Antioxidative activity of natural products from plants

Effect of aqueous Enicostemma littorale Blume extract on key carbohydrate metabolic enzymes, lipid peroxides and antioxidants in alloxan-induced diabetic rats

The present study investigates the effect of oral administration of an aqueous Enicostemma littorale whole plant extract on some key carbohydrate metabolic enzymes and antioxidant defence in alloxan-induced diabetes in rats. Rats were rendered diabetic by alloxan (150 mg kg−1 body weight) administration. Oral administration of E. littorale extract for 45 days increased the activity of hexokinase and decreased the activities of glucose 6-phosphatase and fructose 1,6-bisphosphatase significantly in the serum, liver and kidney of diabetic rats. The extract lowered the concentration of thiobarbituric acid reactive substances and lipid hydroperoxides significantly in brain and increased it significantly in heart in diabetic rats. E. littorale administration increased the concentration of reduced glutathione and the activity of glutathione peroxidase in diabetic rats. The activities of superoxide dismutase and catalase were increased significantly by E. littorale treatment in diabetic rats. The effect of a 2 g kg−1 dose was greater than that of a 1 g kg−1 dose. Insulin (6 units kg−1) normalized all the parameters in diabetic rats. Our study has provided evidence for the antidiabetic activity of E. littorale aqueous extract. This study can also be extrapolated to clinical studies in future.

Salutary effects of Corydalis yanhusuo extract on cardiac hypertrophy due to pressure overload in rats

We have evaluated the effects of an alcohol extract from the rhizome of Corydalis yanhusuo W.T. (CY), a well-known traditional Chinese medicinal herb, on pressure-overloaded cardiac hypertrophy induced by transverse abdominal aorta constriction (TAAC) in rats. Rats were given vehicle or CY extract (200 or 50 mg kg−1 per day) from the second week after induction of pressure overload, for a period of 7 weeks. Haemodynamic parameters, relative heart weight and myocyte cross-sectional area were measured in each group. We also estimated left ventricular (LV) collagen volume fraction (CVF) using Masson trichrome staining, and type I collagen expression by Western blot assay. Chronic TAAC caused notable cardiac hypertrophy and heart dysfunction. Significant collagen deposition and greater type I collagen expression were found in model control rats. These changes were not significantly reversed after treatment with 50 mgkg−1 CY, whereas 200 mgkg−1 significantly improved heart function and prevented cardiac hypertrophy, with parallel reductions in myocardial fibrosis, as evidenced by reduced LV CVF and reduced levels of type I collagen. In conclusion, chronic treatment of rats with CY extract attenuated development of cardiac hypertrophy.

Metabolic characterization of a strain (BM90) of Delftia tsuruhatensis showing highly diversified capacity to degrade low molecular weight phenols

A novel bacterium, strain BM90, previously isolated from Tyrrhenian Sea, was metabolically characterized testing its ability to use 95 different carbon sources by the Biolog system. The bacterium showed a broad capacity to use fatty-, organic- and amino-acids; on the contrary, its ability to use carbohydrates was extremely scarce. Strain BM90 was identified and affiliated to Delftia tsuruhatensis by molecular techniques based on 16S rRNA gene sequencing. D. tsuruhatensis BM90, cultivated in shaken cultures, was able to grow on various phenolic compounds and to remove them from its cultural broth. The phenols used, chosen for their presence in industrial or agro-industrial effluents, were grouped on the base of their chemical characteristics. These included benzoic acid derivatives, cinnamic acid derivatives, phenolic aldehyde derivatives, acetic acid derivatives and other phenolic compounds such as catechol and p-hydroxyphenylpropionic acid. When all the compounds (24) were gathered in the same medium (total concentration: 500 mg/l), BM90 caused the complete depletion of 18 phenols and the partial removal of two others. Only four phenolic compounds were not removed. Flow cytometry studies were carried out to understand the physiological state of BM90 cells in presence of the above phenols in various conditions. At the concentrations tested, a certain toxic effect was exerted only by the four compounds that were not metabolized by the bacterium.

Mitigation of acute ultraviolet B radiation-mediated damages by baicalin in mouse skin

BACKGROUND

Solar ultraviolet (UV) irradiation, in particular UVB with a wavelength range between 290 and 320 nm, induces different hazardous effects on the skin, including sunburn, photoaging and cancer. Protection against sun-induced damage is therefore a highly desirable goal. Chemoprevention is being investigated as a potential approach for the management of UV damages including skin cancer.

AIM

In this study, to determine the relevance of our in vitro findings to in vivo situations, we assessed the effects of baicalin on UVB-mediated damages in mice skin.

METHODS

Balb/C hairless mice were topically pretreated (24 h before UVB) or post-treated (5 min after UVB) with baicalin (1 mg/cm(2) skin area/mouse/100 microl acetone) and were exposed to UVB 24 h later (180 mJ/cm(2)). The animals were sacrificed 1 and 24 h after the UVB exposure. Skin edema, histopathology changes, hydrogen peroxide (H2O2) and cyclobutane pyrimidine dimers (CPDs)-positive cells were assessed to determine the UVB-induced photodamage.

