Role of Curcumin in Common Musculoskeletal Disorders: a Review of Current Laboratory, Translational, and Clinical Data

The Role of Curcumin in Oral Health and Diseases: A Systematic Review

Curcumin (Curcumin) belongs to the polyphenol family. It is extracted by drying the root of a plant of Asian origin, belonging to the Zingiberaceae family. The best-known species is Curcumincuma Longa. Curcumin has been recognized as having great therapeutic powers since ancient times. Studies on curcumin have since confirmed its powerful antioxidant properties, preventing both the formation of free radicals and their neutralization, having anti-inflammatory, antibacterial, immunological, and neuroprotective properties, as well as being a regulator of the intestinal microbiota with beneficial effects on the clinical manifestations of metabolic syndrome. Our study aimed to highlight how all these therapeutic aspects could benefit oral health, both preventing and improving the course of pathological processes. The effect of mouthwashes, and curcumin-based gels on the regulation of bacterial plaque and in the control of gingivitis, was largely comparable to that of using 0.20% chlorhexidine, with fewer side effects. Being a highly hydrophobic substance, it has a high permeability to cross the cell membrane. Bioavailability increases when combined with liposoluble substances (e.g., olive oil) and piperine, which improves absorption. Curcumin also has a negligible degree of toxicity, making it an excellent alternative to the use of gold standard products for oral disinfection.

Evidence for the use of curcumin in radioprotection and radiosensitization

Curcumin has antineoplastic properties and is considered a chemotherapeutic and chemopreventive agent. Curcumin may be associated with radiation therapy (RT) as a radiosensitizer for cancer cells and a radioprotector for normal cells. In principle, it may result in a reduction of RT dosage for the same therapeutic effect on cancer cells, and further reduced damage to normal cells. Though the overall level of evidence is modest, limited to in vivo and in vitro experiences and practically no clinical trials, as the risks of adverse effects are extremely low, it is reasonable to promote the general supplementation with curcumin during RT targeting the reduction of side effects through anti-inflammatory mechanisms.

Alternative Medical Therapy

Background

Complementary/alternative medicine" (CAM) is defined as a diverse range of medical treatments, largely non-allopathic, mostly traditional, and not integrated into the authoritarian healthcare system. Interestingly for some schools, allopathy is alternative/complementary therapy. Osteoporosis is an ever-known disease treated before the era of allopathic medicine. Even though the customary medical system of India is among the most well-known in the world, every continent has its own alternative therapies for various chronic diseases.

Purpose

This review of the scientific information is to help the readers understand how crucial the conceptual underpinnings of alternative medical therapy systems are to the advancement of conventional allopathic practices.

Method

Many older and recent articles about alternative medical therapy in the management of osteoporosis published in scientific journals are reviewed. Relevant information from cross-references on methods of evaluating the efficacy of different modalities and their scientific pathways is included. An effort has been made to summarise the treatment of osteoporosis by these systems. Opinions, impressions, and inferences are added while describing various aspects of these modalities.

Result

The National Library of Medicine has played an active role in publishing studies of the management of osteoporosis by alternative therapies. Many issues of management of osteoporosis still lack reliable treatment. However, good information is now available about choosing alternate medical therapy that has been studied scientifically and has shown promising results.

Conclusion

Medicinal plants and certain natural treatments can treat osteoporosis and its problems. The use of alternate medical therapy has been proven recently by clinical practice and conventional wisdom. This sharing may help the medical practitioner to understand and judiciously allow complementary therapy while treating osteoporosis.

Dendrimers as Nanocarriers for the Delivery of Drugs Obtained from Natural Products

Natural products have proven their value as drugs that can be therapeutically beneficial in the treatment of various diseases. However, most natural products have low solubility and poor bioavailability, which pose significant challenges. To solve these issues, several drug nanocarriers have been developed. Among these methods, dendrimers have emerged as vectors for natural products due to their superior advantages, such as a controlled molecular structure, narrow polydispersity index, and the availability of multiple functional groups. This review summarizes current knowledge on the structures of dendrimer-based nanocarriers for natural compounds, with a particular focus on applications in alkaloids and polyphenols. Additionally, it highlights the challenges and perspectives for future development in clinical therapy.

Nutritional Supplements in the Clinical Management of Tendinopathy: A Scoping Review

INTRODUCTION

Tendinopathy has a high prevalence and incidence in the general population and among athletes, with a lack of consensus among medical practitioners on optimal management strategies. The objective of this scoping review was to evaluate current research on the use of nutritional supplements for treating tendinopathies, including what supplements have been used and what outcomes, outcome measures, and intervention parameters have been reported.

METHODS

Databases searched included Embase, SPORTDiscus, the Cochrane Library, MEDLINE, CINAHL, and AMED. This scoping review considered primary studies investigating nutritional supplements for tendinopathies and was reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Extension for Scoping Reviews.

RESULTS

A total of 1527 articles were identified with 16 included in the review. Studies investigated a range of nutritional supplements in the clinical management of various tendinopathies, including several commercially available proprietary blends of several ingredients. TendoActive (mucopolysaccharides, type I collagen, and vitamin C) was used in 2 studies, TENDISULFUR (methylsulfonylmethane, hydrolyzed collagen, L-arginine, L-lysine, vitamin C, bromelain, chondroitin, glucosamine, Boswellia, and myrrh) was used in 3 studies, and Tenosan (arginine-L-alpha ketoglutarate, hydrolyzed collagen type I, methylsulfonylmethane, vitamin C, bromelain, and vinitrox) was used in 2 studies. Collagen peptides were used in 2 studies, with omega-3 fatty acids, combined fatty acids and antioxidants, turmeric rhizome combined with Boswellia, β-hydroxy β-methylbutyric, vitamin C in isolation and combined with gelatin, and creatine investigated in one study each.

CONCLUSION

Despite a paucity of studies to date, findings from this review suggest that several nutritional compounds may be beneficial in the clinical management of tendinopathies, by exerting anti-inflammatory effects and improving tendon healing. Nutritional supplements may have potential as an adjunctive method to standard treatment methods such as exercise, where their pain-relieving, anti-inflammatory, and structural tendon effects may augment the positive functional outcomes gained from progressive exercise rehabilitation.

