Basic nutritional investigation Antioxidant activity and hepatoprotective effects of whey protein and Spirulina in rats Ahmed S. Gad Ph.D. a , Yasser A. Khadrawy Ph.D. b , Aziza A. El-Nekeety Ph.D. c , Sherif R. Mohamed Ph.D. c , Nabila S. Hassan Ph.D. d , Mosaad A. Abdel-Wahhab Ph.D. c, * a Dairy Science Department, National Research Center, Dokki, Cairo, Egypt b Medical Physiology Department, National Research Center, Dokki, Cairo, Egypt c Food Toxicology and Contaminants Department, National Research Center, Dokki, Cairo, Egypt d Pathology Department, National Research Center, Dokki, Cairo, Egypt article info Article history: Received 3 November 2009 Accepted 5 April 2010 Keywords: Whey protein Spirulina Antioxidant Hepatoprotective Oxidative stress Rats abstract Objectives: The aims of the present study were to evaluate the antioxidant, radical scavenging, and metal-chelating activity of whey protein concentrate (WPC) and Spirulina alone or in combination in vitro and to evaluate their hepatoprotective effects against CCl 4 in vivo. Methods: Five concentrations (20, 40, 60, 80, and 100 mg/100 mL) of WPC, Spirulina, and their combination were tested in vitro. In the in vivo study, eight groups of male rats comprised the control group and the groups treated with WPC, Spirulina alone, or in combination with or without CCl 4 were used. Results: The in vitro study showed that WPC and Spirulina showed antioxidant, radical scavenging, and metal-chelating activities in dose-dependent manner. The in vivo study showed that both agents succeeded in preventing liver damage induced by CCl 4 . This prevention was more pronounced in rats receiving the combination of WPC and Spirulina. Conclusion: Whey protein concentrate and Spirulina have free radical scavenging properties and antioxidant activity. Ó 2011 Elsevier Inc. All rights reserved. Introduction In recent years, there has been an explosive interest in the use of antioxidant nutritional supplements [1,2]. Epidemiologic evidence has suggested that intake of some vitamins, minerals, and other food constituents may help to protect the body against heart disease, cancer, and the aging process, and that antioxi- dants may have a protective effect in preventing these diseases or lessening their severity [3–6]. Several activities of the anti- oxidants are mediated by inhibition of reactive oxygen species, which are generated during the oxidative burst. Thus, the usefulness of antioxidants in protecting cellular components against oxidative stress is well established [7,8]. Whey protein concentrates (WPCs) are a heterogeneous group obtained in milk after casein precipitation at pH 4.6 [9]. The concentrations in milk vary from approximately 5 to 7 g/L. WPCs have decreased tumor incidence and tumor area in dimethylhydrazine-dihydrochloride–induced colon tumors in mice [10]. The major components in decreasing amounts are b-lactoglobulin, a-lactalbumin, bovine serum albumin, and immunoglobulins. Commercial WPC is prepared in the dairy industry as a byproduct of cheese and casein manufacture. WPC contains carbohydrate and lipids [9]; it also contains bioactive substances such as hormones, growth factors, and cytokines, which can have an important physiological role [11]. WPC, a protein complex derived from milk, is being touted as a func- tional food with a number of health benefits. In addition, WPC has the ability to act as an antioxidant [12], antihypertensive, antitumor [13], hypolipidemic, antiviral [14], antibacterial [15], and chelating [16] agent. Compared with other protein sources, WPC has a high concentration of branched-chain amino acid- sdleucine, isoleucine, and valine. Leucine has been identified as a key amino acid in protein metabolism during the translation– initiation pathway of protein synthesis [17]. Spirulina platensis is a blue-green alga (Cyanobacterium, family Oscillatoriaceae). It is gaining more attention because of its nutritional and various medicinal properties [18]. Spirulina is the only blue-green alga commercially cultivated for food use. In 1996, the United Nations World Health Organization declared * Corresponding author. Tel.: þ202-2283-1943; fax: þ202-3337-0931. E-mail address: mosaad_abdelwahhab@yahoo.com (M. A. Abdel-Wahhab). 0899-9007/$ - see front matter Ó 2011 Elsevier Inc. All rights reserved. doi:10.1016/j.nut.2010.04.002 Contents lists available at ScienceDirect Nutrition journal homepage: www.nutritionjrnl.com Nutrition 27 (2011) 582–589