Curcumin Protects Osteoblasts From Oxidative Stress-Induced Dysfunction via GSK3β-Nrf2 Signaling Pathway

Role of oxidative stress in the concurrent development of osteoporosis and tendinopathy: Emerging challenges and prospects for treatment modalities

Both osteoporosis and tendinopathy are widely prevalent disorders, encountered in diverse medical contexts. Whilst each condition has distinct pathophysiological characteristics, they share several risk factors and underlying causes. Notably, oxidative stress emerges as a crucial intersecting factor, playing a pivotal role in the onset and progression of both diseases. This imbalance arises from a dysregulation in generating and neutralising reactive oxygen species (ROS), leading to an abnormal oxidative environment. Elevated levels of ROS can induce multiple cellular disruptions, such as cytotoxicity, apoptosis activation and reduced cell function, contributing to tissue deterioration and weakening the structural integrity of bones and tendons. Antioxidants are substances that can prevent or slow down the oxidation process, including Vitamin C, melatonin, resveratrol, anthocyanins and so on, demonstrating potential in treating these overlapping disorders. This comprehensive review aims to elucidate the complex role of oxidative stress within the interlinked pathways of these comorbid conditions. By integrating contemporary research and empirical findings, our objective is to outline new conceptual models and innovative treatment strategies for effectively managing these prevalent diseases. This review underscores the importance of further in-depth research to validate the efficacy of antioxidants and traditional Chinese medicine in treatment plans, as well as to explore targeted interventions focused on oxidative stress as promising areas for future medical advancements.

Curcumin-loaded scaffolds in bone regeneration

In recent years, there has been a notable surge in the development of engineered bone scaffolds intended for the repair of bone defects. While autografts and allografts have traditionally served as the primary methods in bone tissue engineering, their inherent limitations have spurred the exploration of novel avenues in biomedical implant development. The emergence of bone scaffolds not only facilitates bone reconstruction but also offers a platform for the targeted delivery of therapeutic agents. There exists a pervasive interest in leveraging various drugs, proteins, growth factors, and biomolecules with osteogenic properties to augment bone formation, as the enduring side effects associated with current clinical modalities necessitate the pursuit of safer alternatives. Curcumin, the principal bioactive compound found in turmeric, has demonstrated notable efficacy in regulating the proliferation and differentiation of bone cells while promoting bone formation. Nevertheless, its utility is hindered by restricted water solubility and poor bioavailability. Strategies aimed at enhancing the solubility, stability, and bioavailability of curcumin, including formulation techniques such as liposomes and nanoparticles or its complexation with metals, have been explored. This investigation is dedicated to exploring the impact of curcumin on the proliferation, differentiation, and migration of osteocytes, osteoblasts, and osteoclasts.

High-molecular-weight Hyaluronan Administration Inhibits Bone Resorption and Promotes Bone Formation in Young-age Osteoporosis Rats

Osteoporosis poses a significant global health concern, affecting both the elderly and young individuals, including athletes. Despite the development of numerous antiosteoporotic drugs, addressing the unique needs of young osteoporosis patients remains challenging. This study focuses on young rats subjected to ovariectomy (OVX) to explore the impact of high-molecular-weight hyaluronan (HA) on preventing OVX-induced osteoporosis. Twenty-four rats underwent OVX, while 12 underwent sham procedures (sham control group). Among the OVX rats, half received subcutaneous injections of HA (MW: 2700 kDa) at 10 mg/kg/week into their backs (OVX-HA group), whereas the other half received saline injections (0.5 ml/week) at the same site (OVX-saline group). OVX-HA group exhibited significantly higher percentages of osteoclast surface (Oc. S/BS), osteoblast surface per bone surface (Ob. S/BS), and bone volume/tissue volume (BV/TV) compared with OVX-saline group at the same age. The proportions of Ob. S/BS and BV/TV in the OVX-HA group closely resembled those of the sham control group, whereas the proportion of Oc. S/BS in the OVX-HA group was notably higher than that in the sham control group. In summary, the administration of HA significantly mitigated bone resorption and enhanced bone formation, suggesting a crucial role for HA in the treatment of young adult osteoporosis.

Nutraceuticals and Functional Foods: A Comprehensive Review of Their Role in Bone Health

Bone health is the result of a tightly regulated balance between bone modeling and bone remodeling, and alterations of these processes have been observed in several diseases both in adult and pediatric populations. The imbalance in bone remodeling can ultimately lead to osteoporosis, which is most often associated with aging, but contributing factors can already act during the developmental age, when over a third of bone mass is accumulated. The maintenance of an adequate bone mass is influenced by genetic and environmental factors, such as physical activity and diet, and particularly by an adequate intake of calcium and vitamin D. In addition, it has been claimed that the integration of specific nutraceuticals such as resveratrol, anthocyanins, isoflavones, lycopene, curcumin, lutein, and β-carotene and the intake of bioactive compounds from the diet such as honey, tea, dried plums, blueberry, and olive oil can be efficient strategies for bone loss prevention. Nutraceuticals and functional foods are largely used to provide medical or health benefits, but there is an urge to determine which products have adequate clinical evidence and a strong safety profile. The aim of this review is to explore the scientific and clinical evidence of the positive role of nutraceuticals and functional food in bone health, focusing both on molecular mechanisms and on real-world studies.

Associations of healthy eating index-2015 with osteoporosis and low bone mass density in postmenopausal women: a population-based study from NHANES 2007-2018

Purpose

The current study aimed to explore the associations of diet quality assessed by healthy eating index-2015 (HEI-2015) with risks of osteoporosis and low bone mineral density (BMD) among American postmenopausal women aged 50 years and older.

Methods

Postmenopausal women aged 50 years and older in the National Health and Nutrition Examination Survey from 2007 through 2018 were included in the final sample. Analysis of variance and Rao-Scott adjusted chi-square tests were used to compare the characteristics across tertiles of HEI-2015. Univariate and multivariate weighted logistic regression models were employed to explore the associations of HEI-2015 tertiles and continuous HEI-2015 with the risks of osteoporosis and low BMD. Nonlinear dose-response associations were evaluated using weighted restricted cubic spline analyses, and the contributions of various HEI-2015 components were assessed using weighted quantile sum regression models.

