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Comparative evaluation of the flavonoid content in officinal Tiliae flos and Turkish lime species for quality assessment.

Lime flowers are used for various medicinal purposes in phytotherapy. Flavonoids, volatile oil and mucilage components are known as the active ingredients. In European Pharmacopoeia (EP), a simple thin-layer chromatographic (TLC) technique, which based on the analysis of the flavonoid composition was defined for the qualitative analysis of the drug. In this study, flavonoid composition in the flowers, bracts and leaves of the officinal species, Tilia platyphyllos were studied using a reversed-phase high performance liquid chromatographic (HPLC) technique, in order to develop a rapid, reliable and accurate method for quantitative analysis. The results were further compared with in those parts of two common species growing in Turkey, Tilia rubra and Tilia argentea. Results of the present study revealed that flavonoid composition of each lime species possesses a specific fingerprint HPLC chromatogram depending upon the parts used and evaluation of the data might be helpful in the quality assurance as well as determination of adulteration of the crude drug.

Chromatography, High Pressure Liquid↗

Antioxidant and cyclooxygenase inhibitory phenolic compounds from Ocimum sanctum Linn.

Anti-oxidant bioassay-directed extraction of the fresh leaves and stems of Ocimum sanctum and purification of the extract yielded the following compounds; cirsilineol [1], cirsimaritin [2], isothymusin [3], isothymonin [4], apigenin [5], rosmarinic acid [6], and appreciable quantities of eugenol. The structures of compounds 1-6 were established using spectroscopic methods. Compounds 1 and 5 were isolated previously from O. sanctum whereas compounds 2 and 3 are here identified for the first time from O. sanctum. Eugenol, a major component of the volatile oil, and compounds 1, 3, 4, and 6 demonstrated good antioxidant activity at 10-microM concentrations. Anti-inflammatory activity or cyclooxygenase inhibitory activity of these compounds were observed. Eugenol demonstrated 97% cyclooxygenase-1 inhibitory activity when assayed at 1000-microM concentrations. Compounds 1, 2, and 4-6 displayed 37, 50, 37, 65, and 58% cyclooxygenase-1 inhibitory activity, respectively, when assayed at 1000-microM concentrations. Eugenol and compounds 1, 2, 5, and 6 demonstrated cyclooxygenase-2 inhibitory activity at slightly higher levels when assayed at 1000-microM concentrations. The activities of compounds 1-6 were comparable to ibuprofen, naproxen, and aspirin at 10-, 10-, and 1000-microM concentrations, respectively. These results support traditional uses of O. sanctum and identify the compounds responsible.

Anti-Inflammatory Agents↗

Development of rancidity in wheat germ analyzed by headspace gas chromatography and sensory analysis.

Wheat germ is susceptible to oxidation due to its high content of unsaturated oil. Volatile compounds in stored wheat germ were evaluated using dynamic headspace gas chromatography (HS-GC) and sensory analysis. Preliminary comparisons were also made between freshly prepared wheat germ and wheat germ subjected to microwave heating at 45 and 55 degrees C prior to storage at room temperature. The progress of oxidation was followed in untreated wheat germ for 4 weeks and in heat-treated wheat germ for 7 weeks by HS-GC and sensory evaluation. Significant (p < 0.05) changes in rancid odor and flavor were observed in the untreated wheat germ after 3 weeks, whereas no corresponding difference was observed in the microwave-heated wheat germ after 7 weeks of storage. Identification of a total of 36 volatile compounds was performed according to their mass spectra and Kovats indices. The major volatiles were hexanal, alpha-pinene, 1-hexanol, and 3-carene. In addition to analysis of a short period of storage, 30 volatile compounds were identified from the headspace of wheat germ stored for >1 year.

Chromatography, Gas↗

Novel bioactivities of Curcuma longa constituents.

Bioassay-directed fractionation of ethyl acetate extract from Curcuma longa Linn. rhizomes yielded three curcuminoids, which displayed topoisomerase I and II enzyme inhibition activity. Curcumin III (3) was the most active curcuminoid, inhibiting topoisomerase at 25 micrograms mL-1. Curcumin I (1) and curcumin II (2) inhibited the topoisomerases at 50 micrograms mL-1. Fractionation of the volatile oil from the rhizomes afforded ar-turmerone (4), which displayed mosquitocidal activity with an LD100 of 50 micrograms mL-1 on Aedes aegyptii larvae. Bioassay-directed fractionation of hexane extract from the turmeric leaves yielded labda-8(17),12-diene-15,16 dial (5) with antifungal activity against Candida albicans at 1 micrograms mL-1 and inhibited the growth of Candida kruseii and Candida parapsilosis at 25 micrograms mL-1. In addition, 5 displayed 100% mosquitocidal activity on A. aegyptii larvae at 10 micrograms mL-1.

