Arie Fitzgerald Blank

Melissa officinalis L. essential oil: antitumoral and antioxidant activities

Melissa officinalis L (lemon balm) is a traditional herbal medicine used widely as a mild sedative, spasmolytic and antibacterial agent. This paper focuses on the analysis of the chemical composition and the biological activities of M. officinalis essential oil obtained under controlled harvesting and drying conditions. An in‐vitro cytotoxicity assay using MTT indicated that this oil was very effective against a series of human cancer cell lines (A549, MCF‐7, Caco‐2, HL‐60, K562) and a mouse cell line (B16F10). This oil possessed antioxidant activity, as evidenced by reduction of 1,1‐diphenyl‐2‐picryl‐hydrazyl (DPPH). These results pointed to the potential use of M. officinalis essential oil as an antitumoral agent.

Influence of the harvesting time, temperature and drying period on basil (Ocimum basilicum L.) essential oil

Ocimum basilicum L. essential oil with high concentration of linalool is valuable in international business. O. basilicum essential oil is widely used as seasoning and in cosmetic industry. To assure proper essential oil yield and quality, it is crucial to determine which environmental and processing factors are affecting its composition. The goal of our work is to evaluate the effects of harvesting time, temperature, and drying period on the yield and chemical composition of O. basilicum essential oil. Harvestings were performed 40 and 93 days after seedling transplantation. Harvesting performed at 8:00 h and 12:00 h provided higher essential oil yield. After five days drying, the concentration of linalool raised from 45.18% to 86.80%. O. basilicum should be harvested during morning and the biomass dried at 40oC for five days to obtain linalool rich essential oil.

Composition and acaricidal activity of Lippia sidoides essential oil against two-spotted spider mite (Tetranychus urticae Koch).

The essential oils from accessions of Lippia sidoides Cham. (Verbenaceae) were characterized by GC and GC/MS and investigated for their acaricidal activity against the two-spotted spider mite (Tetranychus urticae Koch). Twenty-nine compounds were identified with potential acaricidal activity. Glass receptacles were used as test chambers. For each dose and exposure time combination, three replicates were used. Each replicate consisted of 30 adult females of T. urticae, 10 mites in each leaf disk of Canavalia ensiformis placed in a Petri dish. Increasing amounts of oil or terpene were applied on a blotting paper strip, fixed on the inner surface of the glass recipient cover, corresponding to 2, 4, 6, 8, and 10 microL/L of air, respectively. Exposure periods were 24, 48, and 72 h. Data obtained in these experiments were submitted to probit analysis. The essential oil of L. sidoides, thymol and carvacrol exhibited potent acaricidal activity against T. urticae.

Evaluation of the analgesic and anti-inflammatory effects of the essential oil of Lippia gracilis leaves.

AIM OF THE STUDY The aim of the present study is to investigate the antinociceptive, anti-inflammatory, and antioxidant activities of essential oil (EO) of Lippia gracilis Schauer (Verbenaceae) leaves to support the medicinal uses claimed by folklore practitioners in the caatinga region (semi-arid) of Northeastern Brazil. MATERIALS AND METHODS The chemical composition and antinociceptive and anti-inflammatory activities of the EO of Lippia gracilis leaves (50-200 mg/kg) were investigated. Antinociceptive activity of the EO was evaluated by writhing test. Anti-inflammatory activity of the EO was evaluated using paw oedema and peritonitis methods. RESULTS Oral treatment with the EO of Lippia gracilis leaves elicited inhibitory activity on acetic acid effect at 50, 100, and 200 mg/kg (30.33+/-2.36, 25.20+/-1.48, and 21.00+/-1.54 abdominal writhes, respectively, P<0.05), as compared with the control group (36.73+/-1.92 writhes). The compound acetylsalicylic acid (ASA, 300 mg/kg) inhibited the acetic acid-induced writhing (12.67+/-0.50 abdominal writhes, P<0.001). Carrageenan-induced oedema formation was reduced with the EO of Lippia gracilis leaves at 200 mg/kg (0.72+/-0.06 mL h, P<0.001) and by the reference compound ASA (300 mg/kg, 0.85+/-0.04 mL h, P<0.001), as compared with the control group (1.76+/-0.06 mL h). Leukocyte migration into the peritoneal cavity induced by carrageenan was reduced with the EO of Lippia gracilis leaves at 50, 100, and 200 mg/kg (13.81+/-0.61, 11.77+/-0.91, and 10.30+/-0.60 leukocytes x 10(6)/mL, respectively, P<0.01), and by the compound dexamethasone (2 mg/kg, 5.34+/-0.33 leukocytes x 10(6)/mL, P<0.001), as compared with the control group (16.71+/-0.54 leukocytes x 10(6)/mL). The analyses of the essential oil allowed the identification of Lippia gracilis as a thymol-p-cymene chemotype (32.68% and 17.82%, respectively). CONCLUSIONS The EO of Lippia gracilis leaves shows antinociceptive and anti-inflammatory activities.