Results

The final sample included 3,421 postmenopausal women aged 50 years and older representative for approximately 28.38 million non-institutionalized U.S. postmenopausal women. Osteoporosis prevalence decreased with HEI-2015 tertiles while the prevalence of low BMD showed no significant decrease. Compared with postmenopausal women in the first tertile of HEI-2015, those with the second (OR: 0.57, 95%CI: 0.38-0.84) and third (OR: 0.48, 95%CI: 0.29-0.78) HEI-2015 tertiles were associated with reduced osteoporosis risk after multivariate adjustments, but no significant association of HEI-2015 with the risk of BMD was identified. Furthermore, similar effects were confirmed in the sensitivity analyses and subgroup analyses and interaction effects. Moreover, significant nonlinear associations were observed between HEI-2015 with osteoporosis risk, and total vegetables, refined grains and greens and beans demonstrated the strongest protective effect among HEI-2015 components against osteoporosis.

Conclusions

This study strongly suggests the significant negative associations of HEI-2015 with osteoporosis risk in American postmenopausal women. These findings highlight the importance of adherence to the dietary guidelines for Americans in reducing the risk of osteoporosis.

Treatment with PB125® Increases Femoral Long Bone Strength in 15-Month-Old Female Hartley Guinea Pigs

Nuclear factor-erythroid 2-related factor-2 (Nrf2) is a transcription factor that serves as a master regulator of anti-inflammatory agents, phase I xenobiotic, and phase II antioxidant enzymes, all of which provide a cytoprotective role during disease progression. We hypothesized that oral administration of a purported phytochemical Nrf2-activator, PB125®, would increase long bone strength in aging Hartley guinea pigs, a model prone to musculoskeletal decline. Male (N = 56) and female (N = 56) guinea pigs were randomly assigned to receive daily oral treatment with either PB125® or vehicle control. Animals were treated for a consecutive 3-months (starting at 2-months of age) or 10-months (starting at 5-months of age) and sacrificed at 5-months or 15-months of age, respectively. Outcome measures included: (1) ANY-maze™ enclosure monitoring, (2) quantitative microcomputed tomography, and (3) biomechanical testing. Treatment with PB125® for 10 months resulted in increased long bone strength as determined by ultimate bending stress in female Hartley guinea pigs. In control groups, increasing age resulted in significant effects on geometric and structural properties of long bones, as well as a trending increase in ultimate bending stress. Furthermore, both age and sex had a significant effect on the geometric properties of both cortical and trabecular bone. Collectively, this work suggests that this nutraceutical may serve as a promising target and preventive measure in managing the decline in bone mass and quality documented in aging patients. Auxiliary to this main goal, this work also capitalized upon 5 and 15-month-old male and female animals in the control group to characterize age- and sex-specific differences on long bone geometric, structural, and material properties in this animal model.

GPAT3 deficiency attenuates corticosterone-caused hepatic steatosis and oxidative stress through GSK3β/Nrf2 signals

The development of nonalcoholic fatty liver disease (NAFLD) may worsen due to chronic stress or prolonged use of glucocorticoids. Glycerol-3-phosphate acyltransferase 3 (GPAT3), has a function in obesity and serves as a key rate-limiting enzyme that regulates triglyceride synthesis. However, the precise impact of GPAT3 on corticosterone (CORT)-induced NAFLD and its underlying molecular mechanism remain unclear. For our in vivo experiments, we utilized male and female mice that were GPAT3-/- and wild type (WT) and treated them with CORT for a duration of 4 weeks. In our in vitro experiments, we transfected AML12 cells with GPAT3 siRNA and subsequently treated them with CORT. Under CORT-treated conditions, the absence of GPAT3 greatly improved obesity and hepatic steatosis while enhancing the expression of genes involved in fatty acid oxidation, as evidenced by our findings. In addition, the deletion of GPAT3 significantly inhibited the production of reactive oxygen species (ROS), increased the expression of antioxidant genes, and recovered the mitochondrial membrane potential in AML12 cells treated with CORT. In terms of mechanism, the absence of GPAT3 encouraged the activation of the glycogen synthase kinase 3β (GSK3β)/nuclear factor-erythroid 2 related factor 2 (Nrf2) pathway, which served as a defense mechanism against liver fat accumulation and oxidative stress. Furthermore, GPAT3 expression was directly controlled at the transcriptional level by the glucocorticoid receptor (GR). Collectively, our findings suggest that GPAT3 deletion significantly alleviated hepatic steatosis and oxidative stress through promoting GSK3β/Nrf2 signaling pathways.

The Use of Nigella sativa in Cardiometabolic Diseases

Nigella sativa L. is an herb that is commonly used in cooking and in traditional medicine, particularly in Arab countries, the Indian subcontinent, and some areas of eastern Europe. Nigella sativa is also called "black cumin" or "black seeds", as the seeds are the most-used part of the plant. They contain the main bioactive component thymoquinone (TQ), which is responsible for the pleiotropic pharmacological properties of the seeds, including anti-oxidant, anti-inflammatory, anti-hypertensive, anti-hepatotoxic, hypoglycemic, and lipid-lowering properties. In this narrative review, both the potential mechanisms of action of Nigella sativa and the fundamental role played by pharmaceutical technology in optimizing preparations based on this herb in terms of yield, quality, and effectiveness have been outlined. Moreover, an analysis of the market of products containing Nigella sativa was carried out based on the current literature with an international perspective, along with a specific focus on Italy.

Effects of nano-micelles curcumin-based photodynamic therapy on expression of RUNX2 as an indicator of bone regeneration in orthodontic tooth movement

OBJECTIVES

The aim was to evaluate the impact of nano-micelles curcumin (NMCur) based photodynamic therapy (PDT) during compressive force application on human PDL-derived fibroblasts (HPDFs) in vitro for up to 6 days on the expression of RUNX2 as an indicator of bone development and remodeling.

MATERIALS AND METHODS

HPDFs viability during 2 g/cm2 compressive force application was investigated using membrane-impermeable DNA-binding stain propidium iodide (PI) in flow cytometry. Gene and protein expressions of RUNX2 were assessed by quantitative reverse transcription polymerase chain reaction (RT-qPCR) and flow cytometry, respectively, following NMCur-PDT at different concentrations of NMCur (25, 50, and 75 µM plus irradiation of 180 mW/cm2 diode laser at the wavelength of 450 ± 10 nm for 5 min) during the static compressive force of 2 g/cm2 on HPDFs via weight approach-based in-vitro loading model up to 6 days. One-way ANOVA and Tukey post hoc tests at a p-value equal to/or less than 0.05 were used to analyze the obtained data.

