Ginkgo biloba extract inhibits tumor necrosis factor-alpha-induced reactive oxygen species generation, transcription factor activation, and cell adhesion molecule expression in human aortic endothelial cells

Oxidative Processes and Xenobiotic Metabolism in Plants: Mechanisms of Defense and Potential Therapeutic Implications

Plants are continuously exposed to environmental challenges, including pollutants, pesticides, and heavy metals, collectively termed xenobiotics. These substances induce oxidative stress by generating reactive oxygen species (ROS), which can damage cellular components such as lipids, proteins, and nucleic acids. To counteract this, plants have evolved complex metabolic pathways to detoxify and process these harmful compounds. Oxidative stress in plants primarily arises from the overproduction of hydrogen peroxide (H2O2), superoxide anions (O2•-), singlet oxygen (1O2), and hydroxyl radicals (•OH), by-products of metabolic activities such as photosynthesis and respiration. The presence of xenobiotics leads to a notable increase in ROS, which can result in cellular damage and metabolic disruption. To combat this, plants have developed a strong antioxidant defense mechanism that includes enzymatic antioxidants that work together to eliminate ROS, thereby reducing their harmful effects. In addition to enzymatic defenses, plants also synthesize various non-enzymatic antioxidants, including flavonoids, phenolic acids, and vitamins. These compounds effectively neutralize ROS and help regenerate other antioxidants, offering extensive protection against oxidative stress. The metabolism of xenobiotic substances in plants occurs in three stages: the first involves modification, which refers to the chemical alteration of xenobiotics to make them less harmful. The second involves conjugation, where the modified xenobiotics are combined with other substances to increase their solubility, facilitating their elimination from the plant. The third stage involves compartmentalization, which is the storage or isolation of conjugated xenobiotics in specific parts of the plant, helping to prevent damage to vital cellular functions. Secondary metabolites found in plants, such as alkaloids, terpenoids, and flavonoids, play a vital role in detoxification and the defense against oxidative stress. Gaining a deeper understanding of the oxidative mechanisms and the pathways of xenobiotic metabolism in plants is essential, as this knowledge can lead to the formulation of plant-derived strategies aimed at alleviating the effects of environmental pollution and enhancing human health by improving detoxification and antioxidant capabilities, as discussed in this review.

Diesel vehicles-derived PM2.5 induces lung and cardiovascular injury attenuates by Securiniga suffruticosa: Involvement of NF-κB-mediated NLRP3 inflammasome activation pathway

Respiratory exposure to Particulate matter (PM), including Diesel exhaust particulate (DEP), causes oxidative stress-induced lung inflammation. Especially, fine particulate matter with an aerodynamic diameter less than 2.5 µm (PM2.5) is a serious air pollutant associated with various health problems including cardiovascular diseases. The present study aimed to examine the inhibitory effect of Securiniga suffruticosa (S. suffruiticosa) on DEP and PM-induced lung and cardiovascular diseases. Mice inhaled DEP by using nebulizer chamber for two weeks. Treatment with S. suffruiticosa reduced the expression of C-X-C motif ligand 1/2 in bronchoalveolar lavage fluid and Muc5ac, ICAM-1, TNF-⍺, IL-6 mRNA in lung were also attenuated by S. suffruiticosa. In thoracic aorta, DEP increased CAMs, TNF-⍺ and inflammasome markers such as NLRP3, Caspase-1, and ASC. However, S. suffruiticosa suppressed these levels. S. suffruiticosa inhibited PM2.5 induced production of intracellular reactive oxygen species (ROS); and inhibited the translocation of NF-κB p65 to the nucleus in human umbilical vein endothelial cells. Taken together, this study proved that exposure to PM2.5 induced both lung and vascular inflammation, however, S. suffruiticosa attenuated this injury via the downregulation of the NLRP3 signaling pathway. These findings suggest that S. suffruiticosa may have potential therapeutic benefit against air pollution-mediated lung and cardiovascular diseases.

Multi-compound and drug-combination pharmacokinetic research on Chinese herbal medicines

Traditional medicine has provided a basis for health care and disease treatment to Chinese people for millennia, and herbal medicines are regulated as drug products in China. Chinese herbal medicines have two features. They normally possess very complex chemical composition. This makes the identification of the constituents that are together responsible for the therapeutic action of an herbal medicine challenging, because how to select compounds from an herbal medicine for pharmacodynamic study has been a big hurdle in such identification efforts. To this end, a multi-compound pharmacokinetic approach was established to identify potentially important compounds (bioavailable at the action loci with significant exposure levels after dosing an herbal medicine) and to characterize their pharmacokinetics and disposition. Another feature of Chinese herbal medicines is their typical use as or in combination therapies. Coadministration of complex natural products and conventional synthetic drugs is prevalent worldwide, even though it remains very controversial. Natural product–drug interactions have raised wide concerns about reduced drug efficacy or safety. However, growing evidence shows that incorporating Chinese herbal medicines into synthetic drug-based therapies delivers benefits in the treatment of many multifactorial diseases. To address this issue, a drug-combination pharmacokinetic approach was established to assess drug–drug interaction potential of herbal medicines and degree of pharmacokinetic compatibility for multi-herb combination and herbal medicine–synthetic drug combination therapies. In this review we describe the methodology, techniques, requirements, and applications of multi-compound and drug-combination pharmacokinetic research on Chinese herbal medicines and to discuss further development for these two types of pharmacokinetic research.

Ginkgo biloba extract ameliorates atherosclerosis via rebalancing gut flora and microbial metabolism

The Ginkgo biloba leave extract (GbE) is widely applied in the prevention and treatment of atherosclerotic cardiovascular diseases in clinical practice. However, its mechanism of actions has not been totally elucidated. In this study, we confirmed the beneficial effects of GbE in alleviating hypercholesterolemia, inflammation and atherosclerosis in Ldlr^-/- mice, which were fed 12 weeks of Western diet (WD). Moreover, 16S rRNA sequencing revealed that GbE treatment reshaped the WD-perturbed intestinal microbiota, particularly decreased the Firmicutes/Bacteroidetes ratio and elevated the abundance of Akkermansia, Alloprevotella, Alistipes, and Parabacteroides. Furthermore, GbE treatment downregulated the intestinal transcriptional levels of proinflammatory cytokines and enhanced the expression of tight junction proteins, exerting the roles of attenuating the intestinal inflammation as well as repairing the gut barrier. Meanwhile, the targeted metabolomic analysis displayed that GbE treatment significantly reversed the dysfunction of the microbial metabolic phenotypes, including promoting the production of short chain fatty acids, indole-3-acetate and secondary bile acids, which were correlated with the atherosclerotic plaque areas. Finally, we confirmed GbE-altered gut microbiota was sufficient to alleviate atherosclerosis by fecal microbiota transplantation. In summary, our findings provide important insights into the pharmacological mechanism underlying the antiatherogenic efficacy of GbE.

Current evidence to support the therapeutic potential of flavonoids in oxidative stress-related dermatoses

BACKGROUND

Skin, as a crucial external defense organ, is more vulnerable to oxidative stress (OS) insult, reactive oxygen species (ROS)-mediated OS in particular. OS results from a redox imbalance caused by various extrinsic stimuli and occurs once the oxidants production overwhelming the antioxidants capacity, through mediating in DNA damage, lipid peroxidation (LPO), protein oxidation and a serial of signaling pathways activation/inactivation, thereby offering favorable conditions for the occurrence and development of numerous diseases especially some dermatoses, e.g. psoriasis, vitiligo, skin photodamage, skin cancer, systemic sclerosis (SSc), chloasma, atopic dermatitis (AD), pemphigus, etc. Targeting OS molecular mechanism, a variety of anti-OS agents emerge, in which flavonoids, natural plant extracts, stand out.

OBJECTIVES

To discuss the possible mechanisms of OS mediating in dermatoses and summarize the properties of flavonoids as well as their applications in OS-related skin disorders.

METHODS

Published papers on flavonoids and OS-related skin diseases were collected and reviewed via database searching on PubMed, MEDLINE and Embase, etc.

RESULTS

It has been confirmed that flavonoids, belonging to polyphenols, are a class of plant secondary metabolites widely distributed in various plants and possess diverse bioactivities especially their potent antioxidant capacity. Moreover, flavonoids benefit to suppress OS via eliminating free radicals and mediating the corresponding signals, further excellently working in the prevention and management of OS-related skin diseases.

CONCLUSION

Flavonoids have the potential therapeutic effects on oxidative stress-related dermatoses. However, more studies on specific mechanism as well as the dosage of flavonoids are needed in future.