Antifungal Agents↗

Non-conventional methods for the control of post-harvest pear diseases.

Pears are highly perishable products, especially during the post-harvest phase, when considerable losses can occur. Among the fungal diseases, blue mold caused by Penicillium expansum, grey mould caused by Botrytis cinerea, Mucor rot caused by Mucor piriformis are common on pear fruits. Other (weak) pathogens like Phialophora malorum, Alternaria spp., and Cladosporium herbarum tend to infect wounds and senescent fruits. A post-harvest fungicide treatment can reduce decay but effectiveness decreases with the appearance of resistant strains. There is a clear need to develop new and alternative methods of controlling post-harvest diseases. The emerging technologies for the control of post-harvest fungal diseases are essentially threefold: application of antagonistic microorganisms, application of natural antimicrobial substances and application of sanitizing products. Two biological control products, Aspire (Candida oleophila I-182) (Ecogen, Langhorne, PA, USA) and Bio-Save 110 (Pseudomonas syringae) (EcoScience, Worcester, MA, USA; formerly Bio-Save 11) are currently registered in the USA for post-harvest application to pears. Other potential biocontrol agents have been isolated from fruit and shown to suppress post-harvest decay in pear. It is important that evaluation of these microorganisms be carried out in a product formulation because the formulation may improve or diminish antagonistic efficacy depending on the concentration of chemical product and the duration of exposure to the treatment. Plants produce a large number of secondary metabolites with antimicrobial effects on post-harvest pathogens. Detailed studies have been conducted on aromatic compounds, essential oils, volatile substances and isothiocyanates, with encouraging results. In particular, allyl-isothiocyanate used as a volatile substance, controls blue mould in 'Conference' and 'Kaiser' pear inoculated with a thiabendazole-resistant strain. Sanitizing products such as chlorine dioxide, peracetic acid and ozone have considerable fungicidal activity against P. expansum and M. piriformis, depending on the concentration of chemical product and the duration of exposure to the treatment. Sanitizing solutions can be integrated easily with current handling and storage practices; however, further research is required to define the effective procedures better.

Antibiosis↗

Pharmacology of Curcuma longa.

The data reviewed indicate that extracts of Curcuma longa exhibit anti-inflammatory activity after parenteral application in standard animal models used for testing anti-inflammatory activity. It turned out that curcumin and the volatile oil are at least in part responsible for this action. It appears that when given orally, curcumin is far less active than after i.p. administration. This may be due to poor absorption, as discussed. Data on histamine-induced ulcers are controversial, and studies on the secretory activity (HCl, pepsinogen) are still lacking. In vitro, curcumin exhibited antispasmodic activity. Since there was a protective effect of extracts of Curcuma longa on the liver and a stimulation of bile secretion in animals, Curcuma longa has been advocated for use in liver disorders. Evidence for an effect on liver disease in humans is not yet available. From the facts that after oral application only traces of curcumin were found in the blood and that, on the other hand, most of the curcumin is excreted via the faeces it may be concluded that curcumin is absorbed poorly by the gastrointestinal tract and/or underlies presystemic transformation. Systemic effects therefore seem to be questionable after oral application except that they occur at very low concentrations of curcumin. This does not exclude a local action in the gastrointestinal tract.

Animals↗

The mechanism underlying the laxative properties of parsley extract.

Parsley has been claimed in folk medicine to possess laxative properties attributed to the presence therein of some volatile oils that are more concentrated in seeds than in stems or leaves. The advocated physiological effect of parsley, does not have, however, any proven scientific background and relies mainly on simple observations and empirical information. This work aims at providing the scientific evidence that would confirm or reject the claimed laxative role of parsley, and at determining its mechanism of action if present. A perfusion technique was used to measure the net fluid absorption from the rat colon. The addition of an aqueous extract of parsley seeds to the perfusion buffer, and the omission of sodium, both reduced significantly net water absorption from the colon, as compared to the control. Parsley, added to a sodium-free buffer did not lead to any further significant change in water absorption as compared to parsley alone inferring that with parsley sodium absorption was already inhibited. Since K+ and Cl- secretion depends on the activity of the NaKCl2 transporter, the latter was inhibited with furosemide which increased significantly net water absorption. When parsley and furosemide were added together, net water absorption was significantly higher than with parsley alone and significantly lower than with furosemide alone. In addition, parsley extract was shown to inhibit the in vitro activity of the Na+-K+ATPase in a colon homogenate and the activity of a partially purified dog kidney ATPase. The results suggest that parsley acts by, inhibiting sodium and consequently water absorption through an inhibition of the Na+-K+ pump, and by stimulating the NaKCl, transporter and increasing electrolyte and water secretion.