Poly(pro-curcumin) Materials Exhibit Dual Release Rates and Prolonged Antioxidant Activity as Thin Films and Self-Assembled Particles

Curcumin is a natural polyphenol that exhibits remarkable antioxidant and anti-inflammatory activities; however, its clinical application is limited in part by its physiological instability. Here, we report the synthesis of curcumin-derived polyesters that release curcumin upon hydrolytic degradation to improve curcumin stability and solubility in physiological conditions. Curcumin was incorporated in the polymer backbone by a one-pot condensation polymerization in the presence of sebacoyl chloride and polyethylene glycol (PEG, M_n = 1 kDa). The thermal and mechanical properties, surface wettability, self-assembly behavior, and drug-release kinetics all depend sensitively on the mole percentage of curcumin incorporated in these statistical copolymers. Curcumin release was triggered by the hydrolysis of phenolic esters on the polymer backbone, which was confirmed using a PEGylated curcumin model compound, which represented a putative repeating unit within the polymer. The release rate of curcumin was controlled by the hydrophilicity of the polymers. Burst release (2 days) and extended release (>8 weeks) can be achieved from the same polymer depending on curcumin content in the copolymer. The materials can quench free radicals for at least 8 weeks and protect primary neurons from oxidative stress in vitro. Further, these copolymer materials could be processed into both thin films and self-assembled particles, depending on the solvent-based casting conditions. Finally, we envision that these materials may have potential for neural tissue engineering application, where antioxidant release can mitigate oxidative stress and the inflammatory response following neural injury.

The Credible Role of Curcumin in Oxidative Stress-Mediated Mitochondrial Dysfunction in Mammals

Oxidative stress and mitochondrial dysfunction are associated with the pathogenesis of several human diseases. The excessive generation of reactive oxygen species (ROS) and/or lack of adequate antioxidant defenses causes DNA mutations in mitochondria, damages the mitochondrial respiratory chain, and alters membrane permeability and mitochondrial defense mechanisms. All these alterations are linked to the development of numerous diseases. Curcumin, an active ingredient of turmeric plant rhizomes, exhibits numerous biological activities (i.e., antioxidant, anti-inflammatory, anticancer, and antimicrobial). In recent years, many researchers have shown evidence that curcumin has the ability to reduce the oxidative stress- and mitochondrial dysfunction-associated diseases. In this review, we discuss curcumin’s antioxidant mechanism and significance in oxidative stress reduction and suppression of mitochondrial dysfunction in mammals. We also discuss the research gaps and give our opinion on how curcumin research in mammals should proceed moving forward.

Effects of Resveratrol, Curcumin and Quercetin Supplementation on Bone Metabolism—A Systematic Review

Phenolic compounds are natural phytochemicals that have recently reported numerous health benefits. Resveratrol, curcumin, and quercetin have recently received the most attention among these molecules due to their documented antioxidant effects. The review aims to investigate the effects of these molecules on bone metabolism and their role in several diseases such as osteopenia and osteoporosis, bone tumours, and periodontitis. The PubMed/Medline, Web of Science, Google Scholar, Scopus, Cochrane Library, and Embase electronic databases were searched for papers in line with the study topic. According to an English language restriction, the screening period was from January 2012 to 3 July 2022, with the following Boolean keywords: (“resveratrol” AND “bone”); (“curcumin” AND “bone”); (“quercetin” AND “bone”). A total of 36 papers were identified as relevant to the purpose of our investigation. The studies reported the positive effects of the investigated phenolic compounds on bone metabolism and their potential application as adjuvant treatments for osteoporosis, bone tumours, and periodontitis. Furthermore, their use on the titanium surfaces of orthopaedic prostheses could represent a possible application to improve the osteogenic processes and osseointegration. According to the study findings, resveratrol, curcumin, and quercetin are reported to have a wide variety of beneficial effects as supplement therapies. The investigated phenolic compounds seem to positively mediate bone metabolism and osteoclast-related pathologies.

Efficacy and Safety of Curcumin and Curcuma longa Extract in the Treatment of Arthritis: A Systematic Review and Meta-Analysis of Randomized Controlled Trial

Background

Modern pharmacological research found that the chemical components of Curcuma longa L. are mainly curcumin and turmeric volatile oil. Several recent randomized controlled trials (RCT) have shown that curcumin improves symptoms and inflammation in patients with arthritis.

Methods

Pubmed, Cochran Library, CNKI, and other databases were searched to collect the randomized controlled trials (RCTs). Then, the risk of bias of RCTs were assessed and data of RCTs were extracted. Finally, RevMan 5.3 was utilized for meta-analysis.

Results

Twenty-nine (29) RCTs involving 2396 participants and 5 types of arthritis were included. The arthritis included Ankylosing Spondylitis (AS), Rheumatoid Arthritis (RA), Osteoarthritis (OA), Juvenile idiopathic arthritis (JIA) and gout/hyperuricemia. Curcumin and Curcuma longa Extract were administered in doses ranging from 120 mg to 1500 mg for a duration of 4-36 weeks. In general, Curcumin and Curcuma longa Extract showed safety in all studies and improved the severity of inflammation and pain levels in these arthritis patients. However, more RCTs are needed in the future to elucidate the effect of Curcumin and Curcuma longa Extract supplementation in patients with arthritis, including RA, OA, AS and JIA.

Conclusion

Curcumin and Curcuma longa Extract may improve symptoms and inflammation levels in people with arthritis. However, due to the low quality and small quantity of RCTs, the conclusions need to be interpreted carefully.

