2007 International Nuclear Atlantic Conference - INAC 2007 Santos, SP, Brazil, September 30 to October 5, 2007 ASSOCIAÇÃO BRASILEIRA DE ENERGIA NUCLEAR - ABEN ISBN: 978-85-99141-02-1 EVALUATION OF FUNGAL BURDEN OF MEDICINAL PLANTS SUBMITTED TO GAMMA RADIATION PROCESS AFTER 30 DAYS Simone Aquino 1 , Edlayne Gonçalez 2 , Tatiana A. dos Reis 2 , Michel M. Araújo 1 , Benedito Corrêa 2 , Anna.L.C.H.Villavicencio 1 . 1 Instituto de Pesquisas Energéticas e Nucleares (IPEN / CNEN - SP) Centro de Tecnologia das Radiações Travessa R. n° 400, Cidade Universitária 05508-910, São Paulo siaq06@hotmail.com 2 Instituto de Ciências Biomédicas (USP) Departamento de Microbiologia, Av. Prof. Lineu Prestes, n° 1374 05508-900, São Paulo correabe@usp.br ABSTRACT Forty samples of medicinal plants (Peumus boldus, Camellia sinensis, Maytenus ilicifolia and Cassia angustifolia), purchased from pharmacies and street market in the five cities of São Paulo State, were irradiated using a 60 Co gamma ray source (Gammacell) with a dose of 10.0 kGy, delivered at dose rate of 3.0 kGy/h. Non- irradiated samples were used as controls of fungal isolates. For fungal counts and identification in medicinal plants a serial dilutions from 10 -1 to 10 -6 of the samples were seeded in duplicates and plated using the method in Dichloran 18% Glycerol Agar (DG 18) and were counted after five days at 25°C. Mycological analysis of control samples revealed the presence of genera Aspergillus and Penicillium, which are known as toxigenic fungi. The process of gamma radiation was effective in reducing the number of colony forming units (cfu/g) in all irradiated samples of medicinal plants after 30 days, using the dose of 10.0 kGy and kept of veiled conditions. 1. INTRODUCTION The past decade has seen a significant increase in the use of herbal medicine. Despite lots of studies on the mycoflora in agricultural products, only a few are concerned with spices and herbal medicines that are more and more common in our daily diet and play an important role in the economy [1]. Some investigators recorded the presence of moulds in medicinal plants, drugs and herbs that are widely consumed as home remedies and raw materials used for the pharmaceutical industries [2, 3]. In some kinds of the tested medicinal plants, the percentage of contamination in packed samples was higher than those non-packed and this may be due to other factors, such as, rise of humidity inside the pack and also unsuitable methods of keeping and storing of the pack [2].