Animals↗

Characterization and body distribution of beta-elemene solid lipid nanoparticles (SLN).

Solid lipid nanoparticles (SLN) containing beta-elemene, a volatile oil used for the treatment of cancer, were prepared by the method combining probe sonication and membrane extrusion. Effects of the formulations and procedures on the characteristics of SLN were investigated. Body distribution of beta-elemene SLN in rats after intravenous administration was compared with that of the commercial emulsion. The results showed that dispersing the surfactant in the melted lipid matrix could obtain smaller particles than that dispersing in the water phase. Increasing the ratio of monostearin in the lipid matrix or the concentration of surfactant reduced the mean volume size of the SLN. Optimized formulation was composed of monostearin and precirol ATO 5 at a mass ratio of 3:7, which was quite stable for 8 months at room temperature. In vitro release of beta-elemene from the SLN was slow and stable without obvious burst release and was found to follow the Higuich equation. After intravenous administration, the beta-elemene levels after 5 min injection of SLN formulation were 1.5, 2.9, and 1.4 times higher than those of beta-elemene emulsion in liver, spleen, and kidney, respectively, while the concentrations of beta-elemene were decreased 30% in heart and lung. Therefore, the SLN containing beta-elemene might be an attractive candidate for the treatment of liver cancer.

Animals↗

Final report on the safety assessment of Juniperus communis Extract, Juniperus oxycedrus Extract, Juniperus oxycedrus Tar, Juniperus phoenicea extract, and Juniperus virginiana Extract.

The common juniper is a tree that grows in Europe, Asia, and North America. The ripe fruit of Juniperus communis and Juniperus oxycedrus is alcohol extracted to produce Juniperus Communis Extract and Juniperus Oxycedrus Extract, respectively. Juniperus Oxycedrus Tar is the volatile oil from the wood of J. oxycedrus. Juniperus Phoenicea Extract comes from the gum of Juniperus phoenicea, and Juniperus Virginiana Extract is extracted from the wood of Juniperus virginiana. Although Juniperus Oxycedrus Tar is produced as a by-product of distillation, no information was available on the manufacturing process for any of the Extracts. Oils derived from these varieties of juniper are used solely as fragrance ingredients; they are commonly produced using steam distillation of the source material, but it is not known if that procedure is used to produce extracts. One report does state that the chemical composition of Juniper Communis Oil and Juniperus Communis Extract is similar, each containing a wide variety of terpenoids and aromatic compounds, with the occasional aliphatic alcohols and aldehydes, and, more rarely, alkanes. The principle component of Juniperus Oxycedrus Tar is cadinene, a sesquiterpene, but cresol and guaiacol are also found. No data were available, however, indicating the extent to which there would be variations in composition that may occur as a result of extraction differences or any other factor such as plant growth conditions. Information on the composition of the other ingredients was not available. All of the Extracts function as biological additives in cosmetic formulations, and Juniperus Oxycedrus Tar is used as a hair-conditioning agent and a fragrance component. Most of the available safety test data are from studies using oils derived from the various varieties of juniper. Because of the expected similarity in composition to the extract, these data were considered. Acute studies using animals show little toxicity of the oil or tar. The oils derived from J. communis and J. virginiana and Juniperus Oxycedrus Tar were not skin irritants in animals. The oil from J. virginiana was not a sensitizer, and the oil from J. communis was not phototoxic in animal tests. Juniperus Oxycedrus Tar was genotoxic in several assays. No genotoxicity data were available for any of the extracts. Juniperus Communis Extract did affect fertility and was abortifacient in studies using albino rats. Clinical tests showed no evidence of irritation or sensitization with any of the tested oils, but some evidence of sensitization to the tar. These data were not considered sufficient to assess the safety of these ingredients. Additional data needs include current concentration of use data; function in cosmetics; methods of manufacturing and impurities data, especially pesticides; ultraviolet (UV) absorption data; if absorption occurs in the UVA or UVB range, photosensitization data are needed; dermal reproductive/developmental toxicity data (to include determination of a no-effect level); two genotoxicity assays (one in a mammalian system) for each extract; if positive, a 2-year dermal carcinogenicity assay performed using National Toxicology Program (NTP) methods is needed; a 2-year dermal carcinogenicity assay performed using NTP methods on Juniperus Oxycedrus Tar; and irritation and sensitization data on each extract and the tar (these data are needed because the available data on the oils cannot be extrapolated). Until these data are available, it is concluded that the available data are insufficient to support the safety of these ingredients in cosmetic formulations.