RESULTS

Our data demonstrated that a topical application of baicalin, either as a pretreatment or as a post-treatment, resulted in a significant decrease in UVB mediated increases in skin edema, skin hyperplasia and infiltration of leukocytes. Further, baicalin treatments (pre and post) also resulted in a significant decrease in UVB mediated (1) generation of H2O2 and (2) formation of DNA photolesions: CPDs.

CONCLUSION

Based on these data, we suggest that baicalin could be developed as an agent for the management of conditions elicited by UV exposure including skin cancer.

Naringin Protects against Rotenone-induced Apoptosis in Human Neuroblastoma SH-SY5Y Cells

Rotenone, a mitochondrial complex I inhibitor, can induce the pathological features of Parkinson's disease (PD). In the present study, naringin, a grapefruit flavonoid, inhibited rotenone-induced cell death in human neuroblastoma SH-SY5Y cells. We assessed cell death and apoptosis by measuring mitogen-activated protein kinase (MAPKs) and caspase (CASPs) activities and by performing 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, 4,6-diamidino-2-phenylindole (DAPI) staining, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining. Naringin also blocked rotenone-induced phosphorylation of Jun NH2-terminal protein kinase (JNK) and P38, and prevented changes in B-cell CLL/lymphoma 2 (BCL2) and BCL2-associated X protein (BAX) expression levels. In addition, naringin reduced the enzyme activity of caspase 3 and cleavages of caspase 9, poly (ADP-ribose) polymerase (PARP), and caspase 3. These results suggest that naringin has a neuroprotective effect on rotenone-induced cell death in human neuroblastoma SH-SY5Y cells.

Preventive effects of a purified extract isolated from Salvia miltiorrhiza enriched with tanshinone I, tanshinone IIA and cryptotanshinone on hepatocyte injury in vitro and in vivo

Salvia miltiorrhiza is traditionally used to treat liver disease in Asia. In this study, we tested the ability of a purified extract of S. miltiorrhiza (PF2401-SF) and its constituents, tanshinone I, tanshinone IIA, and cryptotanshinone, to protect against acute and subacute liver damage induced by carbon tetrachloride by measuring serum transaminase levels, the reduced form of glutathione (GSH), antioxidant enzyme activities, and lipid peroxidation levels in the liver. We also evaluated their ability to protect primary cultured rat hepatocytes from tertiary-butylhydroperoxide (tBH) or d-galactosamine (GalN). PF2401-SF was protective at 50-200mg/kg per day in acute liver injury and 25-100mg/kg per day in subacute liver injury. Tanshinone I, tanshinone IIA, and cryptotanshinon (40 microM), inhibited lactate dehydrogenase leakage, GSH depletion, lipid peroxidation and free radical generation in vitro. PF2401-SF and its major constituents, tanshinone I, tanshinone IIA and cryptotanshinone, can protect against liver toxicity in vivo and in vitro due to its antioxidant effects.

Antioxidant activity and free radical scavenging reactions of hydroxybenzyl alcohols. Biochemical and pulse radiolysis studies

Comparative studies on free radical scavenging by isomers of hydroxybenzyl alcohols (HBAs) were carried out to understand the molecular mechanisms involved in the antioxidant action. Using rat liver mitochondria as model systems, we have examined the radioprotective and antioxidant effects of hydroxybenzyl alcohols. Apart from their ability to scavenge free radicals and ferric reducing power, HBAs have shown good protection against radiation and oxidative stress. Using peroxyl radicals as initiator of reactive oxygen species (ROS), studies were carried out to evaluate antioxidant properties of HBAs against rat liver mitochondrial membrane components such as lipid and protein. Our results show that HBAs are potent inhibitor of lipid peroxidation and protein oxidation thus suggesting their role as free radical scavengers. In the presence of HBAs, restoration of depleted activity of Mn-SOD has also been investigated. In the presence of 2-hydroxybenzyl alcohol (2-HBA) complete restoration in the activity of Mn-SOD was observed on exposure to 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH). Free radical scavenging ability of HBAs were found to be comparable to alpha tocopherol. Pulse radiolysis technique has been used to study the reactions of HBAs with various biologically relevant reactive species such as hydroxyl radical (OH) and trichloromethyl peroxyl radical (CCl3O2). HBAs could scavenge OH radical giving initially OH-adducts which in turn decays to phenoxyl radicals. Reactions of phenoxyl radicals of HBAs with ascorbic acid have been also studied. Redox potential of HBAs has been evaluated with cyclic voltammetry. Studies clearly suggest a structural reactivity correlation between radical scavenging and antioxidant properties of these isomers of HBA. Among the 3 isomers of HBAs, 4-HBA and 2-HBA are found to have better radical scavenging and antioxidant properties than 3-HBA.

