Intestinal anti-spasmodic effect of a phytodrug of Psidium guajava folia in the treatment of acute diarrheic disease Xavier Lozoya a, *, Hortensia Reyes-Morales b , Marco A. Cha ´ vez-Soto a , Marı ´a del Carmen Martı ´nez-Garcı ´a c , Yolanda Soto-Gonza ´lez d ,Svetlana V. Doubova b a Laboratory of Medicinal Plants at Research Unit of Neurological Diseases, Mexican Institute of Social Security (IMSS), Mexico City, Mexico b Epidemiology and Health Services Research Unit, Mexican Institute of Social Security (IMSS), Mexico City, Mexico c Division of Clinical Research, Mexican Institute of Social Security (IMSS), Mexico City, Mexico d Family Medicine Unit No. 23, Mexican Institute of Social Security (IMSS), Mexico City, Mexico Received 15 October 2001; received in revised form 12 June 2002; accepted 17 June 2002 Abstract Ancestral medicinal use of guava(Psidium guajava L. Fam. Myrtaceae ) is today supported by numerous biomedical studies concerning the properties of leaf extracts. However, insufficient clinical studies are reported on the use of this plant resource in the treatment of gastrointestinal ailments. The present work reports a randomized, double-blinded, clinical study performed to evaluate the safety and efficacy of a phytodrug (QG-5 † ) developed from guava leaves, standardized in its content of quercetin and orally administered to a group of adult patients with acute diarrheic disease. Capsules containing 500 mg of the product were administered to 50 patients every 8 h during 3 days. Results obtained showed that the used guava product decreased the duration of abdominal pain in these patients. # 2002 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Psidium guajava L.; Intestinal anti-spasmodic; Phytodrug; Acute diarrheic disease 1. Introduction Psidium guajava L. (fam. Mirtaceae ) is a tree native of the Mesoamerican geographical area, e.g. it is widely distributed in Mexico and in Central American coun- tries. The tree, commonly named guayabo in Spanish and guava in English, is frequently cultivated as a food for its pleasant fruits that also used in the manufacture of the jam. Today, the tree can be found cultivated or growing wild in nearly all the countries of the Tropical World Belt, from the West Coast of Africa to the Pacific Region, including India and China, with varieties originally introduced from America over the past 300 years. The medicinal use of a water infusion prepared with guava tree leaves for the alleviation of gastrointestinal disorders is a common practice originally inherited from traditional Aztec medicine in Mexico. The therapeutic properties of the leaves of this tree are described in detail in many Mexican herbal historical sources of the last 500 years. The plant is always related to the treatment of dysenteries, the relief of cramps, abdominal distention, and curing diarrhea (For historical references, see Lozoya, 1999). Present popular Mexican medicine recommends the use of the guava leaf water decoction for oral administration, three times daily, as an effective remedy to treat acute diarrhea, colic, flatulence, and gastric pain (Aguilar et al., 1994). According to modern ethnomedical information, no side effects are observed in the use of this popular guava leaf remedy and * Corresponding author. Address: Instituto Mexicano del Seguro Social. Centro Medico Nacional Siglo XXI, Hospital de Especialidades, Laboratorio de Plantas Medicinales de la Unidad de Investigacio ´n en Enfermedades Neurolo ´gicas, Av. Cuauhte ´moc 330, Col. Doctores, CP 06920 Mexico, D.F., Mexico. Tel.:  /525-627-69- 00x1021; fax:  /525-19-98-92-19 E-mail address: 4509@axtel.net (X. Lozoya). Journal of Ethnopharmacology 83 (2002) 19  /24 www.elsevier.com/locate/jethpharm 0378-8741/02/$ - see front matter # 2002 Elsevier Science Ireland Ltd. All rights reserved. PII:S0378-8741(02)00185-X