Advance on Resveratrol Application in Bone Regeneration: Progress and Perspectives for Use in Oral and Maxillofacial Surgery

Safety and Efficacy of Resveratrol in Healing of Maxillofacial Fractures: A Randomized Controlled Study

Objectives

To assess the efficacy of resveratrol in improving functional outcomes following open reduction and internal fixation of maxillofacial fractures.

Study Design

A single-center, randomized, parallel group, prospective, double-blind clinical trial was conducted on 40 patients between the age 20 and 60 years, requiring open reduction and internal fixation of maxillofacial fractures. The selected patients were randomly divided into two groups, Group 1 (placebo) and Group 2 (resveratrol) where tablets resveratrol 500 mg were given twice daily for 1 month following open reduction and internal fixation of fractured segments. Bite force was calculated pre-operatively and on the 1st, 4th, 8th and 12th week postoperatively. Serum markers osteocalcin and alkaline phosphate were calculated pre-operatively and at 4th and 12th week postoperatively.

Results

Bite force (690.55 ± 262.00) in the resveratrol group was higher than the placebo group (553.27 ± 300.08) at 12th week postoperatively. However, the difference was non-significant statistically (p = 0.132). Resveratrol group (116.80 ± 55.25) showed better maintenance of serum ALP level as compared to placebo group (107.90 ± 42.99) at 12th week postoperatively, but again it lacked statistical significance (p = 0.573). Resveratrol group after initial reduction at 4th week showed serum osteocalcin levels nearly equal to the preoperative values at 12th week, while the placebo group showed a decline both at 4th and 12th week postoperatively. However, these results were not statistically significant (p = 0.065).

Conclusion

There was no statistically significant difference in bite force, serum ALP level and serum osteocalcin levels between placebo group and resveratrol group. Though not statistically significant but early increased level of serum osteogenic markers, better restoration of bite force in group 2 (tab. Resveratrol) indicates toward its possible optimistic role in maxillofacial fracture healing. More studies with larger sample sizes are needed in order to confirm the efficacy of this drug in maxillofacial fracture.

Phytochemical Compounds Involved in the Bone Regeneration Process and Their Innovative Administration: A Systematic Review

Bone metabolism is a complex process which is influenced by the activity of bone cells (e.g., osteocytes, osteoblasts, osteoclasts); the effect of some specific biomarkers (e.g., parathyroid hormone, vitamin D, alkaline phosphatase, osteocalcin, osteopontin, osteoprotegerin, osterix, RANKL, Runx2); and the characteristic signaling pathways (e.g., RANKL/RANK, Wnt/β, Notch, BMP, SMAD). Some phytochemical compounds-such as flavonoids, tannins, polyphenols, anthocyanins, terpenoids, polysaccharides, alkaloids and others-presented a beneficial and stimulating effect in the bone regeneration process due to the pro-estrogenic activity, the antioxidant and the anti-inflammatory effect and modulation of bone signaling pathways. Lately, nanomedicine has emerged as an innovative concept for new treatments in bone-related pathologies envisaged through the incorporation of medicinal substances in nanometric systems for oral or local administration, as well as in nanostructured scaffolds with huge potential in bone tissue engineering.

Hydrogel Drug Delivery Systems for Bone Regeneration

With the in-depth understanding of bone regeneration mechanisms and the development of bone tissue engineering, a variety of scaffold carrier materials with desirable physicochemical properties and biological functions have recently emerged in the field of bone regeneration. Hydrogels are being increasingly used in the field of bone regeneration and tissue engineering because of their biocompatibility, unique swelling properties, and relative ease of fabrication. Hydrogel drug delivery systems comprise cells, cytokines, an extracellular matrix, and small molecule nucleotides, which have different properties depending on their chemical or physical cross-linking. Additionally, hydrogels can be designed for different types of drug delivery for specific applications. In this paper, we summarize recent research in the field of bone regeneration using hydrogels as delivery carriers, detail the application of hydrogels in bone defect diseases and their mechanisms, and discuss future research directions of hydrogel drug delivery systems in bone tissue engineering.

Emerging Effects of Resveratrol Derivatives in Cells Involved in Oral Wound Healing: A Preliminary Study

Recently, there has been an increasing interest in finding new approaches to manage oral wound healing. Although resveratrol (RSV) exhibited many biological properties, such as antioxidant and anti-inflammatory activities, its use as a drug is limited by unfavorable bioavailability. This study aimed to investigate a series of RSV derivatives (1a-j) with better pharmacokinetic profiles. At first, their cytocompatibility at different concentrations was tested on gingival fibroblasts (HGFs). Among them, derivatives 1d and 1h significantly increased cell viability compared to the reference compound RSV. Thus, 1d and 1h were investigated for cytotoxicity, proliferation, and gene expression in HGFs, endothelial cells (HUVECs), and oral osteoblasts (HOBs), which are the main cells involved in oral wound healing. For HUVECs and HGFs, the morphology was also evaluated, while for HOBs ALP and mineralization were observed. The results showed that both 1d and 1h did not exert negative effects on cell viability, and at a lower concentration (5 µM) both even significantly enhanced the proliferative rate, compared to RSV. The morphology observations pointed out that the density of HUVECs and HGFs was promoted by 1d and 1h (5 µM) and mineralization was promoted in HOBs. Moreover, 1d and 1h (5 µM) induced a higher eNOS mRNA level in HUVECs, higher COL1 mRNA in HGFs, and higher OCN in HOBs, compared to RSV. The appreciable physicochemical properties and good enzymatic and chemical stability of 1d and 1h, along with their promising biological properties, provide the scientific basis for further studies leading to the development of RSV-based agents useful in oral tissue repair.

