PI3K/AKT Signaling Pathway Mediated Autophagy in Oral Carcinoma - A Comprehensive Review.

Oral cancer is the most heterogeneous cancer at clinical and histological levels. PI3K/AKT/mTOR pathway was identified as one of the most commonly modulated signals in oral cancer, which regulates major cellular and metabolic activity of the cell. Thus, various proteins of PI3K/AKT/mTOR pathway were used as therapeutic targets for oral cancer, to design more specific drugs with less off-target toxicity. This review sheds light on the regulation of PI3K/AKT/mTOR, and its role in controlling autophagy and associated apoptosis during the progression and metastasis of oral squamous type of malignancy (OSCC). In addition, we reviewed in detail the upstream activators and the downstream effectors of PI3K/AKT/mTOR signaling as potential therapeutic targets for oral cancer treatment.

Potential Treatment of Dermatophyte Trichophyton rubrum in Rat Model Using Topical Green Biosynthesized Silver Nanoparticles with Achillea santolina Extract.

Trichophyton rubrum is the most common dermatophyte, and can cause cutaneous infections in humans and animals (dermatophytosis). In this study, we investigated the anti-dermatophytic potential of green synthesized silver nanoparticles using Achillea santolina extract (AS-AgNPs) in an in vitro and in vivo rat model of dermal T. rubrum dermatophytosis (TRD). The green synthesis of AS-AgNPs was performed using A. santolina extract and characterized by UV-VIS spectroscopy, zeta potential, imaging (transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Energy dispersive X-ray analysis (EDX). The antifungal activity of AS-AgNPs was determined by the broth microdilution method, conidial germination, and hyphal growth inhibition. TEM and SEM were used to study the mode of the antifungal action of AS-AgNPs. AS-AgNPs inhibited the growth of T. rubrum with an MIC of 128 µg/mL, and suppressed the conidial germination and hyphal growth by 55.3% 84.6%, respectively. AS-AgNPs caused modified mycelial structures, increased cell membrane permeability, and cell wall damage. AS-AgNPs significantly increase the permeability of the fungal membrane, as revealed by reducing ergosterol biosynthesis. An increase in the intracellular ROS and the induction of apoptosis were also observed during AS-AgNP treatment. In addition, AS-AgNPs reduced the cell wall integrity, as shown by the reduction in the ß-(1,3)-d-glucan synthase and chitin synthase activities. AS-AgNPs showed very low toxicity on primary human dermal fibroblasts (HDF) at the MIC. The topical treatment of the infected skin in the TRD rat model with AS-AgNPs showed a significant reduction in the fugal burden after 7 days and a complete clearance of fungal conidia, with a high recovery of epidermal and dermal structures after 14 days, compared to control rats. Interestingly, AS-AgNPs significantly attenuated the infiltrated inflammatory cells, in association with reducing the tissue proinflammatory cytokines including TNF-α, IL-1, IL-6, MOP and IL-17. In conclusion, our data prove AS-AgNPs to be a novel green topical therapy for dermatophytosis caused by T. rubrum.

Therapeutic Effect of Green Synthesized Silver Nanoparticles Using Erodium glaucophyllum Extract against Oral Candidiasis: In Vitro and In Vivo Study.