RESULTS

After 6 days of application of compressive force, 99.21 ± 6.12% of HPDFs were PI negative and therefore considered alive, while only 0.89 ± 0.06% of the population were PI positive and considered dead. In comparison with controls (loaded HPDFs), expression of RUNX2 gene was dose-dependent and the highest expression (14.38-fold; P < 0.01) was observed at a concentration of 75 µM NMCur following 5 min of diode laser irradiation (i.e., 75 µM NMCur-PDT) during compressive force application on day 5. The greatest and lowest upregulations of RUNX2 protein were observed in 75 µM NMCur-PDT during compressive force application on HPDFs, on day 5 (3.19-fold; P < 0.01) and day 6 (2.09-fold; P < 0.05), respectively.

CONCLUSION

NMCur-PDT during weight approach-based in-vitro loading model can promote orthodontic tooth movement by upregulating RUNX2 signaling pathway in HPDFs.

Curcumin alleviates bisphenol AF-induced oxidative stress and apoptosis in caprine endometrial epithelial cells via the Nrf2 signaling pathway

Bisphenol AF (BPAF), a BPA-substitute, has been widely used in industrial compounds throughout the world. Several studies have shown that BPAF has endocrine interference and reproductive toxicity. However, the toxic effects of BPAF on pregnancy and placenta of goats are still unclear. Therefore, the objective of this study was to reveal the toxic effect of BPAF by using an in vitro culture model of caprine endometrial epithelial cells (EECs) and further attempted to alleviate the toxicity by curcumin pretreatment. The results showed that BPAF induces significant effects on EECs, including decreased cell viability and mitochondrial membrane potential (△ψm), elevating intracellular reactive oxygen species (ROS), promoting cell apoptosis through upregulating the expression of Bax, Cytochrome c, and downregulating the expression of Bcl-2. Meanwhile, BPAF induced dysregulation of oxidative stress by increasing the levels of malondialdehyde (MDA) and glutathione peroxidase (GSH-Px) but decreasing the activities of superoxide dismutase (SOD). However, curcumin pretreatment could significantly attenuate BPAF-induced toxic effects in EECs. Further study revealed that BPAF treatment could activate mitogen-activated protein kinase (MAPK) pathway and nuclear factor-erythroid 2-related factor 2 (Nrf2) expression, but curcumin pretreatment significantly inhibited the activation of MAPK signal pathway and Nrf2 expression induced by BPAF. Overall, this study indicated that curcumin could prevent BPAF-induced EECs cytotoxicity, which provides a potential therapeutic strategy for female infertility associated with BPAF exposure.

Curcumin and resveratrol delivery from multi-functionalized calcium phosphate scaffold enhances biological properties

Natural medicinal compounds (NMCs) can assist effectively in treating bone disorders. NMC release kinetics from a ceramic bone tissue engineering scaffold can be tailored. However, inferior physicochemical properties halt their therapeutic applications and need a carrier system for delivery. We developed a multi-functionalized scaffold to understand the effect of curcumin (Cur) and resveratrol (Rsv) on in vitro biological properties. Polycaprolactone (PCL) nanoparticles encapsulated resveratrol in the polymeric matrix. Nanoparticles showed a hydrodynamic diameter of about 180 nm, - 16 mV zeta potential, and up to ~65 % encapsulation efficiency. Scaffolds made of zinc-doped tricalcium phosphate (Zn-TCP) were coated with curcumin followed by either resveratrol (Cur-Rsv) or resveratrol nanoparticles (Cur-Rsv-NP). NMC-loaded scaffolds exhibited a biphasic release pattern over 60 days. Solubility and hydrophobic-hydrophilic interactions affected the NMC release profile. Resveratrol showed rapid release as compared to curcumin. The treated scaffold increased the cell viability of human fetal osteoblast (hFOB) by 1.8-fold as compared to the control. It exhibited a 6-fold increase in cytotoxicity toward osteosarcoma (MG-63) cells as compared to the untreated scaffold. NMCs loaded scaffold effectively inhibited Staphylococcus aureus from colonizing over the scaffold. Zinc doping enhanced osteoblast growth and prevented bacterial colony formation. Such design principle provided a direction for developing multi-functionalized calcium phosphate (CaP) scaffolds against bone diseases for orthopedic applications.

Protective effects of curcumin against osteoporosis and its molecular mechanisms: a recent review in preclinical trials

Osteoporosis (OP) is one of the most common metabolic skeletal disorders and is commonly seen in the elderly population and postmenopausal women. It is mainly associated with progressive loss of bone mineral density, persistent deterioration of bone microarchitecture, and increased fracture risk. To date, drug therapy is the primary method used to prevent and treat osteoporosis. However, long-term drug therapy inevitably leads to drug resistance and specific side effects. Therefore, researchers are constantly searching for new monomer compounds from natural plants. As a candidate for the treatment of osteoporosis, curcumin (CUR) is a natural phenolic compound with various pharmacological and biological activities, including antioxidant, anti-apoptotic, and anti-inflammatory. This compound has gained research attention for maintaining bone health in various osteoporosis models. We reviewed preclinical and clinical studies of curcumin in preventing and alleviating osteoporosis. These results suggest that if subjected to rigorous pharmacological and clinical trials, naturally-derived curcumin could be used as a complementary and alternative medicine for the treatment of osteoporosis by targeting osteoporosis-related mechanistic pathways. This review summarizes the mechanisms of action and potential therapeutic applications of curcumin in the prevention and mitigation of osteoporosis and provides reference for further research and development of curcumin.

Lumican silencing ameliorates β-glycerophosphate-mediated vascular smooth muscle cell calcification by attenuating the inhibition of APOB on KIF2C activity

Adverse cardiovascular events are associated with vascular calcification (VC) process, where vascular smooth muscle cells (VSMCs) differentiate into osteoblastic phenotype and deposit hydroxyapatite crystals. Microtubule-associated protein kinesin family member 2C (KIF2C) expression is decreased obviously in VSMC during calcification induction. Accordingly, we investigate the role and potential mechanism of KIF2C on VSMC calcification. The effects of β-glycerophosphate (β-GP)/KIF2C/lumican (LUM) on calcification, calcium content, alkaline phosphatase (ALP) activity, calcification-related markers, Tubulin, the ratio of polymerized (Po) to free (Fr) tubulin, as well as levels of LUM, apolipoprotein B (APOB), and KIF2C were assessed by Alizarin red S staining, calcium assay kit, ALP assay kit, Western blot, immunofluorescence, and quantitative real-time PCR. The interplay between LUM and APOB was estimated using co-immunoprecipitation and immunofluorescence. As a result, β-GP promoted calcification of human VMSCs (HVMSCs) and repressed KIF2C expression. KIF2C overexpression reversed the effect of β-GP on HVSMCs. LUM silencing attenuated β-GP-induced promotion on HVSMC calcification and increased KIF2C expression by interacting with APOB. Collectively, LUM silencing can alleviate β-GP-induced VSMC calcification through mitigating the repression of APOB on KIF2C expression.

