Effects of Cymbopogon citratus L. essential oil on the growth, morphogenesis and aflatoxin production of Aspergillus flavus ML2-strain

The mycelial growth of Aspergillus flavus Link was completely inhibited using 1.5 (microl/ml or 2.0 (microl/ml of Cymbopogon citratus essential oil applied by fumigation or contact method in Czapek's liquid medium, respectively. This oil was found also to be fungicidal at the same concentrations. The sublethal doses 1.0 and 1.5 (microl/ml inhibited about 65% of fungal growth after five days of incubation and delayed conidiation as compared with the control. Microscopic observations using Light Microscope (LM), Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) were carried out to determine the ultra structural modifications of A. flavus hyphae after treatment with C. citratus essential oil. The hyphal diameter decreased and hyphal wall appeared as precipitates and disappeared in some regions. This oil also caused plasma membrane disruption and mitochondrial structure disorganization. Moreover, Ca(+2), K(+) and Mg(+2) leakages increased from the fumigated mycelium and its total lipid content decreased, while the saturated and unsaturated fatty acids increased. One of the most important results obtained during this study was the ability of C. citratus essential oil at its sublethal dose to completely inhibit aflatoxin B(1) production from A. flavus. These findings increase the possibility of exploiting C. citratus essential oil as an effective inhibitor of biodegradation and storage contaminating fungi and also in fruit juice preservation.     

Effect of Cymbopogon citratus L. essential oil on growth and morphogenesis of Saccharomyces cerevisiae ML2-strain

The growth of Saccharomyces cerevisiae was completely inhibited using 2.0 microl/ml or 4.0 microl/ml of Cymbopogon citratus essential oil applied by fumigation or contact method in Sabouraud's broth medium, respectively. This oil was found also to be fungicidal at the same concentrations. The sublethal doses 1.0 and 3.0 microl/ml inhibited about 98% of yeast growth after 24 hr of incubation as compared with the control. Microscopic observations using Light Microscope (LM), Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) showed morphogenic and ultrastructure changes in the fumigated cells with 1.0 microl/ml of the oil. These changes including decrease in cell size, depressions on the surface of the cells, alteration in cell wall thickness and disruption of plasma membrane. Moreover, Ca(+2), K(+) and Mg(+2) leakages increased from the fumigated cells and its total lipid content decreased. Also, the fatty acid composition was altered with decrease in the amount of saturated fatty acids and increase in the amount of unsaturated fatty acids.     

Anti-Candida albicans activity of essential oils including Lemongrass (Cymbopogon citratus) oil and its component, citral]

The effects of 12 essential oils, popularly used as antifungal treatments in aromatherapy, on growth of Candida albicans were investigated. Mycelial growth of C. albicans, which is known to give the fungus the capacity to invade mucosal tissues, was inhibited in the medium containing 100 micro g/ml of the oils: lemongrass (Cymbopogon citratus), thyme (Thymus vulgaris), patchouli (Pogostemon cablin) and cedarwood (Cedrus atlantica). Not only lemongrass oil but also citral, a major component of lemongrass oil (80%), in the range of 25 and 200 micro g/ml inhibited the mycelial growth but allowed yeast-form growth. More than 200 micro g/ml of citral clearly inhibited both mycelial and yeast-form growth of C. albicans. These results provide experimental evidence suggesting the potential value of lemongrass oil for the treatment of oral or vaginal candidiasis.     

The use of powder and essential oil of Cymbopogon citratus against mould deterioration and aflatoxin contamination of "egusi" melon seeds

