Relationship Between the In Vitro Efficacy, Pharmacokinetics and In Vivo Efficacy of Curcumin

Progress in the study of curcumin metabolism in vivo

Curcumin has diverse biological functions, especially antioxidant and anti-inflammatory properties, but clinical trials have been hindered by its low bioavailability and pharmacokinetic properties. To achieve therapeutic efficacy, understanding curcumin's in vivo metabolism is crucial. We reviewed current research on curcumin metabolism in PubMed, Google Scholar, and CNKI. This article outlines curcumin's metabolic processes in the body via oral and intravenous injection. It suggests that upon entering the human body, curcumin may undergo oxidation, reduction, binding, and microbial community influence.

Comparative Pharmacokinetic Assessment of Curcumin in Rats Following Intratracheal Instillation Versus Oral Administration: Concurrent Detection of Curcumin and Its Conjugates in Plasma by LC-MS/MS

OBJECTIVE

To establish and validate an LC-MS/MS method for the simultaneous determination of curcumin (CUR) as well as its glucuronide conjugate (COG) and sulfate conjugate (COS) in rat plasma. The method was employed to evaluate and compare the pharmacokinetic behaviors of curcumin following oral and intratracheal administration in rats.

METHODS

Rat plasma samples were separated by chromatography on a C18 column after protein precipitation with acetonitrile. Gradient elution with a mobile phase of 0.5 mM ammonium acetate in acetonitrile was utilized. Mass spectrometry detection incorporated an electrospray ionization (ESI) source, multiple reaction monitoring (MRM), and dual-mode (positive and negative) scanning for quantitative analysis. A total of 12 SD rats were randomly divided into two groups and were orally (20 mg/kg) or intratracheally (10 mg/kg) administrated curcumin, respectively. CUR, COG, and COS concentrations in plasma were measured to assess pharmacokinetic disparities.

RESULTS

The method demonstrated linearity within the ranges of 2-400 ng/mL for CUR and COS and 5-1000 ng/mL for COG. Intratracheal administration significantly elevated CUR plasma concentrations compared to oral administration. The exposure of COG was higher than COS following oral administration. Conversely, intratracheal administration resulted in markedly higher COS exposure, with no significant difference in COG exposure after dose normalization between oral and inhalation routes.

CONCLUSIONS

The established LC-MS/MS method provides a reliable tool for the simultaneous measurement of CUR, COG, and COS in rat plasma, facilitating preclinical pharmacokinetic investigations. The study reveals distinct pharmacokinetic profiles for CUR following oral versus intratracheal administration, suggesting that inhalation may offer superior therapeutic efficacy.

Nanophytomedicine: A promising practical approach in phytotherapy

The long and rich history of herbal therapeutic nutrients is fascinating. It is incredible to think about how ancient civilizations used plants and herbs to treat various ailments and diseases. One group of bioactive phytochemicals that has gained significant attention recently is dietary polyphenols. These compounds are commonly found in a variety of fruits, vegetables, spices, nuts, drinks, legumes, and grains. Despite their incredible therapeutic properties, one challenge with polyphenols is their poor water solubility, stability, and bioavailability. This means that they are not easily absorbed by the body when consumed in essential diets. Because of structural complexity, polyphenols with high molecular weight cannot be absorbed in the small intestine and after arriving in the colon, they are metabolized by gut microbiota. However, researchers are constantly working on finding solutions to enhance the bioavailability and absorption of these compounds. This study aims to address this issue by applying nanotechnology approaches to overcome the challenges of the therapeutic application of dietary polyphenols. This combination of nanotechnology and phytochemicals could cause a completely new field called nanophytomedicine or herbal nanomedicine.

Structure and characterization of Tremella fuciformis polysaccharides/whey protein isolate nanoparticles for sustained release of curcumin

BACKGROUND

Whey protein isolate (WPI) nanoparticles can be used in a strategy to improve the bioavailability of curcumin (CUR) although they are generally not stable. Previous studies have indicated that Tremella fuciformis polysaccharides (TFPs) can increase the stability of WPI. This work investigated systematically the characterization and structure of TFP/WPI nanoparticles with differing CUR content.

