Abstract: A method of treating loss of brain function in a patient comprising the steps of preparing a composition comprising a D peptide and a pharmaceutically acceptable carrier. The D peptide has the general structure: A-B-C-D-E-F-G-H in which A is Ala, or absent, B is Ser, Thr or absent, C is Ser, Thr or absent, D is Ser, Thr, Asn, Glu, Arg, Ile, Leu, E is Ser, Thr, Asp, Asn, F is Thr, Ser, Asn, Arg, Gln, Lys, Trp, G is Tyr, and H is Thr, Ser, Arg, Gly. All amino acids in the D peptide are the D stereoisomeric configuration. The peptide composition is administered in a therapeutically effective dose.

Abstract: Chemokine signaling is important in neuropathic pain, with microglial cells expressing CCR2 playing a well established key role. DAPTA, a gp120-derived CCR5 entry-inhibitor has been shown to inhibit CCR5-mediated monocyte migration and to attenuate neuroinflammation. We disclose here that as a stabilized analog of DAPTA, the short peptide All D TTNYT (SEQ ID NO:1) exhibits potent antagonism for both CCR2 (IC50 4.2 pM) and CCR5 (IC50 0.18 pM) in monocyte chemotaxis. Oral administration of All D TTNYT (SEQ ID NO:1) (0.05-1 mg/kg) for 7 days fully prevents mechanical allodynia and inhibits the development of thermal hyperalgesia following partial ligation of the sciatic nerve in rats. Administered from day 8 to day 12, All D TTNYT (SEQ ID NO:1) (0.2-1 mg/kg) reverses already established hypersensitivity.