Phospholipids can prevent the formation of stones

Phospholipids, a class of lipids containing phosphoric acid, play a role in preventing stone formation and dissolving existing stones. The following explains the principles of phospholipids' actions in these two aspects based on the mechanisms of stone formation:

I. Prevention of Stone Formation

1. Gallstones

Fat Emulsification

Phospholipids in bile emulsify fats, breaking them into fine droplets to increase the contact area between fats and lipases, thereby promoting fat digestion and absorption. Meanwhile, phospholipids disperse cholesterol in bile, preventing it from supersaturating and precipitating into crystals. When phospholipid levels in bile decrease, cholesterol solubility drops, making it prone to precipitation and forming cholesterol gallstones.

Regulation of Bile Composition

Phospholipids influence the ratio of cholesterol, bile salts, and lecithin in bile. Under normal conditions, these three components maintain a specific balance to ensure bile stability. Phospholipids enhance the binding capacity between bile salts and cholesterol, keeping cholesterol in the form of soluble mixed micelles and reducing the risk of cholesterol gallstone formation.

2. Kidney Stones

Inhibition of Crystal Formation

Phospholipid molecules have hydrophilic and hydrophobic ends, forming micelle structures in solutions. These micelles can adsorb stone-forming substances in urine, such as calcium ions and oxalate ions, preventing them from combining to form crystals. Additionally, phospholipids alter the surface properties of crystals, inhibiting their growth and aggregation, thus preventing kidney stone formation.

Maintenance of Urine Osmotic Pressure and pH Stability

Phospholipids help maintain normal osmotic pressure and pH in urine. A suitable urinary environment (in terms of osmotic pressure and pH) discourages the supersaturation and precipitation of stone-forming components. For example, an appropriate urinary pH affects the solubility of kidney stone components like calcium oxalate and uric acid. Phospholipids can regulate urinary acid-base balance to some extent, reducing the likelihood of stone formation.

II. Dissolution of Existing Stones

1. Gallstones

Promotion of Cholesterol Stone Dissolution

For cholesterol gallstones, phospholipids enhance the solubility of cholesterol in bile to facilitate stone dissolution. When phospholipid levels in bile increase, they form more stable complexes with cholesterol, gradually softening and dissolving cholesterol stones. Furthermore, phospholipids improve gallbladder contractility, promoting bile excretion and aiding stone passage.

Reduction of Inflammatory Responses

Gallstones often induce inflammatory reactions in the gallbladder or bile ducts, while phospholipids possess anti-inflammatory properties. They regulate the function of inflammatory cells, reduce the release of inflammatory mediators, and alleviate damage to the biliary system caused by inflammation, creating favorable conditions for stone dissolution and excretion.

2. Kidney Stones

Alteration of Stone Surface Charge

Phospholipid molecules carry electrical charges that interact with ions on the surface of kidney stones, changing the stones' surface charge properties. This charge alteration affects the interaction between stones and surrounding urine components, reducing surface adsorption and preventing stones from growing larger. Meanwhile, charged phospholipids promote interactions between stones and urine, making it easier for stones to detach from the urinary tract wall and be excreted with urine.

Enhancement of Urinary Flushing Effect

Phospholipids increase urine viscosity and fluidity, enhancing the flushing effect of urine. As urine flows through the urinary tract, it can more effectively flush out stone fragments or small stones, thus achieving the goal of dissolving stones.