Antioxidative activity of natural products from plants

Anti-inflammatory, antioxidant and anti-acetylcholinesterase activities of Bouvardia ternifolia: potential implications in Alzheimer's disease

Bouvardia ternifolia has been used medicinally to treat inflammation. In the present study, we investigate the anti-Alzheimer's potential effect of the hydroalcoholic extract of B. ternifolia through evaluation of anti-inflammatory and antioxidant activities, quantification of the percentage inhibition of acetylcholinesterase activity, protection effect against β-amyloid fibrillar-induce neurotoxicity, and the identification of the main constituents. Our results show that B. ternifolia extract and ethyl acetate fraction induced anti-inflammatory effects by reducing inflammation by >70 %, while antioxidant test revealed significant IC50 values for flavonoid content fraction (30.67 ± 2.09 μg/ml) and ethyl acetate fraction (42.66 ± 0.93 μg/ml). The maximum inhibition of acetylcholinesterase was exhibited by scopoletin content fraction (38.43 ± 3.94 %), while ethyl acetate fraction exerted neuroprotective effect against β-amyloid peptide (83.97 ± 5.03 %). Phytochemical analysis, showed the presence of 3-O-quercetin glucopyranoside (415 mg/g), rutin (229.9 mg/g), ursolic and oleanolic acid (54 and 20.8 mg/g respectively), 3-O-quercetin rhamnopyranoside (12.8 mg/g), chlorogenic acid (9.5 mg/g), and scopoletin (1.38 mg/g). Our findings support the use of B. ternifolia since the extract induced significant neuroprotection against β-amyloid peptide, anti-inflammatory, antioxidant and anti-acetylcholinesterase effects that could be attributed to its contents of polyphenols, coumarins, and triterpenes, and encourage further studies for development of this extract as therapeutic agent in treatment of Alzheimer's disease.

Antioxidant capacity of "Mexican arnica" Heterotheca inuloides Cass natural products and some derivatives: their anti-inflammatory evaluation and effect on C. elegans life span

It has been suggested that the accumulation of biomolecular damage caused by reactive oxygen species (ROS) contributes to aging. The antioxidant activity is related to the ability of certain compounds to protect against the potentially harmful effect of processes or reactions involving ROS. This ability is associated with the termination of free radical propagation in biological systems. From Heterotheca inuloides various compounds which have shown to possess antioxidant capacity and scavenging ROS. The aim of this study was to determine the antioxidant capacity of additional natural components isolated from H. inuloides and some semisynthetic derivatives, their anti-inflammatory activity and the effect on Caenorhabditis elegans nematode life span. Compounds showed ability to inhibit various biological processes such as lipid peroxidation, scavenge nonbiological important oxidants such as ¹O₂, OH^∙, H₂O₂, and HOCl and scavenge non biological stable free radicals (DPPH). Some cadinane type compounds showed possess antioxidant, ROS scavenging capacity, anti-inflammatory activity, and effect on the C. elegans life span. Flavonoid type compounds increased the life of the nematode and quercetin was identified as the compound with the greatest activity. The modification of chemical structure led to a change in the antioxidant capacity, the anti-inflammatory activity, and the survival of the worm.

Characterization of phenolic compounds and antioxidant properties of Glycyrrhiza glabra L. rhizomes and roots

The present work aims to characterize and quantify the phenolic composition and to evaluate the antioxidant activity of Glycyrrhiza glabra L. (commonly known as licorice) rhizomes and roots.

The pharmacokinetics, bioavailability and excretion of columbianetin acetate and its metabolite columbianetin were analysed in rat plasma by LC-MS/MS after administration of columbianetin acetate and Angelicae pubescentis radix extract

Angelicae pubescentis radix (APR) has been widely used in the clinic for the treatment of rheumatoid arthritis.

Antioxidant and antibacterial activities of exopolysaccharides from Bifidobacterium bifidum WBIN03 and Lactobacillus plantarum R315

