Mast cell degranulation peptide (MCDP) is a kind of multifunctional active peptide. MCDP has significant immune and pharmacological activities, while the specific roles depend on dose concentration. Specifically, at low concentrations, it stimulates mast cell degranulation and histamine release, causing inflammation. Meanwhile, it has an anti-inflammatory effect at high concentrations. Indeed, Bee venom contains MCDP and has abundant anti-inflammatory activity. Moreover, MCDP shows a significant cardiovascular effect, significantly reducing blood pressure in the rat model. But also it is found to block the voltage-sensitive potassium channel, as an epileptic neurotoxin. Here, we’ll introduce a new family of mast cell degranulation peptides isolated from frog skin, the Granuliberin R.

Granuliberin R is a completely different active peptide from the mast cell degranulation peptide.

From: Theoharides TC, et al. Biochim Biophys Acta. 2012 Jan;1822(1):21-33.

Granuliberin R is a dodecapeptide, but directly acts on the mast cell membrane to promote extracellular secretion. Then it (1-100 μg/mL) shows an increase in granule release and histamine secretion in rat peritoneal mast cells. But Granuliberin R (10 μg/mL) doesn’t affect catecholamine and adenine nucleotides release. On the contrary, analogous Mastoparan (10 μg/mL) does, in adrenal chromaffin cells.

In addition, Granuliberin R has an anti-inflammatory effect on the mandibular gingiva of rats. Specifically, Granuliberin R (0.1 mg/mL-10 μg/mL) can interfere with oral keratinocytes proliferation and connective tissue cell activity.

In conclusion, Granuliberin R is a new Mast cell degranulation peptide, that can be isolated from the skin of frogs. Importantly, it acts on mast cells to liberate granules and release histamine.

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