Purification and acute toxicity of a lectin extracted from tepary bean (Phaseolus acutifolius).
Lectins are proteins or glycoproteins known for their ability to agglutinate cells, especially erythrocytes. Several lectins are toxic to mammalian cells both in vitro and in vivo, inhibit growth when incorporated into the diet and are toxic when injected into animals. On the other hand, the use of lectins has been suggested as an alternative in cancer treatment. The objective of the present study was to evaluate the acute toxicity of a lectin extracted and purified from tepary bean (Phaseolus acutifolius, G-400-34) on CD-1 mice. Fetuin affinity chromatography, electrophoretic pattern and Western-immunoblot techniques were used to purify and partially characterize the lectin. This tepary bean line presented high levels of lectin activity. Western blot revealed that the sera reacted with the known PHA subunits in the 34-40 kD range. Four major lectin and lectin-related glycopolypeptides were identified. The purified lectin from tepary bean was a tetrameric one that ran at about 115-120 kD. The LD(50) (ip) was 1100 mg/kg body weight for males and 1120 mg/kg body weight for females. The body weight of experimental animals decreased in a dose-dependent manner. The main target organs affected were small intestine, spleen and thymus. The lectin isolated from tepary bean showed affinity towards fetuin, with high agglutination values and low acute toxicity.
Reynoso-Camacho
R
R
PROPAC (Programa de Posgrado en Alimentos del Centro de la República), Research and Graduate Studies in Food Science, School of Chemistry, Universidad Autónoma de Querétaro, Mexico.
González de Mejía
E
E
Loarca-Piña
G
G
D000818:Animals; D015153:Blotting, Western; D001835:Body Weight / Q000187:drug effects; D002846:Chromatography, Affinity; D004305:Dose-Response Relationship, Drug; D005260:Female; D006386:Hemagglutination Tests; D007421:Intestine, Small / Q000187:drug effects; D007668:Kidney / Q000187:drug effects; D007928:Lethal Dose 50; D008099:Liver / Q000187:drug effects; D008168:Lung / Q000187:drug effects; D008297:Male; D051379:Mice; D008970:Molecular Weight; D009929:Organ Size / Q000187:drug effects; D027805:Phaseolus / Q000737:chemistry*; D037121:Plant Lectins / Q000737:chemistry / Q000302:isolation & purification / Q000633:toxicity*; D011897:Random Allocation; D012737:Sex Factors; D013154:Spleen / Q000187:drug effects; D013950:Thymus Gland / Q000187:drug effects; D023382:Toxicity Tests, Acute
D037121:Plant Lectins