Chemopreventive and Anticancer Role of Resveratrol against Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is one of the most prevailing and aggressive head and neck cancers, featuring high morbidity and mortality. The available conventional treatments suffer from several adverse effects and are often inefficient in terms of their survival rates. Thus, seeking novel therapeutic agents and adjuvants is of the utmost importance for modern society. Natural polyphenolic compounds have recently emerged as promising chemopreventive and anticancer agents. Specifically, the natural compound resveratrol (RSV) has recently gained momentum for this purpose. RSV is useful for treating OSCC due to its antiproliferative, antimetastatic, and proapoptotic effects. Additionally, RSV acts against tumor cells while synergically cooperating with chemotherapeutics, overcoming drug resistance phenomena. Despite these wide-spectrum effects, there are few specific investigations regarding RSV's effects against OSCC animal models that consider different routes and vehicles for the administration of RSV. Interestingly, an injectable RSV-loaded liposome-based formulation was proven to be effective against both in vitro and in vivo OSCC models, demonstrating that the development of RSV-loaded drug delivery systems for systemic and/or loco-regional applications may be the turning point in oral cancer treatment, leading to benefits from both RSV's properties as well as from targeted delivery. Given these premises, this review offers a comprehensive overview of the in vitro and in vivo effects of RSV and its main derivative, polydatin (PD), against OSCC-related cell lines and animal models, aiming to guide the scientific community in regard to RSV and PD use in the treatment of oral precancerous and cancerous lesions.

Nano-Hydroxyapatite Composite Scaffolds Loaded with Bioactive Factors and Drugs for Bone Tissue Engineering

Nano-hydroxyapatite (n-HAp) is similar to human bone mineral in structure and biochemistry and is, therefore, widely used as bone biomaterial and a drug carrier. Further, n-HAp composite scaffolds have a great potential role in bone regeneration. Loading bioactive factors and drugs onto n-HAp composites has emerged as a promising strategy for bone defect repair in bone tissue engineering. With local delivery of bioactive agents and drugs, biological materials may be provided with the biological activity they lack to improve bone regeneration. This review summarizes classification of n-HAp composites, application of n-HAp composite scaffolds loaded with bioactive factors and drugs in bone tissue engineering and the drug loading methods of n-HAp composite scaffolds, and the research direction of n-HAp composite scaffolds in the future is prospected.

Green Extraction of Polyphenols from Waste Bentonite to Produce Functional Antioxidant Excipients for Cosmetic and Pharmaceutical Purposes: A Waste-to-Market Approach

In an ever-growing perspective of circular economy, the development of conscious, sustainable and environmental-friendly strategies to recycle the waste products is the key point. The scope of this work was to validate the waste bentonite from the grape processing industries as a precious matrix to extract polyphenols by applying a waste-to-market approach aimed at producing novel functional excipients. The waste bentonite was recovered after the fining process and opportunely pre-treated. Subsequently, both the freeze dried and the so-called "wet" bentonites were subjected to maceration. PEG200 and Propylene Glycol were selected as solvents due to their ability to dissolve polyphenols and their wide use in the cosmetic/pharmaceutical field. The extracts were evaluated in terms of yield, density, pH after water-dilution, total phenolic (Folin-Ciocalteu) and protein (Bradford) contents, antioxidant power (DPPH), amount of some representative polyphenols (HPLC-DAD), cytocompatibility and stability. Both solvents validated the bentonite as a valuable source of polyphenols and led to colored fluids characterized by an acidic pH after water-dilution. The best extract was obtained from the wet bentonite with PEG200 and highlighted the highest phenolic content and consequently the strongest antioxidant activity. Additionally, it displayed proliferative properties and resulted almost stable over time. Hence, it might be directly used as polyphenols-enriched functional novel raw material for cosmetic and pharmaceutics purposes.

Osteogenic Effect of Fisetin Doping in Bioactive Glass/Poly(caprolactone) Hybrid Scaffolds

Treating large bone defects or fragile patients may require enhancing the bone regeneration rate to overcome a weak contribution from the body. This work investigates the osteogenic potential of nutrient fisetin, a flavonoid found in fruits and vegetables, as a doping agent inside the structure of a SiO₂-CaO bioactive glass-poly(caprolactone) (BG-PCL) hybrid scaffold. Embedded in the full mass of the BG-PCL hybrid during one-pot synthesis, we demonstrate fisetin to be delivered sustainably; the release follows a first-order kinetics with active fisetin concentration being delivered for more than 1 month (36 days). The biological effect of BG-PCL-fisetin-doped scaffolds (BG-PCL-Fis) has been highlighted by in vitro and in vivo studies. A positive impact is demonstrated on the adhesion and the differentiation of rat primary osteoblasts, without an adverse cytotoxic effect. Implantation in critical-size mouse calvaria defects shows bone remodeling characteristics and remarkable enhancement of bone regeneration for fisetin-doped scaffolds, with the regenerated bone volume being twofold that of nondoped scaffolds and fourfold that of a commercial trabecular bovine bone substitute. Such highly bioactive materials could stand as competitive alternative strategies involving biomaterials loaded with growth factors, the use of the latter being the subject of growing concerns.