Revolutionizing bone regeneration: advanced biomaterials for healing compromised bone defects

In this review, we explore the application of novel biomaterial-based therapies specifically targeted towards craniofacial bone defects. The repair and regeneration of critical sized bone defects in the craniofacial region requires the use of bioactive materials to stabilize and expedite the healing process. However, the existing clinical approaches face challenges in effectively treating complex craniofacial bone defects, including issues such as oxidative stress, inflammation, and soft tissue loss. Given that a significant portion of individuals affected by traumatic bone defects in the craniofacial area belong to the aging population, there is an urgent need for innovative biomaterials to address the declining rate of new bone formation associated with age-related changes in the skeletal system. This article emphasizes the importance of semiconductor industry-derived materials as a potential solution to combat oxidative stress and address the challenges associated with aging bone. Furthermore, we discuss various material and autologous treatment approaches, as well as in vitro and in vivo models used to investigate new therapeutic strategies in the context of craniofacial bone repair. By focusing on these aspects, we aim to shed light on the potential of advanced biomaterials to overcome the limitations of current treatments and pave the way for more effective and efficient therapeutic interventions for craniofacial bone defects.

Silibinin Attenuates Experimental Periodontitis by Downregulation of Inflammation and Oxidative Stress

Periodontitis is an oral microbiota-induced inflammatory disease, in which inflammation and oxidative stress play a critical role. Silibinin (SB), a Silybum marianum-derived compound, exhibits strong anti-inflammatory and antioxidative properties. We adopted a rat ligature-induced periodontitis model and a lipopolysaccharide- (LPS-) stimulated human periodontal ligament cells (hPDLCs) model to evaluate the protective effects of SB. In the in vivo model, SB reduced alveolar bone loss and apoptosis of PDLCs in the periodontal tissue. SB also maintained the expression of nuclear factor-E2-related factor 2 (Nrf2), a key regulator of cellular resistance to oxidative stress, and attenuated lipid, protein, and DNA oxidative damages in the periodontal lesion area. Meanwhile, in the in vitro model, SB administration reduced the production of intracellular reactive oxidative species (ROS). Furthermore, SB exerted a strong anti-inflammatory property in both in vivo and in vitro models by inhibiting the expression of inflammatory mediators including nuclear factor-κB (NF-κB) as well as nucleotide binding oligomerization domain- (NOD-) like receptor family pyrin domain-containing 3 (NLRP3) and downregulating the levels of proinflammatory cytokines. This study, for the first time, demonstrates that SB exhibits the anti-inflammatory and antioxidative properties against periodontitis by downregulating the expression of NF-κB and NLRP3 and upregulating Nrf2 expression, suggesting a promising potential clinical application of SB in periodontitis.

Oxidative Stress and Inflammation in Osteoporosis: Molecular Mechanisms Involved and the Relationship with microRNAs

Osteoporosis is characterized by the alteration of bone homeostasis due to an imbalance between osteoclastic bone resorption and osteoblastic bone formation. Estrogen deficiency causes bone loss and postmenopausal osteoporosis, the pathogenesis of which also involves oxidative stress, inflammatory processes, and the dysregulation of the expression of microRNAs (miRNAs) that control gene expression at post-transcriptional levels. Oxidative stress, due to an increase in reactive oxygen species (ROS), proinflammatory mediators and altered levels of miRNAs enhance osteoclastogenesis and reduce osteoblastogenesis through mechanisms involving the activation of MAPK and transcription factors. The present review summarizes the principal molecular mechanisms involved in the role of ROS and proinflammatory cytokines on osteoporosis. Moreover, it highlights the interplay among altered miRNA levels, oxidative stress, and an inflammatory state. In fact, ROS, by activating the transcriptional factors, can affect miRNA expression, and miRNAs can regulate ROS production and inflammatory processes. Therefore, the present review should help in identifying targets for the development of new therapeutic approaches to osteoporotic treatment and improve the quality of life of patients.

Recent Trends in Hydroxyapatite Supplementation for Osteoregenerative Purposes

Bone regeneration has gained attention in the biomedical field, which has led to the development of materials and synthesis methods meant to improve osseointegration and cellular bone activity. The properties of hydroxyapatite, a type of calcium phosphate, have been researched to determine its advantages for bone tissue engineering, particularly its biocompatibility and ability to interact with bone cells. Recently, the advantages of utilizing nanomolecules of hydroxyapatite, combined with various substances, in order to enhance and combine their characteristics, have been reported in the literature. This review will outline the cellular and molecular roles of hydroxypatite, its interactions with bone cells, and its nano-combinations with various ions and natural products and their effects on bone growth, development, and bone repair.

Optineurin regulates NRF2-mediated antioxidant response in a mouse model of Paget's disease of bone

Degenerative diseases affecting the nervous and skeletal systems affect the health of millions of elderly people. Optineurin (OPTN) has been associated with numerous neurodegenerative diseases and Paget's disease of bone (PDB), a degenerative bone disease initiated by hyperactive osteoclastogenesis. In this study, we found age-related increase in OPTN and nuclear factor E2-related factor 2 (NRF2) in vivo. At the molecular level, OPTN could directly interact with both NRF2 and its negative regulator Kelch-like ECH-associated protein 1 (KEAP1) for up-regulating antioxidant response. At the cellular level, deletion of OPTN resulted in increased intracellular reactive oxygen species and increased osteoclastogenic potential. At the tissue level, deletion of OPTN resulted in substantially increased oxidative stress derived from leukocytes that further stimulate osteoclastogenesis. Last, curcumin attenuated hyperactive osteoclastogenesis induced by OPTN deficiency in aged mice. Collectively, our findings reveal an OPTN-NRF2 axis maintaining bone homeostasis and suggest that antioxidants have therapeutic potential for PDB.

