Effects of vitamin E and sesamin on hypertension and cerebral thrombogenesis in stroke-prone spontaneously hypertensive rats

Sesame Genomic Web Resource (SesameGWR): a well-annotated data resource for transcriptomic signatures of abiotic and biotic stress responses in sesame (Sesamum indicum L.)

Sesame (Sesamum indicum L.) is a globally cultivated oilseed crop renowned for its historical significance and widespread growth in tropical and subtropical regions. With notable nutritional and medicinal attributes, sesame has shown promising effects in combating malnutrition cancer, diabetes, and other diseases like cardiovascular problems. However, sesame production faces significant challenges from environmental threats such as charcoal rot, drought, salinity, and waterlogging stress, resulting in economic losses for farmers. The scarcity of information on stress-resistance genes and pathways exacerbates these challenges. Despite its immense importance, there is currently no platform available to provide comprehensive information on sesame, which significantly hinders the mining of various stress-associated genes and the molecular breeding of sesame. To address this gap, here a free, web-accessible, and user-friendly genomic web resource (SesameGWR, http://backlin.cabgrid.res.in/sesameGWR/) has been developed This platform provides key insights into differentially expressed genes, transcription factors, miRNAs, and molecular markers like simple sequence repeats, single nucleotide polymorphisms, and insertions and deletions associated with both biotic and abiotic stresses.. The functional genomics information and annotations embedded in this web resource were predicted through RNA-seq data analysis. Considering the impact of climate change and the nutritional and medicinal importance of sesame, this study is of utmost importance in understanding stress responses. SesameGWR will serve as a valuable tool for developing climate-resilient sesame varieties, thereby enhancing the productivity of this ancient oilseed crop.

Effects of sesame (Sesamum indicum L.) and bioactive compounds (sesamin and sesamolin) on inflammation and atherosclerosis: A review

Inflammation, oxidative stress, obesity, infection, hyperlipidemia, hypertension, and diabetes are the main causes of atherosclerosis, which in the long term lead to hardening of the arteries. In the current study, we reviewed recent findings of the mechanism of sesame and its active compounds of sesamin and sesamolin regulates on atherosclerosis. Sesame can decrease the lipid peroxidation and affect the enzymes, which control the balance of oxidative status in the body. Besides modulating the inflammatory cytokines, sesame regulates the main mediators of the signaling pathways in the process of inflammation, such as prostaglandin E2 (PGE2), nuclear factor kappa light-chain enhancer of activated B cells (NF-kB) and peroxisome proliferator-activated receptor gamma (PPAR-γ). Sesame decreases the growth of different pathogens. It fights against obesity and helps to reduce weight, body mass index (BMI), waist circumference, and lipid count of serum and liver. In addition to lowering fasting blood sugar (FBS), it decreases the hemoglobin A1c (HbA1c) and glucose levels and improves insulin function. With high content of linoleic acid, α-linolenic acid, and total polyunsaturated fatty acid (PUFA), sesame efficiently controls the blood plasma lipids and changes the lipid profile. In the case of hypertension, it maintains the health of endothelium through multiple mechanisms and conserves the response of the arteries to vasodilation. PUFA in sesame suppresses blood clotting and fibrinogen activity. All the mentioned properties combat atherosclerosis and hardening of blood vessels, which are detailed in the present review for sesame.

Sesamin attenuates PM2.5-induced cardiovascular injury by inhibiting ferroptosis in rats

Objective: This study aimed to elucidate the pharmacological effects of sesamin (Ses) and its mechanism of action towards PM_2.5-induced cardiovascular injuries. Method: Forty Sprague Dawley (SD) rats were randomly divided into five groups: a saline control group; a PM_2.5 exposure group; and low-, middle-, and high-dose Ses pretreatment groups. The SD rats were pretreated with different concentrations of Ses for 21 days. Afterward, the rats were exposed to ambient PM_2.5 by intratracheal instillation every other day for a total of three times. The levels of inflammatory markers, including tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β), and interleukin-6 (IL-6), and indicators related to oxidative responses, such as total superoxide dismutase (SOD), reduced glutathione (GSH), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA), were measured in the blood and heart. The expression of ferroptosis-related proteins in heart tissues was determined via western blot and immunohistochemistry. Results: Ses pretreatment substantially ameliorated cardiovascular injuries in rats as evidenced by the decrease in the pathological score and collagen area. The decreased levels of SOD, GSH, and GSH-Px in the heart and serum were inhibited by Ses. In addition, Ses not only notably increased the activity of antioxidant enzymes but also reduced the levels of MDA, CK, LDH, CK-MB, IL-6, TNF-α, IL-1β, and IL-6. Furthermore, Ses pretreatment upregulated the expression levels of GPX4, SLC7A11, TFRC, and FPN1 and inhibited the expression levels of FTH1 and FTL. Conclusion: Ses pretreatment could ameliorate PM_2.5-induced cardiovascular injuries perhaps by inhibiting ferroptosis. Therefore, Ses pretreatment may be a novel strategy for the prevention and treatment of PM_2.5-induced cardiovascular injury.

A novel motif in the 5'-UTR of an orphan gene 'Big Root Biomass' modulates root biomass in sesame

Developing crops with improved root system is crucial in current global warming scenario. Underexploited crops are valuable reservoirs of unique genes that can be harnessed for the improvement of major crops. In this study, we performed genome-wide association studies on seven root traits in sesame (Sesamum indicum L.) and uncovered 409 significant signals, 19 quantitative trait loci containing 32 candidate genes. A peak SNP significantly associated with root number and root dry weight traits was located in the promoter of the gene named 'Big Root Biomass' (BRB), which was subsequently validated in a bi-parental population. BRB has no functional annotation and is restricted to the Lamiales order. We detected the presence of a novel motif 'AACACACAC' located in the 5'-UTR of BRB in single and duplicated copy in accessions with high and small root biomass, respectively. A strong expression level of BRB was negatively correlated with high root biomass, and this was attributed to the gene SiMYB181 which represses the activity of BRB by binding specifically to the single motif but not to the duplicated one. Curiously, the allele that enhanced BRB expression has been intensively selected by modern breeding. Overexpression of BRB in Arabidopsis modulates auxin pathway leading to reduced root biomass, improved yield parameters under normal growth conditions and increased drought stress sensitivity. Overall, BRB represents a solid gene model for improving the performance of sesame and other crops.