The objective of this study was to investigate the antioxidant and antibacterial activities of exopolysaccharide (EPS) from Bifidobacterium bifidum WBIN03 (B-EPS) and Lactobacillus plantarum R315 (L-EPS). The 1,1-diphenyl-2-picrylhydrazyl (DPPH)-radical scavenging, hydroxyl radical-scavenging, and superoxide radical-scavenging abilities were measured to evaluate antioxidant activity. Inhibition of erythrocyte hemolysis and lipid peroxidation was also measured. Both B-EPS and L-EPS had strong scavenging ability against DPPH and superoxide radicals at high concentration. The inhibitory effect of B-EPS on erythrocyte hemolysis was stronger than that of L-EPS in a concentration range from 0.30 to 1.00 mg/mL, whereas the hydroxyl scavenging ability of L-EPS (39.15 ± 0.58%) was significantly higher than that of 0.15 mg/mL ascorbic acid (24.33 ± 1.17%) and B-EPS (17.89 ± 3.30%) at 0.10 mg/mL. The inhibition of lipid peroxidation of 0.50 mg/mL B-EPS and L-EPS was 13.48 ± 1.74% and 12.43 ± 0.51%, respectively, values lower than that of ascorbic acid at the same concentration (23.20 ± 1.41%). Furthermore, all these abilities were enhanced in a concentration-dependent manner. Agar diffusion assay showed that both EPS exhibited antibacterial activities against tested pathogens such as Cronobacter sakazakii, Escherichia coli, Listeria monocytogenes, Staphyloccocus aureus, Candida albicans, Bacillus cereus, Salmonella typhimurium, and Shigella sonnei at 300 μg/mL. In conclusion, both EPS have antimicrobial and antioxidant activities and could have applications in the food industry.

Effects of KH-204 on the expression of heat shock protein 70 and germ cell apoptosis in infertility rat models

Background

Idiopathic infertility is a significant number of causes of male infertility. Empirical treatments are used for idiopathic male infertility, and antioxidant supplementation is a kind of management of oxidative stress related infertility. We investigated the antioxidant effects of the modified Ojayeonjonghwan (KH-204) in a rat model of cryptorchidism.

Method

Male rats were divided into four groups (n = 8 in each): a normal control group, a cryptorchidism-induced control group and two cryptorchidism-induced groups treated p.o. with either 200 or 400 mg/kg, KH-204 for 4 weeks. The testes and epididymides from rats in all groups were removed, weighed and subjected to histological examination and semen analysis after surgery. Oxidative stress was assessed by measuring 8-hydroxy-20-deoxyguanosine (8-OHdG), superoxide dismutase (SOD) and heat shock protein (HSP) levels. Apoptosis was determined using a terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick end-labeling assay.

Results

Treatment with the multi-herbal medicine KH-204 (1) increased the mean weight of the cryptorchid testes; (2) restored sperm counts, motility and germinal cell layer thickness; (3) decreased levels of 8-OHdG and increased levels of SOD; and (4) decreased HSP70 levels and apoptosis.

Conclusions

KH-204 reduces the oxidative stress in an experimental rat model of cryptorchidism, and it may alleviate HSP expression and germ cell apoptosis.

Comparative studies on bioactive constituents in hawk tea infusions with different maturity degree and their antioxidant activities

Hawk tea (Litsea coreana var. lanuginose) is a very popular herbal tea in the southwest of China. According to the maturity degree of raw materials, Hawk tea can usually be divided into three types: Hawk bud tea (HB), Hawk primary leaf tea (HP), and Hawk mature leaf tea (HM). In this study, some of the bioactive constituents and antioxidant properties of the three kinds of Hawk tea infusions were comparatively investigated. The results showed that the contents of total flavonoids, vitamin C, and carbohydrates in Hawk bud tea infusion (HBI) were higher than those in Hawk primary leaf tea infusion (HPI) and Hawk mature leaf tea infusion (HMI). HPI had higher contents of total polyphenols and exhibited better DPPH radical scavenging activity and ferric reducing activity power. HBI could provide more effective protection against erythrocyte hemolysis. As age is going from bud to mature leaf, the ability to inhibit the formation of low density lipoprotein (LDL) conjugated diene and the loss of tryptophan fluorescence decreased. The bioactive constituents and antioxidant activities of Hawk tea infusions were significantly affected by the maturity degree of the raw material.

Identification of licopyranocoumarin and glycyrurol from herbal medicines as neuroprotective compounds for Parkinson's disease

In the course of screening for the anti-Parkinsonian drugs from a library of traditional herbal medicines, we found that the extracts of choi-joki-to and daio-kanzo-to protected cells from MPP⁺-induced cell death. Because choi-joki-to and daio-kanzo-to commonly contain the genus Glycyrrhiza, we isolated licopyranocoumarin (LPC) and glycyrurol (GCR) as potent neuroprotective principals from Glycyrrhiza. LPC and GCR markedly blocked MPP⁺-induced neuronal PC12D cell death and disappearance of mitochondrial membrane potential, which were mediated by JNK. LPC and GCR inhibited MPP⁺-induced JNK activation through the suppression of reactive oxygen species (ROS) generation, thereby inhibiting MPP⁺-induced neuronal PC12D cell death. These results indicated that LPC and GCR derived from choi-joki-to and daio-kanzo-to would be promising drug leads for PD treatment in the future.