Antitumor activity of deoxypodophyllotoxin isolated from Anthriscus sylvestris: Induction of G2/M cell cycle arrest and caspase-dependent apoptosis

An active compound having antitumor activity was isolated from the root of Anthriscus sylvestris. Structural studies revealed that it was deoxypodophyllotoxin (DPPT), and its biological activity was evaluated in HeLa human cervix carcinoma cells. Flow cytometric analysis showed that DPPT arrests the cell cycle in the G2/M phase prior to apoptosis. The mechanisms of action of DPPT involve inhibition of tubulin polymerization, dysregulation of cyclin A and cyclin B1 expression, and activation of caspases-3 and -7.

Vitamin C and the Role of Citrus Juices as Functional Food

The literature on the content and stability of vitamin C (ascorbic acid, AA) in citrus juices in relation to industrial practices is reviewed. The role of vitamin C from citrus juices in human diet is also reviewed. Citrus fruits and juices are rich in several types of bioactive compounds. Their antioxidant activity and related benefits derive not only from vitamin C but also from other phytochemicals, mainly flavonoids. During juice processing, temperature and oxygen are the main factors responsible for vitamin C losses. Nonthermal processed juices retain higher levels of vitamin C, but economic factors apparently delay the use of such methods in the citrus industry. Regarding packing material, vitamin C in fruit juice is quite stable when stored in metal or glass containers, whereas juice stored in plastic bottles has a much shorter shelf-life.

The limiting step for vitamin C absorption in humans is transcellular active transport across the intestinal wall where AA may be oxidized to dehydroascorbic acid (DHAA), which is easily transported across the cell membrane and immediately reduced back to AA by two major pathways. AA bioavailability in the presence of flavonoids has yielded controversial results. Whereas flavonoids seem to inhibit intestinal absorption of AA, some studies have shown that AA in citrus extract was more available than synthetic ascorbic acid alone. DHAA is reported to possess equivalent biological activity to AA, so recent studies often consider the vitamin C activity in the diet as the sum of AA plus DHAA. However, this claimed equivalence should be carefully reexamined.

Humans are one of the few species lacking the enzyme (L-gulonolactone oxidase, GLO) to convert glucose to vitamin C. It has been suggested that this is due to a mutation that provided a survival advantage to early primates, since GLO produces toxic H2O2. Furthermore, the high concentration of AA (and DHAA) in neural tissues could have been the key factor that caused primates (vertebrates with relative big brain) to lose the capacity to synthesize vitamin C.

Oxidative damage has many pathological implications in human health, and AA may play a central role in maintaining the metabolic antioxidant response. The abundance of citrus juices in the Mediterranean diet may provide the main dietary source for natural vitamin C.

Protection of wheat bran feruloyl oligosaccharides against free radical-induced oxidative damage in normal human erythrocytes

The present work assessed the protective effect of water-soluble feruloyl oligosaccharides (FSH), ferulic acid ester of oligosaccharides from wheat bran, against in vitro oxidative damage of normal human erythrocytes induced by a water-soluble free radical initiator, 2,2'-azobis-2-amidinopropane dihydrochloride (AAPH). In the whole process of AAPH-initiated oxidation, hemolysis occurred quickly after the lag time. The rate of hemolysis is correlated dose-dependently with AAPH concentration. Significant decrease in reduced glutathione (GSH) levels of erythrocyte with concomitant enhancement in oxidized gluthione (GSSG) levels was noticed. It was also observed that lipid and protein peroxidation of erythrocytes induced by AAPH was significantly increased, and scanning electron microscopy observations showed that AAPH induced obvious morphological alteration in the erythrocytes from a smooth discoid to an echinocytic form. FSH suppressed depletion of GSH, lipid peroxidation, and methaemoglobin and protein carbonyl group formation of erythrocytes in concentration- and time-dependent manners, remarkably delayed AAPH-induced hemolysis. Morphological changes to erythrocyte caused by AAPH were effectively protected by FSH. It was also observed that FSH could work synergistically with endogenous antioxidants in erythrocytes. These results indicated that FSH efficiently protected normal human erythrocytes against oxidative stress, and they could be used as a potential source of natural antioxidants.

Regulation of polyphenols accumulation by combined overexpression/silencing key enzymes of phenylpropanoid pathway

There is a growing interest in the metabolic engineering of plant with increased desirable polyphenols such as chlorogenic acid (CGA) and rutin. In this study, the effects of overexpression of both phenylalanine ammonia lyase (AtPAL2), the first enzyme of the phenylpropanoid pathway, and hydroxycinnamoyl-CoA quinate:hydroxycinnamoyl transferase (NtHQT), the last enzyme of CGA biosynthesis, and the overexpression of AtPAL2 together with silencing of NtHQT were investigated in tobacco. Transgenic tobacco plants overexpressing AtPAL2 showed two and five times increases of CGA and rutin levels than the wild-type (WT) plants, respectively. Overexpression of NtHQT further increases the accumulation of CGA in the AtPAL2 plants to about three times than that of the WT level, while silencing of NtHQT in AtPAL2 plants results in about 12 times increase in rutin level than that of the WT plants. Simultaneous overexpression of phenylalanine ammonia lyase (PAL) and overexpression/silencing HQT could be used for the production of functional food with increased polyphenols.