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.

Immunomodulatory and anti-inflammatory effects of sesamin: mechanisms of action and future directions

Inflammation is associated with the development and progression of various disorders including atherosclerosis, diabetes mellitus and cancer. Sesamin, a fat-soluble lignan derived from Sesamum indicum seeds and oil, has received increased attention due to its wide array of pharmacological properties including its immunomodulatory and anti-inflammatory potential. To date, no review has been conducted to summarize or analyze the immunomodulatory and anti-inflammatory roles of sesamin. Herein, we provide a comprehensive review of experimental findings that were reported with regards to the ability of sesamin to modulate inflammation, cellular and humoral adaptive immune responses and Th1/Th2 paradigm. The potential influence of sesamin on the cytotoxic activity of NK cells against cancer cells is also highlighted. The molecular mechanisms and the signal transduction pathways underlying such effects are underscored. The metabolism, pharmacokinetics, absorption, tissue distribution and bioavailability of sesamin in different species, including humans, are reviewed. Moreover, we propose future preclinical and clinical investigations to further validate the potential preventive and/or therapeutic efficacy of sesamin against various immune-related and inflammatory conditions. We anticipate that sesamin may be employed in future therapeutic regimens to enhance the efficacy of treatment and dampen the adverse effects of synthetic chemical drugs currently used to alleviate immune-related and inflammatory conditions.

Effects of Sesame Oil Aroma on Mice after Exposure to Water Immersion Stress: Analysis of Behavior and Gene Expression in the Brain

(1) Background: Sesame has been popular as a healthy food since ancient times, and effects of the aroma component of roasted sesame are also expected. However, little research has been reported on its scent; (2) Methods: Jcl:ICR male mice were housed under water immersion stress for 24 h. Then, the scent of saline or sesame oil was inhaled to stress groups for 90 min. We investigated the effects of sesame oil aroma on the behavior and brains of mice; (3) Results: In an elevated plus maze test, the rate of entering to open arm and the staying time were decreased by the stress. These decrements were significantly enhanced by sesame oil aroma. Stress had a tendency to increase the serum corticosterone concentration, which was slightly decreased by the aroma. Expression of Kruppel-like factor-4 (Klf-4) and Dual-specificity phosphatase-1 (Dusp-1) in the striatum were increased by water immersion stress, and the level of Klf-4 and Dusp-1 in the striatum and hippocampus were significantly attenuated by sesame oil aroma (4) Conclusions: The present results strongly suggest that the odor component of sesame oil may have stress suppressing effects. Moreover, Klf-4 and Dusp-1 may be sensitive stress-responsive biomarkers.

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.

Sesamum indicum L. Oil and Sesamin Induce Auditory-Protective Effects Through Changes in Hearing Loss-Related Gene Expression

Changing consumption patterns and increasing health awareness, especially in Europe, are resulting in an increased demand for sesame seeds. In 2016, Asia imported the highest quantity of sesame seeds, followed by Europe and North America. We examined, for the first time, the effects of treatment with sesame oil and sesamin in hearing impairment models. Sesame oil exhibited an ameliorative effect on auditory impairment in a hair cell line in zebrafish and mice. In ototoxic zebrafish larvae, neuromasts and otic cells increased in numbers because of sesame oil. Furthermore, auditory function in noise-induced hearing loss (NIHL) was studied through auditory brainstem response to evaluate the therapeutic effects of sesame oil. Sesame oil reduced the hearing threshold shift in response to clicks and 8, 16-kHz tone bursts in NIHL mice. Auditory-protective effect of sesame oil was seen in zebrafish and mice; therefore, we used chromatographic analysis to study sesamin, which is the major effective factor in sesame oil. To investigate its effects related to auditory function, we studied the hearing-related gene, Tecta, using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide (MTT) assay. Auditory cell proliferation was induced by treatment with sesame oil and sesamin using Tecta (Tectorin Alpha) regulation. The expression of Tecta increases in the apex area of the cochlear hair cells as they grow, and their activity is enhanced by sesame oil and sesamin. These results provide a novel mechanistic insight into the sesame oil activities and suggest that sesamin, the key constituent in sesame oil, is responsible for its auditory function related benefits, including protection of auditory cells and reversal of their impairments.

The role of nutraceuticals in prevention and treatment of hypertension: An updated review of the literature

Hypertension (HTN) is a worldwide epidemic in both developed and developing countries. It is one of the leading causes of major health problems such as cardiovascular disease, stroke, and heart attack. In recent years, several studies have reported associations between specific dietary ingredients and improving HTN. Nutraceuticals are natural food components with pharmacological properties. Reports suggest that functional foods and nutraceutical ingredients might support patients to obtain the desired therapeutic blood pressure (BP) goals and reduce cardiovascular risks by modulating various risk factors such as oxidative stress, renin-angiotensin system hyperactivity, inflammation, hyperlipidemia, and vascular resistance. We review the recent clinical experiments that have evaluated the biological and pharmacological activities of several types of nutraceuticals, including sour tea, cocoa, common spices, vitamin C, vitamin E, lycopene, flavonoids, coenzyme Q10, milk's tripeptides, calcium, magnesium, polyunsaturated fatty acids, and prebiotics in preventing and treating HTN. This review summarizes recent knowledge about the impact of common nutraceuticals for the regulation of BP.