Abortion, Spontaneous↗

Thymoquinone protects against carbon tetrachloride hepatotoxicity in mice via an antioxidant mechanism.

Thymoquinone (TQ) is the major active component of the volatile oil of Nigella sativa seeds. The effects of TQ on carbon tetrachloride (CCl4)-induced hepatotoxicity was investigated in male Swiss albino mice. Carbon tetrachloride (20 microliters/Kg, i.p.) injected into mice, induced damage to liver cells and was followed by the increase in serum alanine aminotransferase (ALT) activity after 24 h. Oral administration of TQ in a single dose (100 mg/Kg) resulted in significant (p < 0.001) protection against the hepatotoxic effects of CCl4. TQ was tested as a substrate for mice hepatic DT-diaphorase in the presence of NADH. TQ appears to undergo reduction to dihydrothymoquinone (DHTQ). Reduction rates as a function of protein (liver homogenate) and substrate (TQ) concentrations are reported. An apparent K(m) of 0.1 mM and an apparent Vmax of 74 mumol/min/g liver were measured. TQ and DHTQ inhibited the in vitro non-enzymatic lipid peroxidation in liver homogenate (induced by Fe(3+)-ascorbate) in a dose dependent manner. In this in vitro model DHTQ was more potent in comparison with TQ and butylated hydroxytoluene (BHT). The IC50 for DHTQ, TQ and BHT were found to be 0.34, 0.87 and 0.58 microM respectively. The data suggest that the in vivo protective action of TQ against CCl4-induced hepatotoxicity may be mediated through the combined antioxidant properties of TQ and its metabolite DHTQ.

Alanine Transaminase↗

Thymoquinone is a potent superoxide anion scavenger.

The antioxidant and pro-oxidant effects of thymoquinone (TQ), a natural main constituent of the volatile oil of Nigella saliva seeds, and a synthetic structurally-related tert-butylhydroquinone (TBHQ), were examined in vitro. Both TQ and TBHQ efficiently inhibited iron-dependent microsomal lipid peroxidation in a concentration-dependent manner with median inhibitory concentration (IC50) values of 16.8 and 14.9 microM, respectively. TBHQ was stronger than TQ as a scavenger of 2,2'-diphenyl-p-picrylhydrazyl radical (DPPH) (IC50 = 5 microM, 200 times more active than TQ) and as a scavenger of hydroxyl radical (OH*) with an IC50 of 4.6 microM (approximately 10 times more active than TQ). TQ was more active than TBHQ as a superoxide anion scavenger with IC50 of 3.35 microM compared to 18.1 microM for TBHQ. Only TBHQ significantly promoted DNA damage in the bleomycin-Fe(III) system. The results suggest that both TQ and TBHQ have strong antioxidant potentials through scavenging ability of different free radicals. Moreover, the data indicate that TQ is acting mainly as a potent superoxide anion scavenger.

Animals↗

Preparation and evaluation of pH-dependent gradient-release pellets for TCM.

This paper is designed to investigate a novel sustained release system for Traditional Chinese Medicinal Compound Recipe (TCMCR) by incorporating three kinds of pH-dependent gradient-release coated pellets into capsules. In our study, dosage reform was conducted on the TCMCR model drug--Guanxin Suhe Wan (GSW), which is in the traditional form of honey bolus, comprising Styrax, Borneolumsyntheticum, Olbanum, Radix aristolochiae and Lignum santali albi. In this study, the beta-CD inclusion complexes were prepared separately for Styrax, Borneolumsyntheticum and the volatile oil extracted from the mixture of Olbanum, Radix aristolochiae and Lignum santali albi. Pellets were prepared in a centrifugal granulator using the powder layering technique and then divided into 3 equal weight portions and coated with HPMC, HPMCP HP-55 and Eudragit L100/S100 to obtain gradient release in stomach, duodenum and jejunum or ileum respectively. On this basis, a pH-dependent sustained-release pellets system, "Guanxin Suhe Sustained-release Capsules"(GSSC), was prepared by mixing the above three kinds of coated pellets at the weight ratio of 1:1:1. Pharmacokinetic (PK) studies between GSW and GSSC were made on male volunteers and isolated guinea pig hearts by plasma drug concentration method and serum pharmacology method respectively. In plasma drug concentration method, Tmax was 0.42 h and 1.08 h for GSW and GSSC respectively, while in the serum pharmacology method, Tmax was 0.56 h and 0.52 h respectively. The relative bioavailability of GSSC to GSW was 95.62% and 121.82% separately in the above two methods, indicating a similarity between the two methods in predicting the PK behavior of GSSC.

