Green tea extract rich in epigallocatechin gallate impairs alveolar bone loss in ovariectomized rats with experimental periodontal disease

Abstract

Periodontal disease and osteoporosis are characterized by bone resorption, and researchers have shown an association between these two diseases through increasing loss of systemic bone mass and triggering alveolar bone loss. Green tea is a common and easily accessible beverage, and evidences show that flavonoid epigallocatechin gallate (EGCG) could decrease bone loss in pathologies such as osteoporosis and periodontal disease. In order to verify its possible effects and apply them in the treatment and prevention of these diseases, this investigation aimed to evaluate the influence of green tea extract (GTE) on bone metabolism of ovariectomized rats after experimental periodontal disease (EPD) by histological, morphological and microtomographic parameters. Wistar female rats were divided into Sham, Sham + EPD, Sham + EPD + GTE, OVX, OVX + EPD and OVX + EPD + GTE groups. Immediately after surgery, gavage administration of 50 mg/kg of green tea extract (GTE) was performed for 60 days, with subsequent induction of periodontal disease by ligature 15 days before euthanasia. Mandible and femur samples were collected for histological, morphometric and microtomographic analysis. The results were analysed by means of statistical software with significance set at 5%. Histological and morphometric analysis showed a significant decrease in alveolar and femoral trabecular bone loss in groups that received GTE. Microtomographic results showed that trabecular thickness and bone surface density values in alveolar bone interradicular septum of the OVX + EPD + GTE groups were similar to the Sham group. The results obtained suggest that green tea extract may improve bone metabolism in osteoporotic rats with periodontal disease.

Molecular Basis of the Curative Effects of Turkish Gall Extracts on Periodontitis

“…[38][39][40][41] Similarly, 1,2,3,4,6-penta-O-galloyl-β-D-glucose is a potent antioxidant capable of down-regulating the expression of IL-6 and TNF-α, and mitigating the expression of genes and proteins involved in NF-kB and MAPK signaling pathways, which contribute to the production of pro-inflammatory cytokines; moreover, it can also improve the survival rate of osteoblasts under oxidative stress, restore mitochondrial dysfunction, inhibit apoptosis and protect osteoblasts, and reduce bone loss in diseases such as osteoporosis and periodontal disease. [42][43][44][45][46] 50 μg/mL Turkish galls extracts without significant cytotoxicity to HPLFs, and 100 μg/mL Turkish galls extracts had significant cytotoxicity against HPLFs. Compaired with blank and just stimulated by 1 μg/ml LPS, 10 and 20 μg/mL Turkish galls promoted cell viability, the results meant 10 and 20 μg/mL Turkish galls might against inflammation of HPLFs.…”

“…Specifically, 1,3,6‐tri‐O‐galloyl‐β‐D‐glucose has been shown to inhibit glucose uptake and possess antioxidant activity, while 1,2,3,6‐tetra‐O‐galloyl‐β‐D‐glucose effectively suppresses cytokine IL‐6 activity and reduces the bone resorption activity of osteoclasts [38–41] . Similarly, 1,2,3,4,6‐penta‐O‐galloyl‐β‐D‐glucose is a potent antioxidant capable of down‐regulating the expression of IL‐6 and TNF‐α, and mitigating the expression of genes and proteins involved in NF‐κB and MAPK signaling pathways, which contribute to the production of pro‐inflammatory cytokines; moreover, it can also improve the survival rate of osteoblasts under oxidative stress, restore mitochondrial dysfunction, inhibit apoptosis and protect osteoblasts, and reduce bone loss in diseases such as osteoporosis and periodontal disease [42–46] …”

Epicatechin gallate promotes vascularization in co-culture of human osteoblasts and outgrowth endothelial cells

“…23,24 In addition, it can also prevent bone tissue loss and promote bone healing after fracture. 33,34 Indeed, some recent studies have confirmed that green tea consumption can decrease the risk of osteoporosis and osteoporosis-related fractures. 35,36 In this study, we have shown that ECG at appropriate concentrations (e.g.…”

The Emerging Role of Plant-Derived Exosomes-Like Nanoparticles in Immune Regulation and Periodontitis Treatment

“…Natural products attract more and more attention in periodontitis treatment due to their therapeutic potential, cost-effectiveness, enough source, and safety. A series of natural products such as honey, propolis, cannabidiol, and green tea show various benefits in periodontitis treatment and prevention including inhibition of periodontal pathogens, anti-inflammation, immunomodulation, and osteogenesis (76)(77)(78)(79)(80)(81)(82)(83)(84)(85). But the low stability, uncertain bioavailability, and limited therapeutic effect of natural products limit their clinical application.…”