Mechanisms of Herb-Drug Interactions Involving Cinnamon and CYP2A6: Focus on Time-Dependent Inhibition by Cinnamaldehyde and 2-Methoxycinnamaldehyde

Enzyme-mediated drug-drug interactions: a review of in vivo and in vitro methodologies, regulatory guidance, and translation to the clinic

Enzyme-mediated pharmacokinetic drug-drug interactions can be caused by altered activity of drug metabolizing enzymes in the presence of a perpetrator drug, mostly via inhibition or induction. We identified a gap in the literature for a state-of-the art detailed overview assessing this type of DDI risk in the context of drug development. This manuscript discusses in vitro and in vivo methodologies employed during the drug discovery and development process to predict clinical enzyme-mediated DDIs, including the determination of clearance pathways, metabolic enzyme contribution, and the mechanisms and kinetics of enzyme inhibition and induction. We discuss regulatory guidance and highlight the utility of in silico physiologically-based pharmacokinetic modeling, an approach that continues to gain application and traction in support of regulatory filings. Looking to the future, we consider DDI risk assessment for targeted protein degraders, an emerging small molecule modality, which does not have recommended guidelines for DDI evaluation. Our goal in writing this report was to provide early-career researchers with a comprehensive view of the enzyme-mediated pharmacokinetic DDI landscape to aid their drug development efforts.

The role and mechanism of cinnamaldehyde in cancer

As cancer continues to rise globally, there is growing interest in discovering novel methods for prevention and treatment. Due to the limitations of traditional cancer therapies, there has been a growing emphasis on investigating herbal remedies and exploring their potential synergistic effects when combined with chemotherapy drugs. Cinnamaldehyde, derived from cinnamon, has gained significant attention for its potential role in cancer prevention and treatment. Extensive research has demonstrated that cinnamaldehyde exhibits promising anticancer properties by modulating various cellular processes involved in tumor growth and progression. However, challenges and unanswered questions remain regarding the precise mechanisms for its effective use as an anticancer agent. This article aims to explore the multifaceted effects of cinnamaldehyde on cancer cells and shed light on these existing issues. Cinnamaldehyde has diverse anti-cancer mechanisms, including inducing apoptosis by activating caspases and damaging mitochondrial function, inhibiting tumor angiogenesis, anti-proliferation, anti-inflammatory and antioxidant. In addition, cinnamaldehyde also acts as a reactive oxygen species scavenger, reducing oxidative stress and preventing DNA damage and genomic instability. This article emphasizes the promising therapeutic potential of cinnamaldehyde in cancer treatment and underscores the need for future research to unlock novel mechanisms and strategies for combating cancer. By providing valuable insights into the role and mechanism of cinnamaldehyde in cancer, this comprehensive understanding paves the way for its potential as a novel therapeutic agent. Overall, cinnamaldehyde holds great promise as an anticancer agent, and its comprehensive exploration in this article highlights its potential as a valuable addition to cancer treatment options.

Cardiovascular Effects of Herbal Products and Their Interaction with Antihypertensive Drugs-Comprehensive Review

Hypertension is a highly prevalent population-level disease that represents an important risk factor for several cardiovascular complications and occupies a leading position in mortality statistics. Antihypertensive therapy includes a wide variety of drugs. Additionally, the potential antihypertensive and cardioprotective effects of several phytotherapy products have been evaluated, as these could also be a valuable therapeutic option for the prevention, improvement or treatment of hypertension and its complications. The present review includes an evaluation of the cardioprotective and antihypertensive effects of garlic, Aloe vera, green tea, Ginkgo biloba, berberine, ginseng, Nigella sativa, Apium graveolens, thyme, cinnamon and ginger, and their possible interactions with antihypertensive drugs. A literature search was undertaken via the PubMed, Google Scholar, Embase and Cochrane databases. Research articles, systematic reviews and meta-analyses published between 2010 and 2023, in the English, Hungarian, and Romanian languages were selected.