Standardized Salvia miltiorrhiza extract suppresses hepatic stellate cell activation and attenuates steatohepatitis induced by a methionine-choline deficient diet in mice

The aim of this study was to examine the effect of standardized extract of Salvia miltiorrhiza (SME) on gene and protein expression of non-alcoholic steatohepatitis (NASH)-related factors in activated human hepatic stellate cells (HSC), and in mice with steatohepatitis induced by a methionine-choline deficient (MCD) diet. Male C57BL/6J mice were placed on an MCD or control diet for 8 weeks and SME (0, 0.1, 0.5 and 1 mg/kg body weight) was administered orally every other day for 4 or 6 weeks. HSCs from the LX-2 cell line were treated with transforming growth factor β-1 (TGF-β1) or TGF-β1 plus SME (0.1–10 μg/mL). To investigate the effect of SME on reactive oxygen species (ROS)-induced condition, LX-2 cells were treated with hydrogen peroxide (H₂O₂) or H₂O₂plus SME (0.1–100 μg/mL). MCD administration for 12 weeks increased mRNA expression of tumor necrosis factor (TNF-α), TGF-β1, interleukin-1β (IL-1β), C-reactive protein (CRP), α-smooth muscle actin (α-SMA), type I collagen, matrix metalloproteinase-2 (MMP-2) and MMP-9. TGF-β1-induced LX-2 cells exhibited similar gene expression patterns. SME treatment significantly reduced the mRNA and protein expression of NASH-related factors in the mouse model and HSCs. Histopathological liver analysis showed improved non-alcoholic fatty liver disease (NAFLD) activity and fibrosis score in SME-treated mice. The in vivo studies showed that SME had a significant effect at low doses. These results suggest that SME might be a potential therapeutic candidate for NAFLD treatment.

Synthesis, characterization, optical properties and theoretical calculations of 6-fluoro coumarin

6-Fluoro coumarin is synthesized and characterized by (1)H NMR and (13)C NMR. The optical properties of the title compound are investigated by UV-vis absorption and fluorescence emission spectra, the results show the title compound can absorb UV-vis light at 319, 269 and 215nm, moreover it exhibits blue-purple fluorescence emission at 416nm. Theoretical studies on molecular structure, infrared spectra (IR), nuclear magnetic resonance ((1)H NMR, (13)C NMR) chemical shifts, UV-vis absorption and fluorescence emission of the synthesized compound have been worked out. Most chemical calculations were performed by density functional theory (DFT) method at the B3LYP/6-311G(d,p) level (NMR at B3LYP/Aug-CC-Pvdz level) using Gaussian 09 program. The compared results reveal that the scaled theoretical vibrational frequencies are in good accordance with the observed spectra; computational chemical shifts are consistent with the experimental values in most parts, except for some minor deviations; the UV-vis absorption calculated matches the experimental one very well, and the fluorescence emission spectrum is in good agreement with the experimental one when the solute-solvent hydrogen-bonding interaction is considered. These good coincidences prove that the computational methods selected can be used to predict these properties of other similar materials where it is difficult to arrive at experimental results.

Effect of fermentation on the antioxidant activity in plant-based foods

This study provides an overview of the factors that influence the effect of fermentation on the antioxidant activity and the mechanisms that augment antioxidative activities in fermented plant-based foods. The ability of fermentation to improve antioxidant activity is primarily due to an increase in the amount of phenolic compounds and flavonoids during fermentation, which is the result of a microbial hydrolysis reaction. Moreover, fermentation induces the structural breakdown of plant cell walls, leading to the liberation or synthesis of various antioxidant compounds. These antioxidant compounds can act as free radical terminators, metal chelators, singlet oxygen quenchers, or hydrogen donors to radicals. The production of protease, α-amylase and some other enzymes can be influenced by fermentation that may have metal ion chelation activity. Because the mechanisms that affect antioxidant activity during fermentation are extremely varied, further investigation is needed to establish the precise mechanisms for these processes.