Cryptotanshinone, a compound from Salvia miltiorrhiza modulates amyloid precursor protein metabolism and attenuates beta-amyloid deposition through upregulating alpha-secretase in vivo and in vitro

The amyloid precursor protein (APP) is cleaved enzymatically by non-amyloidogenic and amyloidogenic pathways. alpha-Secretase cleaves APP within beta-amyloid protein (Abeta) sequence, resulting in the release of a secreted fragment of APP (sAPPalpha) and precluding Abeta generation. Cryptotanshinone (CTS), an active component of the medicinal herb Salvia miltiorrhiza, has been shown to improve learning and memory in several pharmacological models of Alzheimer's disease (AD). However, the effects of CTS on the Abeta plaque pathology and the APP processing in AD are unclear. Here we reported that CTS strongly attenuated amyloid plaque deposition in the brain of APP/PS1 transgenic mice. In addition, CTS significantly improved spatial learning and memory in APP/PS1 mice assessed by the Morris water maze testing. To define the exact molecular mechanisms involved in the beneficial effects of CTS, we investigated the effects of the CTS on APP processing in rat cortical neuronal cells overexpressing Swedish mutant human APP695. CTS was found to decrease Abeta generation in concentration-dependent (0-10muM) manner. Interestingly, the N-terminal APP cleavage product, sAPPalpha was markedly increased by CTS. Further study showed that alpha-secretase activity was increased by CTS. Taken together, our results suggested CTS improved the cognitive ability in AD transgenic mice and promoted APP metabolism toward the non-amyloidogenic products pathway in rat cortical neuronal cells. CTS shows a promising novel way for the therapy of AD.

Antioxidant activity and ultra-performance LC-electrospray ionization-quadrupole time-of-flight mass spectrometry for phenolics-based fingerprinting of Rose species: Rosa damascena, Rosa bourboniana and Rosa brunonii

Roses are one of the most important groups of ornamental plants and their fruits and flowers are used in a wide variety of food, nutritional products and different traditional medicines. The antioxidant activity of methanolic extracts from fresh flowers of three rose species (Rosa damascena, Rosa bourboniana and Rosa brunonii) was evaluated by 1,1-diphenyl-2-picryl hydrazyl (DPPH) free-radical method. The ability to scavenge DPPH radical was measured by the discoloration of the solution. The methanolic extract from R. brunonii exhibited maximum free-radical-scavenging activity (64.5+/-0.38%) followed by R. bourboniana (51.8+/-0.46%) and R. damascena (43.6+/-0.25%) at 100 microg/ml. Simultaneously, ultra-performance liquid chromatography coupled with electrospray ionization-quadrupole time-of-flight mass spectrometry (UPLC-ESI-QTOF-MS) was used to study phenolic composition in the methanolic extracts from the fresh flowers of rose species. The phenolic constituents were further investigated by direct infusion-ESI-QTOF-MS/MS in negative ion mode. Characteristic Electrospray ionization tandem mass spectrometry (ESI-MS/MS) spectra with other diagnostic fragment ions generated by retro Diels-Alder (RDA) fragmentation pathways were recorded for the flavonoids. Distinct similarities were observed in the relative distribution of polyphenolic compounds among the three species. The dominance of quercetin, kaempferol and their glycosides was observed in all the three species.

Inhibitory effects of Baicalin on ultraviolet B-induced photo-damage in keratinocyte cell line

Baicalin, one kind of Chinese herbal medicine with anti-inflammatory and anti-oxidant property, has been commonly used as a clinical medicine. However, little has been known about the effects of Baicalin on ultraviolet (UV) induced photo-aging and photo-carcinogenesis. The photoproduct is critical to the initial event of UV-induced photo-carcinogenesis. The purpose of the present study was to investigate whether Baicalin, in immortalized human keratinocyte HaCaT cells, could inhibit ultraviolet-B (UVB) induced skin damage and its possible underlying mechanisms, such as inhibiting UVB-induced cytotoxicity and apoptosis, cyclobutane pyrimidine dimers (CPDs), down-regulating the expression of regulatory proteins which are related to cell apoptosis and DNA damage/repair. Our study revealed that Baicalin treatment could inhibit the UVB-induced cytotoxicity, apoptosis and CPD level. It also decreased the mRNA expression of apoptosis-regulatory genes (p53-p21 and c-fos), the protein levels of p53, proliferating cell nuclear antigen (PCNA) and repair protein A (RPA), and the secretion of cytokines [interleukin(IL)-6 and tumor necrosis factor (TNF-alpha)]. These results suggested that Baicalin may have an inhibitory effect on the UVB-induced photo-damage by blocking the relevant cytokine secretion and expression of p53-p21, c-fos, PCNA and RPA genes.

[Protective effects of buckwheat hull extract against experimental hippocampus injury induced by trimethyltin in rats]

OBJECTIVES

The main objective of this study is to clarify the protective effects of buckwheat hull extract (BWHE) against toxicant-induced spatial memory impairment and hippocampal neuron injury in rats.

