Krystyna Skalicka-Wozniak

Effects of imperatorin on scopolamine-induced cognitive impairment and oxidative stress in mice

RationaleImperatorin, a naturally occurring furanocoumarin, inactivates gamma-aminobutyric acid transaminase and inhibits acetylcholinesterase activity.ObjectivesThe purpose of our experiment was to examine the influence of imperatorin on cognitive impairment and oxidative stress in the brain induced by scopolamine in male Swiss mice.MethodsIn the present studies, we used scopolamine-invoke memory deficit measured in passive avoidance (PA) paradigm as an animal model of Alzheimer disease (AD).ResultsOur finding revealed that imperatorin administered acutely at the doses of 5 and 10 mg/kg prior to the injection of scopolamine (1 mg/kg) improved memory acquisition and consolidation impaired by scopolamine. Furthermore, repeatable (7 days, twice daily) administration of the highest dose of imperatorin (10 mg/kg) significantly attenuated the effects of scopolamine on memory acquisition, whereas the doses of 5 and 10 mg/kg of this furanocoumarin were effective when memory consolidation was measured. Imperatorin, administered with scopolamine, increased antioxidant enzymes activity and decreased concentration of malondiamide, an indicator of lipid peroxidation level.ConclusionsThese results demonstrate that imperatorin may offer protection against scopolamine-induced memory impairments and possesses antioxidant properties, thus after further preclinical and clinical studies this compound may provide an interesting approach in pharmacotherapy, as well as prophylactics of AD.

Effects of imperatorin on nicotine-induced anxiety- and memory-related responses and oxidative stress in mice.

The purpose of the reported experiments was to examine the effects of imperatorin [9-[(3-methylbut-2-en-1-yl)oxy]-7H-furo[3,2-g]chromen-7-one] on anxiety and memory-related responses induced by nicotine in mice and their relation to the level of nicotine-induced oxidative stress in brain as well as in the hippocampus and the prefrontal cortex. Male Swiss mice were tested for anxiety in the elevated plus maze test (EPM), and for cognition using passive avoidance (PA) procedures. Imperatorin, purified by high-speed counter-current chromatography from methanol extract of fruits of Angelica officinalis, acutely administered at the doses of 10 and 20mg/kg impaired the anxiogenic effect of nicotine (0.1mg/kg, s.c.). Furthermore, acute injections of subthreshold dose of imperatorin (1mg/kg, i.p.) improved processes of memory acquisition when co-administered with nicotine used at non-active dose of 0.05 mg/kg, s.c. Additionally, repeated administration of imperatorin (1mg/kg, i.p., twice daily, for 6 days) improved different stages of memory processes (both acquisition and consolidation) when injected in combination with non-active dose of nicotine (0.05 mg/kg, s.c.) in the PA task. Oxidative stress was assessed by determination of antioxidant enzymes (glutathione peroxidases (GPx), superoxide dismutase (SOD), glutathione reductase (GR)) activities as well as of malondialdehyde (MDA) concentration in the whole brain, the hippocampus and the prefrontal cortex after repeated administration of imperatorin (1mg/kg, 6 days) and single nicotine injection (0.05 mg/kgs.c.) on the seventh day. The results of our research suggest strong behavioural interaction between imperatorin and nicotine at the level of anxiety- and cognitive-like processes. Furthermore, imperatorin inhibited nicotine-induced changes in examined indicators of oxidative stress, especially in the hippocampus and the cortex.

The effects of imperatorin on anxiety and memory-related behavior in male Swiss mice.

The purpose of the reported experiments was to examine the effects of imperatorin [9-(3-methylbut-2-enyloxy)-7H-furo[3,2-g]chromen-7-one], a bioactive furanocoumarin isolated from the fruits of Angelica archangelica (Angelica officinalis) on anxiety and memory-related behaviors of mice. Male Swiss mice were tested for anxiety and cognition, in the elevated plus maze test (EPM), using two different procedures. In the present experiments, imperatorin was administered acutely (at the doses of 5, 10, 20, 30, and 50 mg/kg); injections were made 15, 30, and 60 min before test (anxiety); 30 min before the first trial (memory acquisition); or immediately after the first trial (memory consolidation), as well as subchronically, twice a day for 6 days. On the seventh day, the mice were injected once with imperatorin (10 and 20 mg/kg, i.p.) 30 min before the test (anxiety) and 30 min before the first trial (memory acquisition), or immediately after the first trial (memory consolidation). We observed that imperatorin when administered acutely and repeatedly, at the doses of 10 and 20 mg/kg, exerted an anxiolytic effect on mice tested 30 min after the injection measured in the EPM test. By contrast, no such effect was observed after the acute administration of imperatorin at the doses of 5, 30 and 50 mg/kg. Moreover, other observations carried out 15 and 60 min after a single injection of the drug did not reveal any effect of imperatorin on anxiety behavior in the EPM test. Furthermore, acute and repeated administration of imperatorin (10 and 20 mg/kg) improved different stages of memory processes (both acquisition and consolidation) in a modified EPM test (mEPM). The results of our research suggest imperatorin to be an interesting therapeutical option in disorders with high anxiety levels and memory impairment.