Cerebral Small Vessel Disease (CSVD) - Lessons From the Animal Models

Cerebral small vessel disease (CSVD) refers to a spectrum of clinical and imaging findings resulting from pathological processes of various etiologies affecting cerebral arterioles, perforating arteries, capillaries, and venules. Unlike large vessels, it is a challenge to visualize small vessels in vivo, hence the difficulty to directly monitor the natural progression of the disease. CSVD might progress for many years during the early stage of the disease as it remains asymptomatic. Prevalent among elderly individuals, CSVD has been alarmingly reported as an important precursor of full-blown stroke and vascular dementia. Growing evidence has also shown a significant association between CSVD's radiological manifestation with dementia and Alzheimer's disease (AD) pathology. Although it remains contentious as to whether CSVD is a cause or sequelae of AD, it is not far-fetched to posit that effective therapeutic measures of CSVD would mitigate the overall burden of dementia. Nevertheless, the unifying theory on the pathomechanism of the disease remains elusive, hence the lack of effective therapeutic approaches. Thus, this chapter consolidates the contemporary insights from numerous experimental animal models of CSVD, to date: from the available experimental animal models of CSVD and its translational research value; the pathomechanical aspects of the disease; relevant aspects on systems biology; opportunities for early disease biomarkers; and finally, converging approaches for future therapeutic directions of CSVD.

Depicting the Core Transcriptome Modulating Multiple Abiotic Stresses Responses in Sesame (Sesamum indicum L.)

Sesame is a source of a healthy vegetable oil, attracting a growing interest worldwide. Abiotic stresses have devastating effects on sesame yield; hence, studies have been performed to understand sesame molecular responses to abiotic stresses, but the core abiotic stress-responsive genes (CARG) that the plant reuses in response to an array of environmental stresses are unknown. We performed a meta-analysis of 72 RNA-Seq datasets from drought, waterlogging, salt and osmotic stresses and identified 543 genes constantly and differentially expressed in response to all stresses, representing the sesame CARG. Weighted gene co-expression network analysis of the CARG revealed three functional modules controlled by key transcription factors. Except for salt stress, the modules were positively correlated with the abiotic stresses. Network topology of the modules showed several hub genes predicted to play prominent functions. As proof of concept, we generated over-expressing Arabidopsis lines with hub and non-hub genes. Transgenic plants performed better under drought, waterlogging, and osmotic stresses than the wild-type plants but did not tolerate the salt treatment. As expected, the hub gene was significantly more potent than the non-hub gene. Overall, we discovered several novel candidate genes, which will fuel investigations on plant responses to multiple abiotic stresses.

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 Emerging Oilseed Crop Sesamum indicum Enters the "Omics" Era

Sesame (Sesamum indicum L.) is one of the oldest oilseed crops widely grown in Africa and Asia for its high-quality nutritional seeds. It is well adapted to harsh environments and constitutes an alternative cash crop for smallholders in developing countries. Despite its economic and nutritional importance, sesame is considered as an orphan crop because it has received very little attention from science. As a consequence, it lags behind the other major oil crops as far as genetic improvement is concerned. In recent years, the scenario has considerably changed with the decoding of the sesame nuclear genome leading to the development of various genomic resources including molecular markers, comprehensive genetic maps, high-quality transcriptome assemblies, web-based functional databases and diverse daft genome sequences. The availability of these tools in association with the discovery of candidate genes and quantitative trait locis for key agronomic traits including high oil content and quality, waterlogging and drought tolerance, disease resistance, cytoplasmic male sterility, high yield, pave the way to the development of some new strategies for sesame genetic improvement. As a result, sesame has graduated from an "orphan crop" to a "genomic resource-rich crop." With the limited research teams working on sesame worldwide, more synergic efforts are needed to integrate these resources in sesame breeding for productivity upsurge, ensuring food security and improved livelihood in developing countries. This review retraces the evolution of sesame research by highlighting the recent advances in the "Omics" area and also critically discusses the future prospects for a further genetic improvement and a better expansion of this crop.

Identification of chemical constituents of Zanthoxylum heitzii stem bark and their insecticidal activity against the malaria mosquito Anopheles gambiae

Background

Zanthoxylum heitzii bark extracts have insecticidal properties and have been reported to be used against malaria in Western Africa. Previously, it has been shown that a hexane extract of the bark is toxic to adult females of the mosquito Anopheles gambiae, a malaria vector. As part of our project on the control of malaria vectors using plant extracts, the phytochemistry of Z. heitzii bark hexane extract has been investigated with the aim to identify the major components with adulticidal and larvicidal effects on An. gambiae.

Methods

Z. heitzii stem bark was extracted with hexane, and the extract was fractionated to isolate major components from the bark, identified by NMR spectroscopy. Isolated compounds were tested for toxicity towards adult female An. gambiae mosquitoes and for larvicidal effects towards An. gambiae.

Results

The alkaloid dihydronitidine, the sesquiterpenoid caryophyllene oxide, the amide pellitorine and the lignan sesamin were identified as the major constituents in Z. heitzii bark. Pellitorine was toxic to both adult insects (LD₅₀ 50 ng/mg insect) and larvae (LD₅₀ 13 μg/ml). None of the other compounds were toxic to adults, but caryophyllene oxide and sesamin exhibited moderate larvicidal effects (LD₅₀ > 150 μg/ml). A mixture of the four compounds in the same ratio as in the hexane extract showed higher toxicity (LD₅₀ 34 ng/mg insect) towards adult insects than the pure compounds.

Conclusion

The toxicity of Z. heitzii bark hexane extract to An. gambiae is mostly due to pellitorine, although interactions between pellitorine and other, inactive constituents may enhance the activity of the extract.