Use of Complementary and Alternative Medicine Among Patients With Epilepsy and Diabetes Mellitus, Focusing on the Outcome of Treatment

Introduction: Millions all over the world live with epilepsy, and they may require long-term drug treatment. The use and interest in complementary and alternative medicine (CAM) have grown over the previous years. Coadministration of herbal products with medicines may result in adverse drug reactions (ADRs) and/or unfavorable interactions. The aims of this study were to determine the prevalence of CAM use among patients with epilepsy, to compare the results to those of the patients with diabetes mellitus (DM), to reveal factors that may drive the use of CAM, and to measure outcomes and adherence. It was also our intent to have state-of-the-art information on CAM use in our region among patients with the two diseases above.

Materials and Methods: We conducted a non-interventional study using a self-developed questionnaire. It was distributed among adult patients with either epilepsy or DM who also suffered from cardiovascular consequences. A database was compiled from the anonymous questionnaires filled in voluntarily by the patients. Basic statistics were used to analyze this database.

Results: A total of 227 questionnaires were filled in by 127 patients (55.9%) with epilepsy and 100 patients (44.1%) with DM. Mean age was 54.54 ± 17.33 years. Of the patients, 50.2% were male. Average body weight was 80.3 ± 17.3 kg. Of the patients, 22 (9.7%) used CAM because they believed in CAM. Two of them reported ADRs. Among the patients with epilepsy, the ratio was only 7.9% compared to 12% among those with DM. While the number of CAM users was higher among younger patients with epilepsy, it was the elderly patients with DM who tended to use CAM.

Conclusion: Attention should be paid to reliance on CAM during the follow-up. Our finding that health-conscious patients tend to use CAM more often (than the general population) may indicate it is necessary to discuss CAM usage sincerely. CAMs modulating cytochrome P450 (CYP) enzymes were the most common, leading to interactions with medication used and resulting in ADRs. This shows the importance of educating patients and treating team including clinical pharmacists in this field.

Interactions between Food and Drugs, and Nutritional Status in Renal Patients: A Narrative Review

Drugs and food interact mutually: drugs may affect the nutritional status of the body, acting on senses, appetite, resting energy expenditure, and food intake; conversely, food or one of its components may affect bioavailability and half-life, circulating plasma concentrations of drugs resulting in an increased risk of toxicity and its adverse effects, or therapeutic failure. Therefore, the knowledge of these possible interactions is fundamental for the implementation of a nutritional treatment in the presence of a pharmacological therapy. This is the case of chronic kidney disease (CKD), for which the medication burden could be a problem, and nutritional therapy plays an important role in the patient’s treatment. The aim of this paper was to review the interactions that take place between drugs and foods that can potentially be used in renal patients, and the changes in nutritional status induced by drugs. A proper definition of the amount of food/nutrient intake, an adequate definition of the timing of meal consumption, and a proper adjustment of the drug dosing schedule may avoid these interactions, safeguarding the quality of life of the patients and guaranteeing the effectiveness of drug therapy. Hence, a close collaboration between the nephrologist, the renal dietitian, and the patient is crucial. Dietitians should consider that food may interact with drugs and that drugs may affect nutritional status, in order to provide the patient with proper dietary suggestions, and to allow the maximum effectiveness and safety of drug therapy, while preserving/correcting the nutritional status.

Probing functional interactions between cytochromes P450 with principal component analysis of substrate saturation profiles and targeted proteomics

We investigated the correspondence between drug metabolism routes and the composition of the P450 ensemble in human liver microsomes (HLM). As a probe, we used Coumarin 152 (C152), a fluorogenic substrate metabolized by multiple P450 species. Studying the substrate-saturation profiles (SSP) in seven pooled HLM preparations, we sought to correlate them with the P450 pool's composition characterized by targeted proteomics. This analysis, complemented with the assays with specific inhibitors of CYP3A4 and CYP2C19, the primary C152 metabolizers, demonstrated a significant contrast between different HLM samples. To unveil the source of these differences, we implemented Principal Component Analysis (PCA) of the SSP series obtained with HLM samples with a known composition of the P450 pool. Our analysis revealed that the parameters of C152 metabolism are primarily determined by the content of CYP2A6, CYP2B6, CYP2C8, CYP2E1, and CYP3A5 of those only CYP2B6 and CYP3A5 can metabolize C152. To validate this finding, we studied the effect of enriching HLM with CYP2A6, CYP2E1, and CYP3A5. The incorporation of CYP3A5 into HLM decreases the rate of C152 metabolism while increasing the role of CYP2B6 in its turnover. In contrast, incorporation of CYP2A6 and CYP2E1 reroutes the C152 demethylation towards some P450 enzyme with a moderate affinity to the substrate, most likely CYP3A4. Our results reveal a sharp non-additivity of the individual P450 properties and suggest a pivotal role of P450-P450 interactions in determining drug metabolism routes. This study demonstrates the high potential of our new PCA-based approach in unveiling functional interrelationships between different P450 species.