METHODS

Male Sprague-Dawley (Jsl: SD) rats were fed chow containing 0.75% (w/w) BWHE during the experimental period. Two weeks after the start of the experiment, trimethyltin (TMT) (8 mg/kg bw) was administered orally to 6-week-old rats. After another two weeks, the rats were subjected to the Morris water maze task, which was used to determine spatial memory impairment. On the day after the Morris water maze task was performed, the right hemi-hippocampi were removed from the right half of the brain and weighed. Coronal sections of the left half of the brain were cut into 16-mum sections using a cryostat, and the number of neurons in each hippocampal region was evaluated by counting the surviving neurons using a light microscope.

RESULTS

The impairment of spatial memory and the decrease in the hippocampal weight were observed after the TMT administration. Prolonged supplementation of BWHE seemed to reverse these TMT-induced toxic effects, and also improved the spatial memory of rats.

CONCLUSIONS

The present results suggest that the BWHE supplementation of foods enhanced the spatial memory of rats and may have protective effects against hippocampal neurodegeneration accompanied by spatial memory impairment.

Naringin-induced p21WAF1-mediated G(1)-phase cell cycle arrest via activation of the Ras/Raf/ERK signaling pathway in vascular smooth muscle cells

The flavonoid naringin has been shown to play a role in preventing the development of cardiovascular disease. However, the exact molecular mechanisms underlying the roles of integrated cell cycle regulation and MAPK signaling pathways in the regulation of naringin-induced inhibition of cell proliferation in vascular smooth muscle cells (VSMCs) remain to be identified. Naringin treatment resulted in significant growth inhibition and G(1)-phase cell cycle arrest mediated by induction of p53-independent p21WAF1 expression; expression of cyclins and CDKs in VSMCs was also down-regulated. In addition, among the pathways examined, blockade of ERK function inhibited naringin-dependent p21WAF1 expression, reversed naringin-mediated inhibition of cell proliferation and decreased cell cycle proteins. Moreover, naringin treatment increased both Ras and Raf activations. Transfection of cells with dominant negative Ras (RasN17) and Raf (RafS621A) mutant genes suppressed naringin-induced ERK activity and p21WAF1 expression. Finally, naringin-induced reduction in cell proliferation and cell cycle protein was abolished in the presence of RasN17 and RafS621A mutant genes. The Ras/Raf/ERK pathway participates in p21WAF1 induction, leading to a decrease in cyclin D1/CDK4 and cyclin E/CDK2 complexes and in naringin-dependent inhibition of cell growth. These novel and unexpected findings provide a theoretical basis for preventive use of flavonoids to the atherosclerosis disease.

DNA adducts with antioxidant flavonoids: morin, apigenin, and naringin

Flavonoids have recently attracted a great interest as potential therapeutic drugs against a wide range of free-radical-mediated diseases. The anticancer and antiviral activities of these natural products are implicated in their mechanism of actions. While the antioxidant activity of these natural polyphenolic compounds is well known, their bindings to DNA are not fully investigated. This study was designed to examine the interactions of morin (Mor), naringin (Nar), and apigenin (Api) with calf thymus DNA in aqueous solution at physiological conditions, using constant DNA concentration (6.25 mM) and various drug/DNA(phosphate) ratios of 1/40 to 1. FTIR and UV-Vis spectroscopic methods were used to determine the ligand binding modes, the binding constant, and the stability of DNA in flavonoid-DNA complexes in aqueous solution. Spectroscopic evidence shows both intercalation and external binding of flavonoids to DNA duplex with overall binding constants of K(morin) = 5.99 x 10(3) M(-1), K(apigenin) = 7.10 x 10(4) M(-1), and K(naringin) = 3.10 x 10(3) M(-1). The affinity of ligand-DNA binding is in the order of apigenin > morin > naringin. DNA aggregation and a partial B- to A-DNA transition occurs upon morin, apigenin, and naringin complexation.

RNA binding to antioxidant flavonoids

Flavonoids are an interesting group of natural polyphenolic compounds that exhibit extensive bioactivities such as scavenging free radical, antitumor and antiproliferative effects. The anticancer and antiviral effects of these natural products are attributed to their potential biomedical applications. While flavonoids complexation with DNA is known, their bindings to RNA are not fully investigated. This study was designed to examine the interactions of three flavonoids; morin (Mor), apigenin (Api) and naringin (Nar) with yeast RNA in aqueous solution at physiological conditions, using constant RNA concentration (6.25 mM) and various pigment/RNA (phosphate) ratios of 1/120 to 1/1. FTIR, UV-visible spectroscopic methods were used to determine the ligand binding modes, the binding constant and the stability of RNA in flavonoid-RNA complexes in aqueous solution. Spectroscopic evidence showed major binding of flavonoids to RNA with overall binding constants of K(morin) = 9.150 x 10(3) M(-1), K(apigenin)=4.967 x 10(4) M(-1), and K(naringin)=1.144 x 10(4) M(-1). The affinity of flavonoid-RNA binding is in the order of apigenin>naringin>morin. No biopolymer secondary structural changes were observed upon flavonoid interaction and RNA remains in the A-family structure in these pigment complexes.