Targeted inhibition of TXNRD1 prevents cartilage extracellular matrix degeneration by activating Nrf2 pathway in osteoarthritis

Osteoarthritis, a prevalent orthopedic disease, can affect the elderly and causes impairment. The degradation and aberrant homeostasis of cartilage extracellular matrix figure pivotally in the progression of osteoarthritis. Thioredoxin systems plays a role in a wide range of biological processes, including cell proliferation, apoptosis, and oxidative stress. The present study aimed to investigate the unique function and underlying pathophysiological mechanism of TXNRD1 in chondrocytes. An upregulated expression of TXNRD1 was observed in the articular cartilage of osteoarthritis patients compared with normal articular cartilage. Furthermore, in vitro experiments showed that the expression of TXNRD1 was also abnormally increased in IL-1β-induced primary mouse chondrocytes. Silencing TXNRD1 using siRNA in chondrocytes could effectively inhibit the expression of ADAMTS5 and MMP13, and enhance the expression of COL2A1 and SOX9. The same was true for auranofin, an inhibitor of TXNRD1. This phenomenon indicated that inhibition of TXNRD1 attenuated il-1β-induced metabolic imbalance of extracellular matrix (ECM) and the progression of chondrocyte osteoarthritis. Further mechanism analysis revealed that the activation of Nrf2 signaling pathway and the expression of heme oxygenase-1 (HO-1) were increased upon TXNRD1 inhibition. Furthermore, auranofin was found to attenuate DMM-induced osteoarthritis progression in vivo. Therefore, the pharmacological downregulation of TXNRD1 may provide an effective novel therapy for OA.

Curcumin Prevents Diabetic Osteoporosis through Promoting Osteogenesis and Angiogenesis Coupling via NF-κB Signaling

Diabetic osteoporosis (DOP) is a metabolic disease which is characterized by impaired bone microarchitecture and reduced bone mineral density resulting from hyperglycemia. Curcumin, an effective component extracted from Curcuma longa, exhibits antioxidation, regulation of bone metabolism and hypoglycemic effects. The BMSC-mediated osteogenesis and angiogenesis coupling seems to be important in bone formation and regeneration. We aimed to explore the effect of curcumin on BMSC-mediated osteogenesis-angiogenesis coupling in high glucose conditions and underlying mechanisms. Our results showed that high glucose impaired the osteogenic and proangiogenic ability of BMSCs and that curcumin pretreatment rescued the BMSC dysfunction induced by high-concentration glucose. Inhibition of the high glucose-activated NF-κB signaling pathway has been found to contribute to the protective effects of curcumin on high glucose-inhibited coupling of osteogenesis and angiogenesis in BMSCs. Furthermore, accelerated bone loss and decreased type H vessels were observed in diabetic osteoporosis mice models. However, curcumin treatment prevented bone loss and promoted vessel formation in diabetic osteoporosis mice. Based on these results, we concluded that curcumin ameliorated diabetic osteoporosis by recovering the osteogenesis and angiogenesis coupling of BMSCs in hyperglycemia, partly through inhibiting the high glucose-activated NF-κB signaling pathway.

MiR-125b-5p is targeted by curcumin to regulate the cellular antioxidant capacity

As a natural polyphenolic food supplement and the principal curcuminoid in turmeric, curcumin shows antioxidant, anti-inflammatory, and antitumor activities. However, its specific functional mechanism remains unclear. Our preliminary study indicated that miR-125b-5p was downregulated by a curcumin extract. This study aimed to determine whether miR-125b-5p is involved in the antioxidant regulation of curcumin. The results showed that miR-125b-5p overexpression had a pro-oxidant effect by reducing the cellular antioxidant capacity, as well as decreasing the activities of catalase (CAT) and superoxide dismutase (SOD) in the normal liver cell line LO2. However, miR-125b-5p repression significantly increased the cellular antioxidant capacity and enhanced the activities of CAT and SOD. Further investigation demonstrated that the cellular antioxidant capacity induced by curcumin extract was inhibited by miR-125b-5p overexpression. Thus, curcumin may exhibit antioxidant effects by repressing miR-125b-5p expression, which provides new insights into the molecular antioxidant mechanism of curcumin and other functional food components.

Evaluation of quaternization effect on chitosan-HAP composite for bone tissue engineering application

This study attempts to improve the aqueous solubility of chitosan and utilizes it in the fabrication of composites with hydroxyapatite (HAP). The composites were evaluated as a curcumin delivery vehicle for bone regeneration. The chitosan was modified by quaternization, with a quaternization degree of 5 % for low quaternized chitosan (LQC) and 11 % for high quaternized chitosan (HQC). The modified chitosan, at alkaline pH 11, facilitated in situ HAP growth and formed LQC-HAP and HQC-HAP composites. The quaternization weakens intermolecular hydrogen bonds, facilitates interaction with the apatite precursor ions and promotes the growth of HAP. The modification significantly improved drug encapsulation (2.6 fold) but at the cost of a slight decrease in mechanical strength and increase in drug release. The in vitro studies with human osteoblast-like MG-63 cells established that the curcumin-loaded composites, LQC-HAP-C and HQC-HAP-C are biocompatible, encourage proliferation and promote a 2-fold increase in calcium mineralization over drug-free composites. The study exemplifies the reciprocity between quaternization degree and drug load/release properties and also illustrates that the magnitude of the latter reflects bioactivity. Thus, the quaternized chitosan-based HAP composite with tailorable bio-physicochemical properties becomes an interesting drug delivery system in bone regeneration.

Resveratrol Attenuates High Glucose-Induced Osteoblast Dysfunction via AKT/GSK3β/FYN-Mediated NRF2 Activation

Osteoblast dysfunction, induced by high glucose (HG), negatively impacts bone homeostasis and contributes to the pathology of diabetic osteoporosis (DOP). One of the most widely recognized mechanisms for osteoblast dysfunction is oxidative stress. Resveratrol (RES) is a bioactive antioxidant compound to combat oxidative damage. However, its role in the protection of HG-induced osteoblast dysfunction has not been clarified. Therefore, our study aimed to explore potential regulatory mechanisms of RES for attenuating HG-induced osteoblast dysfunction. Our results showed that osteoblast dysfunction under HG condition was significantly ameliorated by RES via the activation of nuclear factor erythroid 2-related factor (NRF2) to suppress oxidative stress. Furthermore, using Nrf2-shRNA and wortmannin, we identified that activation of NRF2 via RES was regulated by the AKT/glycogen synthase kinase 3β (GSK3β)/FYN axis.