Design and development of biomimetic electrospun sulphonated polyether ether ketone nanofibrous scaffold for bone tissue regeneration applications: in vitro and in vivo study

Bone defect restoration remains challenging in orthopedic medical practices. In this study an attempt is carried out to probe the use of new biomimetic SPEEK (sulfonated polyether ether ketone) based nanofibrous scaffold to deliver amine functionalized hydroxyapatite nanoparticles loaded resveratrol for its potent functionality in osteogenic differentiation. SPEEK polymer with reactive functional group SO₃H was synthesized through process of sulphonation reaction. Amine functionalized nanoparticles with protonated amino groups revamp the molecular interaction by the formation of hydrogen bonds that in turn intensify the bioactivity of the nanofibrous scaffold. Osteoconductive functionalized nanohydroxyapatite enhances the cell proliferation and osteogenicity with improved cell attachment and spreading. The results of FT-IR, XRD, Carbon-Silica NMR and EDX analysis confirmed the amine functionalization of the hydroxyapatite nanoparticles. Surface morphological analysis of the fabricated nanofibers through SEM and AFM analysis shows vastly interconnected porous structure that mimics the bone extracellular matrix, which enhances the cell compatibility. Cell adhesion and live dead assay of the nanoscaffolds express less cytotoxicity. Mineralization and alkaline phosphatase assay establish the osteogenic differentiation of the nanofibrous scaffold. The in vitro biocompatibility studies reveal that the fabricated scaffold was osteo-compatible with MG63 cell lines. Hemocompatibility study further proved that the designed biomimetic nanofibrous scaffold was highly suitable for bone tissue engineering. The results of in vivo analysis in zebrafish model for the fabricated nanofibers demonstrated significant increase in the caudal fin regeneration indicating mineralization of osteoblast. Thus, the commending results obtained instigate the potentiality of the composite nanofibrous scaffold as an effective biomimetic substrate for bone tissue regeneration.

Notoginsenoside R1 Promotes Migration, Adhesin, Spreading, and Osteogenic Differentiation of Human Adipose Tissue-Derived Mesenchymal Stromal Cells

Cellular activities, such as attachment, spreading, proliferation, migration, and differentiation are indispensable for the success of bone tissue engineering. Mesenchymal stromal cells (MSCs) are the key precursor cells to regenerate bone. Bioactive compounds from natural products had shown bone regenerative potential. Notoginsenoside R1 (NGR1) is a primary bioactive natural compound that regulates various biological activities, including cardiovascular protection, neuro-protection, and anti-cancer effects. However, the effect of NGR1 on migration, adhesion, spreading, and osteogenic differentiation of MSCs required for bone tissue engineering application has not been tested properly. In this study, we aimed to analyze the effect of NGR1 on the cellular activities of MSCs. Since human adipose-derived stromal cells (hASCs) are commonly used MSCs for bone tissue engineering, we used hASCs as a model of MSCs. The optimal concentration of 0.05 μg/mL NGR1 was biocompatible and promoted migration and osteogenic differentiation of hASCs. Pro-angiogenic factor VEGF expression was upregulated in NGR1-treated hASCs. NGR1 enhanced the adhesion and spreading of hASCs on the bio-inert glass surface. NGR1 robustly promoted hASCs adhesion and survival in 3D-printed TCP scaffold both in vitro and in vivo. NGR1 mitigated LPS-induced expression of inflammatory markers IL-1β, IL-6, and TNF-α in hASCs as well as inhibited the RANKL/OPG expression ratio. In conclusion, the biocompatible NGR1 promoted the migration, adhesion, spreading, osteogenic differentiation, and anti-inflammatory properties of hASCs.

The combined therapy of mesenchymal stem cell transplantation and resveratrol for diabetes: Future applications and challenges

Diabetes mellitus (DM) is a worldwide chronic epidemic disease of impaired glucose metabolism. Transplantation of mesenchymal stem cells (MSCs) is considered a promising emerging treatment strategy for diabetes. However, the harsh internal environment of DM patients can inhibit the treatment effects of transplanted MSCs. Fortunately, this adverse effect can be reversed by resveratrol (Res). Therefore, we investigated and summarized relevant studies on the combined treatment of diabetes with MSCs and resveratrol. This review presents the therapeutic effects of this combination therapy strategy on DM in glycemic control, anti-inflammatory, anti-oxidative stress and anti-fibrotic. Moreover, this review explained the mechanisms of MSCs and resveratrol in diabetes treatment from 3 aspects, including promoting cell survival and inhibiting apoptosis, inhibiting histiocyte fibrosis, and improving glucose metabolism. These findings help to understand in-depth mechanisms of the treatment of DM and help to propose a potential treatment strategy for DM and its complications.