The effect of sesamin on airway fibrosis in vitro and in vivo

Airway fibrosis, which is a crucial pathological condition occurring in various types of pulmonary disorders, is characterized by accumulation and activation of fibroblast cells, deposition of extracellular matrix (ECM) proteins, and increase of airway basement membrane. Transforming growth factor beta 1 (TGF-β1) is the principal profibrogenic cytokine that is responsible for fibrotic responses. In the present study, we aimed to investigate the antifibrotic effects of the natural polyphenolic compound, sesamin, on TGF-β1-induced fibroblast proliferation and activation, epithelial-mesenchymal transition (EMT), and ovalbumin (OVA)-induced airway fibrosis in vivo. We found that sesamin attenuated TGF-β1-induced proliferation of cultured lung fibroblasts. Sesamin inhibited TGF-β1-stimulated expression of alpha smooth muscle actin (α-SMA), suggesting that sesamin plays an inhibitory role in fibroblast activation. Sesamin blocked upregulation of the mesenchymal markers (fibronectin and vimentin) and downregulation of the epithelial marker (E-cadherin), indicating an inhibitory effect on TGF-β1-induced EMT in A549 cells. TGF-β1-induced Smad3 phosphorylation was also significantly reduced by sesamin in both cultured fibroblast and A549 cells. In the airway fibrosis induced by OVA in mice, sesamin inhibited the accumulation of α-SMA-positive cells and expression of collagen I in the airway. Histological studies revealed that sesamin protected against subepithelial fibrosis by reducing myofibroblast activation and collagen accumulation in the ECM. OVA-induced thickening of basement membrane was significantly alleviated in animals receiving sesamin treatments. These results suggest a therapeutic potential of sesamin as an antifibrotic agent.

Bioactive lignans from sesame (Sesamum indicum L.): evaluation of their antioxidant and antibacterial effects for food applications

Antioxidants protect the body from various disease conditions through their ability to neutralize the effects of free radicals. Synthetic antioxidants are extensively used in processed foods for prevention of oxidation and retention of sensory quality. Consumer awareness and preference has led to a vigorous interest in the search for natural antioxidants. Sesamin and sesamolin, the major lignans present in sesame oil, are known for their antioxidative properties. Roasted sesame oil has a higher concentration of sesamol, the thermally degraded product of sesamolin, which is considered a more potent antioxidant compared to its parent molecule. The isolated lignans and sesamol were tested for their antioxidant, free radical scavenging and antibacterial properties. Sesamol is the best antioxidant and free radical scavenger amongst the molecules studied with IC50 value of 5.44 μg / mL (DPPH radical scavenging activity). Antibacterial assays against food borne pathogens revealed sesamol to be an antimicrobial agent with minimal inhibitory concentration (MIC) of 2 mg /mL in the culture. Its activity was synergistic with γ-tocopherol, also present in sesame seeds. Inhibition of browning (60-65 %) in fruit pulps (apple, banana and potato) was observed in presence of 20 μM sesamol.

Antioxidant Action of Solid Preparation of Xingnaojing in SHRSP

We investigated the antioxidant action of a solid preparation of Xingnaojing (XNJ) and ascorbic acid (AA) in stroke-prone spontaneously hypertensive rats (SHRSP). The total antioxidant states in the plasma, systolic blood pressure, and heart rate were measured every 2 weeks, and lipid peroxidation, expressed as thiobarbituric acid-reactive substances in plasma, was measured in the 6th week. The results showed that AA and XNJ significantly increased the total antioxidant status in plasma and reduced malondialdehyde in the plasma. These data suggest that during 6-week administration, XNJ has antioxidant action on SHRSP, which may relate to its generalized inhibition of lipid peroxidation and promotion of the total antioxidant state. These results demonstrated that orally treated XNJ has an antioxidant effect on SHRSP plasma.

Quercetin and sesamin protect dopaminergic cells from MPP+-induced neuroinflammation in a microglial (N9)-neuronal (PC12) coculture system

A growing body of evidence indicates that the majority of Parkinson's disease (PD) cases are associated with microglia activation with resultant elevation of various inflammatory mediators and neuroinflammation. In this study, we investigated the effects of 2 natural molecules, quercetin and sesamin, on neuroinflammation induced by the Parkinsonian toxin 1-methyl-4-phenylpyridinium (MPP⁺) in a glial-neuronal system. We first established that quercetin and sesamin defend microglial cells against MPP⁺-induced increases in the mRNA or protein levels of 3 pro-inflammatory cytokines (interleukin-6, IL-1β and tumor necrosis factor-alpha), as revealed by real time-quantitative polymerase chain reaction and enzyme-linked immunoabsorbent assay, respectively. Quercetin and sesamin also decrease MPP⁺-induced oxidative stress in microglial cells by reducing inducible nitric oxide synthase protein expression as well as mitochondrial superoxide radicals. We then measured neuronal cell death and apoptosis after MPP⁺ activation of microglia, in a microglial (N9)-neuronal (PC12) coculture system. Our results revealed that quercetin and sesamin rescued neuronal PC12 cells from apoptotic death induced by MPP⁺ activation of microglial cells. Altogether, our data demonstrate that the phytoestrogen quercetin and the lignan sesamin diminish MPP⁺-evoked microglial activation and suggest that both these molecules may be regarded as potent, natural, anti-inflammatory compounds.

Acute and long-term hemodynamic effects of sesame oil consumption in hypertensive men

The possible effects of sesame oil on hemodynamics are unknown. The aim of the study was to investigate the acute and long-term effects of sesame oil on hemodynamic responses in hypertensive men. The authors enrolled 30 hypertensive men in a two-phase study. In the first phase, patients consumed 35 g of either sesame oil or control oil. Central and peripheral blood pressure, pulse wave velocity, augmentation index (AI), C-reactive protein, tumor necrosis factor α, malonydealdehyde, and total antioxidant capacity (TAC) were assessed at fast and 2 hours postprandially. In the second phase, patients consumed 35 g of either sesame oil or control oil daily for 2 months. The above-mentioned parameters were assessed before and following 15, 30, and 60 days of oil consumption. Sesame oil decreased central and peripheral diastolic pressures 1 hour postprandially (P=.006). Fifteen days of sesame oil intake decreased peripheral systolic blood pressure (P=.016) and heart rate-corrected AI75 (P=.017) and increased TAC (P=.007). This is the first study to demonstrate a favorable acute and long-term effect of sesame oil on hemodynamics in hypertensive men. Further research is warranted to establish the potential protective role of sesame oil.