Methyl mercury triggers endothelial leukocyte adhesion and increases expression of cell adhesion molecules and chemokines

Cardiovascular disease is the leading cause of morbidity, mortality, and health care costs in the USA, and around the world. Among the various risk factors of cardiovascular disease, environmental and dietary exposures to methyl mercury, a highly toxic metal traditionally labeled as a neurotoxin, have been epidemiologically linked to human cardiovascular disease development. However, its role in development and promotion of atherosclerosis, an initial step in more immediately life-threatening cardiovascular diseases, remains unclear. This study was conducted to examine the role that methyl mercury plays in the adhesion of monocytes to human microvascular endothelial cells (HMEC-1), and the underlying mechanisms. Methyl mercury treatment significantly induced the adhesion of monocyte to HMEC-1 endothelial cells, a critical step in atherosclerosis, while also upregulating the expression of proinflammatory cytokines interleukin-6, interleukin-8. Further, methyl mercury treatment also upregulated the chemotactic cytokine monocyte chemoattractant protein-1 and intercellular adhesion molecule-1. These molecules are imperative for the firm adhesion of leukocytes to endothelial cells. Additionally, our results further demonstrated that methyl mercury stimulated a significant increase in NF-κB activation. These findings suggest that NF-κB signaling pathway activation by methyl mercury is an important factor in the binding of monocytes to endothelial cells. Finally, by using flow cytometric analysis, methyl mercury treatment caused a significant increase in necrotic cell death only at higher concentrations without initiating apoptosis. This study provides new insights into the molecular actions of methyl mercury that can lead to endothelial dysfunction, inflammation, and subsequent atherosclerotic development.

Chinese Herbal Medicines and Active Metabolites: Potential Antioxidant Treatments for Atherosclerosis

Atherosclerosis is a complex chronic disease that occurs in the arterial wall. Oxidative stress plays a crucial role in the occurrence and progression of atherosclerotic plaques. The dominance of oxidative stress over antioxidative capacity generates excess reactive oxygen species, leading to dysfunctions of the endothelium and accelerating atherosclerotic plaque progression. Studies showed that Chinese herbal medicines and traditional Chinese medicine (TCM) might regulate oxidative stress; they have already been used to treat diseases related to atherosclerosis, including stroke and myocardial infarction. This review will summarize the mechanisms of oxidative stress in atherosclerosis and discuss studies of Chinese herbal medicines and TCM preparations treating atherosclerosis, aiming to increase understanding of TCM and stimulate research for new drugs to treat diseases associated with oxidative stress.

The Aging of Adipocytes Increases Expression of Pro-Inflammatory Cytokines Chronologically

Adipose tissue is a significant producer of pro-inflammatory cytokines in obese and old individuals. However, there is no direct evidence of whether and how aged adipocytes enhance the production of pro-inflammatory markers. We aimed to investigate whether the aging adipocytes increase pro-inflammatory markers. Swiss mouse embryonic-tissue-derived 3T3-L1 cells were differentiated into adipocytes and maintained for 60 days in the conditioned medium or 35 days in the unconditioned medium. Additionally, 20-month-old male C57BL/6 mice were fed a standard chow diet for 37 weeks until they were extremely aged, when ~75% of mice died because of aging. Accumulated lipids, pro-inflammatory markers, and nuclear factor kappa B (NF-κB) pathway markers from differentiated adipocytes were analyzed. Pro-inflammatory markers and NF-κB pathway markers of epididymal white adipose tissues (EWATs) and adipocytes from EWATs were also analyzed. We found that the aging adipocytes chronologically accumulated lipids and increased pro-inflammatory markers interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), and tumor necrosis factor-alpha (TNF-α); at the same time, NF-κB p50 markers were also increased while IκBα protein was decreased significantly in conditioned medium. Similar results were observed when differentiated adipocytes were maintained in the unconditioned medium and the adipocytes from EWATs of aged mice. We demonstrated that aging augmented chronic inflammation through the NF-κB signaling pathway in adipocytes and adipose tissue.

Effect of Probucol on Proliferation of Leukemia, Multiple Myeloma, Lymphoma, and Fibroblast Cells

Objectives

Probucol is a bisphenol antioxidant with antiinflammatory, antilipidemic and antidiabetic effect. Development and progression of cancer is closely related to chronic inflammation and oxidative stress. Agents that target these processes have been shown to modulate cancer cell proliferation. In this regard, the effect of probucol on proliferation of different cancer cell lines was investigated.

Materials and Methods

Different concentrations of probucol solutions were prepared and applied to the following cancer cell lines: K562S (imatinib sensitive) and K562R (imatinib resistant) chronic myeloid leukemia (CML) cells; U937 histiocytic lymphoma cells; HL60 acute myeloid leukemia cells; U266, H929, and RPMI8226 multiple myeloma cells; and L929 fibroblast cells. Cell viability was conducted by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.

Results

Significant toxicity was not exhibited due to probucol treatment (0.1-10 µM) in K562S and K562R CML cells, U937 histiocytic lymphoma cells, HL60 acute myeloid leukemia cells, U266 multiple myeloma cells, and L929 fibroblast cells. However, probucol treatment significantly inhibited the viability of H929 and RPMI8226 multiple myeloma cells at the concentration of 0.5-10 µM and 5-10 µM, respectively.

Conclusion

Probucol treatment slightly inhibited the viability of other cancer cell lines, but significantly inhibited the viability of H929 and RPMI8226 multiple myeloma cells. However, its effect was not potent, since a 50% reduction in cell viability could not be achieved at the concentrations of probucol treatment administered.

Nrf-2 mediated heme oxygenase-1 activation contributes to the anti-inflammatory and renal protective effects of Ginkgo biloba extract in diabetic nephropathy

ETHNOPHARMACOLOGICAL RELEVANCE

Ginkgo biloba extract (GbE) is derived from a medicinal plant and suggested as a treatment for diabetic nephropathy (DN), but the mechanism was not clarified.

AIM OF STUDY

The present study investigated whether GbE prevented DN via activation of heme oxygenase (HO)-1.

MATERIALS AND METHODS

Streptozotocin-induced diabetic mice were fed a high-fat diet to generate DN. Human and murine podocytes were used for the in vitro study.

RESULTS

GbE improved renal function via decreasing glomerular hypertrophy, the kidney/body weight ratio, and albuminuria in DN mice. GbE reversed the reduction of synaptopodin and nephrin and enhanced HO-1 expression in the kidneys of DN mice. GbE decreased the enhancement of TNF-α, IL-6, fibronectin, and lipid accumulation in the glomeruli of DN mice. GbE attenuated the uptake of oxidized low-density lipoprotein and reduced the production of ROS in high glucose-stimulated podocytes, and HO-1 inhibitor treatment abrogated the protective effects of GbE. Nuclear factor erythroid 2-related factor 2 (Nrf-2) siRNA significantly abolished the beneficial effects of GbE via decreased HO-1 expression and enhanced TNF-α and IL-6 levels.

CONCLUSIONS

GbE protected podocytes against hyperglycemia and prevented the development of DN via Nrf-2/HO-1 activation. Our findings provide further mechanistic insight into the potential use of GbE in clinical DN.

New Insight into the Mechanisms of Ginkgo Biloba Extract in Vascular Aging Prevention

BACKGROUND

Aging-associated vascular dysfunction promotes cardiovascular diseases. Recently, Ginkgo biloba extract (GBE) has attracted considerable attention in the prevention of aged vasculature.

METHODS

This review discusses the pathophysiological alterations in aged vasculature and the underlying mechanisms of GBE in vascular aging suppression.

RESULTS

Both arterial stiffening and endothelial dysfunction are critical aging-related vascular phenotypes that result in the progression of cardiovascular diseases in the general population. Consistent oxidative stress and inflammatory reaction lead to vascular dysfunction. GBE ameliorates aging-related vascular dysfunction, due to its antioxidant and anti-inflammatory properties. The main effects of GBE in aged vasculature might be associated with the longevity signaling pathways. GBE also attenuates the progression of vascular aging in diabetes mellitus via regulation of glucose and lipid metabolism.

CONCLUSION

GBE plays an important role in the prevention of vascular aging process. It is a promising therapeutic approach to ameliorate aging-related vascular dysfunction and cardiovascular diseases.