Independent effects of structural optimization and resveratrol functionalization on extracellular matrix scaffolds for bone regeneration

Due to their natural biological activity and low immunogenicity, decellularized extracellular matrix (ECM) materials have aroused interest as potential scaffold materials in tissue engineering. Decellularized small intestinal submucosa (SIS) is one ECM biomaterial that can be easily sourced. In the present study, we tested whether the osteogenesis of SIS scaffolds was enhanced via structural optimization and resveratrol (RSV) functionalization and explored the independent effects of these modifications. We obtained SIS scaffolds with different pore structures by controlling the preparation concentration. The group with superior osteogenic properties was further RSV-functionalized via covalent immobilization. We conducted a series of in vitro and in vivo studies to explore the effects of these two optimization strategies on the osteogenic properties of SIS scaffolds. The results showed that pore structure and RSV functionalization significantly affected the osteogenic properties of SIS scaffolds. With a fabrication concentration of 1%, the SIS scaffolds had superior osteogenic properties. Through covalent coupling, RSV was successfully grafted onto SIS scaffolds, where it was slowly released. The most significant improvements in osteogenic properties were obtained with a coupling concentration of 1%. Furthermore, in in vivo experiments, vascular and new bone tissue formation was enhanced with RSV/SIS scaffolds compared with SIS scaffolds and the blank control group at 4 weeks after implantation. These findings indicate that the RSV/SIS scaffolds obtained via dual optimization strategies show promise as biomaterials in bone tissue engineering.

Fabrication of Resveratrol-Loaded Scaffolds and Their Application for Delaying Cell Senescence In Vitro

In this research, resveratrol (RSV)-loaded scaffolds have been prepared to control the release of resveratrol and used to delay hepatic stellate cell (HSC) senescence in vitro. The functional carboxyl group-COOH is first introduced to the surface of poly(ε-caprolactone/d,l-lactide) (P(CL-DLLA)) under the coadministration of ultra-violet (UV) treatment and photo initiator and then resveratrol are conjugated onto the surface of the modified scaffolds through esterification. The characterization of the structure of RSV-AA-P(CL-DLLA) shows that resveratrol has been successfully conjugated onto the modified surface. Cell growth exhibits a higher level of cell viability and much more obvious agglomeration on the surface of the synthetic RSV-AA-P(CL-DLLA). Meanwhile the activity of senescence-associated β-galactosidase (SA-β-gal) and reactive oxygen species (ROS) is downgulated for cells on RSV-AA-P(CL-DLLA), which suggests that cell senescence is delayed on RSV-AA-P(CL-DLLA). And then it is attested that cells have a lower level of p53 but SIRT1 expression is upregulated on RSV-AA-P(CL-DLLA), which might be related to resveratrol release from RSV-AA-P(CL-DLLA). It also suggested cell senescence on RSV-AA-P(CL-DLLA) has been regulated by p53 and the SIRT1 signaling pathway. In all, the present study shows that RSV-AA-P(CL-DLLA) can be successfully prepared to promote cell growth and delay cell senescence and could be used for cell-based therapy in tissue engineering.

Co-Crystals of Resveratrol and Polydatin with L-Proline: Crystal Structures, Dissolution Properties, and In Vitro Cytotoxicities

Resveratrol (RSV) and polydatin (PD) have been widely used to treat several chronic diseases, such as atherosclerosis, pulmonary fibrosis, and diabetes, among several others. However, their low solubility hinders their further applications. In this work, we show that the solubility of PD can be boosted via its co-crystallization with L-proline (L-Pro). Two different phases of co-crystals, namely the RSV-L-Pro (RSV:L-Pro = 1:2) and PD-L-Pro (PD:L-Pro = 1: 3), have been prepared and characterized. As compared to the pristine RSV and PD, the solubility and dissolution rates of PD-L-Pro in water (pH 7.0) exhibited a 15.8% increase, whereas those of RSV-L-Pro exhibited a 13.8% decrease. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay of pristine RSV, PD, RSV-L-Pro, and PD-L-Pro against lung cancer cell line A549 and human embryonic kidney cell line HEK-293 indicated that both compounds showed obvious cytotoxicity against A549, but significantly reduced cytotoxicity against HEK-293, with PD/PD-L-Pro further exhibiting better biological safety than that of RSV/RSV-L-Pro. This work demonstrated that the readily available and biocompatible L-Pro can be a promising adjuvant to optimize the physical and chemical properties of RSV and PD to improve their pharmacokinetics.

Cyclodextrin based bone regenerative inclusion complex for resveratrol in postmenopausal osteoporosis

Recent preclinical studies have shown that resveratrol (RSV), is a promising remedy for osteoporosis owing to its estrogenic, anti-inflammatory, and antioxidant properties. However, RSV has met limited success due to its poor oral bioavailability and inefficient systemic delivery. In this study, we prepared the inclusion complex of RSV with sulfo-butyl ether β-cyclodextrin (SBE-β-CD) to enhance the aqueous solubility of RSV. The in-silico docking studies and Physico-chemical characterization assays were performed to understand the interaction of RSV inside the SBE-β-CD cavity. The in vivo safety assessment of RSV-SBE-β-CD inclusion complex (R-CDIC) was performed in healthy Wistar rats. The efficacy of the inclusion complex against postmenopausal osteoporosis was further investigated in ovariectomized (OVX) rat model. The alteration in the bone micro-architectural structure was evaluated by microcomputed tomographic scanning, serum biochemical estimations, biomechanical strength and histopathological investigation. Administration of RSV-SBE-β-CD inclusion complex was found to be safe and significantly improved micro-architectural deterioration induced by estrogen withdrawal. Results of bone morphometry and biomechanics study further emboldened the efficacy claim of the RSV-SBE-β-CD complex. Thus, the present study demonstrated the efficacy of the RSV-SBE-β-CD inclusion complex for treating osteolytic degradation in osteoporosis.