STK11 overexpression prevents glucocorticoid-induced osteoporosis via activating the AMPK/SIRT1/PGC1α axis

Osteoporosis (OP) is a frequent orthopedic disease characterized by pain, fractures and deformities. Glucocorticoids are the most common cause of secondary osteoporosis. Here, we aim to explore the function and mechanism of STK11 in glucocorticoid (GC)-induced OP. Human mesenchymal stromal cells (hMSCs) were differentiated under osteogenic or adipogenic culture medium. An in-vitro OP model was induced by dexamethasone (DEX). The viability, differentiation, apoptosis, and ROS level were evaluated for investigating the functions of SKT11 on hMSCs. The SIRT1 inhibitor EX-527, PGC1α inhibitor SR-18292, and AMPK activator metformin were administered into hMSCs for confirming the mechanism of SKT11. Our results showed that STK11 was down-regulated in OP tissues, as well as DEX-treated hMSCs. Overexpressing STK11 attenuated DEX-mediated inhibition of osteogenic differentiation and heightened the activation of the AMPK/SIRT1/PGC1α pathway, whereas STK11 knockdown exerted opposite effects. Inhibiting SIRT1 or PGC1α repressed the promotive effect of STK11 on osteogenic differentiation of hMSCs, while activation of AMPK abated the inhibitory effect of STK11 knockdown on osteogenic differentiation of hMSCs. In conclusion, this study revealed that overexpressing STK11 dampened GC-induced OP by activating the AMPK/SIRT1/PGC1α axis.

Traditional Chinese Medicine Compound-Loaded Materials in Bone Regeneration

Bone is a dynamic organ that has the ability to repair minor injuries via regeneration. However, large bone defects with limited regeneration are debilitating conditions in patients and cause a substantial clinical burden. Bone tissue engineering (BTE) is an alternative method that mainly involves three factors: scaffolds, biologically active factors, and cells with osteogenic potential. However, active factors such as bone morphogenetic protein-2 (BMP-2) are costly and show an unstable release. Previous studies have shown that compounds of traditional Chinese medicines (TCMs) can effectively promote regeneration of bone defects when administered locally and systemically. However, due to the low bioavailability of these compounds, many recent studies have combined TCM compounds with materials to enhance drug bioavailability and bone regeneration. Hence, the article comprehensively reviewed the local application of TCM compounds to the materials in the bone regeneration in vitro and in vivo. The compounds included icariin, naringin, quercetin, curcumin, berberine, resveratrol, ginsenosides, and salvianolic acids. These findings will contribute to the potential use of TCM compound-loaded materials in BTE.

Tanshinone I Mitigates Steroid-Induced Osteonecrosis of the Femoral Head and Activates the Nrf2 Signaling Pathway in Rats

Steroid-induced osteonecrosis of the femoral head (SIONFH) is a frequent orthopedic disease caused by long-term or high-dose administration of corticosteroids. Tanshinone I (TsI), a flavonoid compound isolated from Salvia miltiorrhiza Bunge, has been reported to inhibit osteoclastic differentiation in vitro. This study aimed to investigate whether TsI can ameliorate SIONFH. Herein, SIONFH was induced by intraperitoneal injection of 20 μg/kg lipopolysaccharide every 24 h for 2 days, followed by an intramuscular injection of 40 mg/kg methylprednisolone every 24 h for 3 days. Four weeks after the final injection of methylprednisolone, the rats were intraperitoneally administrated with low-dose (5 mg/kg) and high-dose (10 mg/kg) TsI once daily for 4 weeks. Results showed that TsI significantly alleviated osteonecrotic lesions of the femoral heads as determined by micro-CT analysis. Furthermore, TsI increased alkaline phosphatase activity and expressions of osteoblastic markers including osteocalcin, type I collagen, osteopontin, and Runt-related transcription factor 2 and decreased tartrate-resistant acid phosphatase activity and expressions of osteoclastic markers including cathepsin K and acid phosphatase 5. TsI also reduced inflammatory response and oxidative stress and activated the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway in the femoral heads. Taken together, our findings show that TsI can relieve SIONFH, indicating that it may be a candidate for preventing SIONFH.

Efficacy of nanomicelle curcumin, Nigella sativa oil, and their combination on bone turnover markers and their safety in postmenopausal women with primary osteoporosis and osteopenia: A triple-blind randomized controlled trial

Literature supports the potential effects of nanomicelle curcumin and Nigella sativa on the amelioration of osteoporosis, a health concern of postmenopausal women. This study aimed to evaluate the impacts of nanomicelle curcumin (CUR), Nigella sativa oil (NS), and their combination on bone turnover biomarkers and assess their safety. This triple-blind randomized controlled trial was performed on 120 postmenopausal women aged 50-65 with primary osteoporosis or osteopenia. The subjects were randomly allocated to receive microcrystalline cellulose (placebo), 80 mg of CUR, 1000 mg of NS, or their combination (CUR-NS) for 6 months. All patients were also treated with alendronate (70 mg) and calcium (500 mg), vitamin D (400 IU) supplements. The serum levels of alkaline phosphatase (ALP), osteocalcin (OC), and osteopontin (OP) were measured at the baseline and after the intervention. For safety assessment, the hepatic enzyme levels of aspartate transaminase and alanine transaminase as well as serum urea and creatinine were evaluated. ALP levels were significantly reduced in the NS (p = .029) and CUR-NS (p = .015) groups compared with those in the placebo. After adjustment for the covariates, this effect was still significant in the CUR-NS group (p = .004). The OC levels were decreased in the placebo, CUR, and NS groups, and the OP concentration also was attenuated in all groups through the trial. However, the intergroup differences were not significant for both biomarkers. Evaluating the key renal metabolites and hepatic enzyme levels indicated no toxicity of the administered doses. This study reveals the beneficial effects of CUR-NS on the improvement of some bone turnover biomarkers. These compounds seem to be safe at the current dosage for supplementation in postmenopausal women.