Metabolic Reconfiguration Activates Stemness and Immunomodulation of PDLSCs

Periodontal ligament derived stem cells (PDLSC) are adult multipotent mesenchymal-like stem cells (MSCs) that can induce a promising immunomodulation to interact with immune cells for disease treatment. Metabolic reconfiguration has been shown to be involved in the immunomodulatory activity of MSCs. However, the underlying mechanisms are largely unknown, and it remains a challenging to establish a therapeutic avenue to enhance immunomodulation of endogenous stem cells for disease management. In the present study, RNA-sequencing (RNA-seq) analysis explores that curcumin significantly promotes PDLSC function through activation of MSC-related markers and metabolic pathways. In vitro stem cell characterization further confirms that self-renewal and multipotent differentiation capabilities are largely elevated in curcumin treated PDLSCs. Mechanistically, RNA-seq reveals that curcumin activates ERK and mTOR cascades through upregulating growth factor pathways for metabolic reconfiguration toward glycolysis. Interestingly, PDLSCs immunomodulation is significantly increased after curcumin treatment through activation of prostaglandin E2-Indoleamine 2,3 dioxygenase (PGE2-IDO) signaling, whereas inhibition of glycolysis activity by 2-deoxyglucose (2-DG) largely blocked immunomodulatory capacity of PDLSCs. Taken together, this study provides a novel pharmacological approach to activate endogenous stem cells through metabolic reprogramming for immunomodulation and tissue regeneration.

Preparation, Physicochemical Assessment and the Antimicrobial Action of Hydroxyapatite-Gelatin/Curcumin Nanofibrous Composites as a Dental Biomaterial

In this study, we prepared and evaluated hydroxyapatite-gelatin/curcumin nanofibrous composites and determined their antimicrobial effects against Escherichia coli, Staphylococcus aureus, and Streptococcus mutans. Hydroxyapatite-gelatin/curcumin nanofibrous composites were prepared by the electrospinning method. The prepared nanocomposites were then subjected to physicochemical studies by the light scattering method for their particle size, Fourier transmission infrared spectroscopy (FTIR) to identify their functional groups, X-ray diffraction (XRD) to study their crystallinity, and scanning electron microscopy (SEM) to study their morphology. For the microbial evaluation of nanocomposites, the disk diffusion method was used against Streptococcus mutans, Staphylococcus aureus, and Escherichia coli. The results showed that the nanofibers were uniform in shape without any bead (structural defects). The release pattern of curcumin from the nanocomposite was a two-stage release, 60% of which was released in the first two days and the rest being slowly released until the 14th day. The results of the microbial evaluations showed that the nanocomposites had significant antimicrobial effects against all bacteria (p = 0.0086). It seems that these nanocomposites can be used in dental tissue engineering or as other dental materials. Also, according to the appropriate microbial results, these plant antimicrobials can be used instead of chemical antimicrobials, or along with them, to reduce bacterial resistance.

Osteogenic Differentiation of Mesenchymal Stem Cells via Curcumin-Containing Nanoscaffolds

The diverse pleiotropic pharmacological effects of curcumin nanoformulations have turned it into an attractive natural compound in different health-related problems. A great body of evidence has shown the impact of curcumin and its nanoformulations on the differentiation of stem cells. The current review highlights cellular and molecular mechanisms connected with the osteogenic differentiation of mesenchymal stem cells (MSCs) in the scaffolds benefiting from the presence of nanocurcumin pointing toward the role of inhibitory or stimulant signal transduction pathways in detail. Moreover, the effects of different concentrations as well as the structural modifications of curcumin on the differentiation of MSCs have been addressed.

Early Osteogenic Differentiation Stimulation of Dental Pulp Stem Cells by Calcitriol and Curcumin

Curcumin, as a natural phenolic substance, is extracted from the rhizome of Curcuma longa (turmeric), which is effective in bone healthfulness. Calcitriol is an effective hormone in regulating bone remodeling and mineral homeostasis and immune response. Mesenchymal stem cells (MSCs) are found in most dental tissues and resemble bone marrow-derived MSCs. In this work, we investigated the effect of combination and individual treatment of curcumin and calcitriol on early osteogenic differentiation of dental pulp stem cells (DPSCs). Early osteogenic differentiation was evaluated and confirmed by the gene expression level of ALP and its activity. Curcumin individually and in combination with calcitriol increased ALP activity and osteoblast-specific mRNA expression of ALP when DPSCs were cultured in an osteogenic medium. Calcitriol alone increased the enzyme more than in combination with curcumin. These findings demonstrate that curcumin can induce early osteogenic differentiation of DPSCs like calcitriol as a potent stimulant of osteogenesis.

Prospective, Multicenter Evaluation of a Polyherbal Supplement alongside Standard-of-Care Treatment for Mild Knee Osteoarthritis

BACKGROUND

This study aimed to provide clinical information on general and joint performance from individuals taking Tregocel® (containing curcuminoid and extracts of the herbs Harpagophytum procumbens, Boswellia serrata, Apium graveolens, and Zingiber officinale) alongside a standard therapy of symptomatic mild knee osteoarthritis (OA).

METHODS

This was a multicenter, open-label, prospective, single-arm study, in which Tregocel® was supplemented for 36 weeks. Participants with symptomatic mild knee OA requiring pharmacologic treatment for pain were enrolled. Physical performance (6-minute walk test, WOMAC-pain and functional domain, and heel-thigh distance flexion test), general performance (WOMAC questionnaire), and VAS (Visual Analogue Scale) assessment of knee pain, as well as anti-inflammatory and analgesic medication consumption, were assessed.

RESULTS

Between January and April 2019, 107 participants were enrolled and analysed in per protocol population. Mean age was 59.7 (SD 10.8) years, and there were 68.2% women. Mean observation time was 291.1 (SD 7.7) days. Mean increase in 6MWT result observed at the end of the study was 26.0 (SD 30.4) m (p < 0.001). Median VAS score decreased from 60.0 (IQR 50-72) mm at the beginning of the study to 21.0 (IQR 14-30) mm after 36 weeks of product administration (p < 0.001). Regular knee OA medications were taken in 99.1% of subjects at baseline decreasing to 55.1% at the end of the Tregocel® supplementation.