Experiments were carried out to determine the potential of using the powder and essential oil from dried ground leaves of Cymbopogon citratus (lemon grass) to control storage deterioration and aflatoxin contamination of melon seeds. Four mould species: Aspergillus flavus, A. niger, A. tamarii and Penicillium citrinum were inoculated in the form of conidia suspension (approx. 10(6) conidia per ml) unto shelled melon seeds. The powdered dry leaves and essential oil from lemon grass were mixed with the inoculated seeds at levels ranging from 1-10 g/100 g seeds and 0.1 to 1.0 ml/100 g seeds respectively. The ground leaves significantly reduced the extent of deterioration in melon seeds inoculated with different fungi compared to the untreated inoculated seeds. The essential oil at 0.1 and 0.25 ml/100 g seeds and ground leaves at 10 g/100 g seeds significantly reduced deterioration and aflatoxin production in shelled melon seeds inoculated with toxigenic A. flavus. At higher dosages (0.5 and 1.0 ml/100 g seeds), the essential oil completely prevented aflatoxin production. After 6 months in farmers' stores, unshelled melon seeds treated with 0.5 ml/ 100 g seeds of essential oil and 10 g/100 g seeds of powdered leaves of C. citratus had significantly lower proportion of visibly diseased seeds and Aspergillus spp. infestation levels and significantly higher seed germination compared to the untreated seeds. The oil content, free fatty acid and peroxide values in seeds protected with essential oil after 6 months did not significantly differ from the values in seeds before storage. The efficacy of the essential oil in preserving the quality of melon seeds in stores was statistically at par with that of fungicide (iprodione) treatment.     

Antifungal activity of Lavandula angustifolia essential oil against Candida albicans yeast and mycelial form.

The antifungal activity of the essential oil of Lavandula angustifolia Mill. (lavender oil) and its main components, linalool and linalyl acetate, was investigated against 50 clinical isolates of Candida albicans (28 oropharyngeal strains, 22 vaginal strains) and C. albicans ATCC 3153. Growth inhibition, killing time and inhibition of germ tube formation were evaluated. The chemical composition of the essential oil was determined by gas chromatography and mass spectrometry. Lavender oil inhibited C. albicans growth: mean minimum inhibitory concentration (MIC) of 0.69% (vol./vol.) (vaginal strains) and 1.04% (oropharyngeal strains); mean MFC of 1.1% (vaginal strains) and 1.8% (oropharyngeal strains). Linalool was more effective than essential oil: mean MIC of 0.09% (vaginal strains) and 0.29% (oropharyngeal strains); mean MFC of 0.1% (vaginal strains) and 0.3% (oropharyngeal strains). Linalyl acetate was almost ineffective. Lavender oil (2%) killed 100% of the C. albicans ATCC 3153 cells within 15 min; linalool (0.5%) killed 100% of the cells within 30 s. The essential oil inhibited germ tube formation (mean MIC of 0.09%), as did the main components (MIC of 0.11% for linalool and 0.08% for linalyl acetate). Both the essential oil and its main components inhibited hyphal elongation of C. albicans ATCC 3153 (about 50% inhibition at 0.016% with each substance). Lavender oil shows both fungistatic and fungicidal activity against C. albicans strains. At lower concentrations, it inhibits germ tube formation and hyphal elongation, indicating that it is effective against C. albicans dimorphism and may thus reduce fungal progression and the spread of infection in host tissues.     

Evaluation of miconazole activity contained in human serum to hypha of Aspergillus fumigatus.

Aspergillus fumigatus is an opportunistic pathogen, especially in an immunocompromised host. This fungus grows in a hyphal form in infected tissues; therefore, new tests to examine hyphal susceptibility are needed. In this study, we measured the mycotic activity of miconazole (MCZ) contained in human serum against A. fumigatus using the BioCell-Tracer method. Three serum samples were obtained from the same patient who was injected with 600 mg b.i.d. MCZ daily for 2 days. The concentrations of MCZ in the serum sample were 8.8, 3.5, and 1.6 micro g/ml, respectively. The serum containing 8.8 micro g/ml of MCZ inhibited hyphal growth 90 minutes after administration, and the hypha stopped growing. The serum containing 3.5 micro g/ml MCZ stopped hypha growth 100 minutes after administration, but re-growth of the hypha was observed at this concentration of MCZ. Serum containing 1.6 micro g/ml did not inhibite hyphal growth, nor did control serum have any inhibitory activity foward hyphae. Based on these results, we conclude that the BioCell-Tracer is a useful method for determining the effects on filamentous fungi of antifungal agents in the serum.     