Histone Acetylation in the Epigenetic Regulation of Bone Metabolism and Related Diseases

As the earliest studied epigenetic modification, acetylation has been explored a lot through the years. While bone tissue acts as an indispensable part of body, researches aimed at the relationship between the bone and acetylation became necessary. Some environmental factors like diet may affect the metabolism status that some metabolites especially nicotinamide adenine dinucleotide (NAD) were found able to regulate intracellular histone acetylation in bone metabolism. This review focuses on representing the interaction among acetylation, metabolism, and the bone. The results showed that acetylation connects a lot with bone metabolism, while the explorations about related metabolites like acetyl-CoA or different environmental exposures are still limited. Some acetylation-related therapy methods of bone diseases based on metabolic regulation or epigenetic enzymes were also reviewed.

Controlled release of resveratrol from a composite nanofibrous scaffold: Effect of resveratrol on antioxidant activity and osteogenic differentiation

Biocompatibility, mechanical strength, and osteogenesis properties of three-dimensional scaffolds are critical for bone tissue engineering. In addition, reactive oxygen species accumulate around bone defects and limit the activities of surrounding cells and bone formation. Therefore, the presence of an antioxidant in a bone tissue scaffold is also essential to address this issue. This study aimed to evaluate a composite nanofibrous scaffold similar to the natural extracellular matrix with antioxidant and osteogenic properties. To this end, polylactic acid (PLA)/organophilic montmorillonite (OMMT)/resveratrol (RSV) nanofibers were fabricated using the electrospinning method and characterized. RSV was used as an antioxidant, which promotes osteogenic differentiation, and OMMT was used as a mineral phase to increase the mechanical strength and control the release of RSV. The scaffolds' antioxidant activity was measured using DPPH assay and found 83.75% for PLA/OMMT/RSV nanofibers. The mechanical strength was increased by adding OMMT to the neat PLA. The biocompatibility of the scaffolds was investigated using an MTT assay, and the results did not show any toxic effects on human adipose mesenchymal stem cells (hASCs). Moreover, the Live/Dead assay indicated the appropriate distribution of live cells after 5 days. Cell culture results displayed that hASCs could adhere and spread on the surface of composite nanofibers. Meanwhile, the level of alkaline phosphatase, osteocalcin, and osteopontin was increased for hASCs cultured on the PLA/OMMT/RSV nanofibrous scaffold. Therefore, this study concludes that the RSV-loaded composite nanofibers with antioxidant and osteogenesis properties and appropriate mechanical strength can be introduced for bone tissue regeneration applications.

The Use of Micro- and Nanocarriers for Resveratrol Delivery into and across the Skin in Different Skin Diseases-A Literature Review

In recent years, polyphenols have been extensively studied due to their antioxidant, anticancer, and anti-inflammatory properties. It has been shown that anthocyanins, flavonols, and flavan-3-ols play an important role in the prevention of bacterial infections, as well as vascular or skin diseases. Particularly, resveratrol, as a multi-potent agent, may prevent or mitigate the effects of oxidative stress. As the largest organ of the human body, skin is an extremely desirable target for the possible delivery of active substances. The transdermal route of administration of active compounds shows many advantages, including avoidance of gastrointestinal irritation and the first-pass effect. Moreover, it is non-invasive and can be self-administered. However, this delivery is limited, mainly due to the need to overpassing the stratum corneum, the possible decomposition of the substances in contact with the skin surface or in the deeper layers thereof. In addition, using resveratrol for topical and transdermal delivery faces the problems of its low solubility and poor stability. To overcome this, novel systems of delivery are being developed for the effective transport of resveratrol across the skin. Carriers in the micro and nano size were demonstrated to be more efficient for safe and faster topical and transdermal delivery of active substances. The present review aimed to discuss the role of resveratrol in the treatment of skin abnormalities with a special emphasis on technologies enhancing transdermal delivery of resveratrol.

Quercetin-Based Nanocomposites as a Tool to Improve Dental Disease Management

The restoration and prosthetic rehabilitation of missing teeth are commonly performed using dental implants, which are extremely effective and long-lasting techniques due to their osteointegration ability with the preimplant tissues. Quercetin is a phytoestrogen-like flavonoid well known for its several positive effects on human health, mostly linked to the anti-inflammatory, antioxidant, and antibacterial activities against both Gram-positive and Gram-negative bacteria. Moreover, many studies in dentistry and the maxillofacial fields have highlighted the positive effects of quercetin on osteogenesis, acting on osteoblast activity and angiogenetic process, and promoting soft and hard tissue regeneration. This review focuses on the role of quercetin on the healing and restoration of bony defects, considering the experimental findings of its application both in vitro and in vivo as a mere compound or in association with scaffolds and dental implants having functionalized surfaces.