CONCLUSIONS

During Tregocel® supplementation, participants observed improved functional capacity confirmed in the distance in 6MWT and in the heel-thigh distance flexion test, decreased level of pain, and improved WOMAC scores for all domains.

Cytotoxic, chemosensitizing and radiosensitizing effects of curcumin based on thioredoxin system inhibition in breast cancer cells: 2D vs. 3D cell culture system

Targeting the thioredoxin/thioredoxin reductase (Trx/TrxR) system is a promising strategy to overcome cancer resistance to conventional therapy. The present study investigated the effect of curcumin on the Trx/TrxR system either alone or in combination with chemotherapy, or radiotherapy in human MCF-7 breast cancer cells seeded in 2 and 3D culture systems. Cell viability, thioredoxin reductase 1 (TrxR1) activity, and the genetic expression of Trx, TrxR1, Bcl2 and BAX genes were studied. The findings showed that the mode of culture significantly affected the response of cancer cells to different treatment modalities, as well as their gene expression patterns. Curcumin treatment resulted in a reduction of breast cancer cell proliferation and induction of apoptosis, an effect that may be mediated by manipulating Trx system components, mainly Trx expression, and to a lesser extent TrxR1 expression and concentration. Furthermore, curcumin increased the sensitivity of breast cancer cells to chemotherapy and radiotherapy by reducing Trx and TrxR1 expression levels. Thus, curcumin may have a potential role as a dose-modifying agent that can be used either to sensitize resistant cells to therapy or to reduce the dose of these therapeutic agents.

The Effect of Nanocurcumin in Improvement of Knee Osteoarthritis: A Randomized Clinical Trial

OBJECTIVE

Osteoarthritis is a degenerative disease of the joints. Non-steroidal antiinflammatory drugs (NSAIDs) are being used for the treatment of osteoarthritis. However, their use is limited due to complications, such as gastrointestinal bleeding. Therefore, it is necessary to find alternative treatments for osteoarthritis. Recently, nanomicelle curcumin has been developed to increase the oral bioavailability of curcumin. The aim of this study was to evaluate the effect of nano curcumin on the alleviation of the symptoms of knee osteoarthritis patients.

METHODS

In this randomized, double-blind controlled trial, the intervention group was administered 40 mg of nanocurcumin capsule every 12 hours over a period of six weeks, and the control group received the placebo (similar components of nanomicelle curcumin capsules yet without curcumin). In the final analysis, 36 patients in the nanocurcumin group and 35 patients in the placebo group were enrolled. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) was filled for patients in their first visit and at the end of six weeks. Differences were statistically significant at P-value < 0.05.

RESULTS

There were no significant differences between the two groups regarding gender, age, Kellgren score, and the duration of the disease before the intervention. A significant decrease was observed in the overall score, along with the scores of pain, stiffness and physical activity subscales of the WOMAC questionnaire in patients of the nano curcumin group compared with the placebo group.

CONCLUSION

Nanocurcumin significantly improves the symptoms of osteoarthritis patients.

Efficacy and Safety of Turmeric Extracts for the Treatment of Knee Osteoarthritis: a Systematic Review and Meta-analysis of Randomised Controlled Trials

PURPOSE OF THE REVIEW

Finding appropriate pharmacological options to treat osteoarthritis (OA) remain challenging. We aimed to determine the efficacy and safety of all types of turmeric extracts for the management of knee OA.

RECENT FINDINGS

Sixteen RCTs of up to 16 weeks duration including 1810 adults with knee OA were included. Eleven RCTs compared the efficacy of turmeric extracts with placebo and five with active comparators (NSAIDs). The overall risk bias of included RCTs was moderate. Turmeric extracts significantly reduced knee pain (SMD - 0.82, 95% CI - 1.17 to - 0.47, I² = 86.23%) and improved physical function (SMD - 0.75, 95% CI - 1.18 to - 0.33, I² = 90.05%) compared to placebo but had similar effects compared to NSAIDs. BMI was the major contributor to heterogeneity in the placebo-controlled studies (explained 37.68% and 67.24%, respectively, in the models) and modified the effects of the turmeric on pain and physical function with less improvement with higher BMI (SMD 0.26 95% CI 0.04 to 0.48; SMD 0.48 95% CI 0.21 to 0.74). No significant between-group differences were reported for either biochemical markers or imaging outcomes. Turmeric extracts had 12% fewer adverse events than NSAIDs and similar rates to placebo. Turmeric extract is a safe and effective option for the symptomatic management of knee OA, compared to placebo or NSAIDs. However, current evidence from short-term studies is heterogeneous and has moderate risk of bias leading to some uncertainty about the true effect.

The Effect of Curcumin on the Differentiation of Mesenchymal Stem Cells into Mesodermal Lineage

Curcumin has been placed at the forefront of the researcher's attention due to its pleiotropic pharmacological effects and health benefits. A considerable volume of articles has pointed out curcumin's effects on the fate of stem cell differentiation. In this review, a descriptive mechanism of how curcumin affects the outcome of the differentiation of mesenchymal stem cells (MSCs) into the mesodermal lineage-i.e., adipocyte, osteocyte, and chondrocyte differentiation-is compiled from the literature. The sections include the mechanism of inhibition or induction of MSCs differentiation to each lineage, their governing molecular mechanisms, and their signal transduction pathways. The effect of different curcumin doses and its structural modifications on the MSCs differentiation is also discussed.

Pharmacokinetic assessment of constituents of Boswellia serrata, pine bark extracts, curcumin in combination including methylsulfonylmethane in healthy volunteers

OBJECTIVES

Dietary supplements are increasingly used by people with osteoarthritis. Boswellia serrata extract, curcumin, pine bark extract and methylsulfonylmethane have been identified as having the largest effects for symptomatic relief in a systematic review. It is important to understand whether any pharmacokinetic interactions are among the major constituents of these supplements so as to provide information when considering the combination use of these supplements. The aim of this study was to investigate the pharmacokinetics of the constituents alone and in combination.

