The Potential Role of Curcumin in Modulating the Master Antioxidant Pathway in Diabetic Hypoxia-Induced Complications

Multifaceted physiological and therapeutical impact of curcumin on hormone-related endocrine dysfunctions: A comprehensive review

Over the past five decades, Curcumin (Cur), derived from turmeric (Curcuma longa), has gained considerable attention for its potential therapeutic applications. Synthesizing insights from clinical trials conducted over the last 25 years, this review delves into diseases where Cur has demonstrated promise, offering a nuanced understanding of its pharmacokinetics, safety, and effectiveness. Focusing on specific examples, the impact of Cur on various human diseases is explored. Endocrine glands and associated signaling pathways are highlighted, elucidating how Cur influences cellular signaling. The article underscores molecular mechanisms such as hormone level alteration, receptor interaction, cytokine and adipokine expression inhibition, antioxidant enzyme activity, and modulation of transcription factors. Cur showcases diverse protective mechanisms against inflammation and oxidative damage by suppressing antiapoptotic genes and impeding tumor promotion. This comprehensive overview emphasizes the potential of Cur as a natural agent for countering aging and degenerative diseases, calling for further dedicated research in this realm.

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.

Rhodiola crenulata alleviates hypobaric hypoxia-induced brain injury by maintaining BBB integrity and balancing energy metabolism dysfunction

BACKGROUND/PURPOSE

Rhodiola crenulata (Hook. f. et Thoms.) H. Ohba (R. crenulate), a famous and characteristic Tibetan medicine, has been demonstrated to exert an outstanding brain protection role in the treatment of high-altitude hypoxia disease. However, the metabolic effects of R. crenulate on high-altitude hypoxic brain injury (HHBI) are still incompletely understood. Herein, the anti-hypoxic effect and associated mechanisms of R. crenulate were explored through both in vivo and in vitro experiments.

STUDY DESIGN/METHODS

The mice model of HHBI was established using an animal hypobaric and hypoxic chamber. R. crenulate extract (RCE, 0.5, 1.0 and 2.0 g/kg) and salidroside (Sal, 25, 50 and 100 mg/kg) was given by gavage for 7 days. Pathological changes and neuronal apoptosis of mice hippocampus and cortex were evaluated using H&E and TUNEL staining, respectively. The effects of RCE and Sal on the permeability of blood brain barrier (BBB) were detected by Evans blue staining and NIR-II fluorescence imaging. Meanwhile, the ultrastructural BBB and cerebrovascular damages were observed using a transmission electron microscope (TEM). The levels of tight junction proteins Claudin-1, ZO-1 and occludin were detected by immunofluorescence. Additionally, the metabolites in mice serum and brain were determined using UHPLC-MS and MALDI-MSI analysis. The cell viability of Sal on hypoxic HT22 cells induced by CoCl2 was investigated by cell counting kit-8. The contents of LDH, MDA, SOD, GSH-PX and SDH were detected by using commercial biochemical kits. Meanwhile, intracellular ROS, Ca2+ and mitochondrial membrane potential were determined by corresponding specific labeled probes. The intracellular metabolites of HT22 cells were performed by the targeted metabolomics analysis of the Q300 kit. The cell apoptosis and necrosis were examined by YO-PRO-1/PI, Annexin V/PI and TUNEL staining. In addition, mitochondrial morphology was tested by Mito-tracker red with confocal microscopy and TEM. Real-time ATP production, oxygen consumption rate, and proton efflux rate were measured using a Seahorse analyzer. Subsequently, MCU, OPA1, p-Drp1ser616, p-AMPKα, p-AMPKβ and Sirt1 were determined by immunofluorescent and western blot analyses.