Synergistic anti-inflammatory and osteogenic n-HA/resveratrol/chitosan composite microspheres for osteoporotic bone regeneration

The development of functional materials for osteoporosis is ultimately required for bone remodeling. However, grafts were accompanied by increasing pro-inflammatory cytokines that impaired bone formation. In this work, nano-hydroxyapatite (n-HA)/resveratrol (Res)/chitosan (CS) composite microspheres were designed to create a beneficial microenvironment and help improve the osteogenesis by local sustained release of Res. Study of in vitro release confirmed the feasibility of n-HA/Res/CS microspheres for controlled Res release. Notably, microspheres had anti-inflammatory activity evidenced by the decreased expression of pro-inflammatory cytokines TNF-α, IL-1β and iNOS in RAW264.7 cells in a dose dependent manner. Further, enhanced adhesion and proliferation of BMSCs seeded onto microspheres demonstrated that composite microspheres were conducive to cell growth. The ability to enhance osteo-differentiation was supported by up-regulation of Runx2, ALP, Col-1 and OCN, and substantial mineralization in osteogenic medium. When implanted into bone defects in the osteoporotic rat femoral condyles, enhanced entochondrostosis and bone regeneration suggested that the n-HA/Res/CS composite microspheres were more favorable for impaired fracture healing. The results indicated that optimized n-HA/Res/CS composite microspheres could serve as promising multifunctional fillers for osteoporotic bone defect/fracture treatment.

•

The microspheres with sustained Res release possessed obvious anti-inflammatory activity.

•

The microspheres were favorable for cell growth and osteo-differentiation.

•

Higher Res-loaded microspheres significantly improved entochondrostosis and bone remodeling.

•

The microspheres are promising bone fillers for the healing of osteoporotic bone defects/fractures.

Resveratrol Protects Osteoblasts Against Dexamethasone-Induced Cytotoxicity Through Activation of AMP-Activated Protein Kinase

Purpose

Glucocorticoids are used for the treatment of inflammatory diseases, but glucocorticoid treatment is associated with bone damage. Resveratrol is a phytoalexin found in many plants, and we investigated its protective role on dexamethasone-induced dysfunction in MC3T3-E1 cells and primary osteoblasts.

Materials and Methods

MC3T3-E1 cells and primary osteoblasts were treated with dexamethasone in the presence/absence of different doses of resveratrol for 24 or 48 h. Then, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium (MTT) and lactate dehydrogenase (LDH) assays were used to evaluate cell viability. Apoptosis was analyzed by a flow cytometry. An alkaline phosphatase (ALP) activity assay and Alizarin Red S staining were used to study osteoblast differentiation. Expression of osteoblast-related genes was measured by real-time reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The AMP-activated protein kinase (AMPK) signaling pathway and mitochondrial expression of superoxide dismutase were evaluated by Western blotting. Intracellular reactive oxygen species (ROS), adenosine triphosphate (ATP) content, mitochondrial-complex activity, and mitochondrial DNA content were measured to evaluate mitochondrial function.

Results

Resveratrol induced the proliferation and inhibited apoptosis of osteoblasts in the presence of dexamethasone. Resveratrol increased the ALP activity and mineralization of osteoblasts. Resveratrol also attenuated dexamethasone-induced inhibition of mRNA expression of osteogenesis maker genes, including bone morphogenetic protein-2, osteoprotegerin, runt-related transcription factor-2, and bone Gla protein. Resveratrol alleviated dexamethasone-induced mitochondrial dysfunction. Resveratrol strongly stimulated expression of peroxisome proliferator–activated receptor-γ coactivator 1α and sirtuin-3 genes, as well as their downstream target gene superoxide dismutase-2. Resveratrol induced phosphorylation of AMPK and acetyl-CoA carboxylase (ACC). Blockade of AMPK signaling using compound C reversed the protective effects of resveratrol against dexamethasone.

Conclusion

Resveratrol showed protective effects against dexamethasone-induced dysfunction of osteoblasts by activating AMPK signaling.

Grapevine Cane Extracts: Raw Plant Material, Extraction Methods, Quantification, and Applications

Grapevine canes are viticulture waste that is usually discarded without any further use. However, recent studies have shown that they contain significant concentrations of health-promoting compounds, such as stilbenes, secondary metabolites of plants produced as a response to biotic and abiotic stress from fungal disease or dryness. Stilbenes have been associated with antioxidant, anti-inflammatory, and anti-microbial properties and they have been tested as potential treatments of cardiovascular and neurological diseases, and even cancer, with promising results. Stilbenes have been described in the different genus of the Vitaceae family, the Vitis genera being one of the most widely studied due to its important applications and economic impact around the world. This review presents an in-depth study of the composition and concentration of stilbenes in grapevine canes. The results show that the concentration of stilbenes in grapevine canes is highly influenced by the Vitis genus and cultivar aspects (growing conditions, ultraviolet radiation, fungal attack, etc.). Different methods for extracting stilbenes from grapevine canes have been reviewed, and the extraction conditions have also been studied, underlining the advantages and disadvantages of each technique. After the stilbenes were extracted, they were analyzed to determine the stilbene composition and concentration. Analytical techniques have been employed with this aim, in most cases using liquid chromatography, coupled with others such as mass spectrometry and/or nuclear magnetic resonance to achieve the individual quantification. Finally, stilbene extracts may be applied in multiple fields based on their properties. The five most relevant are preservative, antifungal, insecticide, and biostimulant applications. The current state-of-the-art of the above applications and their prospects are discussed.

