IOSR Journal of Pharmacy and Biological Sciences (IOSR-JPBS) e-ISSN: 2278-3008, p-ISSN:2319-7676. Volume 7, Issue 1 (Jul. – Aug. 2013), PP 42-47 www.iosrjournals.org www.iosrjournals.org 42 | Page Effect of astaxanthin on ethylene glycol induced nephrolithiasis Manju Alex a , Mathews V Varghese a , M Abhilash a , M V Sauganth Paul a R Harikumaran Nair a a School of Biosciences, Mahatma Gandhi University, Priyadarsini Hills P.O. Kottayam, Kerala, India, 686560 Abstract: Nephrolithiasis is one of the most common and painful of urological disorders with a high prevalence rate. The role of calcium oxalate crystals, which are the predominant component of kidney stones in generating oxidative stress, have been clearly demonstrated in previous studies. Astaxanthin, found in marine organisms is a dietary xanthophyll carotenoid with enhanced antioxidative properties and pharmacological effects. In the present study, we have investigated the effect of this natural antioxidant, at a daily dose of 25mg/kg in experimental calcium oxalate nephrolithiasis in male Wistar rats. Liver function markers, hepatic antioxidants, albumin creatinine ratios, renal calcium content and changes in body and kidney weight have been studied to evaluate the effect of this carotenoid in vivo. The effect of citrate, a component of most pharmaceutical drugs for management of nephrolithiasis has also been evaluated for the purpose of comparison with astaxanthin treatment. Astaxanthin is seen to exert a protective effect on the liver and kidney tissues in ethylene glycol treated rats by improving the liver function, restoring the activity of the hepatic antioxidant enzymes, decreasing the albumin creatinine ratios and calcium levels and maintaining the organ to body weight ratio. Our results also indicate that astaxanthin administration is more beneficial than citrate treatment. Keywords: astaxanthin, calcium oxalate, citrate, nephrolithiasis, nephroprotective. I. Introduction Kidney stone disease is one of the most painful and common urological disorders affecting mankind since centuries. Calcium containing stones especially calcium oxy monohydrate (COM) are the most commonly occurring ones to the extent of 75-90% [1]. Several invasive and non invasive procedures are currently employed for the treatment of kidney stones but they are limited by their high cost, severe adverse effects and high recurrence rates [2]. Hence researchers in this area are confronted with the need to develop natural remedies to combat this disease. Organ weight can be the most sensitive indicator of the effect of an experimental compound. Significant differences may occur between the organ weights of a treated and non treated animal even in the absence of evident morphological changes. A criterion called relative organ weight is used here which accommodates the changes in body weights of the experimental animals [3]. Liver is the target organ for the metabolism of all drugs and toxic chemicals. Any drug administered will exert its action at the hepatic level. Hence an evaluation of the hepatic function has been carried out in this study as well by estimating the alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase levels (ALP) as they are released into blood following hepatocellular damage [4]. Kidney is vital in maintenance of homeostasis through the excretion of catabolites like urea, creatinine, uric acid and elevated concentration of these indicates compromised renal function. Oxidative stress has been implicated as a mechanism in oxalate induced renal damage. Hence treatment with antioxidants could be a possible strategy to effectively reduce the damage caused by COM stones. Astaxanthin (3, 3-dihydroxybeta, beta-carotene-4, 4-dione, CAS 472-61-7) is a naturally occurring carotenoid found in variety of plants, algae and sea food such as salmon, trout, red sea bream, shrimp, lobster and fish eggs. It is also present in birds such as flamingos and quails. In many of the aquatic animals in which it is found, astaxanthin has several essential biological functions including protection against oxidation of essential polyunsaturated fatty acids; protection against UV light effects; immune response; pigmentation; etc [5]. Some microorganisms are rich in astaxanthin – the chlorophyte alga Haematococcus pluvialis is believed to accumulate the highest levels of astaxanthin in nature. Astaxanthin exhibits 100-500 times more antioxidant property than α-tocopherol [6]. Moreover, astaxanthin has been found to provide many essential biological functions, including protection against lipid-membrane peroxidation of essential polyunsaturated fatty acids and proteins, DNA damage and UV light effects; it also plays an important role in immunological defence [7]. This has stirred great interest in astaxanthin and promoted numerous research studies concerning its potential benefits to humans and animals. The current study was undertaken to assess the effect of astaxanthin at a dose of 25 mg/kg body weight on relative organ weights, liver marker enzymes, hepatic antioxidant enzymes, calcium levels and serum and urine albumin creatinine ratios in experimentally induced calcium oxalate stone disease. A comparison has also been made with citrate administration used in pharmaceutical preparations for the clinical treatment of kidney stones.