First report on isolation of methyl gallate with antioxidant, anti-HIV-1 and HIV-1 enzyme inhibitory activities from a mushroom (Pholiota adiposa)

In this study, a compound with antioxidant and anti-HIV activities designated as HEB was first isolated from the edible mushroom Pholiota adiposa by extraction with ethanol and ethyl acetate. HEB was then purified by high performance liquid chromatography (HPLC) and identified to be methyl gallate (C8H8O5, 184.1 Da) based on data from its mass spectrum (MS) and nuclear magnetic resonance (NMR) spectrum. HEB displayed strong antioxidant potency in inhibiting, at 1.36 mM concentration, erythrocyte hemolysis and scavenging DPPH radicals and superoxide anion (O2(-)) by 82.4%, 85.6% and 71.4%, respectively. Besides exhibiting a low cytotoxicity, compound HEB demonstrated significant anti-HIV activity in that it inhibited HIV-1 replication in TZM-BL cells infected by pseudovirus with an IC50 value of 11.9 μM. Further study disclosed that HEB inhibited the viral entry process and activities of key enzymes essential for the HIV-1 life cycle. HEB inhibited HIV-1 reverse transcriptase and integrase activities with an IC50 value of 80.1 μM and 228.5 μM, respectively, and at 10 mM concentration inhibited HIV-1 protease activity by 17.1% which was higher than that achieved by the positive control pepstatin A. Interestingly, this study first revealed that H2O2 stimulation not only activated cell oxidative stress responses, but also accelerated HIV-1 long terminal repeat (LTR) promotion in TZM-BL cells, which was significantly reduced by HEB from 18.2% to about 2%. It implied a direct relationship between the antioxidant and anti-HIV activities of the natural active constituent HEB. Nuclear transcription factor kappa B (NF-κB) signal pathways plays an important role in oxidative stress responses. Meanwhile, there is κB target sequence in HIV promoter LTR which is significant for virus replication and gene expression. In this study, Western Blot assay showed that HEB could inhibit the activation of NF-κB signal pathway stimulated by H2O2 in mouse spleen cells through suppressing NF-κB (p65) translocation into nucleus and NF-kappa-B inhibitor (IκB) degradation in cytoplasm. In summary, the antioxidant HEB from P. adiposa could inhibit HIV-1 replication through multiple target sites. The data suggest that natural antioxidant compounds might have a potential for treatment of AIDS.

Comparative study of antioxidant status in androgenic embryos of Aesculus hippocastanum and Aesculus flava

In vivo (leaves and seed embryos) and in vitro (androgenic embryos) antioxidant scavenging activity of Aesculus hippocastanum and Aesculus flava medical plants was examined. Here we report antioxidant enzyme activities of superoxide dismutase, catalase, guaiacol peroxidase and glutathione peroxidase, reduced glutathione quantity, flavonoids, soluble protein contents, quantities of malondialdehyde, and (•)OH radical presence in the investigated plant samples. Total antioxidant capacity of all the samples of A. hippocastanum and A. flava was determined using FRAP, DPPH, and NO(•) radical scavenger capacity. The leaves of A. flava collected from the botanical garden exhibited stronger antioxidant activity (higher activities of SOD, and higher quantities of GSH, TSH, TPC, and scavenging abilities of DPPH and NO(•), and higher FRAP values and lowest quantities of (•)OH and MDA) than in vitro obtained cultures. However, the leaves of A. flava showed higher antioxidant activity than the leaves of A. hippocastanum, and therefore they have a stronger tolerance of oxidative stress. Androgenic embryos of both species had low amount of antioxidants due to controlled in vitro environmental conditions (T, photoperiod, humidity, nutritive factors, and pathogen-free). Our results confirmed that we found optimal in vitro conditions for producing androgenic embryos of both Aesculus species. Also, we assume that horse chestnut androgenic embryos can be used as an alternative source for large-scale aescin production.

Addition of propolis to irinotecan therapy prolongs survival in ehrlich ascites tumor-bearing mice

We investigated possible synergistic action of anticancer drug Irinotecan (IRI) combined with ethanolic (EEP) and water-soluble (WSDP) derivate of propolis on Swiss albino mice injected with Ehrlich ascites tumor (EAT). For survival analysis mice were administered WSDP and EEP (100 mg/kg) daily for 3 consecutive days, beginning on 3rd day after EAT cell (1×10⁶) injection. IRI was administered at a dose of 50 mg/kg on days 1, 13, and 19. We simultaneously studied peripheral white blood cell count, cell types washed from the peritoneal cavity, functional activity of macrophages from peritoneal cavity, and the level of primary DNA damage in leukocytes, kidney, and liver cells using the alkaline comet assay. Three out of 9 mice per group survived the entire duration of the experiment (90 days) in groups treated with IRI combined with WSDP and EEP. All test components increased survival of mice by 7.53% to 231.54%. Combined treatment with IRI and/or WSDP and EEP significantly decreased percentage of tumor cells in the peritoneal cavity as compared to nontreated EAT-injected mice. All treated animals had significantly higher percentage of neutrophils in the peritoneal cavity in comparison to nontreated EAT-injected mice. We observed significantly higher value of DNA damage in leukocytes of mice treated with IRI and combination of IRI and/or WSDP and EEP as compared to nontreated EAT-injected mice, while the same treatment decreased DNA damage in kidney. Our results showed that addition of propolis to IRI treatment enhanced antitumor activity of IRI and prolongs survival in EAT-bearing mice, which definitely deserve further studies to clarify the possible mechanisms of antitumor actions of combined herb-drug treatments.

