Cholelithiasis (gall stone formation) is common global health problem and associated with other hepatobiliary diseases such as stasis of bile, obstruction in bile duct, infection in bile, inflammation of gall bladder valve, liver dysfunction such as reduction in bile salt concentration, high serum bile acid level, high serum cholesterol level, increased serum bilirubin concentration and precipitating factors such as magnesium, calcium, carbonate phosphate and iron which are responsible for gall stone formation. Gall stone are of three types: cholesterol stone, pigment stone and mixed stones based on physico-chemical properties. Cholesterol gall stone are formed in gall bladder, pigment stones in bile canaliculi of liver and mixed stones in entire biliary tract and finally grow and settle down in gall bladder. A characteristic symptom of gallstones is a "gallstone attack" with intense pain in the upper-right side of the abdomen with nausea and vomiting which lasts up to 30 minutes to several hours.

Causes
Risk of cholelithiasis (gall stone formation) was increased with obesity at age near or above 40 especially in female after menopause or pregnancy. As well as lack of melatonin could significantly increased the risk of gall stone formation because melatonin inhibits cholesterol secretion from the gallbladder and enhances the conversion of cholesterol to bile which acts as an antioxidant to reduce oxidative stress to the gallbladder. Hence, scientists believe that cholelithiasis (gall stone formation) is used to cause by a combination of factors such as physiological change, body weight, gallbladder motility (movement), and may be due to dietary habits too.

Role of bile acid level relative to cholelithiasis
Bile acids are produced by the cytochrome P450-mediated oxidation of cholesterol in liver and conjugated with taurine, glycine and with a sulfate or a glucuronide. These are stored in the gallbladder and serve other functions such as eliminating cholesterol from the body as well as to eliminate catabolites from the liver too. In the adult, the total bile acid pool is approximately 1-3 gm which recycles about ten times/ day in enterohepatic circulation. Conjugated bile acids are efficient to form micelles by emulsification of lipids and fat-soluble vitamins in the intestine which are transported via the lacteal system to reduce bacteria flora in the small intestine and biliary tract. Bile acid malabsoption is very common in inflammatory bowel diseases to increase the incidence of gall stones by about twofold in crohn's diseases. Serum bile acids estimation is useful in diagnosis of hepatobiliary, adrenocortical and hepatobiliary diseases.

About Author / Additional Info:
*Corresponding Author:
Dr. Kirti Rani,
Assistant Professor (II),
Amity Institute of Biotechnology,
Amity University Uttar Pradesh, Noida,
Sec-125, Gautam Buddha Nagar, Noida-201303 (UP), India.
Off. Phone no: +120-4392946
Mobile no: +9990329492
Email ID: krsharma@amity.edu, kirtisharma2k@rediffmail.