Superior Bioavailability of a Novel Curcumin Formulation in Healthy Humans Under Fasting Conditions

Curcumin as a potential therapeutic agent for treating neurodegenerative diseases

Neurodegenerative diseases are characterized by the progressive loss of neuronal structure and function, posing a tremendous burden on health systems worldwide. Although the underlying pathological mechanisms for various neurodegenerative diseases are still unclear, a common pathological hallmark is the abundance of neuroinflammatory processes, which affect both disease onset and progression. In this review, we explore the pathways and role of neuroinflammation in various neurodegenerative diseases and further assess the potential use of curcumin, a natural spice with antioxidant and anti-inflammatory properties that has been extensively used worldwide as a traditional medicine and potential therapeutic agent. Following the examination of preclinical and clinical studies that assessed curcumin as a potential therapeutic agent, we highlight the bioavailability of curcumin in the body and discuss both the challenges and benefits of using curcumin as a therapeutic compound for treating neurodegeneration. Although elucidating the involvement of curcumin in aging and neurodegeneration has great potential for developing future CNS-related therapeutic targets, further research is required to elucidate the mechanisms by which Curcumin affects brain physiology, especially BBB integrity, under both physiological and disease conditions.

Innovative Delivery Systems for Curcumin: Exploring Nanosized and Conventional Formulations

Curcumin, a polyphenol with a rich history spanning two centuries, has emerged as a promising therapeutic agent targeting multiple signaling pathways and exhibiting cellular-level activities that contribute to its diverse health benefits. Extensive preclinical and clinical studies have demonstrated its ability to enhance the therapeutic potential of various bioactive compounds. While its reported therapeutic advantages are manifold, predominantly attributed to its antioxidant and anti-inflammatory properties, its efficacy is hindered by poor bioavailability stemming from inadequate absorption, rapid metabolism, and elimination. To address this challenge, nanodelivery systems have emerged as a promising approach, offering enhanced solubility, biocompatibility, and therapeutic effects for curcumin. We have analyzed the knowledge on curcumin nanoencapsulation and its synergistic effects with other compounds, extracted from electronic databases. We discuss the pharmacokinetic profile of curcumin, current advancements in nanoencapsulation techniques, and the combined effects of curcumin with other agents across various disorders. By unifying existing knowledge, this analysis intends to provide insights into the potential of nanoencapsulation technologies to overcome constraints associated with curcumin treatments, emphasizing the importance of combinatorial approaches in improving therapeutic efficacy. Finally, this compilation of study data aims to inform and inspire future research into encapsulating drugs with poor pharmacokinetic characteristics and investigating innovative drug combinations to improve bioavailability and therapeutic outcomes.

Calebin A modulates inflammatory and autophagy signals for the prevention and treatment of osteoarthritis

Introduction

Osteoarthritis (OA) is associated with excessive cartilage degradation, inflammation, and decreased autophagy. Insufficient efficacy of conventional monotherapies and poor tissue regeneration due to side effects are just some of the unresolved issues. Our previous research has shown that Calebin A (CA), a component of turmeric (Curcuma longa), has pronounced anti-inflammatory and anti-oxidative effects by modulating various cell signaling pathways. Whether CA protects chondrocytes from degradation and apoptosis in the OA environment (EN), particularly via the autophagy signaling pathway, is however completely unclear.

Methods

To study the anti-degradative and anti-apoptotic effects of CA in an inflamed joint, an in vitro model of OA-EN was created and treated with antisense oligonucleotides targeting NF-κB (ASO-NF-κB), and IκB kinase (IKK) inhibitor (BMS-345541) or the autophagy inhibitor 3-methyladenine (3-MA) and/or CA to affect chondrocyte proliferation, degradation, apoptosis, and autophagy. The mechanisms underlying the CA effects were investigated by MTT assays, immunofluorescence, transmission electron microscopy, and Western blot analysis in a 3D-OA high-density culture model.

