Inhibition of 20-hydroxyeicosatetraenoic acid synthesis using specific plant lignans: in vitro and human studies

Utility of Cytochrome P450 4F2 Genotyping to Assess Drug Interaction Risk for Brincidovovir, a Cytochrome P450 4F2 Substrate

Smallpox was eradicated in 1980 but remains a biothreat due to the potential release of variola virus into the general population. Brincidofovir, the second medicine approved by the US Food and Drug Administration to treat smallpox, is metabolized by oxidative and hydrolytic pathways. The oxidative pathway is initiated by cytochrome P450 4F2 (CYP4F2), an enzyme lacking clinical probes for drug interaction studies. The aim of this work was to assess the impact of reduced activity CYP4F2 variants (rs2108622, C/T and T/T) on brincidofovir pharmacokinetics as a surrogate for drug inhibition. Genotyping was performed on blood from healthy participants receiving oral (n = 261) and intravenous (IV, n = 49) brincidofovir across 6 phase 1 trials. Plasma concentrations were measured by validated liquid chromatography tandem mass spectrometry methods. After oral administration, subjects with the lowest activity CYP4F2 genotype (T/T) had up to 36% higher AUCinf and 29% higher Cmax while subjects with the moderate activity CYP4F2 genotype (C/T) had similar Cmax and AUCinf compared to those with the wild-type genotype. Little to no increase in brincidofovir exposure parameters was observed following IV administration. Based on the lack of significant increases in brincidofovir plasma concentrations in subjects with low activity CYP4F2, a clinically meaningful drug-drug interaction is not expected with CYP4F2 inhibitor and brincidofovir coadministration.

Exploring human CYP4 enzymes: physiological roles, function in diseases and focus on inhibitors

The cytochrome P450 (CYP)4 family of enzymes are monooxygenases responsible for the ω-oxidation of endogenous fatty acids and eicosanoids and play a crucial part in regulating numerous eicosanoid signaling pathways. Recently, CYP4 gained attention as a potential therapeutic target for several human diseases, including cancer, cardiovascular diseases and inflammation. Small-molecule inhibitors of CYP4 could provide promising treatments for these diseases. The aim of the present review is to highlight the advances in the field of CYP4, discussing the physiology and pathology of the CYP4 family and compiling CYP4 inhibitors into groups based on their chemical classes to provide clues for the future discovery of drug candidates targeting CYP4. Teaser: This review provides an updated view of the physiology and pathology of CYP4 enzymes. CYP4 inhibitors are compiled based on their skeletons to provide clues for the future discovery of drug candidates targeting CYP4.

Characterization of three naturally occurring lignans, sesamol, sesamolin, and sesamin, as potent inhibitors of human cytochrome P450 46A1: Implications for treating excitatory neurotoxicity

CYP46A1 is a brain-specific enzyme responsible for cholesterol homeostasis. Inhibition of CYP46A1 activity serves as a therapeutic target for excitatory neurotoxicity. Sesame is a common medicine and food resource; its component lignans possess various pharmacological activities. In this study, the inhibitory effects of sesame lignans on CYP46A1 activity were investigated. Inhibition kinetics analyses revealed that sesamin and sesamolin produce mixed partial competitive inhibition of CYP46A1, while sesamol produces non-competitive inhibition. Notably, molecular simulations revealed that the sesame lignans have excellent orientations within the active cavity of CYP46A1. Importantly, the sesame lignans had high permeability coefficients and low efflux ratios. Furthermore, sesamin significantly reduced the levels of 24S-hydroxycholesterol in rat plasma and brain tissues, and down-regulated the protein expressions of CYP46A1, NMDAR2A, NMDAR2B, and HMGCR. Collectively, sesame lignans exhibit significant inhibitory effects on CYP46A1 activity, highlighting their potential therapeutic role in treating excitatory neurotoxicity.