Anti-Vascular Inflammatory Effect of Ethanol Extract from Securinega suffruticosa in Human Umbilical Vein Endothelial Cells

Securiniga suffruticosa is known as a drug that has the effect of improving the blood circulation and relaxing muscles and tendons, thereby protects and strengthen kidney and spleen. Therefore, in this study, treatment of Securiniga suffruticosa showed protective effect of inhibiting the vascular inflammation in human umbilical vein endothelial cells (HUVECs) by inducing nitric oxide (NO) production and endothelial nitric oxide synthase (eNOS) coupling pathway. In this study, Securiniga suffruticosa suppressed TNF-α (Tumor necrosis factor–α) induced protein and mRNA levels of cell adhesion molecules such as intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and Interleukin-6 (IL-6). Pretreatment of HUVEC with Securiniga suffruticosa decreased the adhesion of HL-60 cells to Ox-LDL (Oxidized Low-Density-Lipoprotein)-induced HUVEC. Moreover, Securiniga suffruticosa inhibited TNF-α induced intracellular reactive oxygen species (ROS) production. Securiniga suffruticosa also inhibited phosphorylation of IκB-α in cytoplasm and translocation of NF-κB (Nuclear factor-kappa B) p65 to the nucleus. Securiniga suffruticosa increased NO production, as well increased the phosphorylation of eNOS and Akt (protein kinase B) which are related with NO production. In addition, Securiniga suffruticosa increased the protein expression of GTPCH (Guanosine triphosphate cyclohydrolase Ⅰ) and the production of BH4 in HUVEC which are related with eNOS coupling pathway. In conclusion, Securiniga suffruticosa has a protective effect against vascular inflammation and can be a potential therapeutic agent for early atherosclerosis.

Anti‑inflammatory effects of leaf and branch extracts of honeyberry (Lonicera caerulea) on lipopolysaccharide‑stimulated RAW264.7 cells through ATF3 and Nrf2/HO‑1 activation

Honeyberry (Lonicera caerulea) has long been used as a traditional medicine in China, Japan and northern Russia. Functional studies of honeyberry have mainly focused on the fruits, which have been reported to exert various pharmacological activities, including anti-inflammatory activity, with limited or no studies on the other parts of the plant, such as the leaves and branches. In the present study, the anti-inflammatory effects of extracts of the leaves (HBL), branches (HBB) and fruit (HBF) of honeyberry plant were evaluated in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. HBL and HBB significantly inhibited the production of pro-inflammatory mediators in LPS-stimulated RAW264.7 cells, and the inhibitory effects of HBL and HBB were stronger than those of HBF. HBL and HBB blocked the nuclear accumulation of p65 independently of IκB-α. HBL did not inhibit the phosphorylation of ERK1/2 or p38; however, HBB effectively inhibited the phosphorylation of p38 but not ERK1/2. HBL and HBB increased the expression of heme oxygenase-1 (HO-1) protein by inducing the nuclear accumulation of nuclear factor erythroid 2-related factor 2 (Nrf2) through the activation of the reactive oxygen species (ROS)/p38 pathway; the reduction in inducible nitric oxide synthase (iNOS) and interleukin-1β (IL-1β) expression by HBL and HBB was inhibited by HO-1 knockdown. In addition, HBL and HBB increased the expression of activating transcription factor-3 (ATF3), and the reduction in iNOS and IL-1β expression by HBL and HBB was inhibited by ATF3 knockdown. Collectively, HBL and HBB inhibited LPS-induced nuclear factor-κB activation by blocking the nuclear accumulation of p65, increasing HO-1 expression through activation of the ROS/p38/Nrf2 pathway, and increasing ATF3 expression. Furthermore, HBB inhibited LPS-induced p38 phosphorylation. These findings suggest that HBL and HBB may have great potential as natural products for the development of anti-inflammatory drugs.

Swimming exercise activates aortic autophagy and limits atherosclerosis in ApoE-/- mice

BACKGROUND

The aim of this study was to investigate the beneficial effect of swimming exercise on autophagy and atherosclerosis in mice aorta, so as to clarify the possible causal relationship between autophagy activation and atherosclerosis.

METHODS

The body weight was monitored regularly. Hematoxylin-eosin staining and Oil Red O staining was conducted to observe vascular morphology and plaque burden respectively. The levels of serum total cholesterol (TC), triglyceride (TG), soluble intercellular adhesion molecule-1 (sICAM-1), matrix metalloproteinase-9 (MMP-9) and interleukin-6 (IL-6) was examined via Enzyme-linked immu-nosorbent assays (ELISA). The mRNA expression level of autophagy markers, including LC3 and Beclin-1, was examined by real-time quantitative polymerase chain reaction (RT-PCR). The expressions of LC3-II/LC3-I and Beclin-1 are detected by Western blotting and immunohistochemistry.

RESULTS

Compared with the model group, long-term swimming exercise decreased the weight gain of ApoE^-/- mice, improved the structural disorder of artery, reduced the load of atherosclerotic lesion, and attenuated the concentrations of serum TC, TG, sICAM-1, MMP-9, and IL-6. In addition, the expression of autophagy markers LC3 and Beclin-1 increased significantly at the mRNA and protein levels.

CONCLUSION

Long-term swimming exercise could activate the autophagy and reduce atherosclerotic lesion in the aorta of ApoE^-/- mice. Autophagy activation may be one of the mechanisms by which atherosclerosis is improved through exercise.

Dietary Spray-Dried Porcine Plasma Prevents Cognitive Decline in Senescent Mice and Reduces Neuroinflammation and Oxidative Stress

BACKGROUND

Aging is characterized by chronic, low-grade inflammation that correlates with cognitive decline. Dietary supplementation with spray-dried porcine plasma (SDP) reduces immune activation in rodent models of inflammation and aging.

OBJECTIVE

We investigated whether the anti-inflammatory properties of SDP could ameliorate age-related cognitive deterioration and preserve brain homeostasis in an aging mouse model of senescence.

METHODS

Male senescence-accelerated prone 8 (SAMP8) mice were used. In Experiment 1, cognitive performance (n  = 10-14 mice/group) was analyzed by the novel object recognition test in 2-mo-old mice (2M group) and in mice fed a control diet or a diet supplemented with 8% SDP for 2 (4M-CTL and 4M-SDP groups) and 4 mo (6M-CTL and 6M-SDP groups). In Experiment 2, the permeability of the blood-brain barrier and junctional proteins in brain tissue was assessed, as well as synaptic density, oxidative stress markers, and inflammatory genes and proteins in mice from the 2M, 6M-CTL, and 6M-SDP groups ( n = 5-11). Statistical analyses included one-factor ANOVA followed by Fisher's posthoc test.

RESULTS

6M-SDP mice had better cognitive performance than 6M-CTL mice in both short-term (P = 0.024) and long-term (P = 0.017) memory tests. In brain tissue, 6M-SDP mice showed reduced brain capillary permeability (P = 0.034) and increased ZO1 and E-cadherin expression (both P <0.04) compared with 6M-CTL mice. SDP also prevented the NFκB activation observed in 6M-CTL mice (P = 0.002) and reduced Il6 expression and hydrogen peroxide concentration (both P <0.03) observed in 6M-CTL mice. SDP also increased the concentration of IL10 (P = 0.027), an anti-inflammatory cytokine correlated with memory preservation.

CONCLUSIONS

In senescent SAMP8 mice, dietary supplementation with SDP attenuated cognitive decline and prevented changes in brain markers of neuroinflammation and oxidative stress.

MicroRNA-29a-3p Reduces TNFα-Induced Endothelial Dysfunction by Targeting Tumor Necrosis Factor Receptor 1

miR-29a-3p has been shown to be associated with cardiovascular diseases; however, the effect of miR-29a-3p on endothelial dysfunction is unclear. This study aimed to reveal the effects and mechanisms of miR-29a-3p on endothelial dysfunction. The levels of vascular cell adhesion molecule 1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1), and E-selectin were determined by real-time PCR and immunofluorescence staining to reveal the degree of tumor necrosis factor alpha (TNFα)-induced endothelial dysfunction. A luciferase activity assay and cell transfection with a miR-29a-3p mimic or an inhibitor were used to reveal the underlying mechanisms of miR-29a-3p action. Furthermore, the effects of miR-29a-3p on endothelial dysfunction were assessed in C57BL/6 mice injected with TNFα and/or a miR-29a-3p agomir. The results showed that the expression of TNFα-induced adhesion molecules in vascular endothelial cells (EA.hy926 cells, human aortic endothelial cells [HAECs], and primary human umbilical vein endothelial cells [pHUVECs]) and smooth muscle cells (human umbilical vein smooth muscle cells [HUVSMCs]) was significantly decreased following transfection with miR-29a-3p. This effect was reversed by cotransfection with a miR-29a-3p inhibitor. As a key target of miR-29a-3p, tumor necrosis factor receptor 1 mediated the effect of miR-29a-3p. Moreover, miR-29a-3p decreased the plasma levels of TNFα-induced VCAM-1 (32.62%), ICAM-1 (38.22%), and E-selectin (39.32%) in vivo. These data indicate that miR-29a-3p plays a protective role in TNFα-induced endothelial dysfunction, suggesting that miR-29a-3p is a novel target for the prevention and treatment of atherosclerosis.

