Antioxidant Activity In Vitro of Selected Peruvian Medicinal Plants

The oxidative damage caused by free radicals is considered to be related to the development of diseases like atheroesclerosis, cancer, brain dysfunction, arthritis and other inflammatory disorders (Halliwell, 1991; Finkel and Holbrook, 2000). Several synthetic antioxidants, like butylated hydroxyanisole or butylated hydroxytoluene, are effective free radical scavengers, however, they are being restricted because they can be carcinogenic (Ito et al., 1983; Safer and Al-Nughamish, 1999). Thus, there is a growing interest in searching for antioxidants of natural origin, especially those present in medicinal plants.

The purpose of this study is to evaluate the in vital antioxidant activity of 40 plants used in Peruvian traditional medicine for the treatment of several infectious and inflammatory disorders. Plants that have been used extensively for the treatment of inflammatory or infectious diseases may contain radical scavengers compounds that could be used as natural antioxidants.

Plants were collected between May and July 2001 from five different regions of Peru (Table 1). Plants were collected and identified by botanists Irma Fernández (IF), Joaquina Albán (JA), Alfredo Tupayachi (HV), Abundio Sagástegui (AS) and Genaro Yarupaitán (GY). The respective voucher specimens are deposited at the Department of Chemistry of the Pontificia Universidad Católica del Perú, in Lima.

Air-dried powdered plant material was extracted by percolation at room temperature with 95% ethanol. The solvent was then evaporated to dryness under reduced pressure at a temperature lower than 40°C. Yield of extracts in terms of dry starting materials are listed in Table 1. For the antioxidant assay, the extracts were resuspended in ethanol.