METHODS

This study was a randomized, open-label, single-dose, four-treatment, four-period, crossover study with 1-week washout. The pharmacokinetics of the constituents of these supplements when dosed in combination with methylsulfonylmethane were compared to being administered alone. Plasma samples were obtained over 24 h from 16 healthy participants. Eight major constituents were analysed using a validated ultra-high-performance liquid chromatography-tandem mass spectrometry assay.

KEY FINDINGS

The pharmacokinetics of each constituent was characterized, and there were no significant differences in the pharmacokinetic profiles of the constituents when administered as a combination, relative to the constituents when administered alone (P > 0.05).

CONCLUSIONS

These data suggest that interactions between the major constituents of this supplement combination are unlikely and therefore could be investigated to manage patients with osteoarthritis without significant concerns for possible pharmacokinetic interactions.

A biological extract of turmeric (Curcuma longa) modulates response of cartilage explants to lipopolysaccharide

Background

Turmeric is commonly used as a dietary treatment for inflammation, but few studies have evaluated the direct effect of turmeric on cartilage. The purpose of this study was to characterize cartilage explants’ inflammatory responses to lipopolysaccharide in the presence of a simulated biological extract of turmeric.

Methods

Turmeric was incubated in simulated gastric and intestinal fluid, followed by inclusion of liver microsomes and NADPH. The resulting extract (TUR_sim) was used to condition cartilage explants in the presence or absence of lipopolysaccharide. Explants were cultured for 96 h (h); the first 24 h in basal tissue culture media and the remaining 72 h in basal tissue culture media containing TUR_sim (0, 3, 9 or 15 μg/mL). Lipopolysaccharide (0 or 5 μg/mL) was added for the final 48 H. media samples were collected immediately prior to lipopolysaccharide exposure (0 h) and then at 24 and 48 h after, and analyzed for prostaglandin E₂ (PGE₂), glycosaminoglycan (GAG), and nitric oxide (NO). Explants were stained with calcein-AM for an estimate of live cells. Data were analyzed using a 2-way repeated measures (GAG, PGE₂, NO) or 1-way ANOVA without repeated measures (viability). Significance accepted at p < 0.05.

Results

TUR_sim significantly reduced PGE_2, NO and GAG, and calcein fluorescence was reduced. Conclusions: These data contribute to the growing body of evidence for the utility of turmeric as an intervention for cartilage inflammation.

Modulatory effects of curcumin on heat shock proteins in cancer: A promising therapeutic approach

Cancer metastasis represents a multistep process, including alteration of cell adhesion/motility in the microenvironment and sustained angiogenesis, which is essential for supporting cancer growth in tissues that are distant from the primary tumor. There is growing evidence suggesting that heat shock proteins (HSPs) (also known as heat stress proteins), which constitute a family of stress-inducible proteins, may be involved in the pathogenesis of cancer. Curcumin (diferuloylmethane) is a potent anti-inflammatory, antioxidant, antimicrobial, and antitumor agent. Curcumin has been shown to regulate different members of HSPs including HSP27, HSP40, HSP60, HSP70, and HSP90 in cancer. Here, we present extent findings suggesting that curcumin may act as a potential therapeutic agent for the treatment of cancer through its regulation of HSPs.

Recent advances in musculoskeletal local drug delivery

Musculoskeletal disorders are a significant burden on the global economy and public health. Advanced drug delivery plays a key role in the musculoskeletal field and holds the promise of enhancing the repair of degenerated and injured musculoskeletal tissues. Ideally, drug delivery should have the ability to directly deliver therapeutic agents to the diseased/injured sites with a desirable drug level over a period of time. Here, we present a mini-review of the current state-of-the-art research associated with local drug delivery and its use for the treatment of musculoskeletal disorders. First, an overview of drug delivery strategies, with a focus on issues related to musculoskeletal pathology, potential therapeutic strategies, conventional and non-conventional drugs, and various delivery systems, is introduced. Then, we highlight recent advances in the emerging fields of musculoskeletal local drug delivery, involving therapeutic drugs (e.g., genes, small molecule therapeutics, and stem cells), novel delivery vehicles (e.g., 3D printing and tissue engineering techniques), and innovative delivery approaches (e.g., multi-drug delivery and smart stimuli-responsive delivery). The review concludes with future perspectives and associated challenges for developing local drug delivery for musculoskeletal applications. STATEMENT OF SIGNIFICANCE: Three important aspects are highlighted in this manuscript: 1) The advanced musculoskeletal drug delivery is introduced from the aspects ranging from musculoskeletal disorders, potential therapeutic solutions, and various drug delivery systems. 2) The recent advances in the emerging fields of musculoskeletal local drug delivery, involving therapeutic drugs (e.g., genes, small molecule therapeutics, and stem cells), novel delivery vehicles (e.g., 3D printing and tissue engineering technique), and innovative delivery approaches (e.g., multi-drug delivery and smart stimuli-responsive delivery), are highlighted. 3) The challenges and perspectives of future research directions in the development of musculoskeletal local drug delivery are presented.

Curcumin in tissue engineering: A traditional remedy for modern medicine

Curcumin is the principal polyphenolic compound present in turmeric with broad applications in tissue engineering and regenerative medicine. It has some important inherent properties with the potential to facilitate tissue healing, including anti-inflammatory, anti-oxidant, and antibacterial activities. Therefore, curcumin has been used for the treatment of various damaged tissues, especially wound injuries. There are different forms of curcumin, among which nano-formulations are of a great importance in regenerative medicine. It is also important to design sophisticated delivery systems for controlled/localized delivery of curcumin to the target tissues and organs. Although there are many reports on the advantages of this compound, further research is required to fully explore its clinical usage. The review describes the physicochemical and biological properties of curcumin and the current state of the evidence on its applications in tissue engineering. © 2018 BioFactors, 45(2):135-151, 2019.

Combination therapy of curcumin and alendronate modulates bone turnover markers and enhances bone mineral density in postmenopausal women with osteoporosis

OBJECTIVE

This study evaluated the effects of combination therapy of curcumin and alendronate on BMD and bone turnover markers in postmenopausal women with osteoporosis.