Chemical composition and larvicidal properties of the essential oils from Drimys brasiliensis Miers (Winteraceae) on the cattle tick Rhipicephalus (Boophilus) microplus and the brown dog tick Rhipicephalus sanguineus

The essential oil obtained from leaves and stem barks of the Southern Brazilian native Drimys brasiliensis Miers, a tree with medicinal properties, was analyzed by gas chromatography (GC) and GC/mass spectrometry (MS). The oil was characterized by sesquiterpenoids (66%), cyclocolorenone being the most abundant (30.4%), followed by bicyclogermacrene (11.8%) and alpha-gurjunene (6.0%). Laboratory tests were carried out to determine the toxicity of the essential oil on larvae of the cattle tick Rhipicephalus (Boophilus) microplus and the brown dog tick Rhipicephalus sanguineus by the larval immersion test. It was observed that the oil was lethal, killing 100% of the larvae of both ticks at the doses of 25, 12.5, and 6.25 μl/ml. The lowest dose tested, 3.125 μl/ml, was also toxic, killing 95–98% of the larvae.     

Interleukin-15 production by monocyte-derived dendritic cells and T cell proliferation in HIV-infected patients with discordant response to highly active antiretroviral therapy

A discordant response to highly active antiretroviral therapy (HAART) occurs when CD4 T cell counts are stable or increased over time despite persistently detectable HIV-RNA levels. In order to identify immunological factors affecting discordant treatment responses, a total of 27 HIV-infected patients were studied: (a) 10 naive patients (mean CD4+ = 101.5 cells/microl; mean HIV-RNA = 4.8 log10 copies/ml); (b) seven responder patients (mean CD4+ = 908.9 cells/microl); and (c) 10 discordant patients (mean CD4+ = 396.1 cells/microl; mean HIV-RNA = 5.4 log10 copies/ml). Five healthy blood donors were included as HIV-seronegative controls. The following parameters were evaluated: interleukin (IL)-15 production by monocyte-derived dendritic cells (MDDC) after stimulation with lypopolysaccaride (LPS) and Candida albicans; recall and HIV-1-specific antigen lymphocyte proliferation (LP). Increased levels of IL-15 production by MDDC after stimulation with LPS and C. albicans were found both in discordant patients and responder patients. Conversely, a strong reduction of IL-15 levels was observed in naive patients. Discordant patients developed positive LP responses to C. albicans and HIV-1 p24. LP in response to C. albicans and HIV-1 p24 was also positive in responder patients. Decreased LP response was found in naive patients. In conclusion, HIV-infected patients with discordant viro-immunological responses to HAART present increased levels of IL-15 production by MDDC and enhanced recall and HIV-1-specific antigen LP responses, suggesting an improvement in indices of immune function.     

The effect of 5-fluorocytosine on the blastospores and hyphae of Candida albicans.

In Candida albicans the continued increase in dry weight, in cell volume and in hyphal length during 5FC treatment is mainly due to increased amount of carbohydrate despite the decreased amounts of nucleic acids. Incorporation studies with 32PO4 (for RNA) in C. albicans and with 3H-thymidine-monophosphate (for DNA) in a thymidine-utilising strain of Saccharomyces cerevisiae have shown that the decreased amounts of nucleic acids were due to an inhibition of synthesis of RNA and DNA by 5FC. Nuclear-staining techniques on the hyphal phase of C. albicans showed that 5FC inhibits nuclear division. The changes in amounts of protein during 5FC treatment do not wholly explain the changes in cell size although 14C-histidine incorporation experiments showed that protein synthesis continued in the presence of 5FC. 14C-glucose incorporation in the presence of 5FC showed an initial accelerated synthesis of carbohydrate with a maintained level of synthesis after 16 h. This abnormal pattern of synthesis correlates with the increase in amount of carbohydrate and in cell size and hyphal elongation. 5FC inhibits DNA synthesis, and all manifestations of unbalanced growth that culminate in the cell volume changes appear to be a consequence of that inhibition.     

Effect of bile acid derivatives on taurine biosynthesis and extracellular slime production in encapsulated Staphylococcus aureus S-7.