Effects of four medicinal herbs on human vascular endothelial cells in culture

BACKGROUND

Danshen (DS, Salvia miltiorrhiza), Shanchi (SQ, Panax notoginseng), Shanzai (SZ, Hawthorn) and Heshouwu (HSW, Polygonum multiflorum Thunb) are four medicinal herbs commonly used in traditional Chinese medicine and previously shown to have activity that may contribute to cardiovascular protection. This study aims to investigate effects of these herbs on vascular endothelial cells with respect to cell viability and expression of cellular adhesion molecules under inflammatory conditions.

METHODS

Herbal extracts were prepared by an established industrial manufacturing process. Human umbilical vein endothelial cells (HUVEC) were incubated with the herbal extract under normal or serum-free culture and tumor necrosis factor (TNF) alpha stimulation. Cell apoptosis, apoptosis-associated gene expression, expression of cellular adhesion molecules, DNA synthesis, and growth were assessed via morphological examination, Annexin-V staining, Western blotting analysis, Flow-Cytometry, [(3)H]-thymidine incorporation assay, and cell number study.

RESULTS

SZ and HSW significantly inhibited apoptosis in HUVEC undergoing serum deprivation and TNFalpha stimulation, accompanied by down-regulation of caspase-3 gene expression. DS and SQ significantly attenuated TNFalpha-induced expression of adhesion molecule VCAM-1 and also ICAM-1 by DS in the cells. All four herbs at therapeutic concentrations (100 microg/mL) inhibited DNA synthesis (10-42% decrease in [(3)H]-thymidine incorporation rates) and growth (5-10% decrease in cell numbers) in HUVEC under normal cultures.

CONCLUSION

DS, SQ, SZ and HSW are physiologically active on human vascular endothelial cells. The actions by HSW and SZ to reduce apoptosis and DS and SQ to inhibit adhesion molecule expression may help protect endothelial function and inhibit atherogenesis, while their actions to inhibit DNA synthesis and cell growth may weaken the ability of endothelial repair. Further studies are needed to identify the chemical compounds responsible to these physiological effects by these herbs.

Simultaneous determination of tanshinone I, dihydrotanshinone I, tanshinone IIA and cryptotanshinone in rat plasma by liquid chromatography-tandem mass spectrometry: application to a pharmacokinetic study of a standardized fraction of Salvia miltiorrhiza, PF2401-SF

A rapid, sensitive and selective liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for the simultaneous determination of tanshinone I, dihydrotanshinone I, tanshinone IIA and cryptotanshinone, the active components of Salvia miltiorrhiza in rat plasma, was developed. After liquid-liquid extraction with tariquidar as an internal standard, tanshinone I, dihydrotanshinone I, tanshinone IIA and cryptotanshinone were eluted from an Atlantis dC18 column within 5 min with a mixture of methanol and ammonium formate (10 mm, pH 6.5; 85:15, v/v). The analytes were detected by an electrospray ionization tandem mass spectrometry in the selected reaction monitoring (SRM) mode. The standard curves were linear (r=0.999) over the concentration range of 0.25-80 ng/mL for tanshinone I, dihydrotanshinone I, tanshinone IIA and cryptotanshinone in rat plasma. The coefficients of variation and the relative errors of tanshinone I, dihydrotanshinone I, tanshinone IIA and cryptotanshinone for intra- and inter-assay at four quality control (QC) concentrations were 1.1-5.1% and -4.0-6.0%, respectively. The lower limit of quantification for tanshinone I, dihydrotanshinone I, tanshinone IIA and cryptotanshinone was 0.25 ng/mL from 100 microL of plasma. This method was successfully applied to the pharmacokinetic study of tanshinone I, dihydrotanshinone I, tanshinone IIA and cryptotanshinone after oral administration of PF2401-SF, the standardized fraction of Salvia miltiorrhiza enriched with tanshinone I, dihydrotanshinone I, tanshinone IIA and cryptotanshinone to male Sprague-Dawley rats.

Effects of tanshinone IIA on the hepatotoxicity and gene expression involved in alcoholic liver disease

Tanshinone IIA is one of the most abundant constituents of the root of Salvia miltiorrhiza BUNGE which exerts antioxidant and anti-inflammatory actions in many experimental disease models. In the present study, we demonstrated that the standardized fraction of S. miltiorrhiza (Sm-SF) was able to protect RAW 264.7 cells from ethanol-and lipopolysaccharide (LPS)-induced production of superoxide radical, activation of NADPH oxidase and subsequently death of the cells. Among four main components of Sm-SF, tanshinone IIA was the most potent in protecting cells from LPS-and ethanol-induced cytotoxicity. LPS or ethanol induced the expression of CD14, iNOS, and SCD1 and decreased RXR-alpha, which was completely reversed by tanshinone IIA. In H4IIEC3 cells, 10 microM tanshinone IIA effectively blocked ethanol-induced fat accumulation as evidenced by Nile Red binding assay. These results indicate that tanshinone IIA may have potential to inhibit alcoholic liver disease by reducing LPS-and ethanol-induced Kupffer cell sensitization, inhibiting synthesis of reactive oxygen/nitrogen species, inhibiting fatty acid synthesis and stimulating fatty acid oxidation.