Sesamin: A Naturally Occurring Lignan Inhibits CYP3A4 by Antagonizing the Pregnane X Receptor Activation

Inconsistent expression and regulation of drug-metabolizing enzymes (DMEs) are common causes of adverse drug effects in some drugs with a narrow therapeutic index (TI). An important cytochrome, cytochrome P450 3A4 (CYP3A4), is predominantly regulated by a nuclear receptor, pregnane X receptor (PXR). Sesamin, a major lignan constituent in sesame seeds and oil, exhibits a variety of biological functions; however, the effect of sesamin on the modulation of CYP3A4 is not well understood. In this study, the effects of sesamin on the PXR-CYP3A4 pathway were characterized, as well as the underlying mechanisms of those effects. Sesamin potently attenuated CYP3A4 induction in a dose-dependent manner by blocking the activation of PXR. The PXR inducer-mediated inhibition of CYP3A4 was further evidenced by the ability of sesamin to attenuate the effects of several PXR ligands in the CYP3A4 reporter assay. Further mechanistic studies showed that sesamin inhibited PXR by interrupting the interacting with coregulators. These results may lead to the development of new therapeutic and dietary approaches to reduce the frequency of inducer-drug interaction. Sesamin was established as a novel inhibitor of PXR and may be useful for modulating DMEs expression and drug efficacies. Modification of CYP3A4 expression and activity by consumption of sesamin may have important implications for drug safety.

Effect of sesame seed on lipid profile and redox status in hyperlipidemic patients

Pre-clinical studies suggest that sesame and its lignans induce beneficial changes in risk factors related to cardiovascular disease. This study was designed to investigate the effects of sesame on reducing serum lipids and enhancing antioxidant capacity in 38 hyperlipidemic patients who were divided into two groups randomly. For all individuals along the 60 days of study period, the same drug treatments were considered. Intervention group patients were supposed to eat 40 g white sesame seeds daily, and instead of these calories, 240 kcal was removed from their diet. Anthropometric measurements including height, weight and body mass index (BMI) were measured. We assessed lipid profile and oxidative stress indicators such as glutathione peroxidase (GPX), superoxide dismutase (SOD) and thiobarbituric acid reactive substances (TBARS) before and after the intervention. Significant differences among and between the groups were determined by independent t-test and paired sample t-test using 13th version of statistical package for the social sciences. The results showed that the diet with sesame significantly decreased the levels of serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) and TC/HDL-C ratio. Lipid peroxidation (TBARS) decreased while the activities of GPX and SOD were increased. There were no significant changes in anthropometric indexes such as weight and BMI after consumption of sesame. The results suggested that sesame seed supplementation decreased serum TC, LDL-C and lipid peroxidation, and increased antioxidant status in hyperlipidemic patients.

Structural features and bioactivities of the chitosan

Fourier transform infrared (FT-IR) spectroscopic studies (3500-600 cm(-1)) showed some different bands of chitosan. The absorption at 3439 cm(-1) is stretching vibration of -OH and -NH(2) bonds, indicating the association of the hydrogen-bond between them. The bands at 1659, 1599 and 1321 cm(-1) are attributable to the peaks of stretching vibrations of amide I (ν((C=O))), II (δ((N-H))), and the peak of stretching and bending vibrations of III (ν((C-N))) (δ((N-H))). The chitosan showed strong free radical scavenging activities. Pretreatment with chitosan significantly prevented the decrease of antioxidant enzymes activities and the increase of p-JNK at 3 h after renal ischemia and reduced renal tubular epithelial cell apoptosis.

The mechanism underlying the synergetic hypocholesterolemic effect of sesamin and α-tocopherol in rats fed a high-cholesterol diet

Sesamin is a major lignan in sesame seed. We confirmed that ingestion of sesamin and α-tocopherol synergistically reduced the concentration of blood cholesterol in rats given a high-cholesterol diet. To elucidate the molecular mechanism behind this effect, we analyzed the gene-expression profiles in rat liver after co-ingestion of sesamin and α-tocopherol. Six-week-old male Sprague-Dawley rats were fed a 1% cholesterol diet (HC) or HC containing 0.2% sesamin, 1% α-tocopherol or sesamin + α-tocopherol for 10 days. Blood samples were collected on days 1, 3, 7, and 10 and livers were excised on day 10. The gene expressions of ATP-binding cassette, sub-family G (WHITE), members 5 (ABCG5) and 8 (ABCG8) were significantly increased, while the gene expression of apolipoprotein (Apo) A4 was significantly decreased. ABCG5 and ABCG8 form a functional heterodimer that acts as a cholesterol efflux transporter, which contributes to the excretion of cholesterol from the liver. ApoA4 controls the secretion of ApoB, which is a component of low-density-lipoprotein cholesterol. These studies indicate that the cholesterol-lowering mechanism underlying the effects of co-ingestion of sesamin and α-tocopherol might be attributable to increased biliary excretion of cholesterol and reduced ApoB secretion into the bloodstream.

Sesamin modulates tyrosine hydroxylase, superoxide dismutase, catalase, inducible NO synthase and interleukin-6 expression in dopaminergic cells under MPP+-induced oxidative stress

Oxidative stress is regarded as a mediator of nerve cell death in several neurodegenerative disorders, such as Parkinson's disease. Sesamin, a lignan mainly found in sesame oil, is currently under study for its anti-oxidative and possible neuroprotective properties. We used 1-methyl-4-phenyl-pyridine (MPP(+)) ion, the active metabolite of the potent parkinsonism-causing toxin 1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine, to produce oxidative stress and neurodegeneration in neuronal PC12 cells, which express dopamine, as well as neurofilaments. Our results show that picomolar doses of sesamin protected neuronal PC12 cells from MPP(+)-induced cellular death, as revealed by colorimetric measurements and production of reactive oxygen species. We also demonstrated that sesamin acted by rescuing tyrosine hydroxylase levels from MPP(+)-induced depletion. Sesamin, however, did not modulate dopamine transporter levels, and estrogen receptor-alpha and -beta protein expression. By examining several parameters of cell distress, we found that sesamin also elicited a strong increase in superoxide dismutase activity as well as protein expression and decreased catalase activity and the MPP(+) stimulated inducible nitric oxide synthase protein expression, in neuronal PC12 cells. Finally, sesamin possessed significant anti-inflammatory properties, as disclosed by its potential to reduce MPP(+)-induced interleukin-6 mRNA levels in microglia. From these studies, we determined the importance of the lignan sesamin as a neuroprotective molecule and its possible role in complementary and/or preventive therapies of neurodegenerative diseases.