A Comprehensive Review on Distribution, Pharmacological Properties, and Mechanisms of Action of Sesamin

Sesamin is a kind of fat-soluble lignan extracted from sesame seeds or other plants. It has attracted more and more attention because of its extensive pharmacological activities. In this study, we systematically summarized the pharmacological activities of sesamin including antioxidant, anti-inflammatory, anticancer, protection of liver and kidney, prevention of diabetes, hypertension, and atherosclerosis. Studies focus on the abilities of sesamin to attenuate oxidative stress by reducing the levels of ROS and MDA, to inhibit the release of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, etc.), and to induce apoptosis and autophagy in cancer cells through a variety of signaling pathways such as NF-κB, JNK, p38 MAPK, PI3K/AKT, caspase-3, and p53. By inhibiting the production of ROS, sesamin can also enhance the biological activities of NO in blood vessels, improve endothelial dysfunction and hypertension, and change the process of atherosclerotic lesion formation. In line with this, the various pharmacological properties of sesamin have been discussed in this review so that we can have a deeper understanding of the pharmacological activities of sesamin and clear the future development direction of sesamin.

Clinical evidence of dietary supplementation with sesame on cardiovascular risk factors: An updated meta-analysis of randomized controlled trials

The present analysis was to summarize the evidence of the effects of sesame and its derivatives supplementation on cardiovascular disease (CVD) risk factors by performing a meta-analysis of randomized controlled trials (RCTs). Electronic databases were searched from their inception to July 2020. Two investigators independently assessed articles for inclusion, extracted data, and statistical analysis. The quality of included articles was assessed according to the Cochrane risk of bias tool. Major outcomes were synthesized using a random effect model and presented as weighted mean difference and 95% confidence interval. Heterogeneity, subgroup analyses, sensitivity analysis, meta-regression, and publication bias were also conducted. The GRADE approach was used to evaluate the quality of evidence. Overall, 16 trials involving 908 participants were included for statistical pooling. Compared with the control group, sesame intake significantly decreased the levels of total cholesterol, triglycerides, systolic blood pressure, diastolic blood pressure, body weight, body mass index, hip circumference, and waist circumference (P < 0.05). These results were stable in sensitivity analysis, and no significant publication bias was detected. Our findings provided evidence that sesame consumption may reduce the risk of CVD by improving blood lipids, blood pressure, and body weight management. Further large-scale, well-designed RCTs are required to confirm these results.

Lignans of Sesame (Sesamum indicum L.): A Comprehensive Review

Major lignans of sesame sesamin and sesamolin are benzodioxol--substituted furofurans. Sesamol, sesaminol, its epimers, and episesamin are transformation products found in processed products. Synthetic routes to all lignans are known but only sesamol is synthesized industrially. Biosynthesis of furofuran lignans begins with the dimerization of coniferyl alcohol, followed by the formation of dioxoles, oxidation, and glycosylation. Most genes of the lignan pathway in sesame have been identified but the inheritance of lignan content is poorly understood. Health-promoting properties make lignans attractive components of functional food. Lignans enhance the efficiency of insecticides and possess antifeedant activity, but their biological function in plants remains hypothetical. In this work, extensive literature including historical texts is reviewed, controversial issues are critically examined, and errors perpetuated in literature are corrected. The following aspects are covered: chemical properties and transformations of lignans; analysis, purification, and total synthesis; occurrence in Seseamum indicum and related plants; biosynthesis and genetics; biological activities; health-promoting properties; and biological functions. Finally, the improvement of lignan content in sesame seeds by breeding and biotechnology and the potential of hairy roots for manufacturing lignans in vitro are outlined.

Activated PKB/GSK-3β synergizes with PKC-δ signaling in attenuating myocardial ischemia/reperfusion injury via potentiation of NRF2 activity: Therapeutic efficacy of dihydrotanshinone-I