Protective effect of Basella alba and Carpolobia alba extracts against maneb-induced male infertility

CONTEXT

Male infertility is one of the leading causes of social frustration and marginalization, mainly in the developing world. It is attributed to many factors including exposure to agropesticides such as manganese ethylenebis (dithiocarbamate) (maneb), which is one of the most frequently used fungicides in Cameroon. Previous reports support efficiency of some medicinal plants commonly used in Cameroonian folk medicine for the treatment of this disorder.

OBJECTIVE

The present study was aimed at assessing the protective effect of extracts from selected plant species, namely Basella alba L. (Basellaceae) (MEBa) and Carpolobia alba G. Don (Polygalaceae) (AECa), in alleviating the maneb-induced impairment of male reproductive function in Wistar albino rats.

MATERIALS AND METHODS

The rats were treated with vehicle, plant extract (MEBa or AECa), maneb and maneb plus plant extract, respectively, and their fertility was assessed. Animals were thereafter sacrificed and organs (liver, kidneys and reproductive organs) were dissected out and weighed. Serum androgens together with alanine aminotransferase, liver glutathione and thiobarbituric acid reactive species (TBARS) were also measured.

RESULTS AND DISCUSSION

From this study, both plant extracts stimulated testosterone and improved fertility. Administration of MEBa plus maneb prevented fertility reduction by maneb and minimized the inhibitory effect of maneb on testosterone levels. AECa also improved fertility of the maneb-exposed rats, though without restoring testosterone levels, and other investigated parameters remained unaffected by different treatments.

CONCLUSION

These findings emphasized the beneficial effects of B. alba and C. alba extracts on male fertility, and suggest their protective effect against maneb-induced toxicity in male reproductive function.

Vernonia condensata Baker (Asteraceae): a promising source of antioxidants

The present study evaluated the antioxidant potential of Vernonia condensata Baker (Asteraceae). Dried and powdered leaves were exhaustively extracted with ethanol by static maceration followed by partition to obtain the hexane, dichloromethane, ethyl acetate, and butanol fractions. Total phenols and flavonoids contents were determined through spectrophotometry and flavonoids were identified by HPLC-DAD system. The antioxidant activity was assessed by DPPH radical scavenging activity, TLC-bioautography, reducing power of Fe(+3), phosphomolybdenum, and TBA assays. The total phenolic content and total flavonoids ranged from 0.19 to 23.11 g/100 g and from 0.13 to 4.10 g/100 g, respectively. The flavonoids apigenin and luteolin were identified in the ethyl acetate fraction. The IC50 of DPPH assay varied from 4.28 to 75.10 µg/mL and TLC-bioautography detected the antioxidant compounds. The reducing power of Fe(+3) was 19.98 to 336.48  μg/mL, while the reaction with phosphomolybdenum ranged from 13.54% to 32.63% and 56.02% to 135.00% considering ascorbic acid and rutin as reference, respectively. At 30 mg/mL, the ethanolic extract and fractions revealed significant effect against lipid peroxidation. All these data sustain that V. condensata is an important and promising source of bioactive substances with antioxidant activity.

Antioxidant characterization of oak extracts combining spectrophotometric assays and chemometrics

Antioxidant characteristics of leaves, twigs, and acorns from two Serbian oak species Quercus robur L. and Quercus petraea L. from Vojvodina province (northern Serbia) were investigated. 80% ethanol (in water) extracts were used for antiradical power (ARP) determinations against DPPH(•), (•)NO, and O2 (•-) radicals, ferric reducing antioxidant power (FRAP), total phenol, tannin, flavonoid, and proanthocyanidin contents. Permanganate reducing antioxidant capacity (PRAC) was determined using water extracts. Beside, mentioned parameters, soluble proteins, lipid peroxidation (LP), pigments and proline contents were also determined. The data of different procedures were compared and analyzed by multivariate techniques (correlation matrix calculation and principal component analysis (PCA)). PCA found that investigated organs of two different oak tree species possess similar antioxidant characteristics. The superior antioxidant characteristics showed oak leaves over twigs and acorns and seem to be promising source of antioxidants with possible use in industry and pharmacy.

Preliminary report on the safety of a new herbal formula and its effect on sperm quality

PURPOSE

Male infertility is a serious problem, and its prevalence has been increasing. Therefore, we investigated the safety of a new herbal formula and its effects on sperm quality.