Animals↗

Radiation of pollination systems in the Iridaceae of sub-Saharan Africa.

BACKGROUND: Seventeen distinct pollination systems are known for genera of sub-Saharan African Iridaceae and recurrent shifts in pollination system have evolved in those with ten or more species. Pollination by long-tongued anthophorine bees foraging for nectar and coincidentally acquiring pollen on some part of their bodies is the inferred ancestral pollination strategy for most genera of the large subfamilies Iridoideae and Crocoideae and may be ancestral for the latter. Derived strategies include pollination by long-proboscid flies, large butterflies, night-flying hovering and settling moths, hopliine beetles and sunbirds. Bee pollination is diverse, with active pollen collection by female bees occurring in several genera, vibratile systems in a few and non-volatile oil as a reward in one species. Long-proboscid fly pollination, which is apparently restricted to southern Africa, includes four separate syndromes using different sets of flies and plant species in different parts of the subcontinent. Small numbers of species use bibionid flies, short-proboscid flies or wasps for their pollination; only about 2 % of species use multiple pollinators and can be described as generalists. SCOPE: Using pollination observations for 375 species and based on repeated patterns of floral attractants and rewards, we infer pollination mechanisms for an additional 610 species. Matching pollination system to phylogeny or what is known about species relationships based on shared derived features, we infer repeated shifts in pollination system in some genera, as frequently as one shift for every five or six species of southern African Babiana or Gladiolus. Specialized systems using pollinators of one pollination group, or even a single pollinator species are the rule in the family. Shifts in pollination system are more frequent in genera of Crocoideae that have bilaterally symmetric flowers and a perianth tube, features that promote adaptive radiation by facilitating precise shifts in pollen placement, in conjunction with changes in flower colour, scent and tube length. CONCLUSIONS: Diversity of pollination systems explains in part the huge species diversity of Iridaceae in sub-Saharan Africa, and permits species packing locally. Pollination shifts are, however, seen as playing a secondary role in speciation by promoting reproductive isolation in peripheral, ecologically distinct populations in areas of diverse topography, climate and soils. Pollination of Iridaceae in Eurasia and the New World, where the family is also well represented, is poorly studied but appears less diverse, although pollination by both pollen- and oil-collecting bees is frequent and bird pollination rare.

Africa South of the Sahara↗

The use of linear expressions of solute boiling point versus retention to indicate special interactions with the molecular rings of modified cyclodextrin phases in gas chromatography

The boiling points (degrees C, 1 x 10) of diverse C10 polar solutes from volatile oils are set against their relative retention times versus n-undecane to calculate linear equations for 12 commercial modified cyclodextrin (CD) capillary phases. Ten data points are considered for each CD, then solutes are rejected until 5 or more remain that give an expression with a correlation coefficient of at least 0.990 and a standard deviation of less than 5.5. Three phases give almost perfect correlation, and 3 other CDs have difficulty complying. Solutes involved in the equations (most frequently cuminal, linalol, and carvone) are presumed to have a 'standard' polar transient interaction with the molecular rings of the CDs concerned. Several remaining solutes (mostly citral, fenchone, and menthol) exhibit extra retention over the calculated standard (up to 772%), which is believed to indicate a firm 'host' CD or 'guest' solute molecular fit in some cases. Other solutes show less retention than calculated (mostly citronellal, citronellol, estragole, and pulegone). This suggests rejection by the CD, which behaves merely as a conventional stationary phase to them. The intercept constant in the equation for each phase is suggested to be a numerical relative polarity indicator. These b values indicate that 3 hydroxypropyl CDs show the most polarity with values from 28 to 43; and CDs that are fully substituted with inert groups fall in the range of 15 to 20.

Journal Article↗

Correlation coefficients of solute relative retentions for pairs of modified cyclodextrins: evaluation of selectivity by differently responding gas chromatographic stationary phases.