Antioxidants and Atherosclerosis: Mechanistic Aspects

Atherosclerosis is a chronic inflammatory disease which is a major cause of coronary heart disease and stroke in humans. It is characterized by intimal plaques and cholesterol accumulation in arterial walls. The side effects of currently prescribed synthetic drugs and their high cost in the treatment of atherosclerosis has prompted the use of alternative herbal medicines, dietary supplements, and antioxidants associated with fewer adverse effects for the treatment of atherosclerosis. This article aims to present the activity mechanisms of antioxidants on atherosclerosis along with a review of the most prevalent medicinal plants employed against this multifactorial disease. The wide-ranging information in this review article was obtained from scientific databases including PubMed, Web of Science, Scopus, Science Direct and Google Scholar. Natural and synthetic antioxidants have a crucial role in the prevention and treatment of atherosclerosis through different mechanisms. These include: The inhibition of low density lipoprotein (LDL) oxidation, the reduction of reactive oxygen species (ROS) generation, the inhibition of cytokine secretion, the prevention of atherosclerotic plaque formation and platelet aggregation, the preclusion of mononuclear cell infiltration, the improvement of endothelial dysfunction and vasodilation, the augmentation of nitric oxide (NO) bioavailability, the modulation of the expression of adhesion molecules such as vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) on endothelial cells, and the suppression of foam cell formation.

Comparison of Two Ginkgo biloba L. Extracts on Oxidative Stress and Inflammation Markers in Human Endothelial Cells

Atherosclerosis is characterized by interaction between immune and vascular endothelial cells which is mediated by adhesion molecules occurring on the surface of the vascular endothelium leading to massive release of proinflammatory mediators. Ginkgo biloba L. (Ginkgoaceae) standardized extracts showing beneficial effects are commonly prepared by solvent extraction, and acetone is used according to the European Pharmacopoeia recommendations; the well-known Ginkgo biloba acetone extract EGb761® is the most clinically investigated. However, in some countries, the allowed amount of solvent is limited to ethanol, thus implying that the usage of a standardized Ginkgo biloba ethanol extract may be preferred in all those cases, such as for food supplements. The present paper investigates if ethanol and acetone extracts, with comparable standardization, may be considered comparable in terms of biological activity, focusing on the radical scavenging and anti-inflammatory activities. Both the extracts showed high inhibition of TNFα-induced VCAM-1 release (41.1-43.9 μg/mL), which was partly due to the NF-κB pathway impairment. Besides ROS decrease, cAMP increase following treatment with ginkgo extracts was addressed and proposed as further molecular mechanism responsible for the inhibition of endothelial E-selectin. No statistical difference was observed between the extracts. The present study demonstrates for the first time that ethanol and acetone extracts show comparable biological activities in human endothelial cell, thus providing new insights into the usage of ethanol extracts in those countries where restrictions in amount of acetone are present.

Nuclear factor-kappa β as a therapeutic target for Alzheimer's disease

Alzheimer's disease (AD) is a typical progressive, chronic neurodegenerative disorder with worldwide prevalence. Its clinical manifestation involves the presence of extracellular plaques and intracellular neurofibrillary tangles (NFTs). NFTs occur in brain tissues as a result of both Aβ agglomeration and Tau phosphorylation. Although there is no known cure for AD, research into possible cures and treatment options continues using cell-cultures and model animals/organisms. The nuclear factor-kappa β (NF-κβ) plays an active role in the progression of AD. Impairment to this signaling module triggers undesirable phenotypic changes such as neuroinflammation, activation of microglia, oxidative stress related complications, and apoptotic cell death. These imbalances further lead to homeostatic abnormalities in the brain or in initial stages of AD essentially pushing normal neurons toward the degeneration process. Interestingly, the role of NF-κβ signaling associated receptor-interacting protein kinase is currently observed in apoptotic and necrotic cell death, and has been reported in brains. Conversely, the NF-κβ signaling pathway has also been reported to be involved in normal brain functioning. This pathway plays a crucial role in maintaining synaptic plasticity and balancing between learning and memory. Since any impairment in the pathways associated with NF-κβ signaling causes altered neuronal dynamics, neurotherapeutics using compounds including, antioxidants, bioflavonoids, and non-steroidal anti-inflammatory drugs against such abnormalities offer possibilities to rectify aberrant excitatory neuronal activity in AD. In this review, we have provided an extensive overview of the crucial role of NF-κβ signaling in normal brain homeostasis. We have also thoroughly outlined several established pathomechanisms associated with NF-κβ pathways in AD, along with their respective therapeutic approaches.

Nepeta angustifolia attenuates responses to vascular inflammation in high glucose-induced human umbilical vein endothelial cells through heme oxygenase-1 induction

ETHNOPHARMACOLOGICAL RELEVANCE

The traditional folk medicine Nepeta angustifolia C. Y. Wu (NA) reportedly possesses various biological activities, such as anti-inflammatory, analgesic, antihypoxia, and antifatigue effects. In this study, we evaluated the anti-vascular inflammation effects of N. angustifolia extract in human umbilical vein endothelial cells (HUVECs) induced by high glucose (HG) as well as the underlying mechanisms and verified its activity in diabetic rats.

MATERIALS AND METHODS

HUVECs were exposed to 25 mM glucose to induce endothelial dysfunction. Adhesion molecule expression and reactive oxygen species (ROS) were assayed. IκB and IκB phosphorylation, nuclear factor-κB (NF-κB), HO-1 and nuclear factor erythroid 2-related factor 2 (Nrf2) were examined by Western blot. Nuclear localisation of Nrf2 was also examined using immunofluorescence. The in vivo study of NA was tested in diabetic rats in which the thoracic aorta and serum were collected to observe aorta histological change, and evaluate endothelial function and vascular inflammation.

RESULTS

The results revealed that HG can significantly promote the generation of ROS, the expression of cell adhesion molecules (CAMs), and the phosphorylation and degradation of IκB and NF-κB activation in HUVECs. These HG-induced phenomena were suppressed by NA-induced heme oxygenase (HO)- 1 expression in a dose- and time-dependent manner by activating Nrf2. The HO-1 inhibitor tin protoporphyrin also dramatically reversed the NA-induced inhibition of CAM expression and the reduction in ROS production. Furthermore, NA also elicited anti-vascular dysfunction effects in diabetic rats, where endothelial function was improved and vascular inflammation was alleviated.

CONCLUSION

All these findings indicated that NA attenuated high glucose-induced vascular dysfunction in vitro and in vivo.

Effects of Ginkgo biloba leaves (Ginkgo biloba) and Ginkgo biloba extract on nutrient and energy utilization of broilers

An experiment using 112 21-day-old male Arbor Acres broilers that were randomly allocated to 7 treatments with 8 replicates in a completely randomized design was conducted to assess the effects of Ginkgo biloba leaves (Ginkgo biloba, GL) and Ginkgo biloba extract (EGB) on utilization of nutrients of broiler chickens. The dietary treatments were corn-soybean meal based diets: 1) T1, control diet; 2) T2, T1 + 20 g/kg GL; 3) T3, T1 + 40 g/kg GL; 4) T4, T1 + 60 g/kg GL; 5) T5, T1 + 0.4 g/kg EGB; 6) T6, T1 + 0.8 g/kg EGB; and 7) T7, T1 + 1.2 g/kg EGB. Endogenous losses were obtained from another 16 broilers. Excreta samples were collected to analyze the dry matter (DM), organic matter (OM), ether extract (EE), crude protein (CP), gross energy (GE), and amino acids (AA), and GE was analyzed for computation of AME and TME. As compared with those of the control treatment, the apparent digestibility (AD) and true digestibility (TD) of EE, CP, Thr, Val, Ile, Leu, Phe, Lys, His, and Arg were quadratically (P < 0.05) increased; moreover, the AD and TD of Met was linearly (P < 0.05) increased as the concentration of the EGB in the diet increased. Increasing GL from 0 to 60 g/kg of diet linearly (P < 0.05) increased the AD and TD of EE, Thr, Val, Leu, His, and Met and tended (0.05 < P < 0.1) to increase the TME, TMEn, and Arg. Supplementation of EGB increased (P < 0.05) AD and TD of EE, Thr, Val, Ile, Leu, Phe, His, and Arg and tended (0.05 < P < 0.1) to increase Lys as compared with those in the GL-supplemented groups. Dietary supplementation of GL and EGB improved the utilization of nutrients of broiler chickens in a dose-dependent manner, and the optimum supplementation levels of GL or EGB in the diet of broilers was 60 or 0.8 g/kg of diet, respectively.