RESULTS

The results demonstrated that R. crenulate and Sal exert anti-hypoxic brain protection from inhibiting neuronal apoptosis, maintaining BBB integrity, increasing tight junction protein Claudin-1, ZO-1 and occludin and improving mitochondrial morphology and function. Mechanistically, R. crenulate and Sal alleviated HHBI by enhancing the tricarboxylic acid cycle to meet the demand of energy of brain. Additionally, experiments in vitro confirmed that Sal could ameliorate the apoptosis of HT22 cells, improve mitochondrial morphology and energy metabolism by enhancing mitochondrial respiration and glycolysis. Meanwhile, Sal-mediated MCU inhibited the activation of Drp1 and enhanced the expression of OPA1 to maintain mitochondrial homeostasis, as well as activation of AMPK and Sirt1 to enhance ATP production.

CONCLUSION

Collectively, the findings suggested that RCE and Sal may afford a protective intervention in HHBI through maintaining BBB integrity and improving energy metabolism via balancing MCU-mediated mitochondrial homeostasis by activating the AMPK/Sirt1 signaling pathway.

Advancements in Dermatological Applications of Curcumin: Clinical Efficacy and Mechanistic Insights in the Management of Skin Disorders

Curcumin, derived from Curcuma longa (turmeric), exhibits significant potential in dermatology, addressing conditions like atopic dermatitis, psoriasis, chronic wounds, skin cancer, and infections through its anti-inflammatory, antioxidant, anticancer, and antimicrobial properties. This review synthesizes evidence on curcumin's mechanisms, including modulation of immune responses and promotion of wound healing, showcasing its efficacy in reducing inflammation, cytokine levels, and enhancing skin barrier functions. Studies highlight curcumin's ability to selectively target tumor cells, suggesting a multifaceted approach to cancer therapy with minimal side effects. Despite promising therapeutic benefits, challenges remain in bioavailability, potency, and targeted delivery, underscoring the need for further research to optimize dosages, delivery methods, and assess long-term safety. The integration of curcumin into dermatological practice requires a balanced consideration of evidence-based efficacy and safety. Curcumin's comprehensive utility in dermatology, coupled with the necessity for advanced scientific exploration, emphasizes the importance of combining traditional knowledge with contemporary research to improve patient care in dermatology. This approach could significantly enhance outcomes for individuals with skin-related conditions, marking curcumin as a versatile and promising agent in the field.

Effects of hypoxia in the diabetic corneal stroma microenvironment

Corneal dysfunctions associated with Diabetes Mellitus (DM), termed diabetic keratopathy (DK), can cause impaired vision and/or blindness. Hypoxia affects both Type 1 (T1DM) and Type 2 (T2DM) surprisingly, the role of hypoxia in DK is unexplored. The aim of this study was to examine the impact of hypoxia in vitro on primary human corneal stromal cells derived from Healthy (HCFs), and diabetic (T1DMs and T2DMs) subjects, by exposing them to normoxic (21% O2) or hypoxic (2% O2) conditions through 2D and 3D in vitro models. Our data revealed that hypoxia affected T2DMs by slowing their wound healing capacity, leading to significant alterations in oxidative stress-related markers, mitochondrial health, cellular homeostasis, and endoplasmic reticulum health (ER) along with fibrotic development. In T1DMs, hypoxia significantly modulated markers related to membrane permeabilization, oxidative stress via apoptotic marker (BAX), and protein degradation. Hypoxic environment induced oxidative stress (NOQ1 mediated reduction of superoxide in T1DMs and Nrf2 mediated oxidative stress in T2DMs), modulation in mitochondrial health (Heat shock protein 27 (HSP27), and dysregulation of cellular homeostasis (HSP90) in both T1DMs and T2DMs. This data underscores the significant impact of hypoxia on the diabetic cornea. Further studies are warranted to delineate the complex interactions.