Disrupted redox status primarily contributes to myocardial ischemia/reperfusion injury (MIRI). NRF2, the endogenous antioxidant regulator, might provide therapeutic benefits. Dihydrotanshinone-I (DT) is an active component in Salvia miltiorrhiza with NRF2 induction potency. This study seeks to validate functional links between NRF2 and cardioprotection of DT and to investigate the molecular mechanism particularly emphasizing on NRF2 cytoplasmic/nuclear translocation. DT potently induced NRF2 nuclear accumulation, ameliorating post-reperfusion injuries via redox alterations. Abrogated cardioprotection in NRF2-deficient mice and cardiomyocytes strongly supports NRF2-dependent cardioprotection of DT. Mechanistically, DT phosphorylated NRF2 at Ser40, rendering its nuclear-import by dissociating from KEAP1 and inhibiting degradation. Importantly, we identified PKC-δ-(Thr505) phosphorylation as primary upstream event triggering NRF2-(Ser40) phosphorylation. Knockdown of PKC-δ dramatically retained NRF2 in cytoplasm, convincing its pivotal role in mediating NRF2 nuclear-import. NRF2 activity was further enhanced by activated PKB/GSK-3β signaling via nuclear-export signal blockage independent of PKC-δ activation. By demonstrating independent modulation of PKC-δ and PKB/GSK-3β/Fyn signaling, we highlight the ability of DT to exploit both nuclear import and export regulation of NRF2 in treating reperfusion injury harboring redox homeostasis alterations. Coactivation of PKC and PKB phenocopied cardioprotection of DT in vitro and in vivo, further supporting the potential applicability of this rationale.

Invited review: Cytochrome P450 enzyme involvement in health and inflammatory-based diseases of dairy cattle

Dairy cattle are at the greatest risk of developing diseases around the time of calving because of compromised immune responses and the occurrence of oxidative stress. Both the development of compromised immunity and oxidative stress are influenced directly or indirectly by the metabolism of polyunsaturated fatty acids (PUFA) and fat-soluble vitamins. The cytochrome P450 (CYP450) family of enzymes is central to the metabolism of both classes of these compounds, but to date, the importance of CYP450 in the health of dairy cattle is underappreciated. As certain CYP450 isoforms metabolize both PUFA and fat-soluble vitamins, potential interactions may occur between PUFA and fat-soluble vitamins that are largely unexplored. For example, one CYP450 that generates anti-inflammatory oxylipids from arachidonic acid additionally contributes to the activation of vitamin D. Other potential substrate interactions between PUFA and vitamins A and E may exist as well. The intersection of PUFA and fat-soluble vitamin metabolism by CYP450 suggest that this enzyme system could provide an understanding of how immune function and oxidant status interconnect, resulting in increased postpartum disease occurrence. This review will detail the known contributions of bovine CYP450 to the regulation of oxylipids with a focus on enzymes that may also be involved in the metabolism of fat-soluble vitamins A, D, and E that contribute to antioxidant defenses. Although the activity of specific CYP450 is generally conserved among mammals, important differences exist in cattle, such as the isoforms primarily responsible for activation of vitamin D that makes their specific study in cattle of great importance. Additionally, a CYP450-driven inflammatory positive feedback loop is proposed, which may contribute to the dysfunctional inflammatory responses commonly found during the transition period. Establishing the individual enzyme isoform contributions to oxylipid biosynthesis and the regulation of vitamins A, D, and E may reveal how the CYP450 family of enzymes can affect inflammatory responses during times of increased susceptibility to disease. Determining the potential effect of each CYP450 on disease susceptibility or pathogenesis may allow for the targeted manipulation of the CYP450 pathways to influence specific immune responses and antioxidant defenses during times of increased risk for health disorders.

Health benefits of sesamin on cardiovascular disease and its associated risk factors

Sesamin, a major lignin isolated from sesame (Sesamum indicum) seeds and sesame oil, is known to possess antioxidant and anti-inflammatory properties. Several studies have revealed that oxidative stress and inflammation play a major role in a variety of cardiovascular diseases (CVDs). This comprehensive review summarizes the evidence on the effects of sesamin on CVD and its risk factors, principally due to its antioxidant properties. Specifically, this review highlights the mechanisms underlying the anti-hypertensive, anti-atherogenic, anti-thrombotic, anti-diabetic, and anti-obesity, lipolytic effects of sesamin both in vivo and in vitro, and identifies the signaling pathways targeted by sesamin and its metabolites. The data indicates that RAS/MAPK, PI3K/AKT, ERK1/2, p38, p53, IL-6, TNFα, and NF-κB signaling networks are all involved in moderating the various effects of sesamin on CVD and its risk factors. In conclusion, the experimental evidence suggesting that sesamin can reduce CVD risk is convincing. Thus, sesamin can be potentially useful as an adjuvant therapeutic agent to combat CVD and its multitude of risk factors.