Results

In contrast to OA-EN or TNF-α-EN, a treatment with CA protects chondrocytes from stress-induced defects by inhibiting apoptosis, matrix degradation, and signaling pathways associated with inflammation (NF-κB, MMP9) or autophagy-repression (mTOR/PI3K/Akt), while promoting the expression of matrix compounds (collagen II, cartilage specific proteoglycans), transcription factor Sox9, and autophagy-associated proteins (Beclin-1, LC3). However, the preventive properties of CA in OA-EN could be partially abrogated by the autophagy inhibitor 3-MA.

Discussion

The present results reveal for the first time that CA is able to ameliorate the progression of OA by modulating autophagy pathway, inhibiting inflammation and apoptosis in chondrocytes, suggesting that CA may be a novel therapeutic compound for OA.

Therapeutic potential and limitations of curcumin as antimetastatic agent

Treatment of metastatic cancer is one of the biggest challenges in anticancer therapy. Curcumin is interesting nature polyphenolic compound with unique biological and medicinal effects, including repression of metastases. High impact studies imply that curcumin can modulate the immune system, independently target various metastatic signalling pathways, and repress migration and invasiveness of cancer cells. This review discusses the potential of curcumin as an antimetastatic agent and describes potential mechanisms of its antimetastatic activity. In addition, possible strategies (curcumin formulation, optimization of the method of administration and modification of its structure motif) to overcome its limitation such as low solubility and bioactivity are also presented. These strategies are discussed in the context of clinical trials and relevant biological studies.

Role of Turmeric and Curcumin in Prevention and Treatment of Chronic Diseases: Lessons Learned from Clinical Trials

Turmeric (Curcuma longa) has been used for thousands of years for the prevention and treatment of various chronic diseases. Curcumin is just one of >200 ingredients in turmeric. Almost 7000 scientific papers on turmeric and almost 20,000 on curcumin have been published in PubMed. Scientific reports based on cell culture or animal studies are often not reproducible in humans. Therefore, human clinical trials are the best indicators for the prevention and treatment of a disease using a given agent/drug. Herein, we conducted an extensive literature survey on PubMed and Scopus following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The keywords "turmeric and clinical trials" and "curcumin and clinical trials" were considered for data mining. A total of 148 references were found to be relevant for the key term "turmeric and clinical trials", of which 70 were common in both PubMed and Scopus, 44 were unique to PubMed, and 34 were unique to Scopus. Similarly, for the search term "curcumin and clinical trials", 440 references were found to be relevant, of which 70 were unique to PubMed, 110 were unique to Scopus, and 260 were common to both databases. These studies show that the golden spice has enormous health and medicinal benefits for humans. This Review will extract and summarize the lessons learned about turmeric and curcumin in the prevention and treatment of chronic diseases based on clinical trials.

Curcumin Formulations for Better Bioavailability: What We Learned from Clinical Trials Thus Far?

Curcumin has been credited with a wide spectrum of pharmacological properties for the prevention and treatment of several chronic diseases such as arthritis, autoimmune diseases, cancer, cardiovascular diseases, diabetes, hemoglobinopathies, hypertension, infectious diseases, inflammation, metabolic syndrome, neurological diseases, obesity, and skin diseases. However, due to its weak solubility and bioavailability, it has limited potential as an oral medication. Numerous factors including low water solubility, poor intestinal permeability, instability at alkaline pH, and fast metabolism contribute to curcumin's limited oral bioavailability. In order to improve its oral bioavailability, different formulation techniques such as coadministration with piperine, incorporation into micelles, micro/nanoemulsions, nanoparticles, liposomes, solid dispersions, spray drying, and noncovalent complex formation with galactomannosides have been investigated with in vitro cell culture models, in vivo animal models, and humans. In the current study, we extensively reviewed clinical trials on various generations of curcumin formulations and their safety and efficacy in the treatment of many diseases. We also summarized the dose, duration, and mechanism of action of these formulations. We have also critically reviewed the advantages and limitations of each of these formulations compared to various placebo and/or available standard care therapies for these ailments. The highlighted integrative concept embodied in the development of next-generation formulations helps to minimize bioavailability and safety issues with least or no adverse side effects and the provisional new dimensions presented in this direction may add value in the prevention and cure of complex chronic diseases.