SUBJECTS AND METHODS

In a randomized, double-blind trial study, 60 postmenopausal women were divided into three groups: control, alendronate, and alendronate + curcumin. Each group included 20 patients. Total body, total hip, lumbar spine and femoral neck BMDs were measured by dual-energy X-ray absorptiometry (DXA) at baseline and after 12 months of therapy. Bone turnover markers such as bone-specific alkaline phosphatase (BALP), osteocalcin and C-terminal cross-linking telopeptide of type I collagen (CTx) were measured at the outset and 6 months later.

RESULTS

Patients in the control group suffered a significant decrease in BMD and increased bone turnover markers at the end of study. The group treated with only alendronate showed significantly decreased levels of BALP and CTx and increased levels of osteocalcin compared to the control group. The alendronate group also showed significant increases in the total body, total hip, lumbar spine and femoral neck BMDs at the end of study compared to the control group. In the curcumin + alendronate group, BALP and CTx levels decreased and osteocalcin levels increased significantly at the end of study compared to the control and alendronate groups. BMD indexes also increased in four areas significantly at the end of study compared to the control and alendronate groups.

CONCLUSION

The combination of curcumin and alendronate has beneficial effects on BMD and bone turnover markers among postmenopausal women with osteoporosis. Arch Endocrinol Metab. 2018;62(4):438-45.

Which supplements can I recommend to my osteoarthritis patients?

OA is a chronic and disabling joint disease with limited evidence-based pharmacological treatment options available that improve outcomes for patients safely. Faced with few effective pharmacological treatments, the use has grown of dietary supplements and complementary medicines for symptomatic relief among people living with OA. The aim of this review is to provide a summary of existing evidence and recommendations supporting the use of supplements for OA. Systematic reviews and randomized controlled trials investigating oral supplements for treating OA were identified. Limited research evidence supports recommendations for the oral use of Boswellia serrata extract and Pycnogenol, curcumin and methylsulfonylmethane in people with OA despite the poor quality of the available studies. Few studies adequately reported possible adverse effects related to supplementation, although the products were generally recognized as safe. Further high quality trials are needed to improve the strength of evidence to support this recommendation and better guide optimal treatment of people living with OA.

Integrative Medicine for the Treatment of Persistent Pain

Integrative health modalities can provide useful tools in the management of persistent pain in the primary care setting. These modalities, such as acupuncture, mind-body medicine, diet and herbs, and movement strategies can be safely used and may provide patients with hope and empowerment. It is highly recommended that the patient work alongside trained professionals for a given modality and/or an interprofessional team.

Effects of Curcumin on Bone Loss and Biochemical Markers of Bone Turnover in Patients with Spinal Cord Injury

BACKGROUND

Osteoporosis is one of the most common problems of patients with spinal cord injuries (SCIs). The current study aimed to evaluate the antiosteoporotic effects of curcumin on densitometry parameters and biomarkers of bone turnovers among patients with SCI.

MATERIALS AND METHODS

The current controlled clinical trial was conducted among 100 patients with SCI referred to an outpatient clinic of rehabilitation in Ilam City, Iran, in 2013-2015. The intervention group received 110/mg/kg/day curcumin for 6 months and the control group received placebo. Bone mineral density (BMD) was measured in all patients. The level of procollagen type I N-terminal propeptide, serum carboxy-terminal telopeptide of type I collagen, osteocalcin, and bone-specific alkaline phosphates were compared before and after study.

RESULTS

BMD indicators of lumbar, femoral neck, and total hip in the control group significantly decreased compared with the beginning of study. However, in the curcumin group, a significant increase was observed in BMD indicators of lumbar, femoral neck, and hip at the end of study compared with the beginning. There was also a significant difference between interventional and control groups for the mean BMD of femoral neck and hip at the end of study (0.718 ± 0.002 g/cm² vs. 0.712 ± 0.003 g/cm² and 0.742 ± 0.031 g/cm² vs. 0.692 ± 0.016 g/cm², respectively).

CONCLUSIONS

Curcumin, via modulation of densitometry indices and bone resorption markers, showed inhibitory effects on the process of osteoporosis. Treatment with curcumin was significantly associated with a decrease in the osteoporosis progression and bone turnover markers of patients with SCI after 6 months.

Oral curcumin supplementation improves fine motor function in the middle-aged rhesus monkey

Aged individuals experience decreased fine motor function of the hand and digits, which could result, in part, from the chronic, systemic state of inflammation that occurs with aging. Recent research for treating age-related inflammation has focused on the effects of nutraceuticals that have anti-inflammatory properties. One particular dietary polyphenol, curcumin, the principal curcuminoid of the spice turmeric, has been shown to have significant anti-inflammatory effects and there is mounting evidence that curcumin may serve to reduce systemic inflammation. Therefore, it could be useful for alleviating age-related impairments in fine motor function. To test this hypothesis we assessed the efficacy of a dietary intervention with a commercially available optimized curcumin to ameliorate or delay the effects of aging on fine motor function of the hand of rhesus monkeys. We administered oral daily doses of curcumin or a control vehicle to 11 monkeys over a 14- to 18-month period in which they completed two rounds of fine motor function testing. The monkeys receiving curcumin were significantly faster at retrieving a food reward by round 2 of testing than monkeys receiving a control vehicle. Further, the monkeys receiving curcumin demonstrated a greater degree of improvement in performance on our fine motor task by round 2 of testing than monkeys receiving a control vehicle. These findings reveal that fine motor function of the hand and digits is improved in middle-aged monkeys receiving chronic daily administration of curcumin.