Leaf Extracts of Selected Gardening Trees Can Attenuate Quorum Sensing and Pathogenicity of Pseudomonas aeruginosa PAO1

An increasing concern on resistance to multiple-antibiotics has led to the discovery of novel agents and the establishment of new precaution strategy. Numerous plant sources have been widely studied to reduce virulence of pathogenic bacteria by interfering cell-to-cell based communication called quorum sensing (QS). Leaf extracts of 17 gardening trees were collected and investigated for their anti-QS effects using a sensor strain Chromobacterium violaceum CV026. Methanolic extracts of K4 (Acer palmatum), K9 (Acer pseudosieboldianum) and K13 (Cercis chinensis) leaves were selected for further experiments based on their antagonism effect on QS without inhibiting C. violaceum CV026 growth. Subsequently, the leaf extracts on QS-mediated virulence of Pseudomonas aeruginosa PAO1 involved in biofilm formation, motility, bioluminescence, pyocyanin production, QS molecules production, and Caenorhabditis elegans killing activity were evaluated. The biofilm formation ability and swarming motility of P. aeruginosa PAO1 were decreased approximately 50% in the presence of these leaf extracts at a concentration of 1 mg/mL. The expression level of lecA::lux of P. aeruginosa PAO1 and pyocyanin production were also reduced. The three leaf extracts also decreased autoinducer (AI) production in P. aeruginosa PAO1 without direct degradation, suggesting that AI synthesis might have been suppressed by these extracts. The three leaf extracts also showed anti-infection activity in C. elegans model. Taken together, these results suggest that methanolic leaf extracts of K4, K9 and K13 have the potential to attenuate the virulence of P. aeruginosa PAO1.

Inhibitory effect of brassinin on TNF‑α‑induced vascular inflammation in human umbilical vein endothelial cells

Brassinin, a phytoalexin firstly identified as a constituent of Chinese cabbage, has been demonstrated to exhibit antiproliferative effects on various cancer cell lines, by reducing reactive oxygen species (ROS) production via regulation of the antioxidant pathway. The present study aimed to explore the protective effects of brassinin in TNF‑α‑induced vascular inflammation in human umbilical vein endothelial cells (HUVECs). Pretreatment with brassinin significantly inhibited adhesion of U937 cells to TNF‑α‑induced HUVECs in a dose‑dependent manner. Brassinin treatment decreased the expression levels of cell adhesion molecules, including intracellular adhesion molecule‑1 (ICAM‑1), vascular cell adhesion molecule‑1 (VCAM‑1), and endothelial‑selectin (E‑selectin) following stimulation with TNF‑α in HUVECs. In addition, pretreatment with brassinin decreased the protein expression levels of nuclear factor (NF)‑κB p65 in the nucleus, suggesting that brassinin inhibited NF‑κB p65 nuclear translocation. Brassinin treatment also markedly decreased the mRNA expression levels of interleukin‑8 in a dose‑dependent manner. Finally, brassinin pretreatment significantly decreased TNF‑α‑induced intracellular reactive oxygen species (ROS) production in HUVECs compared with control. The present results therefore suggest that brassinin may serve as a potential therapeutic agent for atherosclerosis.

Red Yeast Rice Protects Circulating Bone Marrow-Derived Proangiogenic Cells against High-Glucose-Induced Senescence and Oxidative Stress: The Role of Heme Oxygenase-1

The inflammation and oxidative stress of bone marrow-derived proangiogenic cells (PACs), also named endothelial progenitor cells, triggered by hyperglycemia contributes significantly to vascular dysfunction. There is supporting evidence that the consumption of red yeast rice (RYR; Monascus purpureus-fermented rice) reduces the vascular complications of diabetes; however, the underlying mechanism remains unclear. This study aimed to elucidate the effects of RYR extract in PACs, focusing particularly on the role of a potent antioxidative enzyme, heme oxygenase-1 (HO-1). We found that treatment with RYR extract induced nuclear factor erythroid-2-related factor nuclear translocation and HO-1 mRNA and protein levels in PACs. RYR extract inhibited high-glucose-induced (30 mM) PAC senescence and the development of reactive oxygen species (ROS) in a dose-dependent manner. The HO-1 inducer cobalt protoporphyrin IX also decreased high-glucose-induced cell senescence and oxidative stress, whereas the HO-1 enzyme inhibitor zinc protoporphyrin IX and HO-1 small interfering RNA significantly reversed RYR extract-caused inhibition of senescence and reduction of oxidative stress in high-glucose-treated PACs. These results suggest that RYR extract serves as alternative and complementary medicine in the treatment of these diseases, by inducing HO-1, thereby decreasing the vascular complications of diabetes.

Effect of Paeotang on tumor necrosis factor α-induced vascular inflammation in human umbilical vein endothelial cells

OBJECTIVE

To investigate whether Paeotang (10-50 μg/mL) suppresses tumor necrosis factor α (TNF-α)-induced vascular inflammatory processes in human umbilical vein endothelial cells (HUVEC).

METHODS

The ingredients composed of Paeotang include Glycyrrhiza glabra, Zingiber officinale, Cinnamomum zeylanuicum, Salvia miltiorrhiza, Prunus persica, Paeonia szechuanica, Poria cocos and Cynanchum wilfordii. Herbs were mixed according to equal ratio of weight and ground into a crude powder. The effect of Paeotang on the expression of cell adhesion molecules and protective role in HUVEC stimulated by TNF-α were evaluated.

RESULTS

Pretreatment with Paeotang decreased TNF-α-induced adhesion of HL-60 monocytic cells, as well as protein and mRNA expressions of intracellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1) and endothelial-selectin (E-selectin). Paeotang also dose-dependently inhibited TNF-α-induced matrix metalloproteinase-2 and -9 expressions. Paeotang significantly decreased TNF-α-induced intracellular reactive oxygen species (ROS) production. The Western blot and immunofluorescence analysis showed that Paeotang suppressed the translocation of p65 nuclear factor κB (NF-κB) to the nucleus. In addition, Paeotang inhibited the TNF-α-induced degradation of NF-κB inhibitor α (IκB-α) and by inhibiting the phosphorylation of IκB-α. Furthermore, pretreatment of Paeotang increased the heme oxygenase 1 (HO-1) and nuclear factor erythroid-2-related factor 2 (Nrf2) protein expression in HUVECs stimulated TNF-α. HO-1 was inhibited by Sn-protoporphyrin, HO-1 inhibitor, and increased by cobalt protopophyrin, HO-1 inducer. Furthermore, HO-1 induction was increased by single processing of Paeotang in a dose-dependent manner.

CONCLUSION

These data suggest that Paeotang might be a benefificial therapeutic in vascular inflflammation through regulation of Nrf2-mediated HO-1 expression and inhibition of ROS/NF-κB signaling pathway. Thus, Paeotang maybe serve as a potential anti-atherogenic agent.

The Anti-Inflammatory Effect of Spray-Dried Plasma Is Mediated by a Reduction in Mucosal Lymphocyte Activation and Infiltration in a Mouse Model of Intestinal Inflammation

Spray-dried preparations from porcine and bovine plasma can alleviate mucosal inflammation in experimental models and improve symptoms in patients with enteropathy. In rodents, dietary supplementation with porcine spray-dried plasma (SDP) attenuates intestinal inflammation and improves the epithelial barrier function during intestinal inflammation induced by Staphylococcus aureus enterotoxin B (SEB). The aim of this study was to discern the molecular mechanisms involved in the anti-inflammatory effects of SDP. Male C57BL/6 mice were fed with 8% SDP or control diet (based on milk proteins) for two weeks, from weaning until day 33. On day 32, the mice were given a SEB dose (i.p., 25 µg/mouse) or vehicle. SEB administration increased cell recruitment to mesenteric lymph nodes and the percentage of activated Th lymphocytes and SDP prevented these effects). SDP supplementation increased the expression of interleukin 10 (IL-10) or transforming growth factor- β (TGF-β) compared to the SEB group. The SEB challenge increased six-fold the expression of mucosal addressin cell adhesion molecule 1 (MAdCAM-1) and intercellular adhesion molecule 1 (ICAM-1); and these effects were attenuated by SDP supplementation. SEB also augmented NF-κB phosphorylation, an effect that was prevented by dietary SDP. Our results indicate that the anti-inflammatory effects of SDP involve the regulation of transcription factors and adhesion molecules that reduce intestinal cell infiltration and the degree of the inflammatory response.

Ursolic acid plays a protective role in obesity-induced cardiovascular diseases

The metabolic disturbance of obesity is one of the most common risk factors of atherosclerosis. Resistin, an obesity-induced adipokine, can induce the expression of cell adhesion molecules and the attachment of monocytes to endothelial cells, which play an important role in the development of atherosclerosis. Ursolic acid, a pentacyclic triterpenoid found in fruits and many herbs, exhibits an array of biological effects such as anti-inflammatory and antioxidative properties. The aim of this study was to investigate the potential underlying mechanisms of the effect of ursolic acid on resistin-induced adhesion of U937 cells to human umbilical vein endothelial cells (HUVECs). Our data indicated that ursolic acid suppressed the adhesion of U937 to HUVECs and downregulated the expression of adhesion molecules, vascular cell adhesion molecule-1 (VCAM-1), intracellular cell adhesion molecule-1 (ICAM-1), and E-selectin, in resistin-induced HUVECs by decreasing the production of intracellular reaction oxygen species (ROS) and attenuating the nuclear translocation of NFκB. Ursolic acid appeared to inhibit resistin-induced atherosclerosis, suggesting that ursolic acid may play a protective role in obesity-induced cardiovascular diseases.

