ResumoA mamona (Ricinus communis) é um arbusto da família Euforbiacea cultivada para a obtenção do óleo das sementes. Este óleo apresenta amplo emprego industrial, com destaque para o biodiesel. No entanto, as sementes de mamona apresentam uma potente toxina, a ricina. Trata-se de uma glicoproteína altamente tóxica com ação inativadora de ribossomos. A ação tóxica da ricina é decorrente da inibição da síntese proteica nas células eucarióticas, ocasionando a morte celular. Apenas uma molécula de ricina que entra no citosol é capaz de inativar mais de 1500 ribossomos por minuto. Os sinais clínicos associados com a intoxicação de mamona em animais frequentemente ocorrem em algumas horas após a ingestão das sementes. Este trabalho faz uma revisão da literatura sobre os efeitos tóxicos da ricina e as técnicas para a prevenção da intoxicação. Palavras-chave: Ricinus communis, Euforbiacea, toxalbumina, planta tóxica, toxina AbstractThe castor bean (Ricinus communis) is a bush from Euphorbiacea family cultivated for obtaining oil from the seeds. This oil has broad industrial employment, particularly for biodiesel. However, castor bean seeds exhibit a potent toxin, ricin. It is a glycoprotein with highly toxic action of inactivating ribosomes. The toxic action of ricin is due to inhibition of protein synthesis in eukaryotic cells, causing cell death. Only one molecule of ricin that enters the cytosol is able to inactivate ribosomes over 1500 per minute. Clinical signs associated with castor bean poisoning often occur in animals in a few hours after ingestion of the seeds. This paper reviews the literature on the toxic effects of ricin and techniques for preventing the poisoning.

Gossypol is a highly reactive compound present in cotton (Gossypium spp.). The aim of this work was to determine whether the administration of gossypol conjugated to albumin can immunize rats and thereby prevent the acute hepatotoxicity associated with gossypol. The first experiment consisted of administering the immunogen gossypol-BSA, with or without the Freund's incomplete adjuvant, to rats. The production of antibodies against gossypol was subsequently verified. The second experiment comprised three groups of Wistar rats: VG, CG and CO. The rats from the VG cohort were injected with gossypol-BSA associated with Freund's incomplete adjuvant, and the animals from the CG and CO groups were injected with saline solution. After 21 days, the rats from the VG and CG cohorts were treated with 30 mg/kg of gossypol by intraperitoneal injection, whereas the rats from the CO group received corn oil. After 24 h, the rats were evaluated for clinical signs of pathology, and their serum was biochemically analyzed. It was found that gossypol promoted hepatotoxic effects that were not prevented by the administration of gossypol-BSA. In conclusion, the administration of gossypol-BSA associated with Freund's incomplete adjuvant may be lightly to prevent the acute hepatotoxicity associated with gossypol.