Prolyl-glycyl-proline (PGP) Peptide Prevents an Increase in Vascular Permeability in Inflammation

Abstract

This study was aimed at investigating the effect of prolyl-glycyl-proline (PGP) tripeptide on vascular permeability in rats with an inflammation. It was found that the peptide reduces the rat paw edema induced by a subcutaneous administration of histamine to the same extent as the conventional anti-inflammatory agent diclofenac. However, an assessment of the relative expression level of the cox-2 gene at the inflammation focus using real-time PCR showed that, in contrast to diclofenac, PGP does not affect the cox-2 gene expression. This is indicative of the fact that they have different mechanisms of action. We used the model of acute peritonitis induced by an intraperitoneal injection of thioglycolate to demonstrate that the inflammatory response of an organism is accompanied by increased vascular permeability in the tissues of the stomach and small intestine. Pre-administration (30 minutes before the induction of the inflammation) of PGP prevented this increase, whereby the level of vascular permeability, exudate volume in the peritoneal cavity, and the amount of the Evans Blue dye in this exudate remained at the control level. Therefore, these results suggest that the anti-inflammatory action of PGP is based on its ability to prevent an increase in vascular permeability.

MicroRNA‐194 reduces inflammatory response and human dermal microvascular endothelial cells permeability through suppression of TGF‐β/SMAD pathway by inhibiting THBS1 in chronic idiopathic urticaria

“…Patients were excluded in these conditions: (1) the enrolled patients were lactating women and pregnant women; (2) patients were diagnosed with drugs or food as allergens and with other inducible urticaria; (3) patients had severe immune system diseases of liver, kidney, cardiocerebral vascular, and hematopoietic system and primary diseases; (4) patients systematically used glucocorticoids or immunosuppressive agents; (5) patients had family history of allergies and other systemic allergic diseases. Patients were excluded in these conditions: (1) the enrolled patients were lactating women and pregnant women; (2) patients were diagnosed with drugs or food as allergens and with other inducible urticaria; (3) patients had severe immune system diseases of liver, kidney, cardiocerebral vascular, and hematopoietic system and primary diseases; (4) patients systematically used glucocorticoids or immunosuppressive agents; (5) patients had family history of allergies and other systemic allergic diseases.…”

“…Patients were enrolled if they fit in the following items: (1) the course of disease was greater than or equal to 8 weeks; (2) patients were in a stage of disease activity with wheal occurred every day or nearly every day; (3) patients volunteered to carry out autologous serum skin test. Patients were excluded in these conditions: (1) the enrolled patients were lactating women and pregnant women; (2) patients were diagnosed with drugs or food as allergens and with other inducible urticaria; (3) patients had severe immune system diseases of liver, kidney, cardiocerebral vascular, and hematopoietic system and primary diseases; (4) patients systematically used glucocorticoids or immunosuppressive agents; (5) patients had family history of allergies and other systemic allergic diseases. Fourty healthy volunteers, including 19 females and 21 males with the average age of 37 years and without history of allergic diseases were selected as a control.…”

“…3 In the beginning, the wheals in CIU patients was red but as time goes by they gradually turn pink, and active wheals exhibit degranulated mast cells. 5 The etiology of CIU is not clear, though some researchers suggest that psychologic distress might attribute to it. 5 The etiology of CIU is not clear, though some researchers suggest that psychologic distress might attribute to it.…”

Proline‐containing peptides—New insight and implications: A Review

“…Apart from proinflammatory activity, numerous beneficial effects of proline-containing short sequences were observed. For example, glyprolines regulate the endothelial permeability 34,35 , hemostasis 36,37 , carbohydrate and lipid metabolism 38 as well as protect gastric mucosa 9 .…”

“…Additionally, the anti inflammatory activity of N‐a‐PGP was displayed by increasing interferon gamma (IFN‐γ) production and improving the antibacterial activity of neutrophils. Bondarenko et al have demonstrated the anti inflammatory properties of glyprolines in the animal model. Their results indicated that PGP prevented the increase of vascular endothelial permeability through the direct effect of the tripeptides on blood vessels and the effect on mastocytes as modulators of vascular permeability.…”