Drug-Induced Liver Toxicity and Prevention by Herbal Antioxidants: An Overview

The liver is the center for drug and xenobiotic metabolism, which is influenced most with medication/xenobiotic-mediated toxic activity. Drug-induced hepatotoxicity is common and its actual frequency is hard to determine due to underreporting, difficulties in detection or diagnosis, and incomplete observation of exposure. The death rate is high, up to about 10% for drug-induced liver damage. Endorsed medications represented >50% of instances of intense liver failure in a study from the Acute Liver Failure Study Group of the patients admitted in 17 US healing facilities. Albeit different studies are accessible uncovering the mechanistic aspects of medication prompted hepatotoxicity, we are in the dilemma about the virtual story. The expanding prevalence and effectiveness of Ayurveda and natural products in the treatment of various disorders led the investigators to look into their potential in countering drug-induced liver toxicity. Several natural products have been reported to date to mitigate the drug-induced toxicity. The dietary nature and less adverse reactions of the natural products provide them an extra edge over other candidates of supplementary medication. In this paper, we have discussed the mechanism involved in drug-induced liver toxicity and the potential of herbal antioxidants as supplementary medication.

Inhibition of Human Cytochrome P450 2c8-catalyzed Amodiaquine N-desethylation: Effect of Five Traditionally and Commonly Used Herbs

Background:

In Southeast Asia and many parts of the world, herbal products are increasingly used in parallel with modern medicine.

Objective:

This study aimed to investigate the effects of herbs commonly used in Southeast Asia on activity of cytochrome P450 2C8 (CYP2C8), an important human hepatic enzyme in drug metabolism.

Materials and Methods:

The selected herbs, such as Eurycoma longifolia Jack (ELJ), Labisia pumila (LP), Echinacea purpurea (EP), Andrographis paniculata (AP), and Ginkgo biloba (GB), were subjected to inhibition studies using an in vitro CYP2C8 activity marker, amodiaquine N-desethylase assay. Inhibition parameters, inhibitory concentration 50% (IC₅₀), and K_i values were determined to study the potency and mode of inhibition.

Results:

All herbs inhibited CYP2C8 with the following order of potency: LP > ELJ > GB > AP > EP. LP and ELJ inhibited potently at K_i's of 2 and 4 times the K_i of quercetin, the positive control. The inhibition by LP was uncompetitive in nature as compared to competitive or mixed type inhibition observed with other herbs. GB exhibited moderate inhibitory effect at a K_i6 times larger than quercetin K_i. AP and EP, on the other hand, showed only weak inhibition.

Conclusion:

The herbs we chose represented the more commonly used herbs in Southeast Asia where collision of tradition and modernization in healthcare, if not properly managed, may lead to therapeutic misadventures. We conclude that concurrent consumption of some herbs, in particular, LP and ELJ, may have relevance in drug-herb interactions via CYP2C8 inhibition in vivo.

SUMMARY

Herbs are increasingly used in parallel with modern medicines nowadays. In this study five commonly used herbs in Southeast Asia region, ELJ, LP, EP, AP and GB, were investigated for their in vitro inhibitory potency on CYP2C8, an important drug-metaboliz-ing human hepatic enzyme. All herbs inhibited CYP2C8 activity marker, amodiaquine N-desethylation, with potency order of LP > ELJ > GB >AP > EP. LP, ELJ and GB exhibited K_i values of 2, 4 and 6 times the K_i of quercetin, the positive control, indicating potent to moderate degree of enzyme inhibition. AP and EP, on the other hand, showed only weak inhibition. In summary, concurrent consumption of some herbs especially LP and ELJ may have relevance in drug-herb interactions via CYP2C8 inhibition in vivo.

Abbreviations Used: AQ: Amodiaquine, AP: Andrographis paniculata, CYP: Cytochrome P450, DEAQ: Desethylamodiaquine, EP: Echinacea purpurea, ELJ: Eurycoma longifolia Jack, GB: Ginkgo biloba, K_i: Inhibition constant, LP: Labisia pumila, Vmax: Maximal velocity, K_m: Michaelis-Menten constant.

Sargaquinoic Acid Inhibits TNF-α-Induced NF-κB Signaling, Thereby Contributing to Decreased Monocyte Adhesion to Human Umbilical Vein Endothelial Cells (HUVECs)

Sargaquinoic acid (SQA) has been known for its antioxidant and anti-inflammatory properties. This study investigated the effects of SQA isolated from Sargassum serratifolium on the inhibition of tumor necrosis factor (TNF)-α-induced monocyte adhesion to human umbilical vein endothelial cells (HUVECs). SQA decreased the expression of cell adhesion molecules such as intracellular adhesion molecule-1 and vascular cell adhesion molecule-1 as well as chemotactic cytokines such as interleukin-8 and monocyte chemoattractant protein-1 in TNF-α-treated HUVECs. As a result, SQA prevented monocyte adhesion to TNF-α-induced adhesion. SQA also inhibited TNF-α-induced nuclear factor kappa B (NF-κB) translocation into the nucleus by preventing proteolytic degradation of inhibitor κB-α. Overall, SQA protects against TNF-α-induced vascular inflammation through inhibition of the NF-κB pathway in HUVECs. These data suggest that SQA may be used as a therapeutic agent for vascular inflammatory diseases such as atherosclerosis.

Comparative pharmacokinetics of a proliposome formulation of Ginkgo biloba extract and Ginaton in rats by a sensitive ultra performance liquid chromatography-tandem mass spectrometry method

As a novel oral drug delivery system, proliposome was applied to improve the solubility of active components of Ginkgo biloba extract (GbE). There are currently few reports focusing on the pharmacokinetic characteristics of proliposome of GbE (GbP). A rapid and sensitive ultra performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) method for the simultaneous quantification of active components of GbP and a commercial tablet product (Ginaton) in rat plasma was developed and successfully validated. The method was applied to the comparative pharmacokinetic evaluation of GbP and Ginaton in rat plasma. The results indicated that GbP has a significant effect on absorption, elimination and bioavailability of flavonoids and terpenoid lactones in comparison with Ginaton. The obtained results would be helpful for evaluating the absorption mechanism in the gastrointestinal tract in pharmacokinetic level and guiding the development of the novel oral drug delivery system.

Chinese Herbal Compounds for the Prevention and Treatment of Atherosclerosis: Experimental Evidence and Mechanisms

Atherosclerosis is a leading cause of disability and death worldwide. Research into the disease has led to many compelling hypotheses regarding the pathophysiology of atherosclerotic lesion formation and the resulting complications such as myocardial infarction and stroke. Herbal medicine has been widely used in China as well as other Asian countries for the treatment of cardiovascular diseases for hundreds of years; however, the mechanisms of action of Chinese herbal medicine in the prevention and treatment of atherosclerosis have not been well studied. In this review, we briefly describe the mechanisms of atherogenesis and then summarize the research that has been performed in recent years regarding the effectiveness and mechanisms of antiatherogenic Chinese herbal compounds in an attempt to build a bridge between traditional Chinese medicine and cellular and molecular cardiovascular medicine.

Glatiramer acetate (GA) prevents TNF-α-induced monocyte adhesion to primary endothelial cells through interfering with the NF-κB pathway

Pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α) is considered to be the major one contributing to the process of development of endothelial dysfunction. Exposure to TNF-α induces the expression of a number of proinflammatory chemokines, such as monocyte chemotactic protein-1 (MCP-1), and adhesion molecules, including vascular adhesion molecule-1 (VCAM-1) and E-selectin, which mediate the interaction of invading monocytes with vascular endothelial cells. Glatiramer acetate (GA) is a licensed clinical drug for treating patients suffering from multiple sclerosis (MS). The effects of GA in vascular disease have not shown before. In this study, we found that GA significantly inhibited TNF-α-induced binding of monocytes to endothelial cells. Mechanistically, we found that GA ameliorated the upregulation of MCP-1, VCAM-1, and E-selectin induced by TNF-α. Notably, this process is mediated by inhibiting the nuclear translocation and activation of NF-κB. Our results also indicate that GA pretreatment attenuates the up-regulation of COX-2 and iNOS. These data suggest that GA might have a potential benefit in therapeutic endothelial dysfunction related diseases.

