ovalbumin and Poisoning

Moraea pallida Bak. (yellow tulp) poisoning is the most important plant cardiac glycoside toxicosis in South Africa. The toxic principle, a bufadienolide, is 1α, 2α-epoxyscillirosidine. The aim was to investigate the potential to develop a vaccine against epoxyscillirosidine. Epoxyscillirosidine, proscillaridin and bufalin, were successfully conjugated to hen ovalbumin (OVA), bovine serum albumin (BSA) and keyhole limpet haemocyanin (KLH). There was a low immune response following vaccination of adult male New Zealand White rabbits with epoxyscillirosidine-OVA (n = 3) and OVA (n = 3) using Freund's adjuvant in Trial (T) 1. The immune response improved significantly in T2 following doubling of the dose to 0.8 mg/rabbit and changing the adjuvant to Montanide. In T3, the rabbits (n = 15), allocated into 5 equal groups, vaccinated with proscillaridin-BSA, bufalin-BSA, epoxyscillirosidine-KLH, epoxyscillirosidine-BSA and BSA respectively, using Montanide adjuvant, developed antibodies against the administered immunogens, with epoxyscillirosidine-KLH inducing the highest immune response. Proscillaridin and bufalin antibodies cross-reacted with epoxyscillirosidine in an enzyme linked immunosorbent assay. The conjugation methodology will be adjusted in the future to target optimal conjugation efficiency. Additional vaccination will be conducted in search of neutralizing antibodies against the yellow tulp toxin. The cross-reactivity of proscillaridin and bufalin antibodies with epoxyscillirosidine could be studied in future to explore the potential to prevent yellow tulp poisoning.

Topics: Adjuvants, Immunologic; Animals; Antibodies, Neutralizing; Antibody Specificity; Cholenes; Cross Reactions; Freund's Adjuvant; Hemocyanins; Iridaceae; Male; Mannitol; Oleic Acids; Ovalbumin; Plant Extracts; Poisoning; Rabbits; Vaccination

We investigated the use of immunotherapy on the treatment of sodium arsenite toxicity. Female balb/c mice injected with arsanilic acid conjugated to a carrier protein (ovalbumin) were shown to produce antibodies (arsenic reactive serum, ARS) reactive with arsanilic acid and sodium arsenite. Serum was tested for anti-ARS antibodies using a solid phase radioimmunoassay. The antisera bound to ARS conjugated to the synthetic copolymer glutamic acid60 tyrosine30 when diluted as high as 1:4096. Following multiple injections of 100 micrograms of arsanilic acid--ovalbumin compound, mortality on injection with sodium arsenite 0.87 mg/kg i.p. one week later decreased to 0 deaths in 22 pretreated mice vs 9 deaths in 29 untreated mice (31% mortality; p less than .005). No decrease in mortality was noted at higher challenges (1.15 mg/kg) of sodium arsenite. Antisera from pretreated mice was injected 0.1 cc i.p. into 12 week old female balb/c mice followed by an injection of sodium arsenite 0.87 mg/kg i.p. at 10 minutes. Again a protective effect was observed with 0 deaths in 18 mice vs eight deaths in 21 mice (38%; p less than .005). Seventeen additional mice were given an injection of 0.87 mg/kg i.p. of sodium arsenite. After 30 minutes, all mice became symptomatic whereupon antisera 0.1 cc i.p. was given. The one day mortality (2/17, 12%) was possibly lower than the combined control mortality (17/50, 34%; p less than 0.07). There was no change in mortality noted when antisera was administered to mice acutely exposed to 5 mg/kg HgCl2.

Topics: Acute Disease; Animals; Arsanilic Acid; Arsenic Poisoning; Carrier Proteins; Female; Immunotherapy; Mice; Mice, Inbred BALB C; Ovalbumin; Poisoning