Péricles Barreto Alves

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.

Anxiolytic-like effect of sweet orange aroma in Wistar rats.

Aromatherapy is the use of essential oils as an alternative treatment for medical purposes. Despite the lack of sufficient scientific proof, it is considered a holistic complementary therapy employed to enhance comfort and decrease distress. Citrus fragrances have been particularly used by aromatherapists for the treatment of anxiety symptoms. Based on this claim, the present study investigated the effects of Citrus sinensis (sweet orange) essential oil on Wistar, male rats evaluated in the elevated plus-maze followed by the light/dark paradigm. The animals were exposed to the orange aroma (100, 200 or 400 microl) for 5 min while in a Plexiglas chamber and were then immediately submitted to the behavioural tests. At all doses, C.sinensis oil demonstrated anxiolytic activity in at least one of the tests and, at the highest dose, it presented significant effects in both animal models, as indicated by increased exploration of the open arms of the elevated plus-maze (time: p=0.004; entries: p=0.044) and of the lit chamber of the light/dark paradigm (time: p=0.030). In order to discard the possibility that this outcome was due to non-specific effects of any odour exposure, the behavioural response to Melaleuca alternifolia essential oil was also evaluated, using the same animal models, but no anxiolytic effects were observed. These results suggest an acute anxiolytic activity of sweet orange essence, giving some scientific support to its use as a tranquilizer by aromatherapists.

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.

Two-dimensional coordination polymer matrix for solid-phase extraction of pesticide residues from plant Cordia salicifolia

The 2D coordination polymer (infinity[Gd(DPA)(HDPA)]) was tested for extraction of acephate, chlorpropham, pirimicarb, bifenthrin, tetradifon, and phosalone from the medicinal plant Cordia salicifolia, whose extracts are commercialized in Brazil as diuretic, appetite suppressant, and weight loss products, using GC/MS, SIM. Considering that there are no Brazilian regulations concerning maximum permissible pesticide residue concentrations in medicinal herbs, recovery experiments were carried out (seven replicates), at two arbitrary fortification levels (0.5 and 1.0 mg/kg), resulting in recoveries in range of 20 to 107.7% and SDRSDs were between 5.6 and 29.1% for infinity[Gd(DPA)(HDPA)] sorbent. Detection and quantification limits for herb ranged from 0.10 to 0.15 mg/kg and from 0.15 to 0.25 mg/kg, respectively, for the different pesticides studied. The developed method is linear over the range assayed, 0.5-10.0 microg/mL, with correlation coefficients ranging from 0.9975 to 0.9986 for all pesticides. Comparison between infinity[Gd(DPA)(HDPA)] sorbent and conventional sorbent (neutral alumina) showed similar performance of infinity[Gd(DPA)(HDPA)] polymeric sorbent for three (bifenthrin, tetradifon, and phosalone) out of six pesticides tested.

β‐Cyclodextrin Complex Containing Lippia grata Leaf Essential Oil Reduces Orofacial Nociception in Mice – Evidence of Possible Involvement of Descending Inhibitory Pain Modulation Pathway