Various bile acids were added to cultures of encapsulated strains of Staphylococcus aureus growing in serum-soft agar medium of brain heart infusion broth. We examined effects of these compounds on cellular characteristics such as growth type, cell volume index, clumping factor reaction, slime yield, taurine content, and L-(--)-cysteic acid decarboxylase activity. Upon addition to the medium of either taurochenodeoxycholic acid, taurocholic acid (25 to 50 microgram/ml), or cholic acid (10 to 25 microgram/ml), the colonial morphology of taurine-positive cells (strain S-7) was altered from the diffuse to the compact type in serum-soft agar. Also, the titer of the clumping factor reaction increased, while the cell volume index and slime yield were markedly decreased. Tauro-bile acids, including taurocholic acid, taurochenodeoxycholic acid, taurodehydrocholic acid, and taurodeoxycholic acid (50 microgram/ml) inhibited the synthesis of taurine and resulted in decreased L-(--)-cysteic acid decarboxylase activity. Among all of the derivatives cholic acid itself was found to inhibit slime production and L-(--)-cysteic acid decarboxylase activity to the greatest extent. Glyco-bile acid derivatives and taurolicholic acid (50 to 100 microgram/ml) had no effect on L-(--)-cysteic acid decarboxylase activity. Compounds such as glycodeoxycholic acid (50 to 100 microgram/ml) had no effect upon any of the cellular characteristics tested. No effect was observed upon addition of any of these compounds to cultures of the taurine-negative strain (T-26-B). We did find a correlation between the inhibition of taurine biosynthesis and decreased slime production. Electron micrographs indicated that this encapsulated strain was converted to an unencapsulated state in the presence of bile acids.     

Association of immune complexes and plasma viral load with CD4+ cell depletion, CD8+ DR+ and CD16+ cell counts in HIV+ hemophilia patients. Implications for the immunopathogenesis of HIV-induced CD4+ lymphocyte depletion

OBJECTIVE: There is evidence that HIV induces CD4+ depletion in part by the formation of immune complexes (IC) that attach to CD4+ blood lymphocytes. In the present study we examined the relationship of IC-coated CD4+ blood cells with retroviral replication in HAART-treated patients. PATIENTS And METHODS: 52 hemophilia patients were studied from 1997 to 1999. Lymphocyte subsets, IgM, IgG and gp120 on CD4+ blood cells, in vitro responses of lymphocytes to mitogens, plasma neopterin and plasma viral load were measured. RESULTS: Patients with detectable viral replication and without ICs on CD4+ blood lymphocytes had a lower viral load (4100 versus 21000 HIV-1 mRNA copies/ml; P = 0.079) and higher CD4+ cell counts (310/microl versus 161/microl; P = 0.035) than patients with ICs on circulating CD4+ lymphocytes. Among patients with < 80 HIV-1 mRNA copies/ml, IC- individuals had slightly higher CD4+ lymphocyte counts than IC+ patients (384/microl versus 316/microl; n.s.). Further evidence for the clinical relevance of the ICs was obtained when 18 patients who had an undetectable viral load at previous investigations were analyzed. Among patients with a stable undetectable viral load, CD4+ counts increased in 6 of 8 IC- but in none of 2 IC+ individuals. In patients whose viral load increased during the observation period, 5 of 6 IC- but none of 2 IC+ individuals showed higher CD4+ cell counts. Impaired virus killing is suggested by lower CD16+ (35/microl versus 107/microl; P = 0.016), higher CD3+ DR+ (178/microl versus 66/microl; P = 0.006), and higher CD8+ DR+ (142/microl versus 34/microl; P = 0.017) cell counts in IC(-) patients compared to IC- patients without detectable viral load. Strong retroviral replication induced strong T cell dysfunctions. Fewer CD3+ 25+ blood lymphocytes (19/microl versus 47/microl; P = 0.006) and a lower in vitro response of T lymphocytes to the mitogens Con A (RR: 0.3 versus 1.2; P=0.023) and CD3 mab (RR: 0.5 versus 2.4; P = 0.012) was observed in IC+ patients with detectable versus undetectable viral load. CONCLUSION: Our data suggest that ICs on circulating CD4+ blood lymphocytes are primarily associated with CD4+ lymphocyte depletion whereas the plasma viral load is primarily associated with decreased T lymphocyte activation, lower CD16+ counts, and higher CD8+ DR+ lymphocytes which might be the effector cells for virus elimination.     