Oral candidiasis (OC) is a fungal infection caused by an opportunistic fungi Candida albicans, which is found in the normal flora of healthy people. In this study, we examined the anti-candidal effect of green synthesized silver nanoparticles using leaf extract of Erodium glaucophyllum (EG-AgNPs) against C. albicans in vitro and in vivo. EG-AgNPs were synthesized for the first time using E. glaucophyllum extract and characterized by imaging (transmission electron microscopy (TEM), UV-VIS spectroscopy, zeta potential, X-ray diffraction (XRD), Energy dispersive x-ray analysis (EDX), and Fourier transform infrared spectroscopy (FTIR). A mouse model of OC was used for in vivo study. The agar well diffusion method showed the anti-candidal activity of EG-AgNPs against C. albicans with MIC 50 µg/mL. EG-AgNPs inhibited the dimorphic transition of C. albicans and suppressed the formation of biofilm by 56.36% and 52%, respectively. Additionally, EG-AgNPs significantly inhibited the production of phospholipases and proteinases by 30% and 45%, respectively. EG-AgNPs cause cytoplasm disintegration and deterioration of cell wall as imaged by SEM and TEM. Interestingly, EG-AgNPs did not display any cytotoxicity on the human gingival fibroblast-1 HGF-1 cell line at MIC concentrations. Topical treatment of the tongue of the OC mouse model with EG-AgNPs showed significant reduction in candidal tissue invasion, less inflammatory changes, and no tissue modification, in association with marked low scare and hyphal counts as compared to control group. In conclusion, our data demonstrated the potent inhibitory action of EG-AgNPs on the growth and morphogenesis of C. albicans in vitro and in vivo. Thus, EG-AgNPs represent a novel plausible therapeutic approach for treatment of OC.

A-769662 stimulates the differentiation of bone marrow-derived mesenchymal stem cells into osteoblasts via AMP-activated protein kinase-dependent mechanism.

AMP-activated protein kinase (AMPK) signaling shows an important role in energy metabolism and has recently been involved in osteogenic and adipogenic differentiation. In this study we aimed to investigate the role of AMPK activator, A-769662, in regulating the differentiation of mesenchymal stem cells derived from bone marrow (BMSCs) into osteoblastic and adipocytic cell lineage. The effect of A-769662 on osteogenesis was assessed by quantitative alkaline phosphatase (ALP) activity, matrix mineralization stained with Alizarin red, and gene expression analysis by quantitative polymerase chain reaction (qPCR). Adipogenesis was determined by Oil Red O staining for fat droplets and qPCR analysis of adipogenic markers. A-769662 activated the phosphorylation of AMPKα1 during the osteogenesis of mBMSCs as revealed by western blot analysis. A-769662 promoted the early stage of the commitment of mouse (m) BMSCs differentiation into osteoblasts, while inhibiting their differentiation into adipocytes in a dose-dependent manner. The effects of A-769662 on stimulating osteogenesis and inhibiting adipogenesis of mBMSCs were significantly eliminated in the presence of either AMPKα1 siRNA or Compound C, an inhibitor of AMPK pathway. In conclusion, we identified A-769662 as a new compound that promotes the commitment of BMSCs into osteoblasts versus adipocytes via AMPK-dependent mechanism. Thus our data show A-769662 as a potential osteo-anabolic drug for treatment of osteoporosis.

Carnosol induces the osteogenic differentiation of bone marrow-derived mesenchymal stem cells via activating BMP-signaling pathway.

Carnosol is a phenolic diterpene phytochemical found in rosemary and sage with reported anti-microbial, anti-oxidant, anti-inflammatory, and anti-carcinogenic activities. This study aimed to investigate the effect of carnosol on the lineage commitment of mouse bone marrow-derived mesenchymal stem cells (mBMSCs) into osteoblasts and adipocytes. Interestingly, carnosol stimulated the early commitment of mBMSCs into osteoblasts in dose-dependent manner as demonstrated by increased levels of alkaline phosphatase activity and Alizarin red staining for matrix mineralization. On the other hand, carnosol significantly suppressed adipogenesis of mBMSCs and downregulated both early and late markers of adipogenesis. Carnosol showed to induce osteogenesis in a mechanism mediated by activating BMP signaling pathway and subsequently upregulating the expression of BMPs downstream osteogenic target genes. In this context, treatment of mBMSCs with LDN-193189, BMPR1 selective inhibitor showed to abolish the stimulatory effect of carnosol on BMP2-induced osteogenesis. In conclusion, our data identified carnosol as a novel osteoanabolic phytochemical that can promote the differentiation of mBMSCs into osteoblasts versus adipocytes by activating BMP-signaling.

TAFA2 Induces Skeletal (Stromal) Stem Cell Migration Through Activation of Rac1-p38 Signaling.