RESULTS

The highest encapsulation efficiency of CUR was 98.8% and the highest loading content was 47.88%. The TFP-WPI-CUR with 20 mg mL-1 of CUR had the largest particle size (653.67 ± 21.50 nm) and lowest zeta potential (-38.97 ± 2.51 mV), and the capacity to retain stability across a variety of salt ion and pH conditions for 21 days. According to the findings of the structural analysis, the addition of TFPs and CUR rendered the structure of WPI amorphous, and the β-sheet was reduced. Finally, in vitro release indicated that the TFP-WPI-CUR combination could regulate the sustained release behavior of CUR.

CONCLUSION

In summary, TFP-WPI nanoparticles can be used as carriers for the delivery of CUR, and can expand applications of CUR in the functional food, dietary supplement, pharmaceutical, and beverage industries. © 2023 Society of Chemical Industry.

Chemical modification of curcumin increases its potency against hypopharyngeal carcinoma

Hypopharyngeal carcinoma is notorious for its poor prognosis among all head and neck cancers, posing a persistent challenge in clinical settings. The continuous hyperactivation of the NFκB signalling pathway has been noted in various cancer types, including hypopharyngeal carcinoma. In our quest to develop a novel drug that targets hypopharyngeal cancer via the NFκB pathway, we employed curcumin, a well-known lead compound, and performed chemical modifications to create a mono-carbonyl analogue called L42H17. This compound exhibited exceptional stability and displayed an enhanced binding affinity to myeloid differentiation protein 2 (MD2). Consistent with expectations, L42H17 demonstrated the ability to inhibit TNF-α-induced phosphorylation of inhibitor of κB (IκB) kinase (IKK), prevent IκB degradation, and subsequently impede NFκB-p65 nuclear translocation in hypopharyngeal cancer cells. Additionally, L42H17 exhibited a remarkable capacity to induce cell cycle arrest at the G2-M phase by inactivating the cdc2-cyclin B1 complex. Moreover, it facilitated cell apoptosis by reducing Bcl-2 levels and augmenting the expression of cle-PARP and cle-caspase3. Importantly, we observed a significant enhancement in the anti-cancer efficacy of L42H17 in a patient-derived tumour xenograft (PDTX) model of hypopharyngeal carcinoma. In conclusion, our findings strongly suggest that L42H17 holds promise as a potential candidate drug for the treatment of hypopharyngeal carcinoma in the future.

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.

Potential therapeutic effects of Chinese meteria medica in mitigating drug-induced acute kidney injury

Drug-induced acute kidney injury (DI-AKI) is one of the leading causes of kidney injury, is associated with high mortality and morbidity, and limits the clinical use of certain therapeutic or diagnostic agents, such as antineoplastic drugs, antibiotics, immunosuppressants, non-steroidal anti-inflammatory drugs, and contrast media. In recent years, numerous studies have shown that many Chinese meteria medica, metabolites derived from botanical drugs, and Chinese medicinal formulas confer protective effects against DI-AKI by targeting a variety of cellular or molecular mechanisms, such as oxidative stress, inflammatory, cell necrosis, apoptosis, and autophagy. This review summarizes the research status of common DI-AKI with Chinese meteria medica interventions, including cisplatin, gentamicin, contrast agents, methotrexate, and acetaminophen. At the same time, this review introduces the metabolites with application prospects represented by ginseng saponins, tetramethylpyrazine, panax notoginseng saponins, and curcumin. Overall, this review provides a reference for the development of promising nephroprotectants.

Plumbagin is a novel GPX4 protein degrader that induces apoptosis in hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC), the most common type of primary liver cancer, remains a global health challenge requiring novel and effective therapeutic agents and approaches. Here, we found that a natural product plumbagin can inhibit the growth of HCC cells by inducing the downregulation of GPX4, but not other antioxidant enzymes such as CAT, SOD1, and TXN. Functionally, genetic silence of GPX4 enhances, whereas the overexpression of GPX4 inhibits plumbagin-induced apoptosis (rather than ferroptosis) in HCC cells. Furthermore, GPX4 protein specifically binds the deubiquitinase USP31, but not other deubiquitinases such as CYLD, USP1, USP14, USP20, USP30, USP38, UCHL1, UCHL3, and UCHL5. As an inhibitor of deubiquitinating enzymes, especially USP31, plumbagin induces ubiquitination of GPX4 and subsequent proteasomal degradation of GPX4 in HCC cells. Accordingly, plumbagin-mediated tumor suppression is also associated with the downregulation of GPX4 and the upregulation of apoptosis in a subcutaneous xenograft tumor model. Taken together, these findings demonstrate a novel anticancer mechanism of plumbagin by inducing GPX4 protein degradation.

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.