Polymyxin B-immobilized fiber hemoperfusion with low priming volume in an elderly septic shock patient with marked endotoxemia

An 84-year-old woman with septic shock caused by pyelonephritis is described herein. She was admitted for severe back pain and high fever. Her white blood cell (WBC) count and C-reactive protein (CRP) and endotoxin levels were elevated at 38,000/microl, 40.0 mg/dl, and 8,400 pg/ml, respectively. Her blood pressure was 80/34 mm Hg. Urinalysis revealed occult blood with innumerable WBCs. Plain abdominal radiography showed calcium stones in both kidneys. Septic shock with endotoxemia was diagnosed, and the patient was treated with antibiotics, gamma-globulin, and dopamine. However, her plasma endotoxin level remained high for 3 days. We performed direct hemoperfusion twice using a polymyxin B-immobilized fiber (PMX-F) column with a low priming volume. After PMX-F treatment, the patient's temperature decreased to 36.8 degrees C; her WBC count and CRP level decreased to 9,200/microl and 3.8 mg/dl, respectively. Her plasma endotoxin level decreased to 840 pg/ml after the first treatment and to 188 pg/ml after the second treatment. The next day, her blood endotoxin level further decreased to 32 pg/ml. Her blood pressure increased to 92/60 mm Hg after the first treatment and to 118/76 mm Hg after the second treatment. The patient was discharged on day 26 after admission. Our experience in this case suggests that PMX-F treatment with a low priming volume may be beneficial in elderly patients with septic shock and marked endotoxemia.     

Disease progression, adherence, and response to protease inhibitor therapy for HIV infection in an Urban Veterans Affairs Medical Center

Indinavir therapy has demonstrated promise in the treatment of HIV-1 infection in clinical trials; however, its efficacy in a U.S. Veterans Affairs Medical Center, where access to therapy is generally unimpeded, is unknown. A review of the Miami cohort was conducted for the year beginning May 1996 to evaluate response to indinavir plus two nucleoside analogues. Of 483 HIV-1-positive patients (97% male; mean age, 46.7+/-9.7 years), 266 were offered indinavir based on their having CD4 counts <200 cells/microl or viral loads >10,000 copies/ml. Of these patients, 36% were adherent and experienced significant reductions in viral loads (-93,325+/-147,911 copies/ml) and elevations in CD4+ (111+/-103 cells/microl) and CD8+ (225+/-338 cells/microl) T cell counts. Adherent patients with baseline CD4 counts <100 cells/microl were 4.5 times more likely to have follow-up viral loads >10,000 copies/ml than those with CD4 >200 cells/microl. Adherent patients with CD4 counts <100 cells/microl did not show evidence of immune "exhaustion" because they were equal to those with CD4 counts >200 cells/microl in their capacity to replenish CD4 cells. Nonadherence to the regimen resulted in loss of therapeutic benefit and suggested that strategies to enhance adherence may become an essential component of treatment.     

The antihypertensive effects of fish oil. A controlled study of polyunsaturated fatty acid supplements in essential hypertension

Both n-3 and n-6 polyunsaturated fats have been suggested to lower blood pressure, an effect ascribed to altered biosynthesis of eicosanoids. To test these hypotheses, we studied blood pressure and eicosanoid production during supplementation of dietary fat for four weeks in 32 men with mild essential hypertension. Supplementation was preceded and followed by four-week run-in and recovery periods. Groups of eight subjects received either 10 ml or 50 ml of fish oil (3 or 15 g of n-3 fatty acids) daily, 50 ml of safflower oil (39 g of n-6 fatty acids), or 50 ml of a mixture of oils that approximated the types of fat present in the American diet. The biosynthesis of eicosanoids was assessed by the measurement of urinary metabolites. Blood pressure decreased in the men who received the high dose of fish oil (systolic pressure by a mean of 6.5 mm Hg [P less than 0.03] and diastolic pressure by 4.4 mm Hg [P less than 0.015]), but not in the other groups. Although the formation of vasodilatory prostacyclins (prostaglandins I2 and I3) increased initially, this increase was not maintained as blood pressure fell. The level of thromboxane A2 metabolites fell; metabolites of thromboxane A3 were detected in the groups receiving fish oil. The formation of prostaglandin E2 increased during supplementation with safflower oil and tended to decrease with fish oil; no prostaglandin E3 metabolite was detected. Our data indicate that high doses of fish oil can reduce blood pressure in men with essential hypertension. However, the clinical usefulness and safety of fish oil in the treatment of hypertension will require further study.     

