In vitro study of gossypol's ovarian toxicity to rodents and goats.

Gossypol interferes with reproduction, causing damage to sperm, disrupting the estrous cycle and resulting in embryonic lethality. In females, gossypol administration promotes degeneration of ovarian follicles, but it is unknown whether this effect is direct or indirect. Thus, the aim of this study is to determine whether gossypol interferes with folliculogenesis in vitro in rats, mice and goats. Ovaries from rats and mice and fragments of goat ovaries were grown in cell culture for 24 h or 7 days. Four groups were tested: 0 (control), 5, 10 and 20 µg gossypol/ml. After incubation, the ovaries were fixed and processed for histological analysis. Follicles were classified according to their stage of development as either viable or atretic. It was found that the ovaries of rats, mice and goats cultured with gossypol showed an increase in the proportion of atretic follicles and a consequent reduction in the proportion of viable follicles at all stages of follicular development. Compared to the control group, the viability of all ovarian follicles in the rat, mouse and goat groups was reduced after cultivation for 24 h by 56.9%, 56.5% and 68.0%, respectively, with the highest concentration of gossypol (20 µg/mL), and after seven days, the respective reductions were 65.4%, 65.3% and 88.2%. Thus, it is possible that gossypol may directly affect follicular maturation, and consequently female fertility.

Embryotoxic effects of Poincianella ( Caesalpinia) pyramidalis leaves on pregnant rats.

We investigated the embryotoxic and fetotoxic effects of Poincianella pyramidalis (Tul.) L.P. Queiroz (syn. Caesalpinia pyramidalis Tul.) leaves on pregnant rats ( Rattus norvegicus). Pregnant rats were divided into 4 groups: G1-fed a ration containing 5% P. pyramidalis leaves beginning on day 1 of pregnancy; G2-fed a ration containing 5% P. pyramidalis leaves commencing on day 6 of pregnancy; G3-fed a ration containing 10% P. pyramidalis leaves starting on day 6 of pregnancy; G4-control group. On day 21 of pregnancy, parameters of reproductive performance were recorded. Fetal growth was measured, and fetuses were subjected to external examination and identification of skeletal anomalies. Rations containing P. pyramidalis resulted in dead or undeveloped fetuses and reduced the number, length, and weight of the fetuses. Rations also increased postimplantation losses and the frequency of skeletal anomalies. Furthermore, P. pyramidalis was also responsible for dose-dependent lesions in the placentas. In conclusion, the ingestion of P. pyramidalis promotes fetal and placental damage.

Gossypol toxicity from cottonseed products.

Gossypol is a phenolic compound produced by pigment glands in cotton stems, leaves, seeds, and flower buds (Gossypium spp.). Cottonseed meal is a by-product of cotton that is used for animal feeding because it is rich in oil and proteins. However, gossypol toxicity limits cottonseed use in animal feed. High concentrations of free gossypol may be responsible for acute clinical signs of gossypol poisoning which include respiratory distress, impaired body weight gain, anorexia, weakness, apathy, and death after several days. However, the most common toxic effects is the impairment of male and female reproduction. Another important toxic effect of gossypol is its interference with immune function, reducing an animal's resistance to infections and impairing the efficiency of vaccines. Preventive procedures to limit gossypol toxicity involve treatment of the cottonseed product to reduce the concentration of free gossypol with the most common treatment being exposure to heat. However, free gossypol can be released from the bound form during digestion. Agronomic selection has produced cotton varieties devoid of glands producing gossypol, but these varieties are not normally grown because they are less productive and are more vulnerable to attacks by insects.

Spontaneous and experimental poisoning by Marsdenia megalantha Goyder & Morillo in ruminants and a pig.

Marsdenia megalantha is a rupicolous shrub with succulent roots from the semiarid region of Brazil that is known to cause fatal poisoning in livestock. We reported spontaneous cases of poisoning by M. megalantha roots in bovine, caprine, ovine, and equine species. The clinical and pathological findings of experimental administration of M. megalantha to sheep, goats, a calf and a pig are reported. Three goats, two sheep and a calf were dosed once orally with freshly chopped roots at dose of 25 g wet plant/kg bw; another sheep and a pig were dosed with 10 g wet plant/kg bw. Poisoning occurred in all of the animals except the three goats. Clinical signs of poisoning included tachycardia, opisthotonus, ruminal bloat, dyspnea, nystagmus, mydriasis, ataxia, and recumbence with paddling movements. Pathological evaluation showed segmental laminar neuronal necrosis and spongiosis in the telencephalic cortex and degeneration of Purkinje cells. The picrate paper procedure detected no cyanide in the plant roots, but the reaction used for nitrate detection gave a strongly positive response. In conclusion, M. megalantha is a poisonous plant that produces acute poisoning characterized mainly by nervous disturbances. Livestock producers should offer alternative food during the dry and early rainy seasons to avoid the poisoning by this plant.