MATERIALS AND METHODS

An in vitro cytotoxicity test in TM3 Leydig cells was performed to evaluate cell viability after administration of five types of herbs separately and of a new herbal formula containing these five. An in vivo test in male mice was performed to evaluate the influence of the new herbal formula on the reproductive organs and sperm quality. After the 8- and 28-day oral administration of the new herbal formula, the weights of the reproductive organs were measured and the sperm count and motility were evaluated.

RESULTS

In the in vitro cytotoxicity test, less than 80% cell viability at concentrations of 500 mg/L and 1,000 mg/L of Rubus coreanus Miquel and Cuscuta chinensis Lam was observed. However, more than 80% cell viability was observed at all the tested concentrations of the new herbal formula. After the 8- and 28-day oral administration, there were no considerable changes in body weight. The weights of the testes, epididymis, and seminal vesicles after the 8- and 28-day oral administration were similar to those of the control. The sperm count and activity were significantly improved compared with those of the control group at 8 and 28 days after 100, 200, and 400 mg of oral administration.

CONCLUSIONS

The safety of the new formula and its positive effect on the sperm quality were observed after the oral administration of the formula.

The pharmacokinetics and oral bioavailability studies of columbianetin in rats after oral and intravenous administration

ETHNOPHARMACOLOGICAL RELEVANCE

The roots of Angelica pubescens Maxim. f. biserrata Shan et Yuan (RAP) has been used as Traditional Chinese medicine to treat rheumatic disease in China since ancient times, but its action mechanisms was not well understood. Columbianetin is one of the main active constituents isolated from RAP, which has been shown to have various biological activities, but the absorption characteristics and oral bioavailability dose proportionality of columbianetin in vivo were not studied.

MATERIALS AND METHODS

Male Sprague Dawley rats (210-230 g) received either an intravenous (i.v. 5, 10 and 20 mg kg(-1)) or oral (5, 10 and 20 mg kg(-1)) dose of columbianetin. The levels of columbianetin in plasma were measured by a simple and sensitive reversed-phase high-performance liquid chromatography (HPLC) method. The simple liquid-liquid extraction with ethyl acetate was used for sample preparation. Osthole was selected as internal standard (IS).

RESULTS

The chromatographic separation was accomplished on a C18 column at a flow rate of 1 mL min(-1), where water-methanol was used as mobile phase. The calibration curve of the method was linear in the concentration range of 0.05-2000 μg mL(-1). The intra and inter-day accuracy for columbianetin in rat plasma samples were within 8% and the variation was less than 8.3%. This method was suitable for the determination and pharmacokinetic study of columbianetin in rat plasma after both intravenous and oral administration. The results indicated that maximum plasma concentrations(Cmax) for the columbianetin (17-42 μg mL(-1)) were achieved at 0.3-0.5h post-oral dosing and the apparent volume of distribution (V/F) ranged from 0.38 to 0.44 L. Absolute bioavailability of columbianetin was assessed to be 81.13 ± 45.85, 81.09 ± 33.63 and 54.30 ± 23.19%, respectively. Terminal elimination half-life (T1/2) of the columbianetin after oral dosing was 60-90 min and were 2.5-3.3 fold longer than those observed for the i.v. dosing.

CONCLUSIONS

The pharmacokinetic properties of columbianetin in rat after oral administration were characterized as rapid oral absorption, quick clearance and good absolute bioavailability. The bioavailability of columbianetin ranged from 54 to 81% for 5, 10 and 20 mg kg(-1) oral doses. The bioavailability of columbianetin is independent of the doses studied. Columbianetin showed dose proportionality over the dose range 5-20 mg kg(-1). The results clearly demonstrated that columbianetin was one of the material bases of RAP. Furthermore, an HPLC method was demonstrated in this study for the research of traditional Chinese medicine.

Esculetin suppresses proliferation of human colon cancer cells by directly targeting β-catenin

The Wnt pathway is a promising therapeutic and preventive target in various human cancers. The transcriptional complex of β-catenin-T-cell factor (Tcf), a key mediator of canonical Wnt signaling, has been implicated in human colon cancer development. Current treatment of colon cancer depends on traditional cytotoxic agents with limited effects. Therefore, the identification of natural compounds that can disrupt the β-catenin-TcF complex to suppress cancer cell growth with fewer adverse side effects is needed. To identify compounds that inhibit the association between β-catenin and Tcf, we used computer docking to screen a natural compound library. Esculetin, also known as 6,7-dihydroxycoumarin, is a derivative of coumarin and was identified as a potential small-molecule inhibitor of the Wnt-β-catenin pathway. We then evaluated the effect of esculetin on the growth of various human colon cancer cell lines and its effect on Wnt-β-catenin signaling in cells and in an embryonic model. Esculetin disrupted the formation of the β-catenin-Tcf complex through direct binding with the Lys312, Gly307, Lys345, and Asn387 residues of β-catenin in colon cancer cells. In addition, esculetin effectively decreased viability and inhibited anchorage-independent growth of colon cancer cells. Esculetin potently antagonized the cellular effects of β-catenin-dependent activity, and in vivo treatment with esculetin suppressed tumor growth in a colon cancer xenograft mouse model. Our data indicate that the interaction between esculetin and β-catenin inhibits the formation of the β-catenin-Tcf complex, which could contribute to esculetin's positive therapeutic and preventive effects against colon carcinogenesis.