Regulation of Candida albicans morphogenesis by fatty acid metabolites

Candida albicans is an opportunistic dimorphic fungus that inhabits various host mucosal sites. Conversion from the yeast to the hyphal form has been associated with increased virulence and mucosal invasiveness. C. albicans morphogenesis is regulated by multiple signals and signaling pathways. However, signals that control morphogenesis in vivo are unknown. We investigated the effects of host long chain fatty acids, eicosanoids, and bacterial short chain fatty acids on control of germination. None of the C18 or C20 fatty acids tested had an effect on enhancing germ tube formation (arachidonic acid, oleic acid, linolenic acid, or gamma-linolenic acid). Among the different eicosanoids, both prostaglandin E2 and thromboxane B2 significantly enhanced serum-induced germination by C. albicans. Addition of antiprostaglandin or antithromboxane antibodies to serum alone inhibited germ tube formation by almost 30%, while control antibody had no effect, indicating that these eicosanoids are major morphogenic factors in the serum. Since these molecules also bind to albumin, this may also explain the hyphal transforming activity in serum that associates with albumin. Interestingly, short chain fatty acids (butyric acid), the product of lactic acid bacteria (LAB), inhibited germination. In addition, LAB culture supernatants as well as live LAB also inhibited C. albicans morphogenesis. Overall, these results indicate that fatty acid metabolites and fatty acid pathways can up-regulate and down-regulate germination in C. albicans.     

Modulation of lymphocyte proliferation by enzymes that degrade amino acids.

In a previous study we demonstrated thirteen amino acids to be essential and two to be partially essential for lymphocyte proliferation. Arginine is one of the essential amino acids, and the highly purified arginase strongly inhibited lymphocyte proliferation. The modulation of lymphocyte growth by various amino acid-degrading enzymes was studied. Peripheral lymphocytes were cultured in RPMI 1640 with or without amino acid-degrading enzyme for 72 h. A total of 17 commercial L-amino acid-degrading enzymes were studied. At 10 micrograms/ml, both lysine decarboxylase and asparaginase completely inhibited lymphocyte proliferation, arginase resulted in 78% inhibition and tyrosinase 57% inhibition. Other enzymes inhibited less than 20% lymphocyte proliferation; they included alanine dehydrogenase, arginine decarboxylase, aspartase, glutamic decarboxylase, glutamic dehydrogenase, glutaminase, histidase, histidine decarboxylase, leucine dehydrogenase, phenylalanine decarboxylase, phenylalanine hydroxylase, tryptophanase, and tyrosine decarboxylase. All four enzymes that strongly inhibited lymphocyte proliferation degraded amino acids that are essential for lymphocyte growth.     

Food intake and blood fuels after oil consumption: differential effects in normal and diabetic rats

The mechanisms by which fat feeding suppresses the hyperphagia of diabetic rats were examined. Rats that were allowed to consume a small amount (1.5 ml) of corn oil decreased subsequent food intake within 6 hr after ingesting. Diabetic rats decreased food intake much more than normal rats. Similar results were obtained when oil was given intragastrically. Analysis of blood samples revealed that diabetic rats showed greater increases in plasma ketones and triglycerides and smaller increases in plasma glycerol than normal rats following consumption of 1.5 ml corn oil. This difference between diabetic and normal rats appeared when rats were allowed to eat after oil ingestion as well as when they were fasted. Brief periods of food deprivation (2.5-4.5 hr) substantially increased plasma ketones and glycerol and decreased plasma triglycerides in both diabetic and normal rats. The results indicate that diabetic rats decrease food intake more than normal rats after fat feeding because they oxidize more of the ingested fat.     