Nrf2 Regulation by Curcumin: Molecular Aspects for Therapeutic Prospects

Nuclear factor erythroid 2 p45-related factor (2Nrf2) is an essential leucine zipper protein (bZIP) that is primarily located in the cytoplasm under physiological conditions. Nrf2 principally modulates endogenous defense in response to oxidative stress in the brain.In this regard, Nrf2 translocates into the nucleus and heterodimerizes with the tiny Maf or Jun proteins. It then attaches to certain DNA locations in the nucleus, such as electrophile response elements (EpRE) or antioxidant response elements (ARE), to start the transcription of cytoprotective genes. Many neoplasms have been shown to have over activated Nrf2, strongly suggesting that it is responsible for tumors with a poor prognosis. Exactly like curcumin, Zinc-curcumin Zn (II)-curc compound has been shown to induce Nrf2 activation. In the cancer cell lines analyzed, Zinc-curcumin Zn (II)-curc compound can also display anticancer effects via diverse molecular mechanisms, including markedly increasing heme oxygenase-1 (HO-1) p62/SQSTM1 and the Nrf2 protein levels along with its targets. It also strikingly decreases the levels of Nrf2 inhibitor, Kelch-like ECH-associated protein 1 (Keap1) protein.As a result, the crosstalk between p62/SQSTM1 and Nrf2 could be used to improve cancer patient response to treatments. The interconnected anti-inflammatory and antioxidative properties of curcumin resulted from its modulatory effects on Nrf2 signaling pathway have been shown to improve insulin resistance. Curcumin exerts its anti-inflammatory impact through suppressing metabolic reactions and proteins such as Keap1 that provoke inflammation and oxidation. A rational amount of curcumin-activated antioxidant Nrf2 HO-1 and Nrf2-Keap1 pathways and upregulated the modifier subunit of glutamate-cysteine ligase involved in the production of the intracellular antioxidant glutathione. Enhanced expression of glutamate-cysteine ligase, a modifier subunit (GLCM), inhibited transcription of glutamate-cysteine ligase, a catalytic subunit (GCLC). A variety of in vivo, in vitro and clinical studies has been done so far to confirm the protective role of curcumin via Nrf2 regulation. This manuscript is designed to provide a comprehensive review on the molecular aspects of curcumin and its derivatives/analogs via regulation of Nrf2 regulation.

HO-1 in Bone Biology: Potential Therapeutic Strategies for Osteoporosis

Osteoporosis is a prevalent bone disorder characterized by bone mass reduction and deterioration of bone microarchitecture leading to bone fragility and fracture risk. In recent decades, knowledge regarding the etiological mechanisms emphasizes that inflammation, oxidative stress and senescence of bone cells contribute to the development of osteoporosis. Studies have demonstrated that heme oxygenase 1 (HO-1), an inducible enzyme catalyzing heme degradation, exhibits anti-inflammatory, anti-oxidative stress and anti-apoptosis properties. Emerging evidence has revealed that HO-1 is critical in the maintenance of bone homeostasis, making HO-1 a potential target for osteoporosis treatment. In this Review, we aim to provide an introduction to current knowledge of HO-1 biology and its regulation, focusing specifically on its roles in bone homeostasis and osteoporosis. We also examine the potential of HO-1-based pharmacological therapeutics for osteoporosis and issues faced during clinical translation.

Herbal Preparation (Bromelain, Papain, Curcuma, Black Pepper) Enhances Mineralization and Reduces Glucocorticoid-Induced Osteoporosis in Zebrafish

Natural foods with antioxidant properties, such as curcuma, papain, bromelain and black pepper, have been indicated as a potential natural therapeutic approach against osteoporosis. Zebrafish are an excellent animal model to study the effects of herbal preparations on osteogenesis and bone metabolism, both in physiological and in pathological conditions. Our study was aimed at evaluating whether curcuma-bromelain-papain-pepper herbal preparation (CHP) administered in embryos and adult fish is capable of promoting bone wellness in physiological and osteoporotic conditions. The effect of CHP has been studied in embryonic osteogenesis and glucocorticoid-induced osteoporosis (GIOP) in an adult fish model in which drug treatment induces a bone-loss phenotype in adult scales very similar to that which characterizes the bones of human patients. CHP prevented the onset of the osteoporotic phenotype in the scales of GIOP in adult zebrafish, with the osteoblastic and osteoclastic metabolic activity maintaining unaltered. CHP is also able to attenuate an already established GIOP phenotype, even if the alteration is in an advanced phase, partially restoring the normal balance of the bone markers alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP) and stimulating anabolic reparative processes. The results obtained indicated CHP as a potential integrative antioxidant therapy in human bone-loss diseases.

Notoginsenoside R1 attenuates oxidative stress-induced osteoblast dysfunction through JNK signalling pathway

Oxidative stress (OS)‐induced mitochondrial damage and the subsequent osteoblast dysfunction contributes to the initiation and progression of osteoporosis. Notoginsenoside R1 (NGR1), isolated from Panax notoginseng, has potent antioxidant effects and has been widely used in traditional Chinese medicine. This study aimed to investigate the protective property and mechanism of NGR1 on oxidative‐damaged osteoblast. Osteoblastic MC3T3‐E1 cells were pretreated with NGR1 24 h before hydrogen peroxide administration simulating OS attack. Cell viability, apoptosis rate, osteogenic activity and markers of mitochondrial function were examined. The role of C‐Jun N‐terminal kinase (JNK) signalling pathway on oxidative injured osteoblast and mitochondrial function was also detected. Our data indicate that NGR1 (25 μM) could reduce apoptosis as well as restore osteoblast viability and osteogenic differentiation. NGR1 also reduced OS‐induced mitochondrial ROS and restored mitochondrial membrane potential, adenosine triphosphate production and mitochondrial DNA copy number. NGR1 could block JNK pathway and antagonize the destructive effects of OS. JNK inhibitor (SP600125) mimicked the protective effects of NGR1while JNK agonist (Anisomycin) abolished it. These data indicated that NGR1 could significantly attenuate OS‐induced mitochondrial damage and restore osteogenic differentiation of osteoblast via suppressing JNK signalling pathway activation, thus becoming a promising agent in treating osteoporosis.