3D printed composite scaffolds with dual small molecule delivery for mandibular bone regeneration

Functional reconstruction of craniomaxillofacial defects is challenging, especially for the patients who suffer from traumatic injury, cranioplasty, and oncologic surgery. Three-dimensional (3D) printing/bioprinting technologies provide a promising tool to fabricate bone tissue engineering constructs with complex architectures and bioactive components. In this study, we implemented multi-material 3D printing to fabricate 3D printed PCL/hydrogel composite scaffolds loaded with dual bioactive small molecules (i.e. resveratrol and strontium ranelate). The incorporated small molecules are expected to target several types of bone cells. We systematically studied the scaffold morphologies and small molecule release profiles. We then investigated the effects of the released small molecules from the drug loaded scaffolds on the behavior and differentiation of mesenchymal stem cells (MSCs), monocyte-derived osteoclasts, and endothelial cells. The 3D printed scaffolds, with and without small molecules, were further implanted into a rat model with a critical-sized mandibular bone defect. We found that the bone scaffolds containing the dual small molecules had combinational advantages in enhancing angiogenesis and inhibiting osteoclast activities, and they synergistically promoted MSC osteogenic differentiation. The dual drug loaded scaffolds also significantly promoted in vivo mandibular bone formation after 8 week implantation. This work presents a 3D printing strategy to fabricate engineered bone constructs, which can likely be used as off-the-shelf products to promote craniomaxillofacial regeneration.

Inhibitory effects of resveratrol on orthodontic tooth movement and associated root resorption in rats

OBJECTIVE

To investigate the effect of resveratrol (RSV) on orthodontic tooth movement (OTM) and orthodontic induced root resorption (OIRR) in rats.

METHODS

Thirty-six male Wistar rats used in this study were randomly divided into three groups of 12 animals each. All test subjects underwent a 50 g orthodontic force each, generated from a nickel-titanium closed-coil spring. The control group were fed carboxymethylcellulose (CMC) while rats in other two groups were fed 5 mg/kg/d RSV or 10 mg/kg/d RSV (dissolved in CMC). After 14 days of OTM, all rats were sacrificed, after which each group was randomly divided into two subgroups (6 test subjects in each subgroup). One subgroup was used to measure the amount of OTM and assessed by hematoxylin and eosin (HE) staining, tartrate-resistant acid phosphatase (TRAP) staining, and immunohistochemistry staining of Receptor Activator of Nuclear Factor-κ B Ligand (RANKL), Osteoprotegerin (OPG), Runt-related transcription factor 2 (RUNX2), as well as Osteocalcin (OCN). The second subgroup was used to analyze OIRR via scanning electron microscopy.

RESULTS

Compared with the control group, the RSV groups showed a significant decrease in the distance of OTM and the OIRR ratio (p＜0.05). The number of TRAP positive osteoclasts and the expression of RANKL in periodontal tissue of the RSV groups were significantly inhibited (p＜0.01) while the expression of OPG, RUNX2, and OCN were remarkably promoted (p＜0.05). The effect of 10 mg/kg/d RSV group was more obvious than that of 5 mg/kg/d RSV group (p＜0.05).

CONCLUSIONS

RSV could reduce the extent of OTM and root resorption areas.

Bioadhesive Matrix Tablets Loaded with Lipophilic Nanoparticles as Vehicles for Drugs for Periodontitis Treatment: Development and Characterization

Periodontitis treatment is usually focused on the reduction or eradication of periodontal pathogens using antibiotics against anaerobic bacteria, such as metronidazole (MTR). Moreover, recently the correlation between periodontal diseases and overexpression of reactive oxygen species (ROS) led to the introduction of antioxidant biomolecules in therapy. In this work, bioadhesive buccal tablets, consisting of a hydrophilic matrix loaded with metronidazole and lipophilic nanoparticles as a vehicle of curcumin, were developed. Curcumin (CUR)-loaded nanostructured lipid carriers (NLC) were prepared using glycyrrhetic acid, hexadecanol, isopropyl palmitate and Tween®80 as a surfactant. As method, homogenization followed by high-frequency sonication was used. After dialysis, CUR-NLC dispersion was evaluated in terms of drug loading (DL, 2.2% w/w) and drug recovery (DR, 88% w/w). NLC, characterized by dynamic light scattering and scanning electron microscopy (SEM), exhibited a spherical shape, an average particle size of 121.6 nm and PDI and PZ values considered optimal for a colloidal nanoparticle dispersion indicating good stability of the system. Subsequently, a hydrophilic sponge was obtained by lyophilization of a gel based on trehalose, Natrosol and PVP-K90, loaded with CUR-NLC and MTR. By compression of the sponge, matrix tablets were obtained and characterized in term of porosity, swelling index, mucoadhesion and drugs release. The ability of the matrix tablets to release CUR and MTR when applied on buccal mucosa and the aptitude of actives to penetrate and/or permeate the tissue were evaluated. The data demonstrate the ability of NLC to promote the penetration of CUR into the lipophilic domains of the mucosal membrane, while MTR can penetrate and permeate the mucosal tissue, where it can perform a loco-regional antibacterial activity. These results strongly support the possibility of using this novel matrix tablet for delivering MTR together with CUR for topical treatment of periodontal diseases.

Short-term use of resveratrol in alloplastic graft material applied with calvarial bone defects in rats

PURPOSE

The effects of resveratrol administration on calvarial bone defects with alloplastic graft material was investigated for osteoinductive reaction and bone development in rats.

METHODS

Healthy male rats were randomly divided into 3 groups consisting of 10 rats. Groups were as follows: control (defect) group, defect + graft group, and defect + graft + resveratrol group. A calvarial bone defect was created in all groups, alloplastic bone grafts were applied to the defect in the 2nd and 3rd group, resveratrol (5 mg/kg/day) was added to the drinking water of the animals following graft application for 28 days in the 3rd group.

