RESUMEN

We determined the neutralizing activity of 12 ethanolic extracts of plants against the edema-forming, defibrinating and coagulant effects of Bothrops asper venom in Swiss Webster mice. The material used consisted of the leaves and branches of Bixa orellana (Bixaceae), Ficus nymphaeifolia (Moraceae), Struthanthus orbicularis (Loranthaceae) and Gonzalagunia panamensis (Rubiaceae); the stem barks of Brownea rosademonte (Caesalpiniaceae) and Tabebuia rosea (Bignoniaceae); the whole plant of Pleopeltis percussa (Polypodiaceae) and Trichomanes elegans (Hymenophyllaceae); rhizomes of Renealmia alpinia (Zingiberaceae), Heliconia curtispatha (Heliconiaceae) and Dracontium croatii (Araceae), and the ripe fruit of Citrus limon (Rutaceae). After preincubation of varying amounts of each extract with either 1.0 microg venom for the edema-forming effect or 2.0 microg venom for the defibrinating effect, the mixture was injected subcutaneously (sc) into the right foot pad or intravenously into the tail, respectively, to groups of four mice (18-20 g). All extracts (6.2-200 microg/mouse) partially neutralized the edema-forming activity of venom in a dose-dependent manner (58-76% inhibition), with B. orellana, S. orbicularis, G. panamensis, B. rosademonte, and D. croatii showing the highest effect. Ten extracts (3.9-2000 microg/mouse) also showed 100% neutralizing ability against the defibrinating effect of venom, and nine prolonged the coagulation time induced by the venom. When the extracts were administered either before or after venom injection, the neutralization of the edema-forming effect was lower than 40% for all extracts, and none of them neutralized the defibrinating effect of venom. When they were administered in situ (sc at the same site 5 min after venom injection), the neutralization of edema increased for six extracts, reaching levels up to 64% for C. limon.

Asunto(s)

RESUMEN

We determined the neutralizing activity of 12 ethanolic extracts of plants against the edema-forming, defibrinating and coagulant effects of Bothrops asper venom in Swiss Webster mice. The material used consisted of the leaves and branches of Bixa orellana (Bixaceae), Ficus nymphaeifolia (Moraceae), Struthanthus orbicularis (Loranthaceae) and Gonzalagunia panamensis (Rubiaceae); the stem barks of Brownea rosademonte (Caesalpiniaceae) and Tabebuia rosea (Bignoniaceae); the whole plant of Pleopeltis percussa (Polypodiaceae) and Trichomanes elegans (Hymenophyllaceae); rhizomes of Renealmia alpinia (Zingiberaceae), Heliconia curtispatha (Heliconiaceae) and Dracontium croatii (Araceae), and the ripe fruit of Citrus limon (Rutaceae). After preincubation of varying amounts of each extract with either 1.0 æg venom for the edema-forming effect or 2.0 æg venom for the defibrinating effect, the mixture was injected subcutaneously (sc) into the right foot pad or intravenously into the tail, respectively, to groups of four mice (18-20 g). All extracts (6.2-200 æg/mouse) partially neutralized the edema-forming activity of venom in a dose-dependent manner (58-76 percent inhibition), with B. orellana, S. orbicularis, G. panamensis, B. rosademonte, and D. croatii showing the highest effect. Ten extracts (3.9-2000 æg/mouse) also showed 100 percent neutralizing ability against the defibrinating effect of venom, and nine prolonged the coagulation time induced by the venom. When the extracts were administered either before or after venom injection, the neutralization of the edema-forming effect was lower than 40 percent for all extracts, and none of them neutralized the defibrinating effect of venom. When they were administered in situ (sc at the same site 5 min after venom injection), the neutralization of edema increased for six extracts, reaching levels up to 64 percent for C. limon.

