TIP, or TRPV1 inhibitory peptide (TIP) is a TRPV1 inhibitor corresponding to amino acids 701-709 of the TRPV1 receptor, with Thr705 included as a key component as phosphorylation of this residue causes conformational change and opening of the TRPV1 channel. In cell lines, TIP effectively inhibits capsaicin induced calcium influx and TRPV1 activation and treatment of the immortalised human keratinocyte cell line HaCaT with TIP prevents UV induced increases of MMP-1 and pro-inflammatory cytokines. In mouse skin, TIP inhibits UV induced skin thickening and prevents UV induced expression of MMP-13 and MMP-9. TIP can also attenuate UV induced erythema and the expression of MMP-1, MMP-2, IL-6, and IL-8 in human skin in vivo.
