Toxic activities and biochemical characterization of catfish (Cathorops spixii) skin and sting venoms

¹Mondin, A. C.; ^1,2Junqueira, M. E. P.; ¹Lopes-Ferreira, M.

1 Lab. Imunopatologia – Instituto Butantan, Brasil; 2 Lab. Micro e Imunologia – UNESP – Botucatu, Brasil

Accidents with venomous fishes are very frequent in costal waters of Brazil. Marine catfishes are the venomous fishes that cause the greatest number of accidents in Brazil, specially in southeast littoral, characterized for painful injury, intense edema and some systemic symptoms. The most abundant catfish of this region is the yellow-catfish Cathorops spixii (Ariidae). Three different types of venom can be founded in this fishes: skin venom, sting venom and glandular venom. The objective was to do a biochemical characterization and to evaluate important toxic activities (edema, nociception, hemorrhage and necrosis) induced by Cathorops spixii venoms Swiss (18-22 g) mice. The skin venom, sting venom and a mixture were utilized. In nociceptive and edematogenic assays venoms (0,3; 3; 10; 30 or 60µg / 30µl sterile PBS) were injected in mice paw, whereas in hemorrhagic and necrosis assays, venoms (50; 150 or 300 mg / 50 µL sterile PBS) were injected in mice back. All venoms induced nociception: 3 µg (16,9 ± 12,6 s) of Skin venom, 10 µg (33,0 ± 23,4 s) of Sting venom and 30 µg (66,0 ± 22,8 s) of the mixture. Edema was considered significant when over 30% of control group and was induced by all venoms, too. After 2h, edema was observed to all doses of Skin venom. The edema appears with 10 µg in 15 min and continues until 2 h with higher doses of Sting venom. All doses of the mixture, in all times, from 15 min to 2 h, induced edema. Hemorrhage and necrosis weren’t observed even so high doses were injected. SDS-PAGE (12%) showed a complex pattern with several bands allover the gel. Skin and Sting venoms share some identical bands but there are important differences. Skin venom majority bands are found between 20-30 kDa, 45-60 kDa and over 97 kDa. Sting venom major ones are between 33 kDa and 55-60 kDa. Gel-Filtration (Sephadex) showed 4 (Skin venom) and 5 peaks (Sting venom). In this differential peak, there are molecules with high molecular weight. These results show that both venoms are able to induce important nociception and edema. Besides, there are differences in the eletrophoretical and chromatographic pattern. Purification of some bands and pharmacological assays of nociceptive and edematogenic activities are in progress.

Correspondence to: li_mondin@yahoo.com.br