Luteolin protects against vascular inflammation in mice and TNF-alpha-induced monocyte adhesion to endothelial cells via suppressing IΚBα/NF-κB signaling pathway

Vascular inflammation plays a significant role in the pathogenesis of atherosclerosis. Luteolin, a naturally occurring flavonoid present in many medicinal plants and some commonly consumed fruits and vegetables, has received wide attention for its potential to improve vascular function in vitro. However, its effect in vivo and the molecular mechanism of luteolin at physiological concentrations remain unclear. Here, we report that luteolin as low as 0.5 μM significantly inhibited tumor necrosis factor (TNF)-α-induced adhesion of monocytes to human EA.hy 926 endothelial cells, a key event in triggering vascular inflammation. Luteolin potently suppressed TNF-α-induced expression of the chemokine monocyte chemotactic protein-1 (MCP-1) and adhesion molecules intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1), key mediators involved in enhancing endothelial cell-monocyte interaction. Furthermore, luteolin inhibited TNF-α-induced nuclear factor (NF)-κB transcriptional activity, IκBα degradation, expression of IκB kinase β and subsequent NF-κB p65 nuclear translocation in endothelial cells, suggesting that luteolin can inhibit inflammation by suppressing NF-κB signaling. In an animal study, C57BL/6 mice were fed a diet containing 0% or 0.6% luteolin for 3 weeks, and luteolin supplementation greatly suppressed TNF-α-induced increase in circulating levels of MCP-1/JE, CXCL1/KC and sICAM-1 in C57BL/6 mice. Consistently, dietary intake of luteolin significantly reduced TNF-α-stimulated adhesion of monocytes to aortic endothelial cells ex vivo. Histology shows that luteolin treatment prevented the eruption of endothelial lining in the intima layer of the aorta and preserved elastin fibers' delicate organization as shown by Verhoeff-Van Gieson staining. Immunohistochemistry studies further show that luteolin treatment also reduced VCAM-1 and monocyte-derived F4/80-positive macrophages in the aorta of TNF-α-treated mice. In conclusion, luteolin protects against TNF-α-induced vascular inflammation in both in vitro and in vivo models. This anti-inflammatory effect of luteolin may be mediated via inhibition of the NF-κB-mediated pathway.

Systemic and cerebral exposure to and pharmacokinetics of flavonols and terpene lactones after dosing standardized Ginkgo biloba leaf extracts to rats via different routes of administration

BACKGROUND AND PURPOSE

Flavonols and terpene lactones are putatively responsible for the properties of Ginkgo biloba leaf extracts that relate to prevention and treatment of cardiovascular disease and cerebral insufficiency. Here, we characterized rat systemic and cerebral exposure to these ginkgo compounds after dosing, as well as the compounds' pharmacokinetics.

EXPERIMENTAL APPROACH

Rats received single or multiple doses of ShuXueNing injection (prepared from GBE50 for intravenous administration) or GBE50 (a standardized extract of G. biloba leaves for oral administration). Brain delivery of the ginkgo compounds was assessed with microdialysis. Various rat samples were analysed using liquid chromatography/mass spectrometry.

KEY RESULTS

Slow terminal elimination features of the flavonols counterbalanced the influence of poor oral bioavailability on their systemic exposure levels, which also resulted in significant accumulation of the compounds in plasma during the subchronic treatment with ShuXueNing injection and GBE50. Unlike the flavonols, the terpene lactones had poor enterohepatic circulation due to their rapid renal excretion and unknown metabolism. The flavonol glycosides occurred as major forms in plasma after dosing with ShuXueNing injection, while the flavonol aglycone conjugates were predominant in plasma after dosing with GBE50. Cerebral exposure was negligible for the flavonols and low for the terpene lactones.

CONCLUSION AND IMPLICATIONS

Unlike the significant systemic exposure levels, the levels of cerebral exposure to the flavonols and terpene lactones are low. The elimination kinetic differences between the two classes of ginkgo compounds influence their relative systemic exposure levels. The information gained is relevant to linking ginkgo administration to the medicinal effects.

Oxidative damage and antioxidative therapy in systemic sclerosis

Systemic sclerosis (SSc) is an autoimmune connective tissue disorder of unknown etiology. This disease is characterized by a large variety of clinical patterns, which include the fibrosis of skin and visceral organs causing a variety of clinical manifestations. Genetic and environmental factors participate in the etiology of this disease; however, recently many studies underline the oxidative background influencing the course and complications of this disease. Reactive oxygen species (ROS) synthesized in SSc can mediate extra- and intracellular oxidative processes affecting endothelial cells and fibroblasts. The estimation of prooxidative markers in the pathogenesis of SSc can enable the identification of useful markers for disease activity and, thus, may help in planning appropriate therapy focusing on the fibrotic or vascular pattern. Recently, many attempts have been made to find antioxidative molecules (nutritional and pharmacological) reducing the prooxidant state in a variety of cells—mainly in endothelium and proliferating fibroblasts. This paper presents both the background of oxidative stress processes in systemic sclerosis mediated by different mechanisms and the evidence suggesting which of the dietary and pharmacological antioxidants can be used as therapeutic targets for this disease.

Epigallocatechin gallate attenuates proliferation and oxidative stress in human vascular smooth muscle cells induced by interleukin-1β via heme oxygenase-1

Proliferation of vascular smooth muscle cells (VSMCs) triggered by inflammatory stimuli and oxidative stress contributes importantly to atherogenesis. The association of green tea consumption with cardiovascular protection has been well documented in epidemiological observations, however, the underlying mechanisms remain unclear. This study aimed to elucidate the effects of the most active green tea catechin derivative, (−)-epigallocatechin-3-gallate (EGCG), in human aortic smooth muscle cells (HASMCs), focusing particularly on the role of a potent anti-inflammatory and antioxidative enzyme heme oxygenase-1 (HO-1). We found that pretreatment of EGCG dose- and time-dependently induced HO-1 protein levels in HASMCs. EGCG inhibited interleukin- (IL-)1β-induced HASMC proliferation and oxidative stress in a dose-dependent manner. The HO-1 inducer CoPPIX decreased IL-1β-induced cell proliferation, whereas the HO-1 enzyme inhibitor ZnPPIX significantly reversed EGCG-caused growth inhibition in IL-1β-treated HASMCs. At the molecular level, EGCG treatment significantly activated nuclear factor erythroid-2-related factor (Nrf2) transcription activities. These results suggest that EGCG might serve as a complementary and alternative medicine in the treatment of these pathologies by inducing HO-1 expression and subsequently decreasing VSMC proliferation.

EGb-761 prevents ultraviolet B-induced photoaging via inactivation of mitogen-activated protein kinases and proinflammatory cytokine expression

BACKGROUND

EGb-761 is an antioxidant and anticarcinogen; however, its role as a photoprotector remains unknown.

OBJECTIVE

To determine whether EGb-761 photoprotects human dermal fibroblasts and BALB/c mice skin against ultraviolet B (UVB) light irradiation.

METHODS

To simulate chronic photodamage, shaved BALB/c mice were exposed to UVB irradiation (90mJ/cm(2)) thrice weekly for 3 months. EGb-761 (2mg/cm(2)) was topically applied 1h before irradiation to evaluate its effect. The mechanisms by which EGb-761 protects the skin from photodamage were evaluated by immunohistochemical analysis, enzyme-linked immunosorbent assay (ELISA), and Western blotting.

RESULTS

In BALB/c mice, the signs of photoaging or photodamage, such as coarse wrinkle formation, epidermal hyperplasia, and elastic fiber degeneration, markedly reduced with the topical application of EGb-761. Western blot and ELISA revealed that the activation of MMP-1 in cultured fibroblasts markedly diminished after pretreatment with EGb-761. In addition, EGb-761 inhibited UVB-induced overexpression by the fibroblasts of the proinflammatory cytokines, such as interleukin (IL)-1α, IL-1β, IL-6, and tumor necrosis factor-α. The phosphorylation of the mitogen-activated protein kinase (MAPK) signal transduction pathway components, including extracellular signal-regulated kinase, C-Jun N-terminal kinase, and p38, which are induced by UV irradiation, was significantly inhibited in vivo and in vitro. EGb-761 also diminished the generation of UVB-induced reactive oxygen species (ROS).

CONCLUSIONS

EGb-761 photoprotects mice and cultured fibroblasts, inhibits the UVB-induced phosphorylation of MAPK pathway components, and reduces the expression of the proinflammatory cytokines by suppressing ROS generation. Thus, topically applied EGb-761 may be a promising photoprotective agent.