Modeling Pharmacokinetic Natural Product-Drug Interactions for Decision-Making: A NaPDI Center Recommended Approach

The popularity of botanical and other purported medicinal natural products (NPs) continues to grow, especially among patients with chronic illnesses and patients managed on complex prescription drug regimens. With few exceptions, the risk of a given NP to precipitate a clinically significant pharmacokinetic NP-drug interaction (NPDI) remains understudied or unknown. Application of static or dynamic mathematical models to predict and/or simulate NPDIs can provide critical information about the potential clinical significance of these complex interactions. However, methods used to conduct such predictions or simulations are highly variable. Additionally, published reports using mathematical models to interrogate NPDIs are not always sufficiently detailed to ensure reproducibility. Consequently, guidelines are needed to inform the conduct and reporting of these modeling efforts. This recommended approach from the Center of Excellence for Natural Product Drug Interaction Research describes a systematic method for using mathematical models to interpret the interaction risk of NPs as precipitants of potential clinically significant pharmacokinetic NPDIs. A framework for developing and applying pharmacokinetic NPDI models is presented with the aim of promoting accuracy, reproducibility, and generalizability in the literature. SIGNIFICANCE STATEMENT: Many natural products (NPs) contain phytoconstituents that can increase or decrease systemic or tissue exposure to, and potentially the efficacy of, a pharmaceutical drug; however, no regulatory agency guidelines exist to assist in predicting the risk of these complex interactions. This recommended approach from a multi-institutional consortium designated by National Institutes of Health as the Center of Excellence for Natural Product Drug Interaction Research provides a framework for modeling pharmacokinetic NP-drug interactions.

Natural Products: Experimental Approaches to Elucidate Disposition Mechanisms and Predict Pharmacokinetic Drug Interactions

Natural products have been used by humans since antiquity for both egregious and beneficial purposes. Regarding the latter, these products have long been valued as a rich source of phytochemicals and developed into numerous life-saving pharmaceutical agents. Today, the sales and use of natural products with purported medicinal qualities continue to increase worldwide. However, natural products are not subject to the same premarket testing requirements as pharmaceutical agents, creating critical gaps in scientific knowledge about their optimal use. In addition, due to the common misperception that "natural" means "safe," patients may supplement or replace their prescription medications with natural products, placing themselves at undue risk for subefficacious pharmacotherapy or potentially toxic exposure. Collectively, with few exceptions, researchers, health care providers, and educators lack definitive information about how to inform consumers, patients, and students in the health professions on the safe and optimal use of these products. Recognition of this deficiency by key stakeholders, including the three pillars of biomedical research-industry, academia, and government-has facilitated multiple collaborations that are actively addressing this fundamental knowledge gap. This special issue contains a collection of articles highlighting the challenges faced by researchers in the field and the use of various experimental systems and methods to improve the mechanistic understanding of the disposition and drug interaction potential of natural products. Continued refinement of existing, and development of new, approaches will progress toward the common overarching goal of improving public health. SIGNIFICANCE STATEMENT: Natural products with purported medicinal value constitute an increasing share of the contemporary health care market. Natural products are not subject to the same premarket testing requirements as drug products, creating fundamental scientific knowledge gaps about the safe and effective use of these products. Collaborations among industrial, academic, and governmental researchers in multiple disciplines are anticipated to provide the definitive information needed to fill these gaps and improve public health.