Phenolic acids content, antioxidant and antimicrobial activity of Ligusticum mutellina L.

A simple HPLC method has been used for separation and quantitative analysis of the phenolic acids in the methanolic extracts of Ligusticum mutellina aerial parts. Chlorogenic acid was the predominant phenolic acid. Additionally, gallic, p-OH-benzoic, caffeic, p-coumaric and ferulic acids were identified. Moderate antibacterial and antifungal activity (MIC = 1.25–2.5 mg mL−1) was observed for the methanol extract of L. mutellina herb received from plants in flowering stage against a broad spectrum of bacteria. Micrococcus luteus, Pseudomonas aeruginosa and Candida spp. were the most sensitive to this plant material. Total phenolic content for the methanol extract of L. mutellina herb received from plants in flowering stage was 1.56 g of chlorogenic acid equivalents/100 g dry weight. The methanol extract of L. mutellina herb received from plants in flowering stage showed antioxidant activity with DPPH (IC50 value of 0.40 mg mL−1) and with ABTS (IC50 value of 8.65 mg mL−1).

Volatile compounds in fruits of Peucedanum cervaria (Lap.) L.

The volatile compounds from Peucedanum cervaria (Lap.) L. were obtained by hydrodistillation (HD) and headspace solid‐phase microextraction techniques (HS‐SPME), and then analyzed by GC/MS methods. The composition of samples from a botanical garden was compared with plants collected in the wild. The main compounds of the essential oils of P. cervaria were identified as α‐pinene, sabinene, and β‐pinene (more than 80% of oil). The content of β‐myrcene, limonene+β‐phellandrene, and germacrene D was higher than 1%. The in vitro antibacterial activity of the essential oil was evaluated by the agar dilution method against ten reference strains of Gram‐positive and Gram‐negative bacteria.

Effect of xanthotoxin (8-methoxypsoralen) on the anticonvulsant activity of classical antiepileptic drugs against maximal electroshock-induced seizures in mice.

The effects of xanthotoxin (8-methoxypsoralen) on the anticonvulsant activity of four classical antiepileptic drugs (carbamazepine, phenobarbital, phenytoin and valproate) were studied in the mouse maximal electroshock seizure model. Tonic hind limb extension (seizure activity) was evoked in adult male albino Swiss mice by a current (25 mA, 500 V, 50 Hz, 0.2 s stimulus duration) delivered via auricular electrodes. Total brain concentrations of antiepileptic drugs were measured by fluorescence polarization immunoassay to ascertain any pharmacokinetic contribution to the observed anticonvulsant effects. Results indicate that xanthotoxin (50 and 100 mg/kg, i.p.) significantly potentiated the anticonvulsant activity of carbamazepine against maximal electroshock-induced seizures (P<0.05 and P<0.001, respectively). Similarly, xanthotoxin (100 mg/kg, i.p.) markedly enhanced the anticonvulsant action of valproate in the maximal electroshock seizure test (P<0.001). In contrast, xanthotoxin (100 mg/kg, i.p.) did not affect the protective action of phenobarbital and phenytoin against maximal electroshock-induced seizures in mice. Moreover, xanthotoxin (100 mg/kg, i.p.) significantly increased total brain concentrations of carbamazepine (P<0.001) and valproate (P<0.05), but not those of phenytoin and phenobarbital, indicating pharmacokinetic nature of interactions between drugs. In conclusion, the combinations of xanthotoxin with carbamazepine and valproate, despite their beneficial effects in terms of seizure suppression in mice, were probably due to a pharmacokinetic increase in total brain concentrations of these antiepileptic drugs in experimental animals.