Sulforaphane reduces vascular inflammation in mice and prevents TNF-α-induced monocyte adhesion to primary endothelial cells through interfering with the NF-κB pathway

Sulforaphane, a naturally occurring isothiocyanate present in cruciferous vegetables, has received wide attention for its potential to improve vascular function in vitro. However, its effect in vivo and the molecular mechanism of sulforaphane at physiological concentrations remain unclear. Here, we report that a sulforaphane concentration as low as 0.5 μM significantly inhibited tumor necrosis factor-α (TNF-α)-induced adhesion of monocytes to human umbilical vein endothelial cells, a key event in the pathogenesis of atherosclerosis both in static and under flow conditions. Such physiological concentrations of sulforaphane also significantly suppressed TNF-α-induced production of monocyte chemotactic protein-1 and adhesion molecules including soluble vascular adhesion molecule-1 and soluble E-selectin, key mediators in the regulation of enhanced endothelial cell-monocyte interaction. Furthermore, sulforaphane inhibited TNF-α-induced nuclear factor (NF)-κB transcriptional activity, Inhibitor of NF-κB alpha (IκBα) degradation and subsequent NF-κB p65 nuclear translocation in endothelial cells, suggesting that sulforaphane can inhibit inflammation by suppressing NF-κB signaling. In an animal study, sulforaphane (300 ppm) in a mouse diet significantly abolished TNF-α-increased ex vivo monocyte adhesion and circulating adhesion molecules and chemokines in C57BL/6 mice. Histology showed that sulforaphane treatment significantly prevented the eruption of endothelial lining in the intima layer of the aorta and preserved elastin fibers' delicate organization, as shown by Verhoeff-van Gieson staining. Immunohistochemistry studies showed that sulforaphane treatment also reduced vascular adhesion molecule-1 and monocyte-derived F4/80-positive macrophages in the aorta of TNF-α-treated mice. In conclusion, sulforaphane at physiological concentrations protects against TNF-α-induced vascular endothelial inflammation, in both in vitro and in vivo models. This anti-inflammatory effect of sulforaphane may be, at least in part, associated with interfering with the NF-κB pathway.

Sauchinone from Saururus chinensis protects vascular inflammation by heme oxygenase-1 induction in human umbilical vein endothelial cells

Sauchinone, a diastereomeric lignan isolated from the roots of Saururus chinensis (LOUR.) BAILL. (Saururaceae), is reported to exert a variety of biological activities such as hepatoprotective, anti-inflammatory actions and inhibitory effects on bone resorption. In this study, we investigated the effect of sauchinone in suppressing cell adhesion molecules such as vascular cell adhesion molecule-1 (VCAM-1) and intracellular adhesion molecule-1 (ICAM-1) expression in high glucose stimulated human umbilical vein endothelial cells (HUVEC). Sauchinone inhibited the phosphorylation and degradation of IκB-α, as well as the nuclear translocation of nuclear factor kappa B (NF-κB) p65 caused by the stimulation of high glucose. In addition, sauchinone induced heme oxygenase (HO)-1 expression through nuclear translocation of nuclear factor E2-related factor 2 in HUVEC. The effects of sauchinone on the high glucose-induced expression of VCAM-1 and ICAM-1 and nuclear translocation of NF-κB p65 were partially reversed by transfection of the cells with HO-1 siRNA. These findings suggest that sauchinone-induced HO-1 expression plays a key role in the vascular protective effects of sauchinone in HUVEC.

Inhibitory effect of natural anti-inflammatory compounds on cytokines released by chronic venous disease patient-derived endothelial cells

Large vein endothelium plays important roles in clinical diseases such as chronic venous disease (CVD) and thrombosis; thus to characterize CVD vein endothelial cells (VEC) has a strategic role in identifying specific therapeutic targets. On these bases we evaluated the effect of the natural anti-inflammatory compounds α-Lipoic acid and Ginkgoselect phytosome on cytokines/chemokines released by CVD patient-derived VEC. For this purpose, we characterized the levels of a panel of cytokines/chemokines (n = 31) in CVD patients' plasma compared to healthy controls and their release by VEC purified from the same patients, in unstimulated and TNF-α stimulated conditions. Among the cytokines/chemokines released by VEC, which recapitulated the systemic profile (IL-8, TNF-α, GM-CSF, INF-α2, G-CSF, MIP-1β, VEGF, EGF, Eotaxin, MCP-1, CXCL10, PDGF, and RANTES), we identified those targeted by ex vivo treatment with α-Lipoic acid and/or Ginkgoselect phytosome (GM-CSF, G-CSF, CXCL10, PDGF, and RANTES). Finally, by investigating the intracellular pathways involved in promoting the VEC release of cytokines/chemokines, which are targeted by natural anti-inflammatory compounds, we documented that α-Lipoic acid significantly counteracted TNF-α-induced NF-κB and p38/MAPK activation while the effects of Ginkgo biloba appeared to be predominantly mediated by Akt. Our data provide new insights into the molecular mechanisms of CVD pathogenesis, highlighting new potential therapeutic targets.

Ginkgo suppresses atherosclerosis through downregulating the expression of connexin 43 in rabbits

INTRODUCTION

Ginkgo biloba extract (GBE) EGb761 is widely used for cardiovascular prevention. Here, we investigated the effects of GBE on atherosclerotic lesion development in rabbits with a high-fat diet.

MATERIAL AND METHODS

Forty New Zealand white male rabbits were randomly divided into four groups. The first two were the normal diet group (C) and the high-fat group (HF). The remaining two groups were those who received a high cholesterol diet supplemented with either the standard drug (simvastatin 2 mg/kg/day) or GBE (3 mg/kg/day). At 12 weeks, histopathological and chemical analyses were performed.

RESULTS

Plasma lipid measurement showed that GBE inhibited high-fat diet-induced increase of serum triglyceride (TG), total cholesterol (TC), and low density lipoprotein cholesterol (LDL-C) by 59.1% (0.9 ±0.2 4 mmol/l vs. 2.2 ±0.4 mmol/l), 18.2% (31.1 ±1.4 mmol/l vs. 38.0 ±0.4 mmol/l) and 15% (28.9 ±1.3 mmol/l vs. 34.0±1.0 mmol/l), respectively, at 12 weeks (p < 0.01). The en face Sudan IV-positive lesion area of the aorta in the GBE group (51.7 ±3.1%) was significantly lower compared with that in the HF group (88.2 ±2.2%; p < 0.01). The mean atherosclerotic lesion area of the GBE group was reduced by 53.2% compared with the HF group (p < 0.01). Immunohistochemistry and western blot analysis showed that GBE markedly suppressed high-fat diet-induced upregulation of connexin 43 (Cx43) in rabbits (p < 0.01).

CONCLUSIONS

Thus, our study revealed that GBE prevented atherosclerosis progress through modulating plasma lipid, suppressing atherosclerotic lesion development, and attenuating the expression of Cx43 protein.

Stem-bark of Terminalia arjuna attenuates human monocytic (THP-1) and aortic endothelial cell activation

ETHNOPHARMACOLOGICAL RELEVANCE

Terminalia arjuna - stem bark extract is traditionally used as cardiotonic in Ayurvedic medicine.

AIM OF THE STUDY

The present study was aimed to evaluate the molecular basis for cardioprotective potential of Terminalia arjuna (TA) stem bark, using cell cultures of human monocytic (THP-1) and human aortic endothelial cells (HAECs).

MATERIALS AND METHODS

Inhibitory effect of alcoholic (TAAE) and aqueous (TAWE) extracts of TA-stem bark was assessed on human 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, lipoprotein lipase (LpL) and lipid peroxidation in rat (wistar) liver and heart homogenates. The patterns of H2O2 induced reactive oxygen species (ROS) generation were observed by confocal microscopy. The activities of antioxidant enzymes and reducing power of the cells were measured in a microplate reader. Gene transcripts of proinflammatory markers in THP-1 and HAECs were assayed by real time PCR and levels of inflammatory protein markers by ELISA or flow cytometry. Phytochemical analyses of TAAE and TAWE were done using liquid chromatography, coupled to mass spectrometry (LC-MS).

RESULTS

TAAE and TAWE inhibited the lipid peroxidation and HMG-CoA reductase but had no effect on LpL. Both the extracts attenuated H2O2 mediated ROS generation in THP-1 cells by promoting catalase (CAT), glutathione peroxidase (GPx) activities, and by sustaining cellular reducing power. TAAE was highly effective in attenuating proinflammatory gene transcripts in THP-1 cells and HAECs, whereas the response to TAWE depended on the type of transcript and cell type. Both extracts decreased the levels of typical inflammatory marker proteins, viz. LPS induced tumor necrosis factor (TNF)-α secreted by THP-1 cells and TNF-α induced cell surface adhesion molecules on HAECs, namely vascular cell adhesion molecule-1 (VCAM-1) and E-selectin. Phytochemical analyses indicated the richness in phenolic compounds and terpenes of TAAE and TAWE, while revealing variability in their metabolite profile.

CONCLUSION

Our study scientifically validates the antioxidative and antiinflammatory properties of Terminalia arjuna stem bark. The marked effects on cultured human monocytic and aortic endothelial cells (HAEC) provide the biochemical and molecular basis for therapeutic potential of TA-stem bark against cardiovascular diseases (CVD).