Redox Homeostasis and Nrf2-Regulated Mechanisms Are Relevant to Male Infertility

Infertility represents a significant global health challenge, affecting more than 12% of couples worldwide, and most cases of infertility are caused by male factors. Several pathological pathways are implicated in male infertility. The main mechanisms involved are driven by the loss of reduction-oxidation (redox) homeostasis and the resulting oxidative damage as well as the chronic inflammatory process. Increased or severe oxidative stress leads to sperm plasma membrane and DNA oxidative damage, dysregulated RNA processing, and telomere destruction. The signaling pathways of these molecular events are also regulated by Nuclear factor-E2-related factor 2 (Nrf2). The causes of male infertility, the role of oxidative stress in male infertility and the Keap1-Nrf2 antioxidant pathway are reviewed. This review highlights the regulatory role of Nrf2 in the balance between oxidants and antioxidants as relevant mechanisms to male fertility. Nrf2 is involved in the regulation of spermatogenesis and sperm quality. Establishing a link between Nrf2 signaling pathways and the regulation of male fertility provides the basis for molecular modulation of inflammatory processes, reactive oxygen species generation, and the antioxidant molecular network, including the Nrf2-regulated antioxidant response, to improve male reproductive outcomes.

Characterization of prevalent tyrosine kinase inhibitors and their challenges in glioblastoma treatment

Glioblastoma multiforme (GBM) is a highly aggressive malignant primary tumor in the central nervous system. Despite extensive efforts in radiotherapy, chemotherapy, and neurosurgery, there remains an inadequate level of improvement in treatment outcomes. The development of large-scale genomic and proteomic analysis suggests that GBMs are characterized by transcriptional heterogeneity, which is responsible for therapy resistance. Hence, knowledge about the genetic and epigenetic heterogeneity of GBM is crucial for developing effective treatments for this aggressive form of brain cancer. Tyrosine kinases (TKs) can act as signal transducers, regulate important cellular processes like differentiation, proliferation, apoptosis and metabolism. Therefore, TK inhibitors (TKIs) have been developed to specifically target these kinases. TKIs are categorized into allosteric and non-allosteric inhibitors. Irreversible inhibitors form covalent bonds, which can lead to longer-lasting effects. However, this can also increase the risk of off-target effects and toxicity. The development of TKIs as therapeutics through computer-aided drug design (CADD) and bioinformatic techniques enhance the potential to improve patients' survival rates. Therefore, the continued exploration of TKIs as drug targets is expected to lead to even more effective and specific therapeutics in the future.

Combination of curcumin and catalase protects against chondrocyte injury and knee osteoarthritis progression by suppressing oxidative stress

Knee Osteoarthritis (KOA) is an age-related progressive degenerative joint disease, which is featured with pain, joint deformity, and disability. Accumulating evidence indicated oxidative stress plays a crucial role in the occurrence and development of KOA. Curcumin is a polyphenolic compound with significant antioxidant activity among various diseases while catalase (CAT) is an enzyme degrading hydrogen peroxide in treating oxidative diseases. We previously showed that the expression of CAT was low in cartilage. However, the combination of curcumin and CAT in KOA is still elusive. In this study, we demonstrated that the combination of curcumin and CAT has the potential to inhibit the IL1β-induced chondrocyte apoptosis without cytotoxicity in vitro. Mechanistically, we found that the synergistic application curcumin and CAT not only promotes curcumin's regulation of the NRF2/HO-1 signaling pathway to enhance antioxidant enzyme expression to remove superoxide radicals, but also CAT can further remove downstream hydrogen peroxide which enhances the ability to scavenge reactive oxygen species (ROS). In vivo, studies revealed that combination of curcumin and catalase could better inhibit oxidative stress-induced chondrocyte injury by promoting the expression of ROS scavenging enzymes. In sum, the combination of curcumin and catalase can be used to treat KOA. Thus, combination of curcumin and catalase may act as a novel therapeutic agent to manage KOA and our research gives a rationale for their combined use in the therapeutic of KOA.

