiovascular diseases. Studies have reported the effects of lowering blood cholesterol by fermented dairy products in humans and animals, but the cholesterol-lowering mechanism is unknown.
Probiotic bacteria and bioactive peptides produced by their proteolytic activity have hypocholesterolemic effects. Probiotic bacteria ferment indigestible carbohydrates and produce short-chain fatty acids in the gut, affecting hepatic cholesterol synthesis and cholesterol distribution from plasma to the liver. Probiotic bacteria also interfere with the absorption of cholesterol from the intestine by deconjugating bile salts and preventing reabsorption or direct absorption of cholesterol.
Cholesterol-lowering peptides also reduce cholesterol by binding to cholesterol by electrostatic and hydrophobic reactions or by lowering the micellar solubility of cholesterol and inhibiting cholesterol absorption. The decrease in cholesterol levels may also be due to the direct interaction of arginine and tyrosine with the cholesterol and the formation of the apoprotein-cholesterol complex, which depends on the amount of arginine in the protein.
Recent studies have shown that non-hydrolyzed casein does not affect lowering cholesterol; However, compounds obtained by casein hydrolysis by Bb12 or trypsin and Bb12 reduced cholesterol levels by 24 to 87 %. This bacteria in milk converts casein into peptides that lower cholesterol. There may also be a synergistic effect between peptides and bacterial culture in lowering cholesterol, and Bb12 bacteria culture and its peptides had a more significant cholesterol-lowering effect than peptides alone.
According to studies, fermented dairy products are recommended as a dietary supplement due to their hypocholesterolemic effect in humans and mice. Buffalo yogurt contains Bifidobacterium, which lowers plasma and liver cholesterol levels. Most research has been done to study fermented products, especially cow’s milk yogurt, in reducing cholesterol using Bifidobacterium bifidum, Bifidobacterium langue, and Lactobacillus acidophil.s; However, the mechanism of lowering cholesterol in camel milk remains unclear.
Fermented milk and camel whey protein contain angiotensin-converting enzyme-inhibiting peptides, which regulate blood pressure produced by the proteolytic digestion of casein and whey proteins. Of course, this peptide is resistant to enzymatic proteases and heat, but more research is needed to confirm its effects.
The C-terminal sequence of these peptides binds to the active site of this enzyme and inhibits its activity. Other factors, such as cysteine, insulin-like proteins in whey proteins, and small-size immunoglobulins, may also contribute to the cholesterol-lowering effects of camel milk proteins.
The Lactobacillus helveticus 130B4 releases the angiotensin-converting enzyme-inhibiting peptide (ACE) from camel milk proteins. After enzymatic hydrolysis of camel milk proteins, the ACE inhibitory activity of total casein and beta-casein increased. Whole casein and beta-casein in camel milk had high ACE inhibitory activity after hydrolysis with pepsin, trypsin, and chymotrypsin.
ACE inhibitory activity was higher in cultured camel milk than in cow milk, possibly due to structural differences and higher proline in the initial structure of camel milk casein than in cow milk. Lactic acid bacteria produce ACE inhibitors from camel’s milk, effectively maintaining health. These inhibitors are obtained from the fermentation of milk by the Lactobacillus del brake, Lactobacillus bulgaricus, Lactobacillus helveticus, Saccharomyces cerevisiae, and Lactococcus lactis.
Oxidative stress and subsequent damages occur when antioxidant defense mechanisms cannot cope with endogenous or external reactive oxygen species (ROS) sources. Increased oxidative stress may lead to diabetes mellitus and complications like vascular disease. Therefore, controlling ROS production is essential for the cell’s physiological function.
Conclusion
It proved that consuming camel milk for six months reduced LDL and triacylglycerols in type 1 diabetic cases. A reduction of 1% in cholesterol levels reduces the risk of cardiovascular diseases by 2–3%. More scientific studies are needed to confirm the effectiveness of camel milk on heart health.
References
Alhaj., O.A. A. Kanekanian, A. Peters. 2006. The effect of Bifidobacterium lactic and trypsin on cholesterol. In: International Food and Health Innovation Conference, Malmö, Skane Food Innovation Network, Sweden.
Ali., A.A. A.A. Alyan, and A.S Bahobail. 2013. Effect of fermented camel milk and cow milk containing (bifidobacteria) enriched diet in rats fed on cholesterol level: the Agricultural Science Research Journal, 3:342e6.
Elayan., A.A, A.E Sulieman, and F.A. Saleh. 2008. The hypocholesterolemic effect of Garissa and Garissa containing Bifid bacteria in rats fed on a cholesterol-enriched diet. Asian Journal of Biochemistry, 3: 43-47.
Kawase. M. Effect of administration of fermented milk containing whey protein concentrate to rats and healthy men on serum lipids and blood pressure. Journal Dairy Science.2000;83(2):255-63.
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Mohammadabadi T. and Jain R. 2023. Camel Milk: a superfood for diabetes and a healthy life. Haghshenas’ publication, p. 128.
Mohammadabadi T., Jain R. Rehman, AU., Juwarey, M, Singh M, et al. 2023. Camel Milk – A Nutritious Superfood for Health Complications. Milk Science International (76). 35-43.
Mohammadabadi, T. 2020. Camel milk as an amazing remedy for health complications: A review article. Basrah Journal of Agricultural Science. 33(2).