Antigiardial activity of <Emphasis Type="Italic">Ocimum basilicum</Emphasis> essential oil

In this study, we investigated the effects of Ocimum basilicum essential oil on Giardia lamblia and on the modulation of the interaction of these parasites by peritoneal mouse macrophage. The essential oil (2 mg/ml) and its purified substances demonstrated antigiardial activity. Linalool (300 μg/ml), however, was able to kill 100% parasites after 1 h of incubation, which demonstrates its high antigiardial potential. Pretreatment of peritoneal mouse macrophages with 2 mg/ml essential oil dilution reduced in 79% the association index between these macrophages and G. lamblia, with a concomitant increase by 153% on nitric oxide production by the G. lamblia-ingested macrophages. The protein profiles and proteolitic activity of these parasite trophozoites, previously treated or not with 2 mg/ml essential oil or with the purified fractions, were also determined. After 1 and 2 h of incubation, proteins of lysates and culture supernatants revealed significant differences in bands patterns when compared to controls. Besides, the proteolitic activity, mainly of cysteine proteases, was clearly inhibited by the essential oil (2 mg/ml) and the purified linalool (300 μg/ml). These results suggest that, with G. lamblia, the essential oil from O. basilicum and its purified compounds, specially linalool, have a potent antimicrobial activity. Igor de Almeida and Daniela Sales Alviano contributed equally to this study.     

A pilot study of the use of mycophenolate mofetil as a component of therapy for multidrug-resistant HIV-1 infection

Mycophenolic acid (MPA) increases the activity of both abacavir (ABC) and didanosine (ddI) in vitro against wild-type and multinucleoside-resistant HIV. We treated 7 patients with diagnosed AIDS who did not respond to eight or more antiretroviral therapies in an open label pilot study with mycophenolate mofetil (MMF), ABC, ddI, amprenavir (APV), and ritonavir (RTV), with or without efavirenz (EFV).Therapy was well tolerated despite the patients' advanced disease states. No significant decline in lymphocyte or other blood counts was observed. Median HIV RNA was 5.26 log10 copies/ml at entry, 4.53 log10 copies/ml at 4 weeks, and 5.13 log10 copies/ml at 16 weeks. Median CD4+ count was 34 cells/microl at entry and 39 cells/microl at 16 weeks of therapy. CD4+ counts increased further in five study subjects on extended therapy to 25 weeks (median 27 cells/microl at entry, 66 cells/microl at close), despite loss of virologic suppression in 4 of 5 cases. MPA can induce apoptosis in lymphocytes in vitro. However despite viral rebound, cell surface markers of apoptosis and activation declined in total CD3+ cells and CD3+/CD4+ cells twofold to fourfold in 4 of 5 adherent study subjects at 16 weeks, reaching levels comparable with those found in seronegative donors.Although low-dose MMF appears safe in late-stage HIV disease, this study did not demonstrate virologic efficacy. Higher doses of MMF may be more effective. With careful monitoring of toxicities and pharmacokinetics, MMF deserves further testing in HIV therapy.     

Effects of different concentrations of oxygen-ozone on rats' astrocytes in vitro

Although the widespread use of the oxygen-ozone in pain management, there is currently no consensus on its mechanisms of action and nearly no report for its action on nervous cells. Accordingly, the present study was designed to assess the effects of oxygen-ozone on astrocytes. Astrocytes were cultured in vitro through methods of trypsinization, different-speed cultivation and passaging to purify, then seeded into 24 well plates and divided to one of four groups (n=7) to receive the following treatments: respectively added 400 microl complete medium (CM) after effects of 20 microg/ml oxygen-ozone (Group O-20), 40 microg/ml oxygen-ozone (Group O-40), 60 microg/ml oxygen-ozone (Group O-60); without intervention (Group C). After incubation of 2 h or 4 h, cell morphology was observed and endocellular superoxide dismutase (SOD), endocellular malondialdehyde (MDA), lactate dehydrogenase (LDH) leaking ratio, and dead cells' percentage were detected. The results showed cell damage in Group O-60. As compared with Group C, endocellular SOD increased in all groups, MDA at 2 h increased in Groups O-40 and O-60 and MDA at 4 h decreased in Groups O-20 and O-40; LDH leaking ratio at 2 h in Group O-20 and those at 2 and 4 h in Group O-40 decreased, while LDH leaking ratio at 4 h increased and dead cells' percentage in Group O-60 increased. We conclude that in short time (2 and 4 h), oxygen-ozone of 60 microg/ml showed a damaging role on astrocytes in vitro, while oxygen-ozone of 20 and 40 microg/ml did not show damaging role obviously.