Oral herbal medicines marketed in Brazil for the treatment of osteoarthritis: A systematic review and meta-analysis

Herbal medications are commonly used to manage symptoms associated with osteoarthritis (OA). This systematic review evaluated the effectiveness and safety of oral medications used in Brazil for the treatment of OA. Randomized clinical trials involving adults with OA treated by a herbal medicine or a control group were eligible. The primary outcomes measured were pain, physical function, swelling, stiffness and quality of life; and the secondary outcomes were adverse events, activity limitations and treatment satisfaction. Sixteen studies were included (n = 1,741 patients) in the systematic review and nine studies in the meta-analysis, representing 6 of the 13 herbal medicines studied: Boswellia serrata (n = 2), Curcuma longa (n = 3), Harpagophytum procumbens (n = 1), Salix daphnoides (n = 3), Uncaria guianensis (n = 2) and Zingiber officinale (n = 5). B. serrata was more effective than both placebo and valdecoxib for improvement of pain and physical function. No difference was observed for H. procumbens, C. longa and U. guianensis compared with control. Z. officinale showed improvement of pain over placebo. The evidence was insufficient to support the effective and safe use of these herbal medicines, because the quality of evidence of studies was low. This study guides managers of the Brazilian public health system and prescribers in decision-making regarding the use of these herbal medicines for OA. Copyright © 2017 John Wiley & Sons, Ltd.

Efficacy of Turmeric Extracts and Curcumin for Alleviating the Symptoms of Joint Arthritis: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

Although turmeric and its curcumin-enriched extracts have been used for treating arthritis, no systematic review and meta-analysis of randomized clinical trials (RCTs) have been conducted to evaluate the strength of the research. We systemically evaluated all RCTs of turmeric extracts and curcumin for treating arthritis symptoms to elucidate the efficacy of curcuma for alleviating the symptoms of arthritis. Literature searches were conducted using 12 electronic databases, including PubMed, Embase, Cochrane Library, Korean databases, Chinese medical databases, and Indian scientific database. Search terms used were “turmeric,” “curcuma,” “curcumin,” “arthritis,” and “osteoarthritis.” A pain visual analogue score (PVAS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were used for the major outcomes of arthritis. Initial searches yielded 29 articles, of which 8 met specific selection criteria. Three among the included RCTs reported reduction of PVAS (mean difference: −2.04 [−2.85, −1.24]) with turmeric/curcumin in comparison with placebo (P < .00001), whereas meta-analysis of four studies showed a decrease of WOMAC with turmeric/curcumin treatment (mean difference: −15.36 [−26.9, −3.77]; P = .009). Furthermore, there was no significant mean difference in PVAS between turmeric/curcumin and pain medicine in meta-analysis of five studies. Eight RCTs included in the review exhibited low to moderate risk of bias. There was no publication bias in the meta-analysis. In conclusion, these RCTs provide scientific evidence that supports the efficacy of turmeric extract (about 1000 mg/day of curcumin) in the treatment of arthritis. However, the total number of RCTs included in the analysis, the total sample size, and the methodological quality of the primary studies were not sufficient to draw definitive conclusions. Thus, more rigorous and larger studies are needed to confirm the therapeutic efficacy of turmeric for arthritis.

Insights into the Action Mechanisms of Traditional Chinese Medicine in Osteoarthritis

Osteoarthritis (OA) is a chronic degenerative joint disease characterized by articular cartilage destruction, synovial inflammation, and osteophyte formation. No effective treatments are available. The current pharmacological medications such as nonsteroidal anti-inflammatory drugs (NSAIDs) and analgesics, accompanied by possible adverse effects, might ameliorate OA symptoms. But they do not arrest the progression of OA. Traditional Chinese medicine (TCM) provides medical value by modification of disease and symptoms in OA. Valuable work on exploring TCM merits for OA patients has been investigated using modern technologies, although the complicated interacting network among the numerous components indicates the uncertainty of target specification. This review will provide an overview of the action mechanism of TCM in the last 5 years, discussing the TCM activities of anti-inflammation, antiapoptosis, antioxidation, anticatabolism, and proliferation in OA. TCM is a proposed medical option for OA treatment.

TBI-induced nociceptive sensitization is regulated by histone acetylation

Chronic pain after traumatic brain injury (TBI) is very common, but the mechanisms linking TBI to pain and the pain-related interactions of TBI with peripheral injuries are poorly understood. In these studies we pursued the hypothesis that TBI pain sensitization is associated with histone acetylation in the rat lateral fluid percussion model. Some animals received hindpaw incisions in addition to TBI to mimic polytrauma. Neuropathological analysis of brain tissue from sham and TBI animals revealed evidence of bleeding, breakdown of the blood brain barrier, in the cortex, hippocampus, thalamus and other structures related to pain signal processing. Mechanical allodynia was measured in these animals for up to eight weeks post-injury. Inhibitors of histone acetyltransferase (HAT) and histone deacetylase (HDAC) were used to probe the role of histone acetylation in such pain processing. We followed serum markers including glial fibrillary acidic protein (GFAP), neuron-specific enolase 2 (NSE) myelin basic protein (MBP) and S100β to gauge TBI injury severity. Our results showed that TBI caused mechanical allodynia in the hindpaws of the rats lasting several weeks. Hindpaws contralateral to TBI showed more rapid and profound sensitization than ipsilateral hindpaws. The inhibition of HAT using curcumin 50 mg/kg s.c reduced mechanical sensitization while the HDAC inhibitor suberoylanilide hydroxamic acid 50 mg/kg i.p. prolonged sensitization in the TBI rats. Immunohistochemical analyses of spinal cord tissue localized changes in the level of acetylation of the H3K9 histone mark to dorsal horn neurons. Taken together, these findings demonstrate that TBI induces sustained nociceptive sensitization, and changes in spinal neuronal histone proteins may play an important role.

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Pain after traumatic brain injury (TBI) is common and often persistent.

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Using the rat lateral fluid percussion model, it was observed that hindpaw allodynia is present for three weeks after TBI.

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Damage to pain processing areas of the brain can be demonstrated after TBI.

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Agents regulating the epigenetic acetylation of histone proteins modified the time course of TBI-induced allodynia.