Understanding the mechanisms regulating recruitment of human skeletal (stromal or mesenchymal) stem cells (hMSC) to sites of tissue injury is a prerequisite for their successful use in cell replacement therapy. Chemokine-like protein TAFA2 is a recently discovered neurokine involved in neuronal cell migration and neurite outgrowth. Here, we demonstrate a possible role for TAFA2 in regulating recruitment of hMSC to bone fracture sites. TAFA2 increased the in vitro trans-well migration and motility of hMSC in a dose-dependent fashion and induced significant morphological changes including formation of lamellipodia as revealed by high-content-image analysis at single-cell level. Mechanistic studies revealed that TAFA2 enhanced hMSC migration through activation of the Rac1-p38 pathway. In addition, TAFA2 enhanced hMSC proliferation, whereas differentiation of hMSC toward osteoblast and adipocyte lineages was not altered. in vivo studies demonstrated transient upregulation of TAFA2 gene expression during the inflammatory phase of fracture healing in a closed femoral fracture model in mice, and a similar pattern was observed in serum levels of TAFA2 in patients after hip fracture. Finally, interleukin-1ß was found as an upstream regulator of TAFA2 expression. Our findings demonstrate that TAFA2 enhances hMSC migration and recruitment and thus is relevant for regenerative medicine applications. Stem Cells 2019;37:407-416.

Butein Promotes Lineage Commitment of Bone Marrow-Derived Stem Cells into Osteoblasts via Modulating ERK1/2 Signaling Pathways.

Butein is a phytochemical that belongs to the chalcone family of flavonoids and has antitumor, anti-inflammatory, and anti-osteoclastic bone resorption activities. This study aims to investigate the effects of butein on the differentiation potential of mouse primary bone marrow-derived mesenchymal stem cells (mBMSCs) into osteoblast and adipocyte lineages. Primary cultures of mBMSCs are treated with different doses of butein during its differentiation. Osteoblast differentiation is assessed by alkaline phosphatase (ALP) activity quantification and Alizarin red staining for matrix mineralization, while adipogenesis is assessed by quantification of lipid accumulation using Oil Red O staining. Osteoblastic and adipocytic gene expression markers are determined by quantitative real-time PCR (qPCR). Western blot analysis is used to study the activation of extracellular signal-regulated kinase (ERK1/2). Interestingly, butein promotes the lineage commitment of mBMSCs into osteoblasts, while suppressing their differentiation into adipocytes in a dose-dependent manner. A similar effect of butein is confirmed in human (h) primary BMSCs. Occurring at the molecular level, butein significantly upregulates the mRNA expression of osteoblast-related genes, while downregulating the expression of adipocyte-related genes. The mechanism of butein-induced osteogenesis is found to be mediated by activating the ERK1/2 signaling pathway. To conclude, we identify butein as a novel nutraceutical compound with an osteo-anabolic activity to promote the lineage commitment of BMSCs into osteoblast versus adipocyte. Thus, butein can be a plausible therapeutic drug for enhancing bone formation in osteoporotic patients.

A simple and reliable protocol for long-term culture of murine bone marrow stromal (mesenchymal) stem cells that retained their in vitro and in vivo stemness in long-term culture.

BACKGROUND: Bone marrow derived stromal stem cells (BMSCs) are a clonogenic cell population that is characterized by self-renewal capacity and differentiation potential into osteoblasts, and other mesenchymal cell types. Mouse BMSCs (mBMSCs) are difficult to be cultured and propagated in vitro due to their replicative senescent phenotype, heterogeneity and high contamination with plastic adherent hematopoietic progenitors (HPCs). In this study, we described long-term culture of homogenous population of mBMSCs using simple and highly reproducible approach based on frequent subculturing (FS) at fixed split ratio in the presence of basic fibroblast growth factor (bFGF). RESULTS: Cultured mBMSCs using this protocol (mBMSCs-FS) showed long-term survival in culture > 70 population doubling (PD) and retained their characteristic surface markers and differentiation capacity into osteoblast and adipocyte lineages. When compared to the clonal bone marrow-derived cell line ST2, mBMSCs-FS displayed more enhanced osteoblast differentiation potential and responsiveness to osteogenic factors including BMPs, IGF-1, PDGF, TGFß1,3, FGF, cAMP, Wnt3a and VEGF. In addition, unlike ST2 cells, mBMSCs-FS maintained capacity to form ectopic bone and bone marrow stroma upon in vivo transplantation in immune-compromising mice, even at high PD levels. Interestingly, by applying the same FS + bFGF protocol, we succeeded to obtain long-term cultures of primary neonatal calvarial osteoprogenitor cells (OBs) that were cultured for more than 70 PD and maintained in vitro and in vivo osteoblast differentiation capacities. CONCLUSIONS: Our data provide a simple and reliable protocol for generating long-term cultures of mBMSCs and OBs with retained high in vitro and in vivo osteoblast differentiation capacities for use in pre-clinical and molecular mechanism studies.