Relative retention times versus the n-undecane for ten diverse probe solutes from volatile oils are scatterplotted between pairs of modified cyclodextrin (CD) phases. If the resulting line of best fit has a very high correlation coefficient (r), then the two CDs are behaving similarly and will not give different results. A low value of r between two CD phases indicates they behave contrastingly enough to give different analyses. Presuming a laboratory wants three differently behaving commercial CDs, twelve are considered in this way to find the optimum three pairings (each showing r to be less than 0.800 with an average of less than 0.700). These requirements are met by Chiraldex G-DA (gamma-dipentyl) and A-PH (alpha-hydroxypropyl, dimethyl) with Beta-Dex 225 (beta-diacetyl, butyldimethylsilyl) capillaries. Solutes that fall close to the line of fit between two of the phases are undergoing "normal" transient CD molecular interaction with both. They may then show extra retention with the third phase on the other two plots, which suggests close solute-guest/CD-host molecular fit. Another possibility is that this third modified CD may behave merely as a normal non-CD phase to such a solute (shown by the rejection of it) with a lower retention than is normal. Hierarchical cluster analysis seems unreliable to indicate CD-phase relationships.

Journal Article↗

Inhibition of benzo(a)pyrene-induced forestomach carcinogenesis in mice by thymoquinone.

The modulating effect of thymoquinone (TQ) on benzo(a)pyrene (BP)-induced forestomach tumours was investigated in female Swiss albino mice, receiving oral administration of BP at a dose of 1 mg twice weekly for 4 weeks. Administration of 0.01% of TQ in drinking water 1 week before, during and after BP treatment until the end of the experiment resulted in significant suppression of BP-induced tumourigenesis when compared with the group receiving BP alone. TQ inhibited both BP-induced forestomach tumour incidence and multiplicity by 70% and 67%, respectively. Lipid peroxide accumulation and decreased glutathione (GSH) content and glutathione-S-transferase (GST) and DT diaphorase activities were observed in the liver of BP-treated tumour-bearing mice. TQ alone showed a significant induction in the enzyme activities of hepatic GST and DT diaphorase. Mice treated with TQ along with BP showed almost normal hepatic lipid peroxides and GSH levels, and normal enzyme activities compared to the control group. The present data may indicate the potential of TQ, the main constituent of the volatile oil of Nigella sativa seed, as a powerful chemopreventive agent against BP-induced forestomach tumours in mice. The possible modes of action of TQ may be through its antioxidant and anti-inflammatory activities, coupled with enhancement of detoxification processes.

Analysis of Variance↗

Anesthetic action of methyleugenol and other eugenol derivatives.

A comparative study of four natural eugenol compounds found in the volatile oil fraction of Myristica fragans, namely eugenol (E), methyleugenol (ME), isoeugenol and methylisoeugenol, was carried out in mice. Using a mixture of saline + tween-80 to suspend the compounds and the intraperitoneal route, ME revealed to be the most active and the less toxic in inducing the loss of the righting reflex. ME was further compared with pentobarbital and with the synthetic E derivative, propanidid, using the intraperitoneal route in rats. ME anesthetized the rats more rapidly than pentobarbital; however, the duration of anesthesia was the same for both drugs. Propanidid was not active when injected through the intraperitoneal route. Rats under ME anesthesia could be more easily operated, showed less cyanosis, and recovered better than those under pentobarbital. When injected intravenously in rabbits, ME and propanidid showed equivalent anesthetic effects. Daily intraperitoneal injections of ME in rats and mice for up to 42 days, showed that the drug was not toxic and that the animals became more sensitive to the anesthetic action with repeating the injections. Similarly to pentobarbital, ME induced large amounts of slow wave activity in EEG of rats and did not change the total brain levels of dopamine, norepinephrine, and 5-hydroxytryptamine.

Anesthesia↗

Proliposome-based transdermal delivery of levonorgestrel.

Mesophasic proliposomal system for levonorgestrel was developed and evaluated both in vitro and in vivo. The vesicles were mostly unilamellar, however, few vesicles were multilamellar which budded off spontaneously upon hydration. The release of drug from this system adhered to zero order kinetics. The effect of alcohols and volatile oils on transdermal flux was investigated. The flux was found to be the highest for alcohol, and followed by that for lemon oil. The in vivo studies indicate the requirement for a loading dose, since, a significant lag phase was observed before the therapeutic levels were reached. This system was, however, superior to the PEG-based ointment system which was employed as the control formulation. The results demonstrate the potential of proliposomal system for efficacious transdermal delivery of hydrophobic drugs.

Administration, Cutaneous↗