Preliminary evaluation of the interactions of Panax ginseng and Salvia miltiorrhiza Bunge with 5-fluorouracil on pharmacokinetics in rats and pharmacodynamics in human cells

An increasing number of cancer patients are using herbs in combination with conventional chemotherapeutic treatment. It is therefore important to study the potential consequences of the interactions between herbs and anticancer drugs. The effects of extracts from Panax ginseng (PGS) and Salvia miltiorrhiza Bunge (SMB) on the pharmacokinetics of 5-fluorouracil (5-FU) were performed in vivo and detected by high performance liquid chromatography (HPLC), while, an ATP assay was used to study the pharmacodynamic interactions in vitro. The results of the pharmacokinetic experiments showed a significant increase in the elimination half-life (t1/2(k e )) of 5-FU in the PGS-pretreated group and in the area under the curve (AUC) in the SMB-pretreated group compared with the control group. However, after SMB pretreatment, weight loss was observed in rats. The results of pharmacodynamic experiments showed that neither PGS nor SMB, when used alone, directly inhibited cancer cell growth at 0.1-100 μg/ml. Moreover, PGS had a synergistic cytotoxic effect with 5-FU on human gastric cancer cells but not on normal gastric cells. The results imply that when combined with 5-FU, PGS may be a better candidate for further study. This study might provide insights for the selection of herbal-chemotherapy agent interactions.

Design, synthesis, and vasorelaxation activity of novel imperatorin derivatives

In this study, a series of novel imperatorin derivatives 7a-7e were designed and synthesized. Their vasorelaxation activities were evaluated by the pharmacological experiments in vitro. Most of the tested compounds exhibited better water solubility and vasorelaxation activity in different degrees, especially 7b and 7c with EC50 values of 2.29 and 2.63 μM, respectively on mesenteric artery, 7d and 7e with EC50 values of 1.04 and 2.65 μM, respectively on brain artery. The results indicated that these novel compounds have a potential interest for the development of novel and potent vasorelaxant agents for different kinds of arteries.

Metabolite profiling and biological activities of bioactive compounds produced by Chrysosporium lobatum strain BK-3 isolated from Kaziranga National Park, Assam, India

In an ongoing survey for bioactive potential of microorganisms from different biosphere zones of India, a new Chrysosporium lobatum strain BK-3 was isolated from soil sample collected from a biodiversity hotspot, Kaziranga National Park, Assam, India. Bioactivity-guided purification resulted in the isolation of two bioactive compounds whose chemical structures were elucidated by ¹H and ¹³C Nuclear Magnetic Resonance (NMR), 2D-NMR, Fourier Transform Infra-red (FT-IR) and mass spectroscopic techniques, and were identified as α, β-dehydrocurvularin and curvularin. Only curvularin exhibited 80% acetylcholinesterase (AChE) inhibitory activity. Detailed ligand receptor binding interactions were studied for curvularin by molecular docking studies. Further, both curvularin and α, β-dehydrocurvularin had similar level of cytotoxicity against different human tumour cell lines like A549, HeLa, MDA-MB-231 and MCF-7, while α, β-dehydrocurvularin was active against COLO 205 with a IC₅₀ of 7.9 μM, but curvularin was inactive. α, β-Dehydrocurvularin also showed good superoxide anion scavenging activity with an EC₅₀ value of 16.71 μg ml^-1. Hence, both these compounds exhibited differences in bioactive profiles and this was probably associated with their minor structural differences. This is a first report on bioactive compounds exhibiting AChE inhibitory, cytotoxicity and antioxidant activities from Chrysosporium lobatum strain BK-3.

Antioxidant and anti-inflammatory activities of Pittocaulon species from México

context: Stems and leaves of Pittocaulon spp. (Asteraceae) are used in Mexican traditional medicine as an anti-inflammatory substance and for the treatment of skin injuries.