Asunto(s)

RESUMEN

Thirty-one of 75 extracts of plants used by traditional healers for snakebites, had moderate or high neutralizing ability against the haemorrhagic effect of Bothrops atrox venom from Antioquia and Chocó, north-western Colombia. After preincubation of several doses of every extract (7.8-4000 microg/mouse) with six minimum haemorrhagic doses (10 microg) of venom, 12 of them demonstrated 100% neutralizing capacity when the mixture was i.d. injected into mice (18-20 g). These were the stem barks of Brownea rosademonte (Caesalpiniaceae) and Tabebuia rosea (Bignoniaceae); the whole plants of Pleopeltis percussa (Polypodiaceae), Trichomanes elegans (Hymenophyllaceae) and Senna dariensis (Caesalpiniaceae); rhizomes of Heliconia curtispatha (Heliconiaceae); leaves and branches of Bixa orellana (Bixaceae), Philodendron tripartitum (Araceae), Struthanthus orbicularis (Loranthaceae) and Gonzalagunia panamensis (Rubiaceae); the ripe fruits of Citrus limon (Rutaceae); leaves, branches and stem of Ficus nymphaeifolia (Moraceae). Extracts of another 19 species showed moderate neutralization (21-72%) at doses up to 4 mg/mouse, e.g. the whole plants of Aristolochia grandiflora (Aristolochiaceae), Columnea kalbreyeriana (Gesneriaceae), Sida acuta (Malvaceae), Selaginella articulata (Selaginellaceae) and Pseudoelephantopus spicatus (Asteraceae); rhizomes of Renealmia alpinia (Zingiberaceae); the stem of Strychnos xinguensis (Loganiaceae); leaves, branches and stems of Hyptis capitata (Lamiaceae), Ipomoea cairica (Convolvulaceae), Neurolaena lobata (Asteraceae), Ocimum micranthum (Lamiaceae), Piper pulchrum (Piperaceae), Siparuna thecaphora (Monimiaceae), Castilla elastica (Moraceae) and Allamanda cathartica (Apocynaceae); the macerated ripe fruits of Capsicum frutescens (Solanaceae); the unripe fruits of Crescentia cujete (Bignoniaceae); leaves and branches of Piper arboreum (Piperaceae) and Passiflora quadrangularis (Passifloraceae). When the extracts were independently administered by oral, i.p. or i.v. route either before or after an i.d. venom injection (10 microg), neutralization of haemorrhage dropped below 25% for all the extracts. Additionally, B. rosademonte and P. percussa extracts were able to inhibit the proteolytic activity of B. atrox venom on casein.

Asunto(s)

RESUMEN

In Antioquia and Chocó, traditional healers attend 60% of snakebites. With the aim to produce an inventory of the plants used by the healers to treat snakebites and to document the methods of preparation, administration, the dosage, number of patients treated throughout their years of practice with treatment results, 20 healers with experience in Bothrops, Porthidium and Bothriechis envenomations were interviewed between August, 1996 and November, 1998. They belong to nine black and three indigenous rural communities located near the towns of Bojayá, Vigía del Fuerte, Unguía (Atrato river valley), Nuquí and Bahía Solano (Pacific coast). Based on field interviews, 101 species of plants were identified as used to treat snakebites. The part used of each plant varies according to the species. Sixty plants are used in the form of drinks prepared by infusion, decoction or maceration; 78 as external baths on the affected extremity; 11 for steam application and 39 for poultices; the latter is used mainly when the bite is complicated by local necrosis. In mild and moderate envenomations, they generally use a mixture of three plants, while in severe cases they mix from five to 12, a handful of each one. Treatment is generally performed for 1-3 days, when the patient reacts positively. They reported to have treated 454 patients during their years of experience, 20 of them (4.4%) died. With the guidance of the healers, 77 species of plants were collected and photographed. These plants belong to 41 families, of which Piperaceae (13 species), Araceae (six species), Asteraceae (five species) and Gesneriaceae (three species) have the highest number of species.