Recovery of Sesamin, Sesamolin, and Minor Lignans From Sesame Oil Using Solid Support-Free Liquid-Liquid Extraction and Chromatography Techniques and Evaluation of Their Enzymatic Inhibition Properties

In this study, an integrated process for the recovery of sesamin and sesamolin, two high added-value lignans of sesame oil (SO) was developed, using synchronous extraction and chromatography techniques. The extraction of SO phenolic content was studied using two different extraction techniques: Annular centrifugal extraction (ACE) and centrifugal partition extraction (CPE). The derived data of each experiment were compared in terms of revealing the yields, time, and solvents consumption showing that CPE is the most effective technique, concerning the solvent consumption. The isolation of lignans was achieved using centrifugal partition chromatography (CPC) both on semi-preparative and preparative scale. The biphasic system used for this purpose consisted of the following solvents: n-Hex/EtOAc/EtOH/H₂O in proportion 2:3:3:2 (v/v/v/v) and direct recovery of the two major lignans sesamin and sesamolin was achieved. In parallel the CPC analysis resulted in the isolation of four minor lignans of sesame oil, i.e., samin, sesamol, sesaminol, and episesaminol. Structure elucidation of isolated lignans was based on HRMS/MS and NMR experiments. High-performance liquid chromatography (HPLC) was employed for quantitative analysis of the obtained extracts to determine the purity of the isolated compounds as well. The results of this study demonstrated that sesamin and sesamolin were recovered in purity higher than 95%, verifying the effectiveness of the purposed separation methodology. Finally, due to the general application of sesame oil in cosmetic industry, all the pure compounds were evaluated for their tyrosinase, elastase, collagenase, and hyaluronidase inhibition activity.

The impact of CYP2C19*2, CYP4F2*3, and clinical factors on platelet aggregation, CYP4F2 enzyme activity, and 20-hydroxyeicosatetraenoic acid concentration in patients treated with dual antiplatelet therapy

: The aim of the current study was to evaluate the impact of CYP2C192 (rs4244285), CYP4F23 (rs2108622), and nongenetic factors on platelet aggregation and to investigate the mechanism of CYP4F2's effect on platelet aggregation in the patients treated with dual antiplatelet therapy. A total of 146 patients were included in this study. Ticagrelor or clopidogrel were administered in a loading dose of 180 mg and 600 mg, respectively, in combination with aspirin (300 mg). Blood samples for analysis were taken the next morning after antiplatelet therapy induction. Clopidogrel users with the CYP2C1912 variant had higher platelet aggregation values (median 43, range 30-54%) compared with 11 wild-type carriers (median 33, range 15-77%; P = 0.009). Carriers of the CYP4F213 variant had higher platelet aggregation values than carriers of the 33 variant (median 34, range 8-70% vs. median 24.5, range 10-47%, P = 0.016, respectively). Higher CYP4F2 concentrations were detected in clopidogrel users than in ticagrelor users (median 3.6, range 1.6-22.0 ng/ml vs. median 2.3, range 1.6-27.2 ng/ml, P = 0.056, respectively) and in carriers of the CYP4F213 variant compared with carriers of the 11 variant (median 4.3, range 1.6-27.2 ng/ml vs. median 2.4, range 1.6-22.0 ng/ml, P = 0.009, respectively). No correlation between plasma 20-hydroxyeicosatetraenoic acid and CYP4F2 enzyme concentrations were detected (r = -0.045, P = 0.587). Our results proved that CYP2C192 might significantly affect antiplatelet function of clopidogrel. Plasma CYP4F2 concentrations were significantly lower in ticagrelor users than in clopidogrel users.

Dietary polyphenols for atherosclerosis: A comprehensive review and future perspectives

Atherosclerosis is one of the most prevalent reasons for premature death in adults. Despite the several conventional drugs in the market; many patients are not completely treated. Here we comprehensively review current clinical evidence regarding the efficacy of dietary polyphenols in atherosclerosis and related complications. PubMed, Cochrane library and Scopus were searched from inception until August 2016 to obtain clinical trials in which polyphenols were evaluated in cardiovascular parameters related to atherosclerosis. From total of 13031 results, 49 clinical trials were finally included. Tyrosol derivatives from virgin olive oil, catechins and theaflavins from green and black tea, cocoa polyphenols, and red grape resveratrol, as well as anthocyanins were the most studied polyphenolic compounds which could regulate lipid profile, inflammation and oxidative stress, blood pressure, endothelial function, and cell adhesion molecules. The most important limitations of the included trials were small sample size, short follow up, and unqualified methodology. Future well-designed clinical trials are necessary to provide better level of evidence for clinical decision making.

