Dose-dependent green tea effect on decrease of inflammation in human oral gingival epithelial keratinocytes: in vitro study

Abstract

Objectives This in vitro study aimed to analyze the anti-inflammatory and wound healing potential of green tea extract (GTE) in human gingival epithelial keratinocytes (HGEK) treated with lipopolysaccharides (LPS). Materials and methods A cell viability assay was conducted using MTT to determine nontoxic levels of GTE on immortalized HGEK. Cells were concomitantly treated with LPS (1 μg/ml) and GTE (1 mg/ml, 2.5 mg/ml, 5 mg/ml, and 10 mg/ml) to assess inflammation. Gene expression levels of inflammatory markers IL-β1, IL-6, and TNFα were measured by RT-PCR and their protein production was assessed by ELISA. The scratch wound healing assay was used to investigate the effects of different concentrations of GTE on cell migration. We also explored the effect of GTE on the induction of the Nrf2/HO-1 pathway in the cells with or without LPS. Results GTE at concentrations of 2.5 mg/ml, 5 mg/ml, and 10 mg/ml significantly enhanced cell viability (p < 0.05). And IL-β1, IL-6, and TNFα gene expression presented up to 10-fold decrease compared with LPS-treated cells, which was also similarly found on the protein levels. At the same concentrations, cell migration increased. Conclusions The mechanism results showed that GTE produced the anti-inflammatory response by activating the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway and increasing the level of anti-oxidant protein heme oxygenase-1 (HO-1). Clinical relevance GTE may be potentially used as oral rinse anti-inflammatory drug for treatment and prevention of oral inflammatory diseases, which is shown here by the ability to reduce the inflammation and increase in cell migration in a dosedependent manner.

Hepatosplenic Protective Actions of Spirulina platensis and Matcha Green Tea Against Schistosoma mansoni Infection in Mice via Antioxidative and Anti-inflammatory Mechanisms

“…In this study, the inflammatory cytokines (TNF-α, IFN-γ, IL-10, and IL-13) returned to control serum levels after SP and/or MGT treatment of S. mansoni-infected mice, demonstrating the anti-inflammatory effects of SP and MGT. Green tea and green tea flower extracts downregulate the expression of inflammation markers, including IL-β1, IL-6, and TNFα, in human gingival epithelial keratinocytes and mouse liver treated with lipopolysaccharides (69,70). Theanine, the main component of MGT, and its metabolites, such as glutamine and ethyleneimine, alleviate inflammation by reducing NF-κB activation and neutrophil accumulation in tissues and dampening the Ca 2+ channels to block inflammatory mediator release (71).…”

The potency of PLGA-Encapsulated Epigallocatechin Gallate (EGCG) as adjuvant therapy for chronic kidney disease

“…EGCG has been shown to be anti-inflammatory by suppressing the synthesis and action of inflammatory pathway such as, peroxynitrite, nitric oxide synthase, reactive oxygen species, and also cyclooxygenase-2 [28]. On the other study, EGCG inhibited the levels of pro-inflammatory cytokines including TNF-α, IL-1β, and IL-6 [29].…”

Nutraceutical Targeting of Inflammation-Modulating microRNAs in Severe Forms of COVID-19: A Novel Approach to Prevent the Cytokine Storm

“…A 250 ml cup of brewed green tea provides approximately 25-60 mg of EGCG (roughly 50-60% of the catechins are EGCG). In vitro, a study in human gingival epithelial keratinocytes (HGEK) treated with LPS showed that green tea extracts (2.5, 5, and 10 mg/ml) decreased IL-β1, IL-6 and TNFα gene expression by more than 10-fold (Hagiu et al, 2020). Another study in rats with acetic acid-induced colitis demonstrated that EGCG (50 mg/kg/day for seven days) exerts anti-inflammatory activity by inhibiting the production of TNFa, IFN-gamma and NF-kappaBp65 (Ran et al, 2008).…”