Reversed phase-HPLC for rapid determination of polyphenols in flowers of rose species

A rapid, simple, sensitive, robust, and improved HPLC method was developed and validated for determination of 10 polyphenols, namely gallic acid, catechin, epicatechin, rutin, m-coumaric acid, quercitrin, myricetin, quercetin, apigenin, and kaempferol in fresh flowers of Rosa bourboniana and R. brunonii and in both fresh flowers and marc (left after industrial distillation of rose oil) of R. damascena. Six polyphenols, gallic acid, rutin, quercitrin, myricetin, quercetin, and kaempferol, were detected and quantified in all extracts. The chromatographic separation of 10 polyphenols was achieved in less than 16 min by RP-HPLC (Phenomenex, Luna C18 (2) column, 5 microm, 250 mm x 4.6 mm) using linear gradient elution of water and acetonitrile (0.02% trifluroacetic acid) with a flow rate of 1 mL/min at lambda 280 nm. Standard calibration curves were linear in the range of 0.39-500 microg/mL. Good results were achieved with respect to repeatability (RSD <3%) and recovery (98.6-100.8%). The method was validated for linearity, accuracy, repeatability, LOD, and LOQ.

Requirement for Ras/Raf/ERK pathway in naringin-induced G1-cell-cycle arrest via p21WAF1 expression

Naringin, an active flavonoid found in citrus fruit extracts, has pharmacological utility. The present study identified a novel mechanism of the anticancer effects of naringin in urinary bladder cancer cells. Naringin treatment resulted in significant dose-dependent growth inhibition together with G(1)-phase cell-cycle arrest at a dose of 100 microM (the half maximal inhibitory concentration) in 5637 cells. In addition, naringin treatment strongly induced p21WAF1 expression, independent of the p53 pathway, and downregulated expression of cyclins and cyclin dependent kinases (CDKs). Moreover, treatment with naringin induced phosphorylation of extracellular signal-regulated kinase (ERK), p38 mitogen-activated protein kinase and c-Jun N-terminal kinase. Among the pathways examined, only PD98059, an ERK-specific inhibitor, blocked naringin-dependent p21WAF1 expression. Consistently, blockade of ERK function reversed naringin-mediated inhibition of cell proliferation and decreased cell-cycle proteins. Furthermore, naringin treatment increased both Ras and Raf activation. Transfection of cells with dominant-negative Ras (RasN17) and Raf (RafS621A) mutant genes suppressed naringin-induced ERK activity and p21WAF1 expression. Finally, the naringin-induced reduction in cell proliferation and cell-cycle proteins also was abolished in the presence of RasN17 and RafS621A mutant genes. These data demonstrate that the Ras/Raf/ERK pathway participates in p21WAF1 induction, subsequently leading to a decrease in the levels of cyclin D1/CDK4 and cyclin E-CDK2 complexes and naringin-dependent inhibition of cell growth. Overall, these unexpected findings concerning the molecular mechanisms of naringin in 5637 cancer cells provide a theoretical basis for the therapeutic use of flavonoids to treat malignancies.

Protective effects of baicalin and octreotide on multiple organ injury in severe acute pancreatitis

PURPOSE

To discuss the application value of Baicalin which is a new drug by comparing the protecting effects of Baicalin and Octreotide on multiple organs (pancreas, liver, kidney, and lung) in Severe acute pancreatitis (SAP).

METHODS

The improved Aho method was adopted to prepare SAP rat models via retrograde injection of 3.5% sodium taurocholate to the pancreatic duct. The 135 SAP rat models after being prepared were randomly divided into the model group, Baicalin treatment group and Octreotide treatment group with 45 rats in each group; another 45 were selected to be the sham operation group, which only received abdomen opening surgery. The groups were then randomly divided into 3 h, 6 h and 12 h groups with 15 rats in each group, 10 min after successful modeling, the Baicalin treatment group was first injected with a 5% Baicalin injection at a dose of 10 mg/100 g via external jugular-vein passage followed by continuous intravenous administration (10 mg/h/100 g) by microinfusion pump; the Octreotide treatment group was first injected by Octreotide at a dose of 0.2 ug/100 g via external jugular-vein passage followed by continuous intravenous transfusion (10 mg/h/100 g) by microinfusion pump at a transfusion speed of 0.2 ug/h/100 g. The sham operation group and model group were injected with saline of equivalent volume at the corresponding time points after operation. The following observations were carried out 3, 6 and 12 h after operation: (1) mortalities of all rat groups followed by batch execution of rats and observation of the gross pathological changes of multiple organs; (2) observation of the pathological changes of multiple organ samples fixed according to the relevant requirements after HE staining; and (3) serum content of amylase, NO, malonaldehyde (MDA), and tumor necrosis factor alpha (TNF-alpha).

