Compositions and methods for treating toxicity associated with exposure to radiation and side effects of treatments for hyperproliferative disorders are provided. Typically the compositions are administered in an effective amount reduce one or more adverse side effects. The side effects to be treated include, but are not limited to reduced appetite and weight loss. The methods typically include administering to a subject a composition including a protein transduction domain, a target signal, and a transcription factor A—mitochondrial polypeptide in an amount effective to inhibit, reduce or alleviate weight loss or to increase or induce appetite.