The treatment of orofacial pain remains a major challenge for modern medicine. Thus, we prepared and physicochemically characterized a new β‐cyclodextrin complex containing Lippia grata leaf essential oil (β‐CD/EO) to investigate their possible antinociceptive activity in animal models of orofacial pain. The results of Differential scanning calorimeter (DSC) and Thermogravimetry/derivative thermogravimetry (TG/DTG) showed that the products prepared by Slurry complexation (SC) method were able to incorporate greater amounts of EO. In the X‐ray diffractogram, it was shown that complex between EO and β‐CD was formed. Male Swiss mice were pre‐treated with β‐CD/EO (6, 12 or 24 mg/kg, per os, gavage, p.o.), morphine (5 mg/kg, i.p.) or vehicle (distilled water, p.o.) 1 hr before treatment with formalin (20 μL, 2%), capsaicin (20 μL, 2.5 μg) or glutamate (40 μL, 25 μM) into the right upper lip. Our results demonstrated that p.o. treatment with β‐CD/EO was significantly (p < 0.05 or p < 0.001) capable of reducing the nociceptive face‐rubbing behaviour in both phases of the formalin test. β‐CD/EO‐treated mice were also significantly (p < 0.05 or p < 0.001) protected against nociception induced by capsaicin and glutamate. For the action in the central nervous system (CNS), ninety minutes after the treatment, the mice were perfused, the brains collected, crioprotected, cut in a criostate and submitted to an immunofluorescence protocol for Fos protein. The immunofluorescence protocol demonstrated that the β‐CD/EO significantly activated (p < 0.05; p < 0.01 or p < 0.001) the motor cortex, the Locus ceruleus, the nucleus raphe magnus and the periaqueductal gray of the CNS. These effects apparently did not alter, in tested doses, the motor coordination of mice in the rota‐rod test. Our results proposed that β‐CD/EO might present an important draft of drug to the study of new compounds for the treatment of orofacial pain.

Effect of sweet orange aroma on experimental anxiety in humans.

OBJECTIVES The objective of this study was to evaluate the potential anxiolytic effect of sweet orange (Citrus sinensis) aroma in healthy volunteers submitted to an anxiogenic situation. DESIGN Forty (40) male volunteers were allocated to five different groups for the inhalation of sweet orange essential oil (test aroma: 2.5, 5, or 10 drops), tea tree essential oil (control aroma: 2.5 drops), or water (nonaromatic control: 2.5 drops). Immediately after inhalation, each volunteer was submitted to a model of anxiety, the video-monitored version of the Stroop Color-Word Test (SCWT). OUTCOME MEASURES Psychologic parameters (state-anxiety, subjective tension, tranquilization, and sedation) and physiologic parameters (heart rate and gastrocnemius electromyogram) were evaluated before the inhalation period and before, during, and after the SCWT. RESULTS Unlike the control groups, the individuals exposed to the test aroma (2.5 and 10 drops) presented a lack of significant alterations (p>0.05) in state-anxiety, subjective tension and tranquillity levels throughout the anxiogenic situation, revealing an anxiolytic activity of sweet orange essential oil. Physiologic alterations along the test were not prevented in any treatment group, as has previously been observed for diazepam. CONCLUSIONS Although more studies are needed to find out the clinical relevance of aromatherapy for anxiety disorders, the present results indicate an acute anxiolytic activity of sweet orange aroma, giving some scientific support to its use as a tranquilizer by aromatherapists.

Ocimum basilicum leaf essential oil and (-)-linalool reduce orofacial nociception in rodents: a behavioral and electrophysiological approach

The present study investigated the antinociceptive effects of Ocimum basilicum L. (Lamiaceae) leaf essential oil (LEO) and (-)-linalool (LIN) in formalin (2%)-, glutamate (25 µM)- and capsaicin (2.5 µg)- induced orofacial nociception models in mice. The involvement of these substances was further evaluated on the neuronal excitability of the hippocampal dentate gyrus. Male mice (n=8/group) were pretreated separately with LEO and by LIN (50, 100, and 200 mg/kg, i.p.), morphine (5 mg/kg, i.p.) and vehicle (saline + Tween 80 0.2%), before injection of nociceptive agent into the right upper lip (perinasal area). The LEO and LIN reduced the nociceptive face-rubbing behaviour in both phases on formalin test. LEO and LIN, at high doses, produced significantly antinociceptive effect in the capsaicin and glutamate tests. In hippocampal slices, LEO inhibited the population spike generated by stimulation of the hylus (antidromic stimulation), with an IC50 of 0.1±0.05 mg/mL. This response was reversibly blocked by lidocaine (0.5 mg/mL), a known voltage-dependent sodium channel antagonist and by LIN (0.5 mg/mL). Our results suggest that LEO and LIN modulate neurogenic and inflammatory pain in the tests of orofacial nociception induced by formalin, capsaicin and glutamate. Part of these effects may be associated with decreased peripheral and central neuronal excitability.