ABSTRACT
OBJECTIVE: Introduction: The connective tissue remodeling is essential for periodontal and salivary glands (SG) pathology. Recently there has been demonstrated the number of pharmacological effects of green tea (Camellia sinensis) such as antioxidant, anti-inflammatory, anti-aging, antibacterial, antiviral and DNA-protective effects, associated with the presence of epigallocatechin-3-gallate (EGCG) as an inducer of the Keap1 / Nrf2 / antioxidant response element signaling pathway. However, the EGCG effects on the components of soft connective tissues of periodontium and SG are still unclear. The aim: To investigate the effect of EGCG on markers of disruption of periodontal and submandibular SG connective tissues in rats during the conditions of experimental systemic inflammation (SI). PATIENTS AND METHODS: Materials and methods: The studies were conducted on 30 white rats of the Wistar line, divided into 3 groups: the 1st included intact animals, the 2nd was made up of animals after induced SI (by intraperitoneal administration of lipopolysaccharide Salmonella typhi), and the 3rd included animals, which were injected EGCG (production of Sigma-Aldrich, Inc., USA) intraperitoneally in a dose of 21.1 mg / kg 3 times a week, starting on the 30th day of SI induction. The level of collagenolysis was assessed by the content of free hydroxyproline (FHP). The process of depolymerization of proteoglycans and sialoglycoproteins was evaluated by determining their monomers, glycosaminoglycans (GAGs) and N-acetylneuraminic acid (NANA) respectively. The molar roots exposure index (MREI) was calculated. RESULTS: Results: Administering EGCG reduced the content of FHP by 33.3 % (p<0.01), the content of GAGs by 39.4% (p<0.02), and content of NANA by 34.3% (p<0.001) in the soft periodontal tissues compared with the relevant findings in the second group of the animals. In this condition the concentration of these compounds in the calcified components of periodontium (alveolar bone) lowered as well: FHP - by 41.9% (p<0.001), GAGs - by 41.0% (p<0.001), NANA - by 53.3% (p<0.001), MREI reduced to 27.1+1.6, i.e. by 27.7% (p<0.01) compared with the relevant findings in the second group of the animals. The administration of EGCG also reduced the content of FHP by 37.8% (p<0.001), the content of GAGs by 39.8% (p<0.001), and the content of NANA by 37.6% (p<0.001) in SG tissues compared with the relevant results of the second group of the animals. CONCLUSION: Conclusions: The administration of EGCG under modeled systemic inflammation is an effective means of preventing and correcting the disruption of connective tissue of periodontium and submandibular salivary glands in rats: it reduces collagenolysis and depolymerization of proteoglycans and glycoproteins.