5'-hydroxy Auraptene stimulates osteoblast differentiation of bone marrow-derived mesenchymal stem cells via a BMP-dependent mechanism.

BACKGROUND: Identifying bone anabolic agents is a superior strategy for the treatment of osteoporosis. Naturally, derived coumarin derivatives have shown osteoanabolic effect in vitro and in vivo. In this study, we investigated the effect of 5'-Hydroxy Auraptene (5'-HA), a coumarin derivative that newly isolated from Lotus lalambensis Schweinf on the differentiation of the mouse bone marrow-derived mesenchymal (skeletal) stem cells (mBMSCs) into osteoblast and adipocyte. METHODS: The effect of 5'-HA on mBMSCs cell proliferation and osteoblast differentiation was assessed by measuring cell viability, quantitative alkaline phosphatase (ALP) activity assay, Alizarin red staining for matrix mineralization and osteogenic gene array expression. Adipogenesis was measured by Oil Red O staining and quantitative real time PCR (qPCR) analysis of adipogenic markers. Regulation of BMPs signaling pathways by 5'-HA was measured by Western blot analysis and qPCR. RESULTS: 5'-HA showed to stimulate the differentiation of mBMSCs into osteogenic cell lineage in a dose-dependent manner, without affecting their differentiation into adipocytic cell lineage. Treatment of mBMSCs with 5'-HA showed to promote significantly the BMP2-induced osteogenesis in mBMSCs via activating Smad1/5/8 phosphorylation and increasing Smad4 expression. Blocking of BMP signaling using BMPR1 selective inhibitor LDN-193189 significantly inhibited the stimulatory effect of 5'-HA on osteogenesis. CONCLUSIONS: Our data identified 5'-HA, as a novel coumarin derivative that function to stimulate the differentiation of mBMSCs into osteoblasts in BMP-signaling dependent mechanism.

Marrow adipocytes inhibit the differentiation of mesenchymal stem cells into osteoblasts via suppressing BMP-signaling.

BACKGROUND: Reduced bone formation is associated with increased bone marrow fat in many bone-loss related diseases including aging, post-menopause, and anorexia nervosa. Several lines of evidence suggested the regulation of osteogenesis and adipogenesis of the bone marrow-derived mesenchymal (skeletal) stem cells (BMSCs) by paracrine mediators. This study aimed to investigate the impact of adipocytes-secreted factors on the cell proliferation and osteoblast differentiation of BMSCs. METHODS: Serum free conditioned medium (CM-Adipo) was collected from stromal ST2 cells-derived adipocytes. Cell viability, quantitative alkaline phosphatase (ALP) activity assay, Alizarin red staining for matrix mineralization and osteogenic gene array expression were performed to determine the effect of CM-Adipo on cell proliferation and osteoblast differentiation of primary murine BMSCs (mBMSCs). Regulation of BMPs and NF-κB signaling pathways by CM-Adipo were detected by Western blot analysis and gene reporter assay. RESULTS: CM-Adipo showed no effect on cell viability/proliferation of primary mBMSCs as compared to CM-control. On the other hand, CM-Adipo significantly inhibited the commitment of mBMSCs into osteoblastic cell lineage in dose-dependent manner. CM-Adipo was found to dramatically inhibit the BMP2-induced osteoblast differentiation and to activate the inflammatory NF-κB signaling in mBMSCs. Interestingly, treatment of mBMSCs with the selective inhibitor of NF-κB pathway, BAY11-770682, showed to retrieve the inhibitory effect of CM-Adipo on BMP2-induced osteoblast differentiation in mBMSCs. CONCLUSIONS: Our data demonstrated that the marrow adipocytes exert paracrine inhibitory effect on the osteoblast differentiation of mBMSCs by blocking BMPs signaling in a mechanism mediated by adipokines-induced NF-κB pathway activation.