Consumption of bonito extract suppresses the decrease in cerebral blood flow in stroke-prone spontaneously hypertensive rats

The effect of consuming bonito extract (BE) on cerebral blood flow was evaluated in stroke-prone spontaneously hypertensive rats (SHRSP), a cerebrovascular disease model. BE dissolved in drinking water was given to 5-week-old male SHRSP for 7 weeks. Tap water was given to the control group. At the age of 12 weeks, blood flow and vascular diameter were measured in the middle cerebral artery. Both cerebral blood flow and cerebral vessel width were greater in the BE group than in the control group. Also, stroke occurred in 7 (with death in 2) of the 8 animals in the control group but in none of the 6 animals in the BE group. To clarify its mechanism, the expressions of nitrogen oxide synthase (NOS) and the superoxide dismutase activity (SOD) in the brain were evaluated. NOS mRNA expression and SOD activity in the cerebrum were higher in the BE group. These results suggest that the consumption of BE suppresses the decrease of cerebral blood flow and reduces the risk of stroke to maintain vasorelaxation through the production of nitrogen oxide and suppression of active oxygen generation.

Neuronal vulnerability of stroke-prone spontaneously hypertensive rats to ischemia and its prevention with antioxidants such as vitamin E

Stroke-prone spontaneously hypertensive rats (SHRSP/Izm) develop severe hypertension, and more than 95% of them die of cerebral stroke. Hypoxic stimulation followed by oxygen reperfusion induces neuronal damage in both normotensive Wistar Kyoto/Izm (WKY/Izm) and SHRSP/Izm rats, and the percentage of neurons that undergo apoptosis during hypoxia-reperfusion is markedly higher in SHRSP/Izm rats than in WKY/Izm rats. The biochemical characteristics of the SHRSP/Izm rats, unlike those of WKY/Izm rats, might act as a factor in the stroke proneness of SHRSP/Izm rats. In the hippocampus, the formation of hydroxyl radicals and the cerebral blood flow-independent formation of nitric oxide (NO) were strongly increased after reperfusion in SHRSP/Izm rats, and the neuronal expression of the thioredoxin and Bcl-2 genes was significantly decreased in the SHRSP/Izm rats compared with the WKY/Izm rats. On the other hand, the effects of antioxidants against neuronal death associated with cerebral ischemia-reperfusion were stronger in the SHRSP/Izm rats, in which the addition of vitamin E or ebselen almost completely inhibited neuronal death. Namely, the addition of 100 microg/ml of vitamin E under hypoxia/reoxygenation (H/R) conditions completely inhibited WKY and SHRSP/Izm neuronal death. Vitamin E exerts a marked inhibitory effect against neuronal damage via its incorporation into mitochondrial membranes, where it captures reactive oxygen and free radicals. The susceptibility of neurons to apoptosis in SHRSP/Izm rats is partly due to an insufficiency of mitochondrial redox regulation and apoptosis-inhibitory proteins. In this review, we describe the neuronal vulnerability of SHRSP/Izm rats induced by cerebral ischemia and the effects of antioxidants such as vitamin E.

Sesame supplementation does not improve cardiovascular disease risk markers in overweight men and women

BACKGROUND AND AIMS

Pre-clinical studies suggest that sesame and its lignans induce beneficial changes in risk factors related to cardiovascular disease and increase the bioavailability of mammalian lignans. However, only very few intervention trials have investigated the potential bioactivities of sesame in humans. We aimed to investigate the effects of sesame supplementation in humans on blood lipids, blood pressure, systemic oxidative stress, inflammatory biomarkers and mammalian lignan metabolism.

METHODS AND RESULTS

We conducted a randomized, placebo-controlled cross-over intervention trial at a university research centre. Overweight or obese men and women (n=33) consumed 25g/d of sesame ( approximately 50mg/d of sesame lignan) and an iso-caloric placebo matched for macronutrient composition for 5 wks each. Each intervention period was preceded by a 4-wk washout period. Blood lipid profiles, day time ambulatory blood pressure, oxidative stress and inflammatory biomarkers and urinary mammalian lignans were measured before and after each intervention. Results are presented as the effect of sesame supplementation relative to placebo. Urinary excretion of the mammalian lignans, enterolactone and enterodiol, increased by approximately 8-fold (P<0.001). Blood lipids and blood pressure were not altered. In addition, markers of systemic inflammation (C-reactive protein, interleukin-6, tumor necrosis factor-alpha) and lipid peroxidation (F(2)-isoprostanes) were not affected.

CONCLUSION

Supplementation with 25g/d of sesame can significantly increase the exposure to mammalian lignans. However, this did not cause any improvement in markers of cardiovascular disease risk in overweight or obese men and women.

Effect of glutathione peroxidase mimic ebselen (PZ51) on endothelium and vascular structure of stroke‐prone spontaneously hypertensive rats

BACKGROUND

To investigate whether extrinsic antioxidant seleno-glutathione peroxidase mimic ebselen (PZ51) can protect endothelium and vascular structure of stroke-prone spontaneously hypertensive rats (SHRsp) during the chronic process of hypertension.

METHODS

Twenty-two 8-week-old SHRsp were randomized into a PZ51 group and a control group, and administered by gavage for 6 weeks. We examined the level of nitric oxide (NO) and malonaldehyde (MDA) in plasma. The intima-media thickness (IMT) of the common carotid artery (CCA) was measured by an image-analysis system. The endothelium of the CCA was observed by scanning electron microscopy. The eNOS protein of the major artery was assayed by immunohistochemistry and western blotting.

RESULTS

Compared with the control group, PZ51 decreased plasma MDA (7.88+/-1.06 vs 10.88+/-1.73 nmol/l, p<0.001) and increased plasma NO (40.02+/-9.74 vs 22.22+/-10.05 micromol/l, p<0.001), increased eNOS protein expression (8.25+/-2.36 vs 4.46+/-3.14, p=0.026), decreased IMT (69.85+/-5.47 vs 76.60+/-6.53 microm, p<0.05) significantly and alleviated the damage to the endothelium of the CCA.

