The toxicology of gossypol acetic acid and (-)-gossypol.

The toxicity of gossypol has been investigated in Sprague-Dawley rats at dosages of 0, 0.5, 5.0 and 25 mg/kg per day of (+/-)-gossypol acetic acid. The most significant toxicological finding was marked suppression of body weight gain in rats receiving 25 mg/kg per day. Terminal studies showed 6 out of 20 rats receiving 25 mg/kg per day to have varying degrees of testicular pathology. Five mg/kg per day was shown to be a "no effect" level. A study in cynomolgus monkeys at 25 mg/kg per day of (+/-)-gossypol acetic acid for 13 weeks induced death, a variety of clinical signs, extensive biochemical change and pathology in the heart, liver, kidney and testes. The toxicity of (-)-gossypol was investigated in male cynomolgus monkeys at dosages of 1.5, 4 or 5 mg/kg/day for 4 weeks. No animals died. Clinical signs involving the gastrointestinal tract, adverse effects on body weight gain, consistent biochemical changes in serum proteins, calcium, inorganic phosphorus and serum cholesterol were recorded at 4 mg/kg per day and above. Morphological change was not induced.