Asunto(s)

RESUMEN

Twelve of 74 ethanolic extracts of plants used by traditional healers for snakebites in the northwest region of Colombia, were active against lethal effect of Bothrops atrox venom when they were i.p. injected into mice (18-20 g). After preincubation of sublethal doses of every extract (0.5-4.0 mg/mouse) with 1.5 i.p. lethal dose 50% (LD50) (99.3 microg) of venom, seven of them demonstrated 100% neutralizing capacity within 48 h. These were the stem barks of Brownea rosademonte (Caesalpiniaceae) and Tabebuia rosea (Bignoniaceae); rhizomes of Renealmia alpinia (Zingiberaceae) and Heliconia curtispatha (Heliconiaceae); the whole plants of Pleopeltis percussa (Polypodiaceae) and Trichomanes elegans (Hymenophyllaceae); and the ripe fruits of Citrus limon (Rutaceae). The other five extracts showing partial neutralization (45-80%; 10-30% survival rate in the control group receiving the venom alone; P<0.05) were: leaves, branches and stem of Costus lasius (Costaceae); the whole plant of Sida acuta (Malvaceae); rhizomes of Dracontium croatii (Araceae); leaves and branches of Bixa orellana (Bixaceae) and Struthanthus orbicularis (Loranthaceae). When the extracts were independently administered per oral or i.p. route 60 min before an i.m. venom injection (204 microg=1.5 i.m. LD50), C. limon, T. elegans, B. orellana and T. rosea extracts had partial and significant neutralizing capacity against B. atrox venom lethal effect. C. limon extract was also partially effective when it was administered either i.v. 15 min before or i.p. 5 min after an i.m. venom injection. Three of the 12 extracts with anti-lethal effect (C. limon, D. croatii and S. acuta) were devoid of antiphospholipase A2 activity, when they were tested against one minimum indirect hemolytic dose of B. atrox venom (2 microg) in agarose-erythrocyte-egg yolk gels.

Asunto(s)

RESUMEN

A comparative study was performed on the pharmacology and biochemistry of venoms from three subspecies of Lachesis muta (L. m. stenophrys, L. m. muta and L. m. rhombeata) from Brazil, Colombia and Costa Rica. All venoms induced lethal, hemorrhagic, edema-forming, myotoxic, coagulant and defibrinating effects, showing also proteolytic and indirect hemolytic activities. The venoms of L. m. stenophrys from Costa Rica and L. m. muta from Cascalheira, Brazil, had the highest lethal and hemorrhagic activities and the venom of L. m. rhombeata showed the highest coagulant activity, whereas no significant differences were observed in myotoxic and edema-forming activities at most of the time intervals studied. In addition, venoms showed similar electrophoretic patterns on SDS-polyacrylamide gel electrophoresis. In conclusion, despite quantitative differences in toxic and enzymatic activities, together with subtle variations in electrophoretic patterns, our results indicate that experimental envenomation by these venoms induce a qualitatively similar pathophysiological profile.

Asunto(s)

Asunto(s)

RESUMEN

This investigation compared the ability of six Latin American antivenoms (monovalent antibothropic INS, Santafé de Bogotá; polyvalent INS; polyvalent probiol, Santafé de Bogotá; antibothropic Instituto Butantan, IB, São Paulo, Brazil; polyvalent Instituto Clodomiro Picado, ICP, San José, Costa Rica; polyvalent MYN, Mexico) to neutralize various pharmacological and enzymatic effects of Bothrops atrox venom from Antioquia and Chocó, north-west of Colombia. Our results demonstrated conspicuous differences in the ability of the six antivenoms. In terms of neutralization of lethality, the highest efficacy was observed in the polyvalent INS and the lowest in the polyvalent MYN antivenom. All antivenoms were highly effective in the neutralization of hemorrhage, polyvalent INS and probiol being the highest. In the neutralization of edema-forming activity, the most effective antivenom was the polyvalent (ICP); monovalent (INS) and polyvalent (MYN) were the least effective. All antivenoms were effective in the neutralization of the myotoxic activity of B. atrox venom, the most effective being the polyvalent (INS) and antibothropic (IB). Defibrinating activity was neutralized by all antivenoms; polyvalent (MYN) showed the lowest efficiency. Polyvalent (ICP) antivenom had the highest neutralizing ability against the indirect hemolytic effect of B. atrox venom; polyvalent (MYN) did not neutralize this enzymatic activity. Overall, the polyvalent antivenom (INS) showed the highest neutralizing ability.

Asunto(s)