Sidoides Essential Oil Research Articles

Positive effect of lippia sidoides essential oil associated with carboxymethylcellulose in the control of anthracnose in avocado

The fungus Colletotrichum gloeosporioides, which is the causal agent of anthracnose disease in green-skinned avocados, is responsible for significant postharvest fruit losses. In this context, strategies should be considered to avoid this problem. The use of essential oil (EO) can represent an alternative to contribute to antifungal activity, avoiding the use of chemical products, as their indiscriminate use can have harmful effects on human health. It is known that essential oil (EO) may exhibit antifungal activity and can be used as an alternative to chemical products. Therefore, the potential of using Lippia sidoides EO to control this fungus was investigated through in vitro evaluation (MIC and EC50) on C. gloeosporioides isolated from avocados. Furthermore, the potential of incorporating this oil with carboxymethylcellulose (CMC) for postharvest treatment in avocados was assessed in vivo to control anthracnose and maintain their physicochemical and sensory quality. The EO from L. sidoides demonstrated a MIC of 125 μl L−1 and an EC50 of 46.83 μl L−1 against this pathogen. The results indicated that the CMC edible coating associated with L. sidoides EO exhibited a positive effect on fruit quality during cold storage. In terms of sensory aspects, avocados treated with L. sidoides EO associated with CMC showed improved appearance compared to the control treatment. These findings suggest that L. sidoides EO has potential in the postharvest treatment of avocados. Additionally, these results are significant and unprecedented for this crop, as research on the postharvest effects of incorporating this EO with edible coatings in avocados is still limited.Graphical

Effect of carboxymethylcellulose-based edible coatings incorporating essential oil on Botrytis cinerea and strawberry attributes

The highly perishable strawberry is susceptible to postharvest fungal infections, such as gray mold caused by Botrytis cinerea. Current control methods involve synthetic fungicides, which can leave residues, harm the environment, and lead to resistance. There is a rising interest in safe and eco-friendly pesticide alternatives like essential oils (EOs). In the present study, the antifungal activity of the EOs from Eucalyptus staigeriana, Lippia sidoides, and Pimenta pseudocaryophyllus was evaluated against B. cinerea. An in vitro experiment assessed the direct contact between the fungus and various EOs, identifying the most potent antifungal EO. This EO underwent chemical composition analysis, along with investigations into its impact on pathogen morphology, in vivo activity with carboxymethylcellulose (CMC), and effects on postharvest and sensory quality of strawberries. In vitro, L. sidoides EO exhibited the most significant antifungal activity, characterized by its major compound thymol, which induced dehydration and rupture of pathogen hyphae. In the in vivo experiment, strawberries treated with CMC and L. sidoides EO showed reduced disease severity. During the 18-day storage period, the postharvest quality of strawberries demonstrated enhancement, characterized by increased antioxidant activity and decreased mass loss, while exhibiting minimal changes in sensory attributes.

Evaluation of essential oils and diluents against Chrysomya megacephala, an important mechanical vector

Chrysomya megacephala represents a major threat to public health. It is a mechanical vector of various pathogens, such as viruses, bacteria, and protozoan cysts, while their larvae may cause myiasis. The alternative to synthetic insecticides, which are harmful to the environment and man`s health, is to use natural insecticides that are safe for both. Plant derivatives have gained prominence in this field, but little is known about how the diluents used in the formulations can influence the insecticidal activity, and the physiology of insects. In this work, among the diluents tested, ethanol, DMSO and miglyol did not affect the viability and the development of C. megacephala, while propylene glycol and mixtures containing Tween® 20 or Tween® 80 caused mortality and increased the total development time from newly hatched larvae to adult. Furthermore, essential oils and their compounds were solubilized in selected diluents to evaluate their insecticidal activities against C. megacephala. Lippia sidoides essential oil, which contained 96.14% thymol, caused mortality of 90%, while Laurus nobilis essential oil caused mortality of 63.7%. The monoterpenoids 1,8-cineole at 125 μg/μL and linalool at 30 μg/μL, that are the main constituents of L. nobilis essential oil, caused mortality of 67.6% and 100% respectively. These effects were confirmed by scanning electronic microscopy. The present study also showed that linalool and the thymol-enriched fraction of L. sidoides essential oil were as active as the synthetic insecticide used as positive control.