Can sesame consumption improve blood pressure? A systematic review and meta-analysis of controlled trials

Hypertension is a major risk factor for cardiovascular disease, myocardial infarction, stroke and renal failure. Sesame consumption may benefit blood pressure (BP) owing to its high polyunsaturated fatty acid, fibre, phytosterol and lignan contents. To clarify this, a systematic review and meta-analysis of controlled trials was conducted. The PubMed (MEDLINE), Cumulative Index to Nursing and Allied Health Literature (CINAHL) and Cochrane Library (Central) databases were systematically searched until August 2016. Eight controlled trials with a total of 843 participants met the eligibility criteria. A random effect meta-analysis showed that sesame consumption can reduce systolic BP (-7.83 mmHg, 95% CI: -14.12, -1.54; P < 0.05, I²  = 99%) and diastolic BP (-5.83 mmHg, 95% CI: -9.58, -2.08; P < 0.01, I²  = 98%). To reduce the heterogeneity, the meta-analysis was limited to high methodology quality trials (n = 4), which resulted in a significant reduction in systolic BP (-3.23 mmHg, 95% CI: -5.67, -0.79; I²  = 33%) and a non-significant reduction in diastolic BP (-2.08 mmHg, 95% CI: -4.85, 0.69; I²  = 62%). This study concluded that sesame consumption can reduce systolic and diastolic BP. However, further investigations with larger sample sizes and better methodology quality are required to confirm the BP-lowering effect of sesame consumption. © 2017 Society of Chemical Industry.

The role of 20-HETE in cardiovascular diseases and its risk factors

Arachidonic acid (AA) is metabolized in mammals by enzymes of the CYP4A and 4F families to 20-hydroxyeicosatetraeonic acid (20-HETE) which plays an important role in the regulation of renal function, vascular tone and arterial pressure. In the vasculature, 20-HETE is a potent vasoconstrictor, the up-regulation of which contributes to inflammation, oxidative stress, endothelial dysfunction and an increase in peripheral vascular resistance in models of obesity, diabetes, ischemia/reperfusion, and vascular oxidative stress. Recent studies have established a role for 20-HETE in normal and pathological angiogenic conditions. We discuss in this review the synthesis of 20-HETE and how it and various autacoids, especially the renin-angiotensin system, interact to promote hypertension, vasoconstriction, and vascular dysfunction. In addition, we examine the molecular mechanisms through which 20-HETE induces these actions and the clinical implication of inhibiting 20-HETE production and activity.

20-HETE and blood pressure regulation: clinical implications

20-Hydroxy-5, 8, 11, 14-eicosatetraenoic acid (20-HETE) is a cytochrome P450 (CYP)-derived omega-hydroxylation metabolite of arachidonic acid. 20-HETE has been shown to play a complex role in blood pressure regulation. In the kidney tubules, 20-HETE inhibits sodium reabsorption and promotes natriuresis, thus, contributing to antihypertensive mechanisms. In contrast, in the microvasculature, 20-HETE has been shown to play a pressor role by sensitizing smooth muscle cells to constrictor stimuli and increasing myogenic tone, and by acting on the endothelium to further promote endothelial dysfunction and endothelial activation. In addition, 20-HETE induces endothelial angiotensin-converting enzyme, thus, setting forth a potential feed forward prohypertensive mechanism by stimulating the renin-angiotensin-aldosterone system. With the advancement of gene sequencing technology, numerous polymorphisms in the regulatory coding and noncoding regions of 20-HETE-producing enzymes, CYP4A11 and CYP4F2, have been associated with hypertension. This in-depth review article discusses the biosynthesis and function of 20-HETE in the cardiovascular system, the pharmacological agents that affect 20-HETE action, and polymorphisms of CYP enzymes that produce 20-HETE and are associated with systemic hypertension in humans.

