Blood Glucose-lowering Effect of T.procumbens L.: A Pilot Clinical Study in Individuals with Type 2 Diabetes Gauri S. Desai, 1,2 Shirish V. Desai, 2 Rajendra S. Gavaskar, 3 Vanisree Mulabagal, 4 Yonnie Wu 5 and Suresh T. Mathews 1 * 1 Department of Nutrition and Dietetics, Boshell Diabetes and Metabolic Diseases Research Program, Auburn University, Auburn, AL 36830, USA 2 Bhagawati Industrial and Organic Products, Kolhapur, Maharashtra, India 3 GTL Foundation, Sindhudurg, Maharashtra, India 4 Department of Chemical Engineering, Tuskegee University, Tuskegee, AL 36088, USA 5 Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849, USA Traditional knowledge, in vitro studies, and studies using animal models suggest that Tridax procumbens L. exhibits blood glucose-lowering properties and antiinflammatory effects. In this study, we evaluated the blood glucose-lowering effect of T. procumbens supplementation in individuals with type 2 diabetes. An extract (asava) of T. procumbens L. was prepared following Ayurveda guidelines. Chemical and microbial analyses indicated pres- ence of phenolics, flavonoids, and carotenoids, and absence of microbial contamination, aflatoxins, heavy metals, and pesticide residues. A chemical fingerprint of T. procumbens L. asava, developed using Ultra high pressure liquid chromatography/electron spray ionization-mass spectrometry (UPLC/ESI-MS) in negative mode, suggest the pres- ence of several compounds including polyphenols. T. procumbens asava demonstrated strong total antioxidant capacity, Fe 3+ reducing potential, Fe 2+ chelation, H 2 O 2 scavenging activity, and inhibition of lipid peroxida- tion. We recruited 20 type 2 diabetic individuals from Kolhapur, India. Participants received 15mL of T. procumbens asava, twice daily, for 4 weeks, while continuing their prescribed antidiabetic medications. Fasting blood glucose decreased by 11% in men (p < 0.01) and 20% in women (p < 0.05), and post-prandial blood glucose concentrations were lowered by 26% in men (p < 0.001) and 29% in women (p < 0.001) following 4 weeks of asava supplementation. No adverse events or side effects were reported. This is the first clinical study demonstrating a significant blood glucose-lowering effect of T. procumbens asava in type 2 diabetes. Copyright © 2015 John Wiley & Sons, Ltd. Keywords: Tridax procumbens; diabetes; blood glucose control; antioxidants. Supporting information may be found in the online version of this article (Supplementary Material) INTRODUCTION Tridax procumbens Linn., (family Asteraceae), a common herb, native to the tropical Americas, is known for several potential therapeutic activities. Traditionally, it has been used, in certain parts of India, to alleviate symptoms of inflamed skin, mouth sores, skin infections, bleeding wounds, diarrhea, rheumatism, and epistaxis (Ayyanar and Ignacimuthu, 2005). Extensive field excursions and collection of ethnobotanical information from local inhabitants of Gond and Kharwar communites from Sonabhardra district, Uttar Pradesh, India, also revealed the use of T. procumbens plant paste for bleeding wounds, cuts, and stings (Singh et al., 2002). Ethnomedicinal information collected from six districts, namely, Alwar, Bharatpur, Dausa, Dholpur, Karouli, and Sawai Madhopur within the eastern parts of Rajasthan, India, verified that T. procumbens was commonly used as ethnomedicine (21.63% informants reported use of T. procumbens), third in line following Azadirachta indica (neem) and Ocimum sanctum (holy basil) (Upadhyay et al., 2010). Inhabitants from regions including Mandesh (Maharashtra, India) and Udaipur (Rajasthan, India) have reported the use of T. procumbens for diabetes management (Bhagwat et al., 2008; Pareek et al., 2009). Although T. procumbens has not been included in Charaka Samhitha, Sushruta Samhitha, Ashtanga Hridayam, or Ashtanga Sangraha, the classical texts of Ayurveda, there has been an increased interest to include this in Ayurveda pharmacopeias (Kethamakka and Deogade, 2014). Diabetes is one of the major causes of premature illness and death worldwide. According to the International Di- abetes Federation, 382 million people globally have dia- betes, and this is projected to rise to 592 million by 2035 (International Diabetes Federation, 2013). Conventional drug therapy uses oral hypoglycemic agents as the first line of therapy in the management of diabetes. However, increasing costs of conventional antidiabetic therapy and associated side effects can result in non-adherence and poor blood glucose control (Hauber et al., 2009). According to the National Health Statistics Report, the use of complementary and alternative medicine/therapies * Correspondence to: Suresh T. Mathews, Department of Nutrition and Dietetics, 260 Lem Morrison Dr., 101 PSB, Auburn University, AL 36849, USA. E-mail: mathest@auburn.edu PHYTOTHERAPY RESEARCH Phytother. Res. 29: 1404–1411 (2015) Published online 22 June 2015 in Wiley Online Library (wileyonlinelibrary.com) DOI: 10.1002/ptr.5394 Copyright © 2015 John Wiley & Sons, Ltd. Received 22 April 2014 Revised 20 April 2015 Accepted 20 May 2015