Impact of edible chitosan–cassava starch coatings enriched with Lippia gracilis Schauer genotype mixtures on the shelf life of guavas (Psidium guajava L.) during storage at room temperature

The effect of edible chitosan-cassava starch (CH-CS) coatings containing a mixture of Lippia gracilis Schauer genotypes (EOM) on the shelf life of guavas during storage at room temperature for 10 days was studied. Sixteen formulations were prepared with a range of chitosan and essential oil mixtures concentrations, and the in vitro antimicrobial activity was tested. Formulations containing 2.0% cassava starch, 2.0% chitosan and 1.0%, 2.0% or 3.0% EOM were most effective in inhibiting the growth of the majority of bacteria. The edible CH-CS coating and CH-CS with 1.0% (CH-CS-EOM1) or 3.0% EOM (CH-CS-EOM3) were added to guavas and the shelf life was evaluated. On the tenth day of storage, total aerobic mesophilic bacteria and mould and yeast counts were statistically lower (p<0.05) in the CH-CS-EOM1- or CH-CS-EOM3-coated fruits than CH-CS-coated fruits. In addition, fruits coated with CH-CS or CH-CS-EOM showed no significant changes of total soluble solids content, while CH-CS-EOM-coated fruits showed lower titratable acidity than CH-CS-coated fruits at the end of storage. CH-CS-EOM3-coated guavas showed lower a(∗) and b(∗) values and higher L(∗) and hue values than those with other coatings.

Acaricidal activity of Lippia gracilis essential oil and its major constituents on the tick Rhipicephalus (Boophilus) microplus.

The present study aimed to evaluate the activity of Lippia gracilis Schauer essential oil obtained from different L. gracilis genotypes and their major components, carvacrol and thymol against Rhipicephalus (Boophilus) microplus (cattle tick) larvae and engorged females. The larval test was performed parallel to the adult immersion test for engorged females for four L. gracilis genotypes. Similar tests were further performed for their major compounds carvacrol and thymol. Carvacrol (LC50 of 0.22 and 4.46 mg/mL, to larvae and engorged females, respectively) was more efficient than thymol (LC50 of 3.86 and 5.50 mg/mL, to larvae and engorged females, respectively). The lethal concentrations obtained for the isolated essential oil from genotypes LGRA-201 against larvae (1.31 mg/mL) and LGRA-106 against engorged females (4.66 mg/mL) confirmed the acaricidal activity of L. gracilis essential oil and its effectiveness in controlling the southern cattle tick.

Plant age and genotype affect the bacterial community composition in the tuber rhizosphere of field-grown sweet potato plants.

The hypothesis that sweet potato genotypes containing different starch yields in their tuberous roots can affect the bacterial communities present in the rhizosphere (soil adhering to tubers) was tested in this study. Tuberous roots of field-grown sweet potato of genotypes IPB-149 (commercial genotype), IPB-052, and IPB-137 were sampled three and six months after planting and analyzed by denaturing gradient gel electrophoresis (DGGE) and pyrosequencing analysis of 16S rRNA genes PCR-amplified from total community DNA. The statistical analysis of the DGGE fingerprints showed that both plant age and genotypes influenced the bacterial community structure in the tuber rhizosphere. Pyrosequencing analysis showed that the IPB-149 and IPB-052 (both with high starch content) displayed similar bacterial composition in the tuber rhizosphere, while IPB-137 with the lowest starch content was distinct. In comparison with bulk soil, higher 16S rRNA gene copy numbers (qPCR) and numerous genera with significantly increased abundance in the tuber rhizosphere of IPB-137 (Sphingobium, Pseudomonas, Acinetobacter, Stenotrophomonas, Chryseobacterium) indicated a stronger rhizosphere effect. The genus Bacillus was strongly enriched in the tuber rhizosphere samples of all sweet potato genotypes studied, while other genera showed a plant genotype-dependent abundance. This is the first report on the molecular identification of bacteria being associated with the tuber rhizosphere of different sweet potato genotypes.