Pharmacological Inhibition of Protein Kinase G1 Enhances Bone Formation by Human Skeletal Stem Cells Through Activation of RhoA-Akt Signaling.

Development of novel approaches to enhance bone regeneration is needed for efficient treatment of bone defects. Protein kinases play a key role in regulation of intracellular signal transduction pathways, and pharmacological targeting of protein kinases has led to development of novel treatments for several malignant and nonmalignant conditions. We screened a library of kinase inhibitors to identify small molecules that enhance bone formation by human skeletal (stromal or mesenchymal) stem cells (hMSC). We identified H-8 (known to inhibit protein kinases A, C, and G) as a potent enhancer of ex vivo osteoblast (OB) differentiation of hMSC, in a stage- and cell type-specific manner, without affecting adipogenesis or osteoclastogenesis. Furthermore, we showed that systemic administration of H-8 enhances in vivo bone formation by hMSC, using a preclinical ectopic bone formation model in mice. Using functional screening of known H-8 targets, we demonstrated that inhibition of protein kinase G1 (PRKG1) and consequent activation of RhoA-Akt signaling is the main mechanism through which H-8 enhances osteogenesis. Our studies revealed PRKG1 as a novel negative regulator of OB differentiation and suggest that pharmacological inhibition of PRKG1 in hMSC implanted at the site of bone defect can enhance bone regeneration. Stem Cells 2015;33:2219-2231.

Telomerase activity promotes osteoblast differentiation by modulating IGF-signaling pathway.

The contribution of deficient telomerase activity to age-related decline in osteoblast functions and bone formation is poorly studied. We have previously demonstrated that telomerase over-expression led to enhanced osteoblast differentiation of human bone marrow skeletal (stromal) stem cells (hMSC) in vitro and in vivo. Here, we investigated the signaling pathways underlying the regulatory functions of telomerase in osteoblastic cells. Comparative microarray analysis and Western blot analysis of telomerase-over expressing hMSC (hMSC-TERT) versus primary hMSC revealed significant up-regulation of several components of insulin-like growth factor (IGF) signaling. Specifically, a significant increase in IGF-induced AKT phosphorylation and alkaline phosphatase (ALP) activity were observed in hMSC-TERT. Enhanced ALP activity was reduced in presence of IGF1 receptor inhibitor: picropodophyllin. In addition, telomerase deficiency caused significant reduction in IGF signaling proteins in osteoblastic cells cultured from telomerase deficient mice (Terc(-/-)). The low bone mass exhibited by Terc(-/-) mice was associated with significant reduction in serum levels of IGF1 and IGFBP3 as well as reduced skeletal mRNA expression of Igf1, Igf2, Igf2r, Igfbp5 and Igfbp6. IGF1-induced osteoblast differentiation was also impaired in Terc(-/-) MSC. In conclusion, our data demonstrate that impaired IGF/AKT signaling contributes to the observed decreased bone mass and bone formation exhibited by telomerase deficient osteoblastic cells.

MicroRNA-138 regulates osteogenic differentiation of human stromal (mesenchymal) stem cells in vivo.