OBJECTIVE

This study evaluated the antioxidant activity of methanol (MeOH) and dichloromethane (DC) extracts of five Pittocaulon species.

MATERIALS AND METHODS

DC and MeOH extracts from flowers, roots, and stems of Pittocaulon praecox (Cav.) H. Rob. & Brettell, P. bombycophole (Bullock) H. Rob. & Brettell, P. filare (Mc Vaugh) H. Rob. & Brettell, P. velatum (Greenm.) Rob. & Brettell and P. hintonii H. Rob. & Brettell.

RESULT AND DISCUSSION

In the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, the flower extracts obtained with MeOH were the most active with IC(50) values ranging from 51.83 ± 4.08 to 154.19 ± 8.39 ppm. In the thiobarbituric acid reactive substances (TBARS) model, the best activity was shown by DC extracts of roots with IC(50) values ranging from 55.54 ± 1.28 to 160.82 ± 5.37 ppm. The MeOH extract of flowers of P. bombycophole had the highest IC(50) value in both DPPH (51.83 ± 4.08 ppm) and TBARS (39.78 ± 1.97 ppm). The samples with the best values in the antioxidant activity assays were evaluated in the anti-inflammatory tests. The DC root extract of P. velatum at a dose of 1 mg/ear produced the greatest reduction (84.96%) of the 2-O-tetradecanoylphorbol-13-acetate (TPA)-induced mouse ear edema. This extract also reduced the activity of the enzyme myeloperoxidase (MPO) (73.65%) at the same dose. In contrast, DC root extract of this species did not show significant inhibition of the increase in paw edema induced by carrageenan at the doses tested (100 mg/kg).

CONCLUSION

These results support the traditional use of these plants as anti-inflammatory. DC extracts of P. velatum and MeOH extracts of P. bombycophole may be a potential resource of natural anti-inflammatory and antioxidant compounds, respectively. Additional studies must be done to identify the compounds responsible of the activity on these plants and to establish the mechanism of action.

Skin ageing: natural weapons and strategies

The fact that the skin is the most visible organ makes us aware of the ageing process every minute. The use of plant extracts and herbs has its origins in ancient times. Chronological and photo-ageing can be easily distinguished clinically, but they share important molecular features. We tried to gather the most interesting evidence based on facts about plants and plant extracts used in antiaging products. Our main idea was to emphasize action mechanisms of these plant/herbal products, that is, their “strategies” in fighting skin ageing. Some of the plant extracts have the ability to scavenge free radicals, to protect the skin matrix through the inhibition of enzymatic degradation, or to promote collagen synthesis in the skin. There are some plants that can affect skin elasticity and tightness. Certainly, there is a place for herbal principles in antiaging cosmetics. On the other hand, there is a constant need for more evaluation and more clinical studies in vivo with emphasis on the ingredient concentration of the plant/herbal products, its formulation, safety, and duration of the antiaging effect.

Biochemical composition and antioxidant capacity of extracts from Podophyllum hexandrum rhizome

BACKGROUND

Podophyllum hexandrum Royle (P. hexandrum) is a perennial herb and widely used in clinic. The present study was designed to separate and identify the biochemical composition and antioxidant capacity of extracts from P. hexandrum rhizome.

METHODS

The ethyl acetate and ethanol extracts from P. hexandrum rhizome were analyzed by GC-MS (gas chromatography-mass spectrometry), and the antioxidant capacity of the extracts and the components was tested by using the DPPH (2, 2-diphenylpicrylhydrazyl) and FRAP (Ferric reducing/antioxidant power) assays.

RESULTS

The rhizome extracts had greater antioxidant capacity than the petiole extracts in DPPH and FRAP assays. About 16 kinds of main reactive oxygen components were identified in the extracts. Components of PADE (Phthalic acid, diisobutyl ester), BADE (1,2-Benzenedicarboxylic acid, diisooctyl ester), Polyneuridine, PODD (Podophyllotoxin, deoxy), β-Sitosterol and POD (Podophyllotoxin) showed the antioxidant capacity in some degree. PODD, POD, and Polyneuridine showed stronger antioxidant capacity with the IC50 and FRAP values of 9.61 ± 0.81 and 2923.98 ± 21.89 μM, 9.98 ± 0.24 and 2847.27 ± 14.82 μM, and 13.37 ± 0.35 and 2404.32 ± 36.88 μM, respectively, than the positive control ASA (Ascorbic acid) with the values of 60.78 ± 1.22 and 1267.5 ± 30.24 μM (P < 0.01).

CONCLUSIONS

PODD, POD, and Polyneuridine are very critical for the antioxidant capacity in the extract of P. hexandrum rhizome. These results provide useful biochemical basis and information for the potential use of this plant.