A novel solvent-free co-grinding preparation improves curcumin bioavailability in healthy volunteers: A single-center crossover study

Curcumin, from the rhizome of turmeric (Curcuma longa L.), has a wide variety of biological activities. Unfortunately, its poor water-solubility greatly limits its bioavailability. The purpose of this study was to evaluate CUMINUP60®, a novel preparation utilizing a solvent-free, co-grinding method designed to improve curcumin's bioavailability. We performed a single-center crossover experiment to compare the new product with standard 95% curcumin in the blood plasma of twelve healthy adults (10 males, 2 females). Total bioavailability of curcumin and its sulfate and glucuronide conjugates from the test product, measured by their areas under the curve over 12 h (AUC_0-T), showed a combined increase of 178-fold over standard curcumin and its conjugates from the reference product. The new product represents a significant improvement for providing greater bioavailability of curcumin, as compared with several other branded preparations. It therefore has broad applications for preparing curcumin as a more effective health ingredient in functional foods, beverages, and nutraceuticals.

Comparative Pharmacokinetic of Curcuminoids Formulations with an Omega-3 Fatty Acids Monoglyceride Carrier: A Randomized Cross-Over Triple-Blind Study

There is a growing interest for curcuminoids in the general population and the scientific research community. Curcuminoids, derived from turmeric spice, are lipophiles and therefore have a low solubility in water which hence have a low bioavailability in the human plasma. To circumvent this issue, a natural product developed by Biodroga Nutraceuticals combined curcuminoids with omega-3 fatty acids (OM3) esterified in monoglycerides (MAG). The objective was to perform a 24 h pharmacokinetics in humans receiving a single dose of curcuminoid formulated by three different means, and to compare their plasma curcuminoids concentration. Sixteen males and fifteen females tested three formulations: 400 mg of curcuminoids powder extract, 400 mg of curcuminoids in rice oil and 400 mg of curcuminoids with 1 g MAG-OM3. Blood samples were collected at 0, 1, 2, 3, 4, 5, 6, 8, 10 and 24 h post dose intake. Plasma samples were analyzed by ultra high-performance liquid chromatography with a triple quadrupole mass spectrometer (UPLC-MS/MS). Twenty-four hours after a single dose intake, the total plasma curcuminoids area under the curve (AUC) reached 166.8 ± 17.8 ng/mL*h, 134.0 ± 12.7 ng/mL*h and 163.1 ± 15.3 ng/mL*h when curcuminoids were provided with MAG-OM3, with rice oil or in powder, respectively. The C_max of total curcuminoids reached between 11.9-17.7 ng/mL at around 4 h (T_max). One-hour post-dose, the curcuminoids plasma concentration was 40% higher in participants consuming the MAG-OM3 compared to the other formulations. Thus, in a young population, plasma curcuminoids 24 h pharmacokinetics and its increase shortly after the single dose intake were higher when provided with MAG-OM3 than rice oil.

Enhancement of Release and Solubility of Curcumin from Electrospun PEO-EC-PVP Tripolymer-Based Nanofibers: A Study on the Effect of Hydrogenated Castor Oil