CONCLUSION

Administration of PZ51 for 6 weeks can protect the endothelium and inhibit vascular remodeling, maybe due to its suppression of lipid peroxide formation and increase in eNOS protein expression.

Antihypertensive effects of sesamin in humans

Sesamin, one of the lignans contained in sesame, has been considered to have medicinal effects. It has been reported that sesamin suppressed the development of hypertension in rats. In this study, using a double-blind, cross-over, placebo-controlled trial, we investigated the effect of 4-wk administration of sesamin on blood pressure (BP) in mildly hypertensive humans. Twenty-five middle-aged subjects with mild hypertension were divided into two groups, matched by age and body mass index. Twelve subjects were allocated to 4-wk intake of capsules with 60 mg sesamin per day and 13 subjects to 4-wk intake of a placebo (period 1). After a 4-wk washout period, the subjects received the alternative administration for 4 wk (period 2). BP decreased with statistical significance with the administration of sesamin (systolic: 137.6+/-2.2 to 134.1+/-1.7 mmHg, p=0.044, diastolic: 87.7+/-1.3 to 85.8+/-1.0 mmHg, p=0.045), but little changed with the placebo (systolic: 135.0+/-1.8 to 135.1+/-1.7 mmHg, diastolic: 85.9+/-1.2 to 86.6+/-1.2 mmHg). In conclusion, 4-wk administration of 60 mg sesamin significantly decreased BP by an average of 3.5 mmHg systolic BP and 1.9 mmHg diastolic BP. These results suggest that sesamin has an antihypertensive effect in humans. Epidemiological studies suggested that a 2-3 mmHg decrease in BP reduces the rate of cardiovascular diseases; therefore, it is considered that BP reduction achieved by sesamin may be meaningful to prevent cardiovascular diseases.

A survey of sesamin and composition of tocopherol variability from seeds of eleven diverse sesame (Sesamum indicum L.) genotypes using HPLC-PAD-ECD

The objective of this study was to determine the composition and content of sesamin and desmethyl tocopherols such as alpha-tocopherol (alphaT), delta-tocopherol (deltaT) and gamma-tocopherol (gammaT) in seeds of sesame (Sesamum indicum L.) for 11 genotypes conserved in the United States Department of Agriculture (USDA), Agricultural Research Service (ARS) and Plant Genetic Resources Conservation Unit (PGRCU) in Griffin, Georgia, USA. Seed accessions studied were collections from eight countries worldwide, including one landrace from Thailand and two cultivars from Texas, USA. Novel methodologies and analytical techniques described herein consisted of reverse-phase high-performance liquid chromatography (HPLC) connected in series with two detection systems specific for each analyte class. Photodiode array detection was employed for sesamin analysis and electrochemical array detection was used in the determination of tocopherols. A preliminary study was conducted to assess sesamin levels in 2003 and tocopherol levels in 2004 from sesame seed samples conserved at the USDA, ARS and PGRCU. In 2005, sesame seed samples were grown, harvested and evaluated for sesamin as well as tocopherol levels. The overall results (n = 3) showed that sesamin, alphaT, deltaT and gammaT levels were 0.67-6.35 mg/g, 0.034-0.175 microg/g, 0.44-3.05 microg/g and 56.9-99.3 microg/g respectively, indicating that the sesame seed accessions contained higher levels of sesamin and gammaT compared with alphaT and deltaT. Statistical analysis was conducted and significant differences were observed among the 11 different sesame genotypes. This suggests that genetic, environmental and geographical factors influence sesamin and desmethyl tocopherol content.

Salt: its role in chronic kidney disease

Few controversies in medicine have such a long history as that of whether salt is identifiably dangerous or not dangerous. The most common reported association between excess dietary salt intake and clinical outcome has been in the field of hypertension, but dietary sodium intake mediates effects that go far beyond, and are independent of, extracellular fluid expansion and elevation in blood pressure. For nephrologists, clinical trials that demonstrate no negative outcome of a high salt diet in the general population are thus not particularly assuasive, because patients with chronic kidney disease (CKD) represent an entity that is by no means comparable to the general population. This review takes a look at the challenges associated with salt balance in CKD patients (particularly at K/DOQI stage 5), followed by a summary of current concepts believed to play a part in salt-mediated pathophysiology, and the conclusion, based on the present state of scientific knowledge, that it appears advisable to advocate low dietary salt intake in this patient population.

Sesamin, a lignan of sesame, down-regulates cyclin D1 protein expression in human tumor cells

Sesamin is a major lignan constituent of sesame and possesses multiple functions such as antihypertensive, cholesterol-lowering, lipid-lowering and anticancer activities. Several groups have previously reported that sesamin induces growth inhibition in human cancer cells. However, the nature of this growth inhibitory mechanism remains unknown. The authors here report that sesamin induces growth arrest at the G1 phase in cell cycle progression in the human breast cancer cell line MCF-7. Furthermore, sesamin dephosphorylates tumor-suppressor retinoblastoma protein (RB). It is also shown that inhibition of MCF-7 cell proliferation by sesamin is correlated with down-regulated cyclin D1 protein expression, a proto-oncogene that is overexpressed in many human cancer cells. It was found that sesamin-induced down-regulation of cyclin D1 was inhibited by proteasome inhibitors, suggesting that sesamin suppresses cyclin D1 protein expression by promoting proteasome degradation of cyclin D1 protein. Sesamin down-regulates cyclin D1 protein expression in various kinds of human tumor cells, including lung cancer, transformed renal cells, immortalized keratinocyte, melanoma and osteosarcoma. Furthermore, depletion of cyclin D1 protein using small interfering RNA rendered MCF-7 cells insensitive to the growth inhibitory effects of sesamin, implicating that cyclin D1 is at least partially related to the antiproliferative effects of sesamin. Taken together, these results suggest that the ability of sesamin to down-regulate cyclin D1 protein expression through the activation of proteasome degradation could be one of the mechanisms of the antiproliferative activity of this agent.