RESULTS

Increase in osteoclasts and necrotic changes were observed histopathologically in the control group. In the 2nd group, reduction of inflammation, congestion of blood vessels, increased osteblastic activity, osteoinductive effect, progression of osteocyte development and increased collagen fibers in connective tissue were observed. In the 3rd group, osteoblasts seemed to secrete bone matrix and accelerate osteoinductive effect with increased osteopregenitor activity and positive osteopontin and osteonectin expressions.

CONCLUSION

Resveratrol treatment was thought to be an alternative and supportive drug for implant application by inducing new bone formation in the calvaral defect region as a result of short-term treatment.

The effects of resveratrol on metabolic status in patients with type 2 diabetes mellitus and coronary heart disease

This study was performed to investigate the effects of resveratrol on metabolic status in patients with type 2 diabetes mellitus (T2DM) and coronary heart disease (CHD). This randomized, double-blind, placebo-controlled trial was performed with 56 patients having T2DM and CHD. The patients were randomly divided into two groups to receive either 500 mg resveratrol per day (n = 28) or placebo (n = 28) for 4 weeks. Resveratrol reduced fasting glucose (β-10.04 mg dL^-1; 95% CI, -18.23, -1.86; P = 0.01), insulin (β-1.09 μIU mL^-1; 95% CI, -1.93, -0.24; P = 0.01) and insulin resistance (β-0.48; 95% CI, -0.76, -0.21; P = 0.001) and significantly increased insulin sensitivity (β 0.006; 95% CI, 0.001, 0.01; P = 0.02) when compared with the placebo. Resveratrol also significantly increased HDL-cholesterol levels (β 3.38 mg dL^-1; 95% CI, 1.72, 5.05; P < 0.001) and significantly decreased the total-/HDL-cholesterol ratio (β-0.36; 95% CI, -0.59, -0.13; P = 0.002) when compared with the placebo. Additionally, resveratrol caused a significant increase in total antioxidant capacity (TAC) (β 58.88 mmol L^-1; 95% CI, 17.33, 100.44; P = 0.006) and a significant reduction in malondialdehyde (MDA) levels (β-0.21 μmol L^-1; 95% CI, -0.41, -0.005; P = 0.04) when compared with the placebo. Resveratrol upregulated PPAR-γ (P = 0.01) and sirtuin 1 (SIRT1) (P = 0.01) in the peripheral blood mononuclear cells (PBMCs) of T2DM patients with CHD. Resveratrol supplementation did not have any effect on inflammatory markers. Four-week supplementation of resveratrol in patients with T2DM and CHD had beneficial effects on glycemic control, HDL-cholesterol levels, the total-/HDL-cholesterol ratio, TAC and MDA levels. Resveratrol also upregulated PPAR-γ and SIRT1 in the PBMCs of T2DM patients with CHD.

Autophagy drives osteogenic differentiation of human gingival mesenchymal stem cells

BACKGROUND/AIM

Autophagy is a macromolecular degradation process playing a pivotal role in the maintenance of stem-like features and in the morpho-functional remodeling of the tissues undergoing differentiation. In this work we investigated the involvement of autophagy in the osteogenic differentiation of mesenchymal stem cells originated from human gingiva (HGMSC).

METHODS

To promote the osteogenic differentiation of HGMSCs we employed resveratrol, a nutraceutical known to modulate autophagy and cell differentiation, together with osteoblastic inductive factors. Osteoblastic differentiation and autophagy were monitored through western blotting and immunofluorescence staining of specific markers.

RESULTS

We show that HGMSCs can differentiate into osteoblasts when cultured in the presence of appropriate factors and that resveratrol accelerates this process by up-regulating autophagy. The prolonged incubation with dexamethasone, β-glycerophosphate and ascorbic acid induced the osteogenic differentiation of HGMSCc with increased expression of autophagy markers. Resveratrol (1 μM) alone elicited a less marked osteogenic differentiation yet it greatly induced autophagy and, when added to the osteogenic differentiation factors, it provoked a synergistic effect. Resveratrol and osteogenic inductive factors synergistically induced the AMPK-BECLIN-1 pro-autophagic pathway in differentiating HGMSCs, that was thereafter downregulated in osteoblastic differentiated cells. Pharmacologic inhibition of BECLIN-1-dependent autophagy precluded the osteogenic differentiation of HGMSCs.

CONCLUSIONS

Autophagy modulation is instrumental for osteoblastic differentiation of HGMSCs. The present findings can be translated into the regenerative cell therapy of maxillary / mandibular bone defects.

Modulatory Effects of Plant Polyphenols on Bone Remodeling: A Prospective View From the Bench to Bedside

During the past, a more comprehensive knowledge of mechanisms implicated in bone resorption processes has driven researchers to develop a compound library of many small molecules that specifically interfere with the genesis of osteoclast precursors cells. Natural compounds that suppress osteoclast commitment may have therapeutic value in treating pathologies associated with bone resorption like osteoporosis, rheumatoid arthritis, bone metastasis, and periodontal disease. The present review is focused on the current knowledge on the polyphenols derived from plants that could be efficacious in suppressing osteoclast differentiation and bone resorption.