Analysis of MsTERT Gene Expression Profile in Alfalfa (Medicago sativa) Indicates Their Response to Abiotic Stress and Seed Aging

Seed aging is always taken as a crucial factor for vigor loss due to delayed seed germination and seedling growth, which limits hay production. Many studies have found that telomeres are closely related to abiotic stress and seed vigor. However, the molecular mechanism of telomeres' response to abiotic stress, seed vigor, and the maintenance mechanism of plant telomere homeostasis still remain unclear. Alfalfa (Medicago sativa) enjoys the title of "King of Forage", and is an important protein forage for the dairy industry as planted in the world. This comprehensive investigation was performed to explore the molecular characterization, phylogenetic relationship, and gene expression analysis of MsTERT under abiotic stress and during seed aging in alfalfa. In this study, MsTERT was identified from the 'Zhongmu 1' alfalfa genome and encoded a coding sequence (CDS) of 3615 bp in length, consisting of telomerase- RNA-Binding Domain (RBD) and Reverse Transcriptase (RT) domains, 1024 amino acids, an isoelectric point of 9.58, and a relative molecular mass of 138.94 kD. Subcellular localization showed that MsTERT was mainly localized in the nucleus and mitochondria. The results of the expression profile showed that MsTERT was observed to respond to various stress conditions such as salt (100 mmol/L NaCl) and drought (20% PEG 6000). Furthermore, exogenous hormones IAA, ABA, and GA3 showed the potential to affect MsTERT expression. Additionally, MsTERT also responded to seed aging. Our results revealed a marginal but significant association between relative telomere length, MsTERT expression, and seed germination percentage, suggesting that the length of telomeres was shortened, and expression of MsTERT decreased with alfalfa seed aged. These results provide some evidence for the hypothesis of relative telomere length and/or TERT expression serving as biomarkers of seed aging. Although this finding is helpful to offer a new way to elucidate the molecular mechanism of vigor loss in alfalfa seed, further investigation is required to elucidate the molecular mechanism by which the MsTERT gene regulates seed vigor.

Curcumin: Overview of Extraction Methods, Health Benefits, and Encapsulation and Delivery Using Microemulsions and Nanoemulsions

Curcumin is the principal curcuminoid found in the rhizomes of turmeric. Due to its therapeutic action against cancer, depression, diabetes, some bacteria, and oxidative stress, it has been used widely in medicine since ancient times. Due to its low solubility, the human organism cannot completely absorb it. Advanced extraction technologies, followed by encapsulation in microemulsion and nanoemulsion systems, are currently being used to improve bioavailability. This review discusses the different methods available for curcumin extraction from plant material, methods for the identification of curcumin in the resulting extracts, its beneficial effects on human health, and the encapsulation techniques into small colloidal systems that have been used over the past decade to deliver this compound.

Modulation of Nrf2/HO-1 by Natural Compounds in Lung Cancer

Oxidative stresses (OSs) are considered a pivotal factor in creating various pathophysiological conditions. Cells have been able to move forward by modulating numerous signaling pathways to moderate the defects of these stresses during their evolution. The company of Kelch-like ECH-associated protein 1 (Keap1) as a molecular sensing element of the oxidative and electrophilic stress and nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2) as a master transcriptional regulator of the antioxidant response makes a master cytoprotective antioxidant pathway known as the Keap1/Nrf2 pathway. This pathway is considered a dual-edged sword with beneficial features for both normal and cancer cells by regulating the gene expression of the array of endogenous antioxidant enzymes. Heme oxygenase-1 (HO-1), a critical enzyme in toxic heme removal, is one of the clear state indicators for the duality of this pathway. Therefore, Nrf2/HO-1 axis targeting is known as a novel strategy for cancer treatment. In this review, the molecular mechanism of action of natural antioxidants on lung cancer cells has been investigated by relying on the Nrf2/HO-1 axis.