Nanostructured Lipid Carriers Loaded with Lippia sidoides Essential Oil as a Strategy to Combat the Multidrug-Resistant Candida auris

The emerging pathogen Candida auris is an emerging fungal pathogen that was associated with nosocomial infectious outbreaks. Its worldwide incidence and the emerging multidrug-resistant strains highlight the urgency for novel and effective antifungal treatment strategies. Lippia sidoides essential oil (LSEO) proved antifungal activity, including anti-Candida. However, it may undergo irreversible changes when in contact with external agents without adequate protection. Herein, we encapsulated LSEO in nanostructured lipid carriers (NLC) through the hot emulsification method followed by sonication. NLC matrix was based on oleic acid and Compritol® 888, or a combination of carnauba wax and beeswax, stabilized by sodium dodecyl sulfate. Eight formulations were produced and characterized by the determination of the particle size (213.1 to 445.5 nm), polydispersity index (around 0.3), and ζ-potential (−93.1 to −63.8 mV). The antifungal activity of nanoparticles and LSEO against C. auris and the in vivo toxicity in Galleria mellonella model were also evaluated. Both NLC and LSEO exhibited potent activity against the yeast, with Minimum Inhibitory Concentration between 281 and 563 µg/mL, and did not evidence toxicity in the in vivo model. Therefore, this study confirms the viability of NLCs loaded with LSEO in combating drug-resistant pathogens as a potential new therapeutic strategy for managing of candidemia.

Study of the scientific production of the antibacterial activity of the chemical compounds of the essential oil of Lippia sidoides

Lippia sidoides Cham. has widespread use in folk medicine because its essential oil (EO) presents great antibacterial properties. In Brazil, this plant has been introduced in governmental programs for herbal medicine, due to its recognized therapeutic activities. This promoted greater interest in the search for new molecules with antimicrobial activity in this EO which have been described by several authors. Thus, this work aimed to present a study of the scientific production of antibacterial activity of the chemical compounds from L. sidoides essential oil (LSEO). The inclusion criteria were articles which assessed the chemical components and antibacterial activity through the inhibition diameter, Minimum Inhibitory Concentration (MIC), and Minimal Bactericidal Concentration (MBC), published between 2000 and 2020. Of the 996 studies identified, 55 met the inclusion criteria. In descending order, the most frequently detected chemical components found in LSEO were: thymol, p-cymene, and caryophillene. Regarding to the origin, the results showed that the extraction of EO were carried out mainly in the Northeast (55.5%) and Southeast (19%) regions of Brazil; and the part of the plant most used for the production were the leaves. In addition, the essential oil showed strong antibacterial activity against most of the bacteria tested.

Study of the scientific production of the antibacterial activity of the chemical compounds of the essential oil of Lippia sidoides

Lippia sidoides Cham. has widespread use in folk medicine because its essential oil (EO) presents great antibacterial properties. In Brazil, this plant has been introduced in governmental programs for herbal medicine, due to its recognized therapeutic activities. This promoted greater interest in the search for new molecules with antimicrobial activity in this EO which have been described by several authors. Thus, this work aimed to present a study of the scientific production of antibacterial activity of the chemical compounds from L. sidoides essential oil (LSEO). The inclusion criteria were articles which assessed the chemical components and antibacterial activity through the inhibition diameter, Minimum Inhibitory Concentration (MIC), and Minimal Bactericidal Concentration (MBC), published between 2000 and 2020. Of the 996 studies identified, 55 met the inclusion criteria. In descending order, the most frequently detected chemical components found in LSEO were: thymol, p-cymene, and caryophillene. Regarding to the origin, the results showed that the extraction of EO were carried out mainly in the Northeast (55.5%) and Southeast (19%) regions of Brazil; and the