Elucidating the molecular mechanisms that regulate human stromal (mesenchymal) stem cell (hMSC) differentiation into osteogenic lineage is important for the development of anabolic therapies for treatment of osteoporosis. MicroRNAs (miRNAs) are short, noncoding RNAs that act as key regulators of diverse biological processes by mediating translational repression or mRNA degradation of their target genes. Here, we show that miRNA-138 (miR-138) modulates osteogenic differentiation of hMSCs. miRNA array profiling and further validation by quantitative RT-PCR (qRT-PCR) revealed that miR-138 was down-regulated during osteoblast differentiation of hMSCs. Overexpression of miR-138 inhibited osteoblast differentiation of hMSCs in vitro, whereas inhibition of miR-138 function by antimiR-138 promoted expression of osteoblast-specific genes, alkaline phosphatase (ALP) activity, and matrix mineralization. Furthermore, overexpression of miR-138 reduced ectopic bone formation in vivo by 85%, and conversely, in vivo bone formation was enhanced by 60% when miR-138 was antagonized. Target prediction analysis and experimental validation by luciferase 3' UTR reporter assay confirmed focal adhesion kinase, a kinase playing a central role in promoting osteoblast differentiation, as a bona fide target of miR-138. We show that miR-138 attenuates bone formation in vivo, at least in part by inhibiting the focal adhesion kinase signaling pathway. Our findings suggest that pharmacological inhibition of miR-138 by antimiR-138 could represent a therapeutic strategy for enhancing bone formation in vivo.

The Inhibitory Effect of Geraniol on CCL4-induced Hepatorenal Toxicity in Pregnant Mice through the PI3K/AKT Signaling Pathway.

Background: Hepatotoxicity caused by CCL4 is well known. Geraniol (GNL) has high antioxidant effect that can induces liver regeneration. However, the protective effect of GNL effect on CCL4-induced hepatorenal toxicity in pregnant mice has not yet been studied. Objective: To investigate whether GNL could protect against oxidative stress induced by CCL4 via the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, which is regulated by phosphatidylinositol 3 kinase/protein kinase B (PI3K/AKT), and has been found to have protective effects on renal and hepatic tissues. Materials and Methods: Forty-eight female albino mice weighing 25-30 g were randomly allocated to 4 groups: Group I served as a control; Group II received a toxicity-inducing single dose of 15 µL of CCL4 on the 4th day after mating; Group III received 40 mg/kg GNL + CCL4 (with GNL from the 1st day of assimilation to delivery); and Group IV received GNL alone from the 1st day of assimilation to the end of the delivery period. GNL was evaluated for its protective effects on hepatotoxicity in CCL4-treated pregnant mice. Litter size, weight, survival rate, and resorption were recorded. In addition, H & E staining was done for liver and kidney pathology as well as biochemical markers and oxidative markers malondialdehyde, superoxide dismutase, and catalase were analyzed. Results: CCL4 significantly reduced survival rate and increased resorption after exposure. Alanine transaminase and aspartate aminotransferase concentrations in the serum, tissue MDA, blood urea nitrogen, and creatinine were increased after CCL4 exposure. GNL improved enzyme and antioxidant levels and prevented CCL4-induced hepatic injury in mice. Caspase-3 cleavage was decreased by GNL, which increased PI3K, phosphorylated AKT, Nrf2, and B-cell lymphoma 2. Conclusion: GNL demonstrates a protective effect against CCl4-induced hepatorenal toxicity, mediated through the activation of the PI3K/AKT signaling pathway and the upregulation of Nrf2. These findings highlight the potential therapeutic implications of GNL in mitigating oxidative stress and inflammation in liver and kidney tissues.

Epigenetic modulation of long noncoding RNA H19 in oral squamous cell carcinoma-A narrative review.

Oral squamous cell carcinoma (OSCC) showed a seemingly increasing incidence in the last decade. In India, despite the use of tobacco decreased rapidly, in the past five years, the incidence pattern of OSCC over gender and age showed a drastic shift. About 51 % of the head and neck cancers are not associated with habits. Studies exploring various contributing factors in the incidence of this malignancy have documented. Recently, the epigenetic factors associated with the induction and progression of OSCC were explored. More than 90 % of the human genome is made up of non-coding transcriptome, which believed to be noises. However, these non-coding RNAs were identified to be the major epigenetic modulators, which raises concern over incidence of carcinoma in non-habit patients. H19 is a long non coding RNA which proved to be an effective biomarker in various carcinoma. Its role in oral squamous cell cancer was not investigated in depth. This review discusses in detail the various epigenetic role of H19 in inducing oral carcinogenesis.