Olives and Bone: A Green Osteoporosis Prevention Option

Skeletal degeneration due to aging, also known as osteoporosis, is a major health problem worldwide. Certain dietary components confer protection to our skeletal system against osteoporosis. Consumption of olives, olive oil and olive polyphenols has been shown to improve bone health. This review aims to summarize the current evidence from cellular, animal and human studies on the skeletal protective effects of olives, olive oil and olive polyphenols. Animal studies showed that supplementation of olives, olive oil or olive polyphenols could improve skeletal health assessed via bone mineral density, bone biomechanical strength and bone turnover markers in ovariectomized rats, especially those with inflammation. The beneficial effects of olive oil and olive polyphenols could be attributed to their ability to reduce oxidative stress and inflammation. However, variations in the bone protective, antioxidant and anti-inflammatory effects between studies were noted. Cellular studies demonstrated that olive polyphenols enhanced proliferation of pre-osteoblasts, differentiation of osteoblasts and decreased the formation of osteoclast-like cells. However, the exact molecular pathways for its bone health promoting effects are yet to be clearly elucidated. Human studies revealed that daily consumption of olive oil could prevent the decline in bone mineral density and improve bone turnover markers. As a conclusion, olives, olive oil and its polyphenols are potential dietary interventions to prevent osteoporosis among the elderly.

Relationship and interactions of curcumin with radiation therapy

Curcumin is widely reported to have remarkable medicinal - and antineoplastic - properties. This review details curcumin’s relationship with radiotherapy (RT), principally as a radiosensitizer for various malignancies and a radioprotector for normal tissues. First, examples of radiosensitization are provided for various cancers: Pediatric, lymphoma, sarcoma, prostate, gynecologic, pancreas, liver, colorectal, breast, lung, head/neck, and glioma. It is not the purpose of this article to comprehensively review all radiosensitization data; however, high-quality studies are discussed in relationship to currently-controversial RT questions for many cancers, and thus the importance of developing a natural radiosensitizer. Attention is then shifted to radioprotection, for which supporting research is discussed for the following RT toxicities: Dermatitis, pneumonitis, cataractogenesis, neurocognition, myelosuppression, secondary malignancies, and mucositis/enteritis. Though there is fewer data for radioprotection, the overall quality of clinical evidence is higher, and small clinical trials implicating the efficacy of curcumin for RT toxicities (vs placebo/current therapies) are also detailed. Though the overall level of evidence for curcumin as a radiosensitizer and radioprotector is low, it must be recognized that risks of adverse effects are exceedingly low, and clinicians may need to judge the yet-unproven rewards with low toxicity risks.

Curcumin slows osteoarthritis progression and relieves osteoarthritis-associated pain symptoms in a post-traumatic osteoarthritis mouse model

Background

Curcumin has been shown to have chondroprotective potential in vitro. However, its effect on disease and symptom modification in osteoarthritis (OA) is largely unknown. This study aimed to determine whether curcumin could slow progression of OA and relieve OA-related pain in a mouse model of destabilization of the medial meniscus (DMM).

Methods

Expression of selected cartilage degradative-associated genes was evaluated in human primary chondrocytes treated with curcumin and curcumin nanoparticles and assayed by real-time PCR. The mice subjected to DMM surgery were orally administered curcumin or topically administered curcumin nanoparticles for 8 weeks. Cartilage integrity was evaluated by Safranin O staining and Osteoarthritis Research Society International (OARSI) score, and by immunohistochemical staining of cleaved aggrecan and type II collagen, and levels of matrix metalloproteinase (MMP)-13 and ADAMTS5. Synovitis and subchondral bone thickness were scored based on histologic images. OA-associated pain and symptoms were evaluated by von Frey assay, and locomotor behavior including distance traveled and rearing.

Results

Both curcumin and nanoparticles encapsulating curcumin suppressed mRNA expression of pro-inflammatory mediators IL-1β and TNF-α, MMPs 1, 3, and 13, and aggrecanase ADAMTS5, and upregulated the chondroprotective transcriptional regulator CITED2, in primary cultured chondrocytes in the absence or presence of IL-1β. Oral administration of curcumin significantly reduced OA disease progression, but showed no significant effect on OA pain relief. Curcumin was detected in the infrapatellar fat pad (IPFP) following topical administration of curcumin nanoparticles on the skin of the injured mouse knee. Compared to vehicle-treated controls, topical treatment led to: (1) reduced proteoglycan loss and cartilage erosion and lower OARSI scores, (2) reduced synovitis and subchondral plate thickness, (3) reduced immunochemical staining of type II collagen and aggrecan cleavage epitopes and numbers of chondrocytes positive for MMP-13 and ADAMTS5 in the articular cartilage, and (4) reduced expression of adipokines and pro-inflammatory mediators in the IPFP. In contrast to oral curcumin, topical application of curcumin nanoparticles relieved OA-related pain as indicated by reduced tactile hypersensitivity and improved locomotor behavior.

Conclusion

This study provides the first evidence that curcumin significantly slows OA disease progression and exerts a palliative effect in an OA mouse model.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-016-1025-y) contains supplementary material, which is available to authorized users.

The Potential of Curcumin in Treatment of Spinal Cord Injury

Current treatment for spinal cord injury (SCI) is supportive at best; despite great efforts, the lack of better treatment solutions looms large on neurological science and medicine. Curcumin, the active ingredient in turmeric, a spice known for its medicinal and anti-inflammatory properties, has been validated to harbor immense effects for a multitude of inflammatory-based diseases. However, to date there has not been a review on curcumin's effects on SCI. Herein, we systematically review all known data on this topic and juxtapose results of curcumin with standard therapies such as corticosteroids. Because all studies that compare the two show superior results for curcumin over corticosteroids, it could be true that curcumin better acts at the inflammatory source of SCI-mediated neurological injury, although this question remains unanswered in patients. Because curcumin has shown improvements from current standards of care in other diseases with few true treatment options (e.g., osteoarthritis), there is immense potential for this compound in treating SCI. We critically and systematically summarize available data, discuss clinical implications, and propose further testing of this well-tolerated compound in both the preclinical and the clinical realms. Analyzing preclinical data from a clinical perspective, we hope to create awareness of the incredible potential that curcumin shows for SCI in a patient population that direly needs improvements on current therapy.