ORIGINAL PAPER Effect of Streptomyces 23-2B metabolites on hepatic lipid peroxidation and some antioxidant parameters in Wister rats Nahla S. El-Shenawy Received: 5 February 2010 / Accepted: 29 March 2010 / Published online: 4 April 2010 Ó Springer Science+Business Media B.V. 2010 Abstract Streptomyces 23-2B is one of actinomycetes associated with marine clam Donax trunculus and has potential source of bioactive metabolites, which possesses a broad spectrum antibiotic and anticancer activities. This study aims to evaluate the effect of Streptomyces 23-2B metabolites on hepatic lipid peroxidation (LPO), reduced glutathione (GSH) levels, as well as serum uric acid, total cholesterol (TC), triglyceride (TG), nitric oxide (NO) and tumor necrosis factor-alpha (TNF-a) levels of rat. Animals were divided into four groups: the control group, which received 0.1 ml of 10% Tween-80 by intraperitoneally injection, and the other three experimental groups, which received 10% Tween 80 solution of Streptomyces 23-2B metabolites in doses of 0.5, 5 and 50 mg/kg body weight at an interval 2 days for 2 weeks. LPO levels showed signifi- cant decrease with the lowest doses. The effect at a dose of 50 mg/kg of Streptomyces 23-2B metabolites on TG was more pronounced than the other two doses (0.5 and 5 mg/kg body weight). Hypocholesterolemia was recorded in the treated rats with 0.5 and 5 mg/kg of Streptomyces 23-2B. However, the highest dose enhanced the elevation of serum TNF-a and NO levels. Thus, the present study reveals that Streptomyces 23-2B metabolite is a newly discovered bio- material from microorganisms. The novel substance showed inhibitory activity against LPO in rat liver homogenate and improving the immune response by releasing TNF-a and NO in serum. Keywords Glutathione Á Lipid peroxidation Á Cholesterol Á Triglyceride Á TNF-a Á Nitric oxide Abbreviations ROS Reactive oxygen species TNF-a Alpha tumour necrosis factor NO Nitric oxide TC Total cholesterol TG Triglyceride LPO Lipid peroxidation GSH Glutathione Introduction Many efforts have been made to develop and improve immunotherapy strategies for the treatment of malignan- cies. The use of biological response modifiers (BRMs) for enhancing host defense responses against tumors is one of the most attractive alternatives to cytotoxic drugs (Sche- petkin et al. 2005). Activation of the innate immune system protects against foreign antigens, including tumors (Yoon et al. 2008). Stimulation of the innate immune system has been attempted with a number of strategies, including cytokines constituents isolated from microor- ganisms and herbal plants, and some have reached the clinical trials. The primary mechanism of immune stim- ulation by BRMs is activation of macrophages or natural killer cells (Mukherjee et al. 2001; Wasser 2002; Villinger 2003), which can then lyse or inhibit the growth of tumor cells. Indeed, many experimental studies and clinical trials showed that natural immunity played an important role in blocking metastasis from primary tumors (Yoon et al. 2008). In response to physiologically challenging conditions, such as immune reactions, macrophages release excessive amounts of cytokines, interleukins and prostanoids, often N. S. El-Shenawy (&) Zoology Department, Faculty of Science, Suez Canal University, El Daaeri kilo 4, Ismailia 41522, Egypt e-mail: elshenawy_nahla@hotmail.com 123 World J Microbiol Biotechnol (2010) 26:2185–2191 DOI 10.1007/s11274-010-0403-x