The present invention relates to treatment of diabetes, toll-like receptor 4 (TLR-4) modulators and methods for using the same. Particularly, the present invention provides an isolated peptide from pneumolysin (PLY peptide) which is effective in treatment of diabetes. In addition, the PLY peptide of the present invention is a TLR-4 antagonist and thus can be used in the treatment of a disease or condition associated with TLR-4 activation. The present invention also provides treatment of diabetes with a TLR-4 antagonist.
