Research Article COMPARATIVE STUDY OF ALCOHOLIC AND AQUEOUS EXTRACTS OFTRIBULUS TERRESTRIS ON SPECIFIC AND NON SPECIFIC IMMUNE RESPONSES IN WISTAR RATS: AN IN VIVO STUDY ANITA TILWARI ab* , N.P. SHUKLA a , P. UMA DEVI c Centre of Excellence in Biotechnology, M.P. Council of Science and Technology, Vigyan Bhawan, Bhopal, IndiaSchool of Biotechnology, Rajiv Gandhi Technical University, Airport Bypass Road, Bhopal Jawahar lal Nehru Cancer Hospital and Reasearch Centre , Bhopal, Madhya Pradesh, India. Email: anita_tilwari@yahoo.com Received: 30 July 2012, Revised and Accepted: 18 May 2013 ABSTRACT The present study was aimed to study the effect of alcoholic and aqueous extracts of fruits of Tribulus terrestris, commonly known as Gokhru, (belongs to family, Zygophyllaceae) on specific and non specific immune functions in Wistar rats. The immunomodulatory activity was investigated by phagocytic carbon clearance, antibody titre, and Delayed type hypersensitivity test. Control group received 0.1% Carboxyl methyl cellulose and treated groups received different concentrations (0.5, 1, 2 mg/kg b.w.) of alcoholic and aqueous extracts of fruits of Tribulus terrestris intraperitoneally. The study revealed that alcoholic and aqueous extracts of fruits of Tribulus terrestris has exhibited the immunostimulatory activity by increasing humoral antibody titre and delayed hypersensitivity reaction as indicated by increase in footpad thickness, it also shown significant increase in phagocytic activity in wistar rats at different concentrations which reveals increase in the specific and non specific immune responses. The present investigation reveals that both the aqueous and alcoholic extract of the plant possess the potent immunomodulatory activity; further investigation is required to isolate the active compound to see its mechanism of action and to develop an immunostimulating agent among herbal origin. Keywords: Immunostimulant, Phagocytic index, Humoral immunity, cell mediated immunity. INTRODUCTION Medicinal plants are rich source of secondary metabolites and are used for the treatment of many diseases. Many synthetic drugs are developed as immunomodulators but the major drawback of these drugs is many side effects such as myelosuppression, which is undesirable. Immunomodulator of herbal origin appears to be a better alternative to overcome the above problem [1,2,3]. The function and efficacy of the immune system may be influenced by many exogenous factors like food and pharmaceuticals, physical and psychological stress and hormones etc. resulting in their immunostimulation or immunosupression. The healthy state believed to be based on a sophisticated fine tuning of immunoregulatory mechanism [4,5]. Immunostimulators have been known to support T-cell function, activate macrophages and granulocytes, and complement natural killer cells apart from affecting the production of various effector molecules generated by activated cells (Paraimmunity) [6]. It is expected that these non- specific effects offer protection against different pathogens, including bacteria, fungi, viruses and so on, and constitute an alternative to conventional chemotherapy [7]. Ayurveda, the oldest medicinal system in the world, provides leads to find therapeutically useful compounds from plants. Therefore, ayurvedic knowledge supported by modern science is necessary to isolate, characterise, and standardise the active constituents from herbal source. Recent screening with plants has revealed many compounds like flavonoids, alkaloids, saponins, terpenoids, monoterpenoids (linalool), glycoproteins, polysaccharides, tannins, essential fatty acids, phenolics compounds and vitamins having pronounced antioxidant, antineoplastic, antiulcer, anti-inflammatory and immunostimulating potential [8]. This combination of traditional and modern knowledge can produce better antiulcer, anticancer and immunomodulatory drugs with very few side effects. Tribulus terrestris, commonly known as Gokhru, puncture vine and goathead, etc. is a shrub belonging to the family Zygophyllaceae. Historically, Tribulus terrestris was used by the cultures of India and Greece as a rejuvenation tonic [9]. It was also used as a therapy for a variety of health conditions affecting the liver, kidney, cardiovascular and immune systems [10] . Today, Tribulus terrestris in combination with a variety of herbal products is used in headaches, eye conditions such as itching, conjunctivitis and weak vision, and nervousness[11]. This herb has also been used in connection with high blood pressure and rib pain[12]. . The inhibitory effect of saponins from Tribulus terestris on Bcap-37 breast cancer cell line in vitro were also studied [13]. Pande and Vijaykumar [14] and Rao et al [15] successfully demonstrated the immunomodulating activity of a combination of extracts of these plants. It has tonic and aphrodisiac properties [16] . The therapeutic properties of Tribulus terrestris have been attributed to the presence of active compounds saponins, alkaloids and flavonoids etc [17] . Thus in our present study, we have attempted to evaluate the immunomodulatory potency of alcoholic and aqueous extracts of fruits of Tribulus terrestris on specific and non specific immune responses. MATERIALS AND METHODS Animals Inbred Wistar rats of either sex, 3-4 weeks old were obtained from the National Institute of Nutrition, Hyderabad and were acclimatized for 3-4 weeks in the animal house of Jawaharlal Nehru Cancer Hospital and Research Centre, Bhopal, under standard conditions of temperature (23 ± 2 o C), relative humidity (50 ± 5%) and light (10:14 h of light and dark respectively). The animals were housed in polypropylene cages containing sterile paddy husk (procured locally) as bedding and fed with standard animal feed and filtered, acidified water ad libitum. Seven to eight weeks old and weighing 150 to 200g animals were selected for the experiments. Research was conducted in accordance with the guidelines of internationally accepted principles for laboratory animal use and cares (CPCSEA), as approved by the Institutional Animal Ethics Committee. Plant material and extract preparation Fruits of Tribulus terrestris (voucher specimen no.13424), were collected from the suburbs of Bhopal and identified at the State Forest Research Institute, Jabalpur, M.P. India, where a voucher specimen has been preserved for future identification. The plant parts were thoroughly washed with tap water and dried on filter paper sheets under shade at room temperature for more than one month. The International Journal of Pharmacy and Pharmaceutical Sciences ISSN- 0975-1491 Vol 5, Suppl 3, 2013 A A c c a a d d e e m mi i c c S S c c i i e e n n c c e e s s