Preliminary Toxicity Profile of Arotinoids SMR-2 and SMR-6 in Male B6D2F1 Mice

The study investigated the preliminary in vivo toxicity of arotinoids SMR-2 and SMR-6 in male B6D2F1 mice, comparing them to retinoic acid (RA). Mice were dosed with varying levels of SMR-2, SMR-6, and RA, with dose levels increased after 29 days due to initial lack of toxicity. The study found that SMR compounds were approximately 100-fold more toxic than RA, inducing hypervitaminosis A symptoms such as weight loss, alopecia, and skin scaling. Elevated white blood cell counts and microscopic lesions in various organs were observed in the SMR groups. The results suggested that immune stimulation might be an early response to retinoids, with skin, leukopoietic tissues, reproductive organs, stomach, and bone being primary targets for toxicity.