Curcuma aromatica Salisb. Protects from Acetaminophen-Induced Hepatotoxicity by Regulating the Sirt1/HO-1 Signaling Pathway

Acetaminophen (APAP) overdose-induced hepatotoxicity reduces the activity of sirtuin-1 (Sirt1) along with heme oxygenase 1 (HO-1) and promotes inflammatory responses and oxidative stress. Although the extract of Curcuma aromatica Salisb. (CAS) possesses hepatoprotective properties, scientific evidence on whether CAS prevents hepatotoxicity and the underlying molecular mechanisms are lacking. Here, we hypothesized that CAS ameliorates hepatotoxicity by inhibiting inflammation and oxidative stress via Sirt1/HO-1 signaling. CAS pretreatment at doses of 200 and 400 μg/mL significantly increased cell viability in APAP-treated primary hepatocytes. The expression of inducible nitric oxide synthase (iNOS) substantially increased after APAP treatment; however, this expression significantly decreased in cells pretreated with 100, 200, and 400 µg/mL CAS. CAS increased Sirt1 and HO-1 levels in APAP-treated hepatocytes in a dose-dependent manner. When CAS was orally administered to mice at doses of 20 or 100 mg/kg for 7 days, the APAP-induced increase in serum aspartate aminotransferase and alanine aminotransferase levels was inhibited. Moreover, CAS decreased IL-6, TNF-α, and IL-1β, increased IL-10, suppressed ROS generation, increased glutathione levels, inhibited iNOS and cyclooxygenase-2, and enhanced Sirt1 and HO-1 in the mouse model of APAP-induced hepatotoxicity. These findings suggest that CAS could be used as a natural hepatoprotective drug to treat APAP-induced injury.

The Effect of Curcumin Nanoparticles on Paracetamol-induced Liver Injury in Male Wistar Rats

INTRODUCTION

Curcumin is a naturally occurring compound that has antioxidant properties, acts as a hepatoprotective, and lowers lipid peroxidation. However, curcumin's low solubility and bioavailability are its primary drawbacks and prevent its use as a therapeutic agent. In this study, curcumin nanoparticles will be created using the ultrasonic-assisted extraction method, and their effectiveness against paracetamol-induced changes in ALT, AST, SOD, MDA, and TNF-α will be compared to that of pure curcumin.

PURPOSE

This study aimed to determine the hepatoprotective effect of curcumin nanoparticles in paracetamol- induced rats as a model for liver injury.

METHODS

Thirty-six male Wistar rats, aged 6 to 8 weeks, with a minimum weight of 120 grams, were used in an experimental laboratory investigation with a post-test-only group design. Rats in each group received 100 mg/kgBW pure curcumin, 100 mg/kgBW curcumin nanoparticles, and 50 mg/kgBW curcumin nanoparticles for 7 days before paracetamol induction. On day 8, 300 mg/kgBW of paracetamol was intraperitoneally injected to cause liver damage. One of the groups received NAC as an antidote 10 hours after paracetamol induction. Detection of ALT and AST using a Chemistry Analyzer. ELISA approach for the detection of SOD, MDA, and TNF-α. The Roenigk score was calculated by two examiners after the liver histopathology preparations were stained using the Hematoxylin-Eosin method. Post hoc analyses were performed after the One Way Annova and Kruskal Wallis tests to examine the data.

RESULTS

According to PSA results, the smallest formula that formed curcumin nanoparticles (10.2 nm) was 8 g of curcumin formula mixed with a mixture of Tween 20 4.5 ml, Kolliphor EL 1.5 ml, Propylene Glycol 1.5 ml, and Capryol 90 1 ml for 21 minutes using an ultrasonic process. MDA and TNF-α levels, as well as the liver's histological Roenigk score, were significantly lower in the 100 mg/kgBB pure curcumin group (C100) when compared to the model group (model). The levels of AST, MDA, TNF-α, and the liver histopathology score were significantly lower in the 100 mg/kgBB (NC100) and 50 mg/kgBB (NC50) curcumin nanoparticle groups compared to the model group (model) and pure curcumin group (C100) (p< 0.05).