Chondroprotective and anti-inflammatory effects of sesamin

Osteoarthritis (OA) is a major disability of elderly people. Sesamin is the main compound in Sesamun indicum Linn., and it has an anti-inflammatory effect by specifically inhibiting Δ5-desaturase in polyunsaturated fatty acid biosynthesis. The chondroprotective effects of sesamin were thus studied in a porcine cartilage explant induced with interleukin-1beta (IL-1β) and in a papain-induced osteoarthritis rat model. With the porcine cartilage explant, IL-1β induced release of sulfated-glycosaminoglycan (s-GAG) and hydroxyproline release, and this induction was significantly inhibited by sesamin. This ability to inhibit these processes might be due to its ability to decrease expression of MMP-1, -3 and -13, which can degrade both PGs and type II collagen, both at the mRNA and protein levels. Interestingly, activation of MMP-3 might also be inhibited by sesamin. Moreover, in human articular chondrocytes (HACs), some pathways of IL-1β signal transduction were inhibited by sesamin: p38 and JNK. In the papain-induced OA rat model, sesamin treatment reversed the following pathological changes in OA cartilage: reduced disorganization of chondrocytes in cartilage, increased cartilage thickness, and decreased type II collagen and PGs loss. Sesamin alone might increase formation of type II collagen and PGs in the cartilage tissue of control rats. These results demonstrate that sesamin efficiently suppressed the pathological processes in an OA model. Thus, sesamin could be a potential therapeutic strategy for treatment of OA.

Antihypertensive and antioxidant effects of dietary black sesame meal in pre-hypertensive humans

BACKGROUND

It has been known that hypertension is an independent risk factor for cardiovascular disease (CVD). CVD is the major cause of morbidity and mortality in developed and developing countries. Elevation of blood pressure (BP) increases the adverse effect for cardiovascular outcomes. Prevention of increased BP plays a crucial role in a reduction of those outcomes, leading to a decrease in mortality. Therefore, the purpose of this study was to investigate the effects of dietary black sesame meal on BP and oxidative stress in individuals with prehypertension.

METHODS

Twenty-two women and eight men (aged 49.8 ± 6.6 years) with prehypertension were randomly divided into two groups, 15 subjects per group. They ingested 2.52 g black sesame meal capsules or placebo capsules each day for 4 weeks. Blood samples were obtained after overnight fasting for measurement of plasma lipid, malondialdehyde (MDA) and vitamin E levels. Anthropometry, body composition and BP were measured before and after 4-week administration of black sesame meal or a placebo.

RESULTS

The results showed that 4-week administration of black sesame meal significantly decreased systolic BP (129.3 ± 6.8 vs. 121.0 ± 9.0 mmHg, P < 0.05) and MDA level (1.8 ± 0.6 vs. 1.2 ± 0.6 μmol/L, P < 0.05), and increased vitamin E level (29.4 ± 6.0 vs. 38.2 ± 7.8 μmol/L, P < 0.01). In the black sesame meal group, the change in SBP tended to be positively related to the change in MDA (R = 0.50, P = 0.05), while the change in DBP was negatively related to the change in vitamin E (R = -0.55, P < 0.05). There were no correlations between changes in BP and oxidative stress in the control group.

CONCLUSIONS

These results suggest the possible antihypertensive effects of black sesame meal on improving antioxidant status and decreasing oxidant stress. These data may imply a beneficial effect of black sesame meal on prevention of CVD.

Dietary lignans: physiology and potential for cardiovascular disease risk reduction

The present review of the literature on lignan physiology and lignan intervention and epidemiological studies was conducted to determine if lignans decrease the risks of cardiovascular disease in Western populations. Five intervention studies using flaxseed lignan supplements indicated beneficial associations with C-reactive protein, and a meta-analysis that included these studies also suggested lignans have a lowering effect on plasma total and low-density lipoprotein cholesterol. Three intervention studies using sesamin supplements indicated possible lipid- and blood pressure-lowering associations. Eleven human observational epidemiological studies examined dietary intakes of lignans in relation to cardiovascular disease risk. Five showed decreased risk with either increasing dietary intakes of lignans or increased levels of serum enterolactone (an enterolignan used as a biomarker of lignan intake), five studies were of borderline significance, and one was null. The associations between lignans and decreased risk of cardiovascular disease are promising, but they are yet not well established, perhaps due to low lignan intakes in habitual Western diets. At the higher doses used in intervention studies, associations were more evident.