Correlations between the Peptide Hormone Ghrelin and Proinflammatory Cytokines in Experimental Periodontitis Models of Female Rats at Different Stages of the Life Cycle

Ghrelin mediated regulation of neurosynaptic transmitters in depressive disorders

Ghrelin is a peptide released by the endocrine cells of the stomach and the neurons in the arcuate nucleus of the hypothalamus. It modulates both peripheral and central functions. Although ghrelin has emerged as a potent stimulator of growth hormone release and as an orexigenic neuropeptide, the wealth of literature suggests its involvement in the pathophysiology of affective disorders including depression. Ghrelin exhibits a dual role through the advancement and reduction of depressive behavior with nervousness in the experimental animals. It modulates depression-related signals by forming neuronal networks with various neuropeptides and classical neurotransmitter systems. The present review emphasizes the integration and signaling of ghrelin with other neuromodulatory systems concerning depressive disorders. The role of ghrelin in the regulation of neurosynaptic transmission and depressive illnesses implies that the ghrelin system modulation can yield promising antidepressive therapies.

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Ghrelin is the orexigenic type of neuropeptide.

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It binds with the growth hormone secretagogue receptor (GHSR).

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GHSR is ubiquitously present in the various brain regions.

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Ghrelin is involved in the regulation of depression-related behavior.

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The review focuses on the neurotransmission and signaling of ghrelin in neuropsychiatric and depressive disorders.

Ghrelin and oral diseases

Eating food is one of the most complicated behaviours in mammals, especially humans. The primary function of ghrelin is regulation of the appetite level and its stimulation. It is also responsible for the body's energy balance and glucose homeostasis. Ghrelin has been shown to affect many brain structures, which confirms the presence of ghrelin receptors in the brain. Studies are also conducted to assess the possible role of ghrelin in anxiety states and in memory disorders and motor dysfunctions. Ghrelin has been found in saliva and salivary glands, teeth and gums, and in the taste buds of the tongue epithelium; it is also secreted by mucosal cells and gingival fibroblasts. The presence of ghrelin in developmental enamel, especially in odontoblasts and ameloblasts, may suggest its regulatory role in the development of teeth. Patients with chronic periodontitis have significantly higher concentrations of ghrelin in the peripheral blood serum, as compared to the control group. Ghrelin plays a special role in the proliferation of cancer cells and in the development of neoplastic metastases. The abundant presence of ghrelin receptors in cancer cells is considered an important target in the treatment of neoplasms. Ghrelin is a hormone whose multidirectional mechanism of action has not yet been fully understood. However, its ubiquitous occurrence in the human body and its very diverse participation in metabolic processes may prove to be a significant obstacle in achieving the expected clinical effect of ghrelin as an effective drug in selected disease units.

Effects of ınjectable platelet-rich fibrin in experimental periodontitis in rats

Injectable platelet-rich fibrin (i-PRF) is an effective biological material that positively contributes to angiogenesis, wound healing, inflammation, regeneration processes, etc. This research aimed to evaluate the effect of i-PRF in rats with experimental periodontitis. Following the development of ligature-induced periodontitis, 24 Wistar albino rats were divided into three groups. Group-1: scaling and root planing (only-SRP); Group-2: SRP + i-PRF; Group-3: only- i-PRF. Heart blood from six donors was used for the i-PRF application. i-PRF was administered as a subgingival injection in the relevant groups on the 1st, 3rd, and 7th days. The tissues were evaluated histopathologically and immunohistochemically. Also, bone structures were examined using micro-CT. According to the data obtained, no statistically significant difference was observed among the groups in terms of bone resorption, inflammation, bone volume, bone levels (mesial/distal), and IL-1β, IFN-ɤ, TNF-α, VEGF values (p > 0.05). However, bone mineral density was statistically significantly different among the groups (Group3 > Group2 > Group1) (p < 0.0001). Subgingival injection of only-i-PRF showed promising results in periodontitis treatment but contribution to SRP has not been proved according to this study results. The study results suggested that the i-PRF application was as effective as SRP in reducing bone loss, modulating inflammatory process, and effecting cytokines in experimental periodontitis. The significant effect of i-PRF on bone mineral density was the most remarkable result.