Comparative analysis of sesame lignans (sesamin and sesamolin) in affecting hepatic fatty acid metabolism in rats

Effects of sesamin and sesamolin (sesame lignans) on hepatic fatty acid metabolism were compared in rats. Rats were fed either a lignan-free diet, a diet containing 0.6 or 2 g/kg lignan (sesamin or sesamolin), or a diet containing both sesamin (1.4 g/kg) and sesamolin (0.6 g/kg) for 10 d. Sesamin and sesamolin dose-dependently increased the activity and mRNA abundance of various enzymes involved in hepatic fatty acid oxidation. The increase was much greater with sesamolin than with sesamin. These lignans increased parameters of hepatic fatty acid oxidation in an additive manner when added simultaneously to an experimental diet. In contrast, they decreased the activity and mRNA abundance of hepatic lipogenic enzymes despite dose-dependent effects not being necessarily obvious. Sesamin and sesamolin were equally effective in lowering parameters of lipogenesis. Sesamolin accumulated in serum at 33- and 46-fold the level of sesamin at dietary concentrations of 0.6 and 2 g/kg, respectively. The amount of sesamolin accumulated in liver was 10- and 7-fold that of sesamin at the respective dietary levels. Sesamolin rather than sesamin can account for the potent physiological effect of sesame seeds in increasing hepatic fatty acid oxidation observed previously. Differences in bioavailability may contribute to the divergent effects of sesamin and sesamolin on hepatic fatty acid oxidation. Sesamin compared to sesamolin was more effective in reducing serum and liver lipid levels despite sesamolin more strongly increasing hepatic fatty acid oxidation.

Corosolic acid prevents oxidative stress, inflammation and hypertension in SHR/NDmcr-cp rats, a model of metabolic syndrome

Corosolic acid (CRA), a constituent of banaba leaves, has been reported to have anti-inflammatory and hypoglycemic activities. The aim of this study was to determine the effects of CRA on metabolic risk factors including obesity, hypertension, hyperinsulinemia, hyperglycemia, and hyperlipidemia together with oxidative stress and inflammation, all of which are characteristic of the SHR/NDmcr-cp (cp/cp) (SHR-cp) rat, an animal model of metabolic syndrome. Six-week-old male SHR-cp rats were fed a high fat diet containing 0.072% CRA for 14 weeks. Treatment with CRA lowered blood pressure, which was elevated in control animals, by 10% after 8 weeks, and serum free fatty acids by 21% after 2 weeks. CRA treatment resulted in decreases in the levels of the oxidative stress markers thiobarbituric acid-reactive substances and 8-hydroxydeoxyguanosine by 27% and 59%, respectively, after 2 weeks. CRA treatment also reduced the levels of myeloperoxidase markers, 3-nitrotyrosine and 3-chlorotyrosine by 38% and 39%, respectively, after 10 weeks, and tended to decrease the levels of high sensitivity C-reactive protein, a marker of inflammation, after 6 weeks. However, CRA had no effect on weight gain or hyperglycemia. These results demonstrate that CRA can ameliorate hypertension, abnormal lipid metabolism, and oxidative stress as well as the inflammatory state in SHR-cp rats. This implies that CRA can be beneficial for preventing atherosclerosis-related diseases that are an increasing health care problem worldwide.

Sesamol induces nitric oxide release from human umbilical vein endothelial cells

Sesamol, which is derived from sesame seed lignans, is reportedly an antioxidant. Nitric oxide (NO), the most important vascular relaxing factor, is regulated in the endothelium. In addition, NO is involved in protecting endothelium and has antiatherosclerotic and antithrombotic activities. The endothelium produces NO through the regulation of both endothelial NO synthase (eNOS) expression and activity in endothelial cells. This study sought to investigate the effect of sesamol on NO released from human umbilical vein endothelial cells (HUVEC) and to examine the expression and activity of eNOS. Sesamol induced NO release from endothelial cells in a dose-dependent manner (from 1 to 10 microM), as measured 24 h after treatment; the expression of the eNOS gene at both transcription and translation levels; and NOS activity in endothelial cells. The content of cGMP was also increased by sesamol through NO signaling. The transcription of eNOS induced by sesamol was confirmed through the activation of PI-3 kinase-Akt (protein kinase B) signaling. The results demonstrate that sesamol induces NOS signaling pathways in HUVEC and suggest a role for sesamol in cardiovascular reactivity in vivo.

Antihypertensive effect of green coffee bean extract on mildly hypertensive subjects

A water-soluble green coffee bean extract (GCE) has been shown to be effective against hypertension in both spontaneously hypertensive rats and humans. This multicenter, randomized, double-blind, placebo-controlled, parallel group study evaluated the dose-response relationship of GCE in 117 male volunteers with mild hypertension. Subjects were randomized into four groups: a placebo and three drug groups that received 46 mg, 93 mg, or 185 mg of GCE once a day. After 28 days, systolic blood pressure (SBP) in the placebo, 46 mg, 93 mg, and 185 mg groups was reduced by -1.3+/-3.0 mmHg, -3.2+/-4.6 mmHg, -4.7+/-4.5 mmHg, and -5.6+/-4.2 mmHg from the baseline, respectively. The decreases in SBP in the 93 mg group (p<0.05) and the 185 mg group (p<0.01) were statistically significant compared with the placebo group. Diastolic blood pressure (DBP) in the placebo, 46 mg, 93 mg, and 185 mg groups was reduced by -0.8+/-3.1 mmHg, -2.9+/-2.9 mmHg, -3.2+/-3.2 mmHg, and -3.9+/-2.8 mmHg from the baseline, respectively, and significant effects were observed in the 93 mg group (p<0.05) and the 185 mg group (p<0.01) compared with the placebo group. Both blood pressures were significantly reduced in a dose-related manner by GCE (p<0.001). Adverse effects caused by GCE were not observed. The results suggested that daily use of GCE has a blood pressure-lowering effect in patients with mild hypertension.