This study reveals the state-of-the-art fabrication of a tripolymer-based electrospun nanofiber (NF) system to enhance the release, solubility, and transdermal penetration of curcumin (Cur) with the aid of in situ release of infused castor oil (Co). In this regard, Cur-loaded Co-infused polyethylene oxide (PEO), ethyl cellulose (EC), and polyvinyl pyrrolidone (PVP) tripolymer-based NF systems were developed to produce a hybridized transdermal skin patch. Weight percentages of 1-4% Cur and 3-10% of Co were blended with PEO-EC-PEO and PEO-EC-PVP polymer systems. The prepared NFs were characterized by SEM, TEM, FT-IR analysis, PXRD, differential scanning calorimetry (DSC), and XPS. Dialysis membranes and vertical Franz diffusion cells were used to study the in vitro drug release and transdermal penetration, respectively. The results indicated that maintaining a Cur concentration of 1-3 wt % with 3 wt % Co in both PEO-EC-Co-Cur@PEO and PEO-EC-Co-Cur@PVP gave rise to nanofibers with lowered diameters (144.83 ± 48.05-209.26 ± 41.80 nm and 190.20 ± 59.42-404.59 ± 45.31 nm). Lowered crystallinity observed from the PXRD patterns and the disappearance of exothermic peaks corresponding to the melting point of Cur suggested the formation of an amorphous NF structure. Furthermore, the XPS data revealed that the Cur loading will possibly take place at the inner interface of PEO-EC-Co-PEO and PEO-EC-Co-PVP NFs rather than on the surface. The beneficiary role of Co on the release and dermal penetration of Cur was further confirmed from the respective release data which indicated that PEO-EC-Co-Cur@PEO would lead to a rapid release (4-5 h), while PEO-EC-Co-Cur@PVP would lead to a sustained release over a period of 24 h in the presence of Co. Transdermal penetration of the released Cur was further evidenced with the development of color in the receiver compartment of the diffusion cell. DPPH results further corroborated that a sustained antioxidant activity is observed in the released Cur where the free-radical scavenging activity is intact even after subjecting to an electrospinning process and under extreme freeze-thaw conditions.

Phytochemicals in Skeletal Muscle Health: Effects of Curcumin (from Curcuma longa Linn) and Sulforaphane (from Brassicaceae) on Muscle Function, Recovery and Therapy of Muscle Atrophy

The mobility of the human body depends on, among other things, muscle health, which can be affected by several situations, such as aging, increased oxidative stress, malnutrition, cancer, and the lack or excess of physical exercise, among others. Genetic, metabolic, hormonal, and nutritional factors are intricately involved in maintaining the balance that allows proper muscle function and fiber recovery; therefore, the breakdown of the balance among these elements can trigger muscle atrophy. The study from the nutrigenomic perspective of nutritional factors has drawn wide attention recently; one of these is the use of certain compounds derived from foods and plants known as phytochemicals, to which various biological activities have been described and attributed in terms of benefiting health in many respects. This work addresses the effect that the phytochemicals curcumin from Curcuma longa Linn and sulforaphane from Brassicaceae species have shown to exert on muscle function, recovery, and the prevention of muscle atrophy, and describes the impact on muscle health in general. In the same manner, there are future perspectives in research on novel compounds as potential agents in the prevention or treatment of medical conditions that affect muscle health.

Curcumin: The Golden Nutraceutical on the Road to Cancer Prevention and Therapeutics. A Clinical Perspective

Cancer is considered as the major public health scourge of the 21st century. Although remarkable strides were made for developing targeted therapeutics, these therapies suffer from lack of efficacy, high cost, and debilitating side effects. Therefore, the search for safe, highly efficacious, and affordable therapies is paramount for establishing a treatment regimen for this deadly disease. Curcumin, a known natural, bioactive, polyphenol compound from the spice turmeric (Curcuma longa), has been well documented for its wide range of pharmacological and biological activities. A plethora of literature indicates its potency as an anti-inflammatory and anti-cancer agent. Curcumin exhibits anti-neoplastic attributes via regulating a wide array of biological cascades involved in mutagenesis, proliferation, apoptosis, oncogene expression, tumorigenesis, and metastasis. Curcumin has shown a wide range of pleiotropic anti-proliferative effect in multiple cancers and is a known inhibitor of varied oncogenic elements, including nuclear factor kappa B (NF-κB), c-myc, cyclin D1, Bcl-2, VEGF, COX-2, NOS, tumor necrosis factor alpha (TNF-α), interleukins, and MMP-9. Further, curcumin targets different growth factor receptors and cell adhesion molecules involved in tumor growth and progression, making it a most promising nutraceutical for cancer therapy. To date, curcumin-based therapeutics have completed more than 50 clinical trials for cancer. Although creative experimentation is still elucidating the immense potential of curcumin, systematic validation by proper randomized clinical trials warrant its transition from lab to bedside. Therefore, this review summarizes the outcome of diverse clinical trials of curcumin in various cancer types.