Antimicrobial action and anti-corrosion effect against sulfate reducing bacteria by lemongrass (Cymbopogon citratus) essential oil and its major component, the citral

The anti-corrosion effect and the antimicrobial activity of lemongrass essential oil (LEO) against the planktonic and sessile growth of a sulfate reducing bacterium (SRB) were evaluated. Minimum inhibitory concentration (MIC) of LEO and its major component, the citral, was 0.17 mg ml-1. In addition, both LEO and citral showed an immediate killing effect against SRB in liquid medium, suggesting that citral is responsible for the antimicrobial activity of LEO against SRB. Transmission electron microscopy revealed that the MIC of LEO caused discernible cell membrane alterations and formed electron-dense inclusions. Neither biofilm formation nor corrosion was observed on carbon steel coupons after LEO treatment. LEO was effective for the control of the planktonic and sessile SRB growth and for the protection of carbon steel coupons against biocorrosion. The application of LEO as a potential biocide for SRB growth control in petroleum reservoirs and, consequently, for souring prevention, and/or as a coating protection against biocorrosion is of great interest for the petroleum industries.

Estabelecimento de alecrim-pimenta in vitro

Lippia sidoides Cham. is a native shrub from the semi-arid region of Northeast Brazil. Its essential oil has high commercial value, due to the major compounds thymol and carvacrol, which have strong antimicrobial and antiseptic properties. The effect of concentrations and immersion time in sodium hypochlorite, culture media, the use of antibiotic and antioxidants on in vitro establishment of L. sidoides were evaluated. The assays were conducted in a completely randomized design. We evaluated the concentrations 0.2; 0.4; 0.6 and 0.8% of sodium hypochlorite and 8; 12; 16 and 20 minutes of immersion, in a 4 x 4 factorial scheme; the concentrations 0; 50; 100; 150 and 200 mg L-1 of cefotaxime sodium; the medium cultures MS, B5 and WPM; and the effect of antioxidants (PVP: 0.5 and 2 g L-1; and activated charcoal: 3 and 12 g L-1). The concentration of 0.8% of sodium hypochlorite resulted in a significantly higher (p<0.01) number of leaves per shoot: 1.88. For the other characteristics we did not observe any significant effect of sodium hypochlorite concentrations: the contamination varied from 33.7 to 50.6%; the number of new shoots varied from 1.17 to 1.65, and the number of leaves per explant varied from 1.77 to 3.07. Although we did not observe significant difference for immersion times, 12 and 16 minutes of immersion tend to result in minor contamination. Increasing the immersion time from 16 to 20 minutes tends to induce a reduction of new shoots (form 1.52 to 1.22), number of leaves per explant (from 2.62 to 1.81) and number of leaves per shoot (from 1.70 to 1.24). The use of cefotaxime sodium reduced significatively the bacterial contamination (55.23% at the control treatment; 9.99% at the 200 mg L-1 concentration), increasing the survival of explants from 0 (control) to 37.32% (200 mg L-1). The medium cultures offered statistically identical results. All the evaluated antioxidants, even at the lowest concentrations, reduced the oxidation from 50% (control) to as little as 10%. For in vitro establishment of L. sidoides nodal segments, the results indicate immersion of explants for 16 minutes in a 0.8% sodium hypochlorite solution, 200 mg L-1 of cefotaxime sodium, WPM, MS or B5 culture medium, and 3.0 g L-1 of activated charcoal or 0.5 g L-1 of PVP.

Cyclodextrin-Complexed Ocimum basilicum Leaves Essential Oil Increases Fos Protein Expression in the Central Nervous System and Produce an Antihyperalgesic Effect in Animal Models for Fibromyalgia

O. basilicum leaves produce essential oils (LEO) rich in monoterpenes. The short half-life and water insolubility are limitations for LEO medical uses. β-Cyclodextrin (β-CD) has been employed to improve the pharmacological properties of LEO. We assessed the antihyperalgesic profile of LEO, isolated or complexed in β-CD (LEO/β-CD), on an animal model for fibromyalgia. Behavioral tests: mice were treated every day with either LEO/β-CD (25, 50 or 100 mg/kg, p.o.), LEO (25 mg/kg, p.o.), tramadol (TRM 4 mg/kg, i.p.) or vehicle (saline), and 60 min after treatment behavioral parameters were assessed. Therefore, mice were evaluated for mechanical hyperalgesia (von Frey), motor coordination (Rota-rod) and muscle strength (Grip Strength Metter) in a mice fibromyalgia model. After 27 days, we evaluated the central nervous system (CNS) pathways involved in the effect induced by experimental drugs through immunofluorescence protocol to Fos protein. The differential scanning analysis (DSC), thermogravimetry/derivate thermogravimetry (TG/DTG) and infrared absorption spectroscopy (FTIR) curves indicated that the products prepared were able to incorporate the LEO efficiently. Oral treatment with LEO or LEO-βCD, at all doses tested, produced a significant reduction of mechanical hyperalgesia and we were able to significantly increase Fos protein expression. Together, our results provide evidence that LEO, isolated or complexed with β-CD, produces analgesic effects on chronic non-inflammatory pain as fibromyalgia.