Antagonizing effects of curcumin against mercury-induced autophagic death and trace elements disorder by regulating PI3K/AKT and Nrf2 pathway in the spleen

Mercury is a naturally occurring element and highly toxic to humans even at a low dosage. Curcumin is a polyphenol found in turmeric (Curcuma longa), widely used as a treatment strategy to improve antioxidant and anti-inflammatory properties. The purpose of this study was to investigate the potential protective mechanisms of curcumin in spleen damage induced by HgCl₂. The mice were given curcumin by intragastric administration 2 h before HgCl₂ injection for 24 h. At first, splenic transcriptome analysis showed that 3334 genes (2134 up and 1200 down) were differently expressed in HgCl₂-induced spleen damage model. Notably, KEGG enrichment showed phosphatidylinositol 3-kinase (PI3K)-AKT might be a key signaling pathways in HgCl₂-induced spleen damage. Furthermore, our data demonstrated that HgCl₂ could induce autophagic cell death, evidenced by increases the protein expression of PI3K, AKT, LC3-II and p62 and the number of apoptotic cells. Furthermore, we found that curcumin significantly combated autophagic cell death, sodium overload and calcium leak induced by HgCl₂. Simultaneously, further studies demonstrated that curcumin significantly activated nuclear factor (erythroid-derived-2)-like 2 (Nrf2) signaling pathway, and subsequent enhancing antioxidant defenses. Taken together, our data indicated that inorganic mercury could result in autophagic cell death, which may be related to the regulation of PI3K-AKT signaling cascades. Furthermore, Nrf2-mediated antioxidant defenses may be the target of curcumin to confers an adaptive survival response to resist spleen damage induced by HgCl₂. The present study perfects the mechanism theory of HgCl₂-induced spleen damage and provides a way for pharmacological intervention to prevent spleen injury.

The effect of nanomicelle curcumin supplementation and Nigella sativa oil on the expression level of miRNA-21, miRNA-422a, and miRNA-503 gene in postmenopausal women with low bone mass density: A randomized, triple-blind, placebo-controlled clinical trial with factorial design

This study aimed to investigate the effect of nanomicelle curcumin (CUR), Nigella sativa oil (NS), and CUR and NS on the plasma levels of miR-21, miR-422a, and miR-503 expression in postmenopausal women with low bone mass density (BMD). This randomized, triple-blind, placebo-controlled clinical trial with a factorial design was conducted on 120 postmenopausal women from the integrated healthcare system, Tabriz-Iran. The BMD was determined using dual-energy X-ray absorptiometry (DEXA). Women were randomly divided into four groups of 30 participants: (a) CUR (80 mg) and placebo of NS, (b) NS (1,000 mg) and placebo of CUR, (c) CUR (80 mg) and NS (1,000 mg), and (d) both placebos (containing microcrystalline cellulose). The plasma level of miRNA-21, miRNA-422a, and miRNA-503 was determined by qRT-PCR. The expression level of miRNAs at the baseline was similar. At the end of the intervention, only the expression level of miRNA-21 changed statistically significantly between the four groups (p = .037) and between the NS and placebo groups (p = .005). Also, its expression in the two groups receiving NS (p = .037) and NS-CUR (p = .043) was significantly increased. NS and NS-CUR supplementation can increase the expression level of miRNA-21 in postmenopausal women with low bone density, and bring perspective to further studies of the target.

Role of Exosomal MicroRNAs and Their Crosstalk with Oxidative Stress in the Pathogenesis of Osteoporosis

Osteoporosis (OP) is an aging-related disease involving permanent bone tissue atrophy. Most patients with OP show high levels of oxidative stress (OS), which destroys the microstructure of bone tissue and promotes disease progression. Exosomes (exos) help in the delivery of microRNAs (miRNAs) and allow intercellular communication. In OP, exosomal miRNAs modulate several physiological processes, including the OS response. In the present review, we aim to describe how exosomal miRNAs and OS contribute to OP. We first summarize the relationship of OS with OP and then detail the features of exos along with the functions of exo-related miRNAs. Further, we explore the interplay between exosomal miRNAs and OS in OP and summarize the functional role of exos in OP. Finally, we identify the advantages of exo-based miRNA delivery in treatment strategies for OP. Our review seeks to improve the current understanding of the mechanism underlying OP pathogenesis and lay the foundation for the development of novel theranostic approaches for OP.

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.

Non-flavonoid polyphenols in osteoporosis: preclinical evidence

The development of progressive osteopenia and osteoporosis (OP) is due to the imbalance between bone resorption and bone formation, determining a lower bone resistance, major risks of fractures, with consequent pain and functional limitations. Flavonoids, a class of polyphenols, have been extensively studied for their therapeutic activities against bone resorption, but less attention has been given to a whole series of molecules belonging to the polyphenolic compounds. However, these classes have begun to be studied for the treatment of OP. In this systematic review, comprehensive information is provided on non-flavonoid polyphenolic compounds, and we highlight pathways implicated in the action of these molecules that act often epigenetically, and their possible use for OP treatment and prevention.

Anti-Viral Potential and Modulation of Nrf2 by Curcumin: Pharmacological Implications

Nuclear factor erythroid 2-related factor 2 (Nrf2) is an essential transcription factor that maintains the cell's redox balance state and reduces inflammation in different adverse stresses. Under the oxidative stress, Nrf2 is separated from Kelch-like ECH-associated protein 1 (Keap1), which is a key sensor of oxidative stress, translocated to the nucleus, interacts with the antioxidant response element (ARE) in the target gene, and then activates the transcriptional pathway to ameliorate the cellular redox condition. Curcumin is a yellow polyphenolic curcuminoid from Curcuma longa (turmeric) that has revealed a broad spectrum of bioactivities, including antioxidant, anti-inflammatory, anti-tumor, and anti-viral activities. Curcumin significantly increases the nuclear expression levels and promotes the biological effects of Nrf2 via the interaction with Cys151 in Keap1, which makes it a marvelous therapeutic candidate against a broad range of oxidative stress-related diseases, including type 2 diabetes (T2D), neurodegenerative diseases (NDs), cardiovascular diseases (CVDs), cancers, viral infections, and more recently SARS-CoV-2. Currently, the multifactorial property of the diseases and lack of adequate medical treatment, especially in viral diseases, result in developing new strategies to finding potential drugs. Curcumin potentially opens up new views as possible Nrf2 activator. However, its low bioavailability that is due to low solubility and low stability in the physiological conditions is a significant challenge in the field of its efficient and effective utilization in medicinal purposes. In this review, we summarized recent studies on the potential effect of curcumin to activate Nrf2 as the design of potential drugs for a viral infection like SARS-Cov2 and acute and chronic inflammation diseases in order to improve the cells' protection.