Rare Coumarins Induce Apoptosis, G1 Cell Block and Reduce RNA Content in HL60 Cells

Abstract The rare coumarins stenocarpin, stenocarpin isobutyrate, oficinalin, oficinalin isobutyrate, 8-methoxypeucedanin and the known xanthotoxin, isoimperatorin, bergapten, peucedanin and 8–methoxyisoimperatorin were isolated from Peucedanum luxurians Tamamsch. (Apiaceae) and identified by means of spectral data (1D and 2D NMR). Their immunomodulating activity was evaluated by flow cytometry and their influence on HL60 cells as well as on PHA-stimulated PBLs was tested. All tested coumarins induce apoptosis (maximal in the 48 h culture) and decrease cell proliferation in a time- and dose-dependent manner, especially in HL60 cells. They also induce partial G1 block, but only in HL60 cells (at 100 µM concentrations). Dose-dependent reduction of RNA content was also found in G1 cells treated by the coumarins. All of the tested coumarins also possessed immunomodulatory activities. Bergapten and xanthotoxin were found to be the best candidates for further evaluation as anti-cancer drugs.

Scopolamine-Induced Memory Impairment Is Alleviated by Xanthotoxin: Role of Acetylcholinesterase and Oxidative Stress Processes

Xanthotoxin, popularly occurring furanocoumarin, which can be found in plants from the Apiaceae family, was isolated from fruits of Pastinaca sativa L. by mean of high-performance countercurrent chromatography, and its effects on the scopolamine-induced cognitive deficits in male Swiss mice using the passive avoidance (PA) test were evaluated. To measure the acquisition of memory processes, xanthotoxin (1, 2.5, 5 mg/kg) was administered 30 min before PA test and scopolamine was administered 10 min after xanthotoxin. To measure the consolidation of memory processes, xanthotoxin (1 and 2.5 mg/kg) was injected immediately after removing the mouse from the apparatus and 10 min after scopolamine was administered. In subchronic experiments, mice were injected with xanthotoxin (1 mg/kg) or saline, 6 days, twice daily. At 24 h after the last injection of the drugs, the hippocampus and the prefrontal cortex were removed for biochemical assays. The results demonstrated that either single (2.5 and 5 mg/kg) or repeatable (1 mg/kg) administration of xanthotoxin significantly increased index of latency (IL) in both acquisition and consolidation of memory processes, showing some procognitive effects. The behavioral tests also showed that an acute (2.5 mg/kg) and subchronic (1 mg/kg) administration of xanthotoxin prevent memory impairment induced by injection of scopolamine (1 mg/kg). Observed effects could be due to the inhibition of acetylcholinesterase activities and amelioration of oxidative stress processes in the hippocampus and the prefrontal cortex. It was suggested that xanthotoxin could show neuroprotective effect in scopolamine-induced cognitive impairment connected to cholinergic neurotransmission and oxidative stress in the brain structures.

Adulteration and safety issues in nutraceuticals and dietary supplements: innocent or risky?

At present, nutraceuticals and related products such as dietary supplements defined as concentrated sources of nutrients or other substances with a nutritional or physiological effect are the popular segments of the food industry in great demand worldwide. The term “ nutraceutical ” is derived from a combination of “nutrition” and “pharmaceutical” and describes products that afford health benefits, including the prevention and treatment of diseases. Due to fast expansion in this area, a magnificent number of nutraceuticals and dietary supplements with basic nutritional value and offering health assistance is available in the marketplace. Although nutraceuticals and dietary supplements are often regarded as low risk, a great concern about these products is arising due to the fact that their health claims are sometimes untrustworthy according to various market analyses. The regulations on nutraceuticals or dietary supplements differ in Europe and the United States and the most frequent negative issue with nutraceuticals is intentional adulteration, contamination, and misreporting on the claimed content by the manufacturers, which may cause serious hazards in human health. In this chapter, an updated overview on regulatory issues in connection with adulteration and contamination cases reported in nutraceuticals and dietary supplements will be presented using reported market analyses.

Nigella damascena L. Essential Oil—A Valuable Source of β-Elemene for Antimicrobial Testing

The most commonly used plant source of β-elemene is Curcuma wenyujin Y. H. Chen & C. Ling (syn. of Curcuma aromatic Salisb.) with its content in supercritical CO2 extract up to 27.83%. However, the other rich source of this compound is Nigella damascena L. essential oil, in which β-elemene accounts for 47%. In this work, the effective protocol for preparative isolation of β-elemene from a new source—N. damascena essential oil—using high performance counter-current chromatography HPCCC was elaborated. Furthermore, since sesquiterpens are known as potent antimicrobials, the need for finding new agents designed to combat multi-drug resistant strains was addressed and the purified target compound and the essential oil were tested for its activity against a panel of Gram-positive and Gram-negative bacteria, fungi, and mycobacterial strains. The application of the mixture of petroleum ether, acetonitrile, and acetone in the ratio 2:1.5:0.5 (v/v) in the reversed phase mode yielded β-elemene with high purity in 70 min. The results obtained for antimicrobial assay clearly indicated that N. damascena essential oil and isolated β-elemene exert action against Mycobacterium tuberculosis strain H37Ra.