Effects of Senecio selloi (Spreng.) DC flower extract on mitochondrial membrane peroxidation and enzyme activities

Ethnobotanical use of plants may include poisonous species. Senecio (Asteraceae) is used as medicinal around the world. Senecio selloi (Spreng.) is widespread in Argentina. Purposes of this study were to investigate phytochemistry and in vitro activity of a methanolic extract of plant flowers on mitochondrial membrane peroxidation and enzyme activities. Chemiluminescence was used to test peroxidative effects, and thiazolyl blue tetrazolium bromide test (MTT) for cell viability. Results indicate presence of flavonoids and pyrrolizidine alkaloids. Regarding chemiluminescence, extract showed protective effect against peroxidation, while MTT demonstrated lower activities of mitochondrial dehydrogenases and cytosolic reductases, effects that were attributed to flavonoids and pyrrolizidine alkaloids, respectively. When ingested, pyrrolizidine alkaloids undergo hepatic biotransformation that cause damage to cells. On the contrary, toxicity does not take place when there is no metabolization. These situations may explain the ethnobotanical use of some poisonous senecios in human and veterinary medicine.