RESULTS

(1) The survival rate of the sham operation group and all treatment groups was 100%, whilst the 12 h survival of the model group was 66.67% (10/15), indicating a significant difference (P < 0.05). (2) The gross pathological changes and changes under light microscopy of multiple organs aggravated with time after modeling. The pathological changes of all treatment groups were milder than those of the model group at different time points by various degrees, most obviously at 6 h and 12 h. The gross pathological changes showed a similarity between the Octreotide and Baicalin treatment groups in terms of the pathological changes of pancreatic tissue. The therapeutic effects of Octreotide on kidney and lung were superior to those in the Baicalin treatment group while the pathological manifestations of the Baicalin treatment group were superior to those of the Octreotide treatment group. (3) There was no marked difference between the Baicalin and Octreotide treatment groups in terms of plasma amylase levels at all time points (P > 0.05). Although the plasma amylase levels of the Baicalin treatment group were lower than those of the model group at all time points, the levels in the Baicalin treatment group were significantly lower than those in the model group only at 3 h (P < 0.05), and there was no marked difference in the levels between the Baicalin treatment group and model groups at 6 and 12 h (P > 0.05); the levels in the Octreotide treatment group were significantly lower than in the model group at 6 h (P < 0.05), and there was no marked difference between the levels in the Octreotide treatment group and model group at 3 h and 12 h (P > 0.05). (4) The serum NO contents of the Baicalin treatment group were significantly lower than those of the model group (P < 0.05), while in the Octreotide treatment group it was obviously lower than in the model group at 3 and 12 h (P < 0.01); in this regard there was no marked difference between the Baicalin and Octreotide treatment groups at different time points (P > 0.05). (5) The serum MDA contents of the Baicalin treatment group were significantly lower than those of the model group (P < 0.01), while in the Octreotide treatment group it was significantly less than the model group at 6 and 12 h (P < 0.05), and in the Baicalin treatment group was significantly less than in the Octreotide treatment group at 12 h (P < 0.05). (6) There was no marked difference among the model group, Baicalin treatment group and Octreotide treatment group in terms of serum TNF-alpha content at 3 h and 12 h (P > 0.05). At 6 h the value in the Baicalin treatment group was significantly less than in the model group (P < 0.001), in the Octreotide treatment group it was significantly less than in the model group (P < 0.001), and the Octreotide treatment group it was significantly less than in the Baicalin treatment group (P < 0.01).

CONCLUSIONS

Both Baicalin and Octreotide have obvious protective effects on the multiple organ injury in SAP with mechanisms associated to manifold factors. By comparing the pharmacologic effects of Octreotide and Baicalin, we believe that Baicalin as a new drug has a protective effect on multiple organs of a SAP rat model similar to that of Octreotide and is worth further study and development.

Genotoxic effects of tanshinones from Hyptis martiusii in V79 cell line

The genotoxic effect of two tanshinones isolated from roots of Hyptis martiussi Benth (Labiatae) was studied using V79 (Chinese hamster lung) cells by the alkaline comet assay and micronucleus test. Tanshinones were incubated with the cells at concentrations of 1, 3, 6 and 12 microg/mL for 3 h. Tanshinones were shown to be quite strongly genotoxic against V79 cells at all tested concentrations. The data obtained provide support to the view that tanshinones has DNA damaging activity in cultured V79 cells under the conditions of the assays.

1,4,5-Trihydroxy-7-methoxy-9H-fluoren-9-one, a new cytotoxic compound from Dendrobium chrysotoxum

A new compound, 1,4,5-trihydroxy-7-methoxy-9H-fluoren-9-one, has been isolated together with two known fluorenones, dendroflorin and denchrysan A, from the whole plant of Dendrobium chrysotoxum, a plant of Dendrobium genus, used as a health-food. The structure of the fluorenones has been determined on the basis of spectroscopic studies. The isolated compounds were evaluated in vitro for their inhibitory ability against the growth of human leukaemia cell lines K562 and HL-60, human lung adenocarcinoma A549, human hepatoma BEL-7402 and human stomach cancer SGC-7901. All three fluorenones displayed selective cytotoxicity against BEL-7402 with IC50 values of 1.49, 0.97 and 1.38μg/ml, respectively.

Geographical traceability of propolis by high-performance liquid-chromatography fingerprints

A rapid fingerprint method was developed for investigating and inferring geographical origin of Chinese propolis by using high performance liquid chromatography-ultraviolet detection (HPLC-UV). 120 samples were analyzed from 17 different locations of 10 provinces of China in this study. In the HPLC chromatograms, eight major compounds were identified as flavonoids, including rutin, myricetin, quercetin, kaempferol, apigenin, pinocembrine, chrysin and galangin. Both correlation coefficient of similarity in chromatograms and relative peak areas of characteristic compounds were calculated for quantitative expression of the HPLC fingerprints. Our results revealed that the presence or absence of specific peaks and similarity evaluation in simulative mean chromatograms among different regions could efficiently identify and distinguish Chinese propolis from different geographical origins.