CONCLUSION

Curcumin nanoparticles showed better hepatoprotective ability than pure curcumin.

Nrf2 Modulation in Breast Cancer

Reactive oxygen species (ROS) are identified to control the expression and activity of various essential signaling intermediates involved in cellular proliferation, apoptosis, and differentiation. Indeed, ROS represents a double-edged sword in supporting cell survival and death. Many common pathological processes, including various cancer types and neurodegenerative diseases, are inflammation and oxidative stress triggers, or even initiate them. Keap1-Nrf2 is a master antioxidant pathway in cytoprotective mechanisms through Nrf2 target gene expression. Activation of the Nfr2 pathway benefits cells in the early stages and reduces the level of ROS. In contrast, hyperactivation of Keap1-Nrf2 creates a context that supports the survival of both healthy and cancerous cells, defending them against oxidative stress, chemotherapeutic drugs, and radiotherapy. Considering the dual role of Nrf2 in suppressing or expanding cancer cells, determining its inhibitory/stimulatory position and targeting can represent an impressive role in cancer treatment. This review focused on Nrf2 modulators and their roles in sensitizing breast cancer cells to chemo/radiotherapy agents.

Action Sites and Clinical Application of HIF-1α Inhibitors

Hypoxia-inducible factor-1α (HIF-1α) is widely distributed in human cells, and it can form different signaling pathways with various upstream and downstream proteins, mediate hypoxia signals, regulate cells to produce a series of compensatory responses to hypoxia, and play an important role in the physiological and pathological processes of the body, so it is a focus of biomedical research. In recent years, various types of HIF-1α inhibitors have been designed and synthesized and are expected to become a new class of drugs for the treatment of diseases such as tumors, leukemia, diabetes, and ischemic diseases. This article mainly reviews the structure and functional regulation of HIF-1α, the modes of action of HIF-1α inhibitors, and the application of HIF-1α inhibitors during the treatment of diseases.

Protective Effect of Curcumin, Chrysin and Thymoquinone Injection on Trastuzumab-Induced Cardiotoxicity via Mitochondrial Protection

Mitochondrial dysfunction may lead to cardiomyocyte death in trastuzumab (TZM)-induced cardiotoxicity. Accordingly, this study was designed to evaluate the mitochondrial protective effects of curcumin, chrysin and thymoquinone alone in TZM-induced cardiotoxicity in the rats. Forty-eight male adult Wistar rats were divided into eight groups: control group (normal saline), TZM group (2.5 mg/kg I.P. injection, daily), TZM + curcumin group (10 mg/kg, I.P. injection, daily), TZM + chrysin (10 mg/kg, I.P. injection, daily), TZM + thymoquinone (0.5 mg/kg, I.P. injection, daily), curcumin group (10 mg/kg, I.P. injection, daily), chrysin group (10 mg/kg, I.P. injection, daily) and thymoquinone group (10 mg/kg, I.P. injection, daily). Blood and tissue were collected on day 11 and used for assessment of creatine phosphokinase, lactate dehydrogenase (LDH), troponin, malondialdehyde (MDA) amount, glutathione levels and mitochondrial toxicity parameters. TZM increased mitochondrial impairments (reactive oxygen species formation, mitochondrial swelling, mitochondrial membrane potential collapse and decline in succinate dehydrogenase activity) and histopathological alterations (hypertrophy, enlarged cell, disarrangement, myocytes degeneration, infiltration of fat in some areas, hemorrhage and focal vascular thrombosis) in rat heart. As well as TZM produced a significant increase in the level of CK, LDH, troponin, MDA, glutathione disulfide. In most experiments, the co-injection of curcumin, chrysin and thymoquinone with TZM restored the level of CK, LDH, troponin, MDA, GSH, mitochondrial impairments and histopathological alterations. The study revealed the cardioprotective effects of curcumin, chrysin and thymoquinone against TZM-induced cardiotoxicity which could be attributed to their antioxidant and mitochondrial protection activities.