Geraniol attenuates oxidative stress and neuroinflammation-mediated cognitive impairment in D galactose-induced mouse aging model.

D-galactose (D-gal) administration was proven to induce cognitive impairment and aging in rodents' models. Geraniol (GNL) belongs to the acyclic isoprenoid monoterpenes. GNL reduces inflammation by changing important signaling pathways and cytokines, and thus it is plausible to be used as a medicine for treating disorders linked to inflammation. Herein, we examined the therapeutic effects of GNL on D-gal-induced oxidative stress and neuroinflammation-mediated memory loss in mice. The study was conducted using six groups of mice (6 mice per group). The first group received normal saline, then D-gal (150 mg/wt) dissolved in normal saline solution (0.9%, w/v) was given orally for 9 weeks to the second group. In the III group, from the second week until the 10th week, mice were treated orally (without anesthesia) with D-gal (150 mg/kg body wt) and GNL weekly twice (40 mg/kg body wt) four hours later. Mice in Group IV were treated with GNL from the second week up until the end of the experiment. For comparison of young versus elderly mice, 4 month old (Group V) and 16-month-old (Group VI) control mice were used. We evaluated the changes in antioxidant levels, PI3K/Akt levels, and Nrf2 levels. We also examined how D-gal and GNL treated pathological aging changes. Administration of GNL induced a significant increase in spatial learning and memory with spontaneously altered behavior. Enhancing anti-oxidant and anti-inflammatory effects and activating PI3K/Akt were the mechanisms that mediated this effect. Further, GNL treatment upregulated Nrf2 and HO-1 to reduce oxidative stress and apoptosis. This was confirmed using 99mTc-HMPAO brain flow gamma bioassays. Thus, our data suggested GNL as a promising agent for treating neuroinflammation-induced cognitive impairment.

Nimbolide: promising agent for prevention and treatment of chronic diseases (recent update).

Background: Nimbolide, a bioactive compound derived from the neem tree, has garnered attention as a potential breakthrough in the prevention and treatment of chronic diseases. Recent updates in research highlight its multifaceted pharmacological properties, demonstrating anti-inflammatory, antioxidant, and anticancer effects. With a rich history in traditional medicine, nimbolide efficacy in addressing the molecular complexities of conditions such as cardiovascular diseases, diabetes, and cancer positions it as a promising candidate for further exploration. As studies progress, the recent update underscores the growing optimism surrounding nimbolide as a valuable tool in the ongoing pursuit of innovative therapeutic strategies for chronic diseases. Methods: The comprehensive search of the literature was done until September 2020 on the MEDLINE, Embase, Scopus and Web of Knowledge databases. Results: Most studies have shown the Nimbolide is one of the most potent limonoids derived from the flowers and leaves of neem (Azadirachta indica), which is widely used to treat a variety of human diseases. In chronic diseases, nimbolide reported to modulate the key signaling pathways, such as Mitogen-activated protein kinases (MAPKs), Wingless-related integration site-ß (Wnt-ß)/catenin, NF-κB, PI3K/AKT, and signaling molecules, such as transforming growth factor (TGF-ß), Matrix metalloproteinases (MMPs), Vascular Endothelial Growth Factor (VEGF), inflammatory cytokines, and epithelial-mesenchymal transition (EMT) proteins. Nimbolide has anti-inflammatory, anti-microbial, and anti-cancer properties, which make it an intriguing compound for research. Nimbolide demonstrated therapeutic potential for osteoarthritis, rheumatoid arthritis, cardiovascular, inflammation and cancer. Conclusion: The current review mainly focused on understanding the molecular mechanisms underlying the therapecutic effects of nimbolide in chronic diseases.

The crosstalk between transforming growth factor-ß1 and delta like-1 mediates early chondrogenesis during embryonic endochondral ossification.

Delta like-1 (Dlk1)/preadipocyte factor-1 (Pref-1)/fetal antigen-1 (FA1) is a novel surface marker for embryonic chondroprogenitor cells undergoing lineage progression from proliferation to prehypertrophic stages. However, mechanisms mediating control of its expression during chondrogenesis are not known. Thus, we examined the effect of a number of signaling molecules and their inhibitors on Dlk1 expression during in vitro chondrogenic differentiation in mouse embryonic limb bud mesenchymal micromass cultures and mouse embryonic fibroblast (MEF) pellet cultures. Dlk1/Pref-1 was initially expressed during mesenchymal condensation and chondrocyte proliferation, in parallel with expression of Sox9 and Col2a1, and was downregulated upon the expression of Col10a1 by hypertrophic chondrocytes. Among a number of molecules that affected chondrogenesis, transforming growth factor-ß1 (TGF-ß1)-induced proliferation of chondroprogenitors was associated with decreased Dlk1 expression. This effect was abolished by TGF-ß signaling inhibitor SB431542, suggesting regulation of Dlk1/FA1 by TGF-ß1 signaling in chondrogenesis. TGF-ß1-induced Smad phosphorylation and chondrogenesis were significantly increased in Dlk1(-/-) MEF, while they were blocked in Dlk1 overexpressing MEF, in comparison with wild-type MEF. Furthermore, overexpression of Dlk1 or addition of its secreted form FA1 dramatically inhibited TGF-ß1-induced Smad reporter activity. In conclusion, our data identified Dlk1/FA1 as a downstream target of TGF-ß1 signaling molecule that mediates its function in embryonic chondrogenesis. The crosstalk between TGF-ß1 and Dlk1/FA1 was shown to promote early chondrogenesis during the embryonic endochondral ossification process.

Salivaomics to decode non-coding RNAs in oral cancer. A narrative review.

Oral cancer is the most debilitating disease which affects the orderly life of a human. With so much advancement in research and technology, the average life expectancy of an individual with oral cancer appears to be about 5 years. The changing trend in incidence of oral cancer among young individuals and women without tobacco habits are ascending. Non habit related oral cancer are taking centre stage and multiple factors which induce complex biology are associated in such scenarios. To decipher the aetiology and to understand the process, these cancerous conditions are to be studied at molecular level. Saliva, the most non-invasively obtained body fluid are assessed for biomarkers exclusively in liquid biopsy. This fluid gives a huge platform to study number of molecules associated with oral cancer. Non coding RNAs are transcripts with no protein coding function. They are gaining more importance in recent times. Long noncoding RNA, microRNA are major types of noncoding transcriptome that influences in progression of oral cancer. They seem to play an important role in health and disease. Apart from these, circulating tumour cells, exosomes, extracellular vesicles, antigens and other proteins can be studied from saliva. This review is aimed to update the knowledge on current biomarkers in saliva associated with oral cancer and their epigenetic role in disease progression as well recent advances in detecting these markers to identify the stage of the disease, which will help in deciding the treatment protocol.

Polyphenols Mediate Neuroprotection in Cerebral Ischemic Stroke-An Update.

Stroke is one of the main causes of mortality and disability, and it is due to be included in monetary implications on wellbeing frameworks around the world. Ischemic stroke is caused by interference in cerebral blood flow, leading to a deficit in the supply of oxygen to the affected region. It accounts for nearly 80-85% of all cases of stroke. Oxidative stress has a significant impact on the pathophysiologic cascade in brain damage leading to stroke. In the acute phase, oxidative stress mediates severe toxicity, and it initiates and contributes to late-stage apoptosis and inflammation. Oxidative stress conditions occur when the antioxidant defense in the body is unable to counteract the production and aggregation of reactive oxygen species (ROS). The previous literature has shown that phytochemicals and other natural products not only scavenge oxygen free radicals but also improve the expressions of cellular antioxidant enzymes and molecules. Consequently, these products protect against ROS-mediated cellular injury. This review aims to give an overview of the most relevant data reported in the literature on polyphenolic compounds, namely, gallic acid, resveratrol, quercetin, kaempferol, mangiferin, epigallocatechin, and pinocembrin, in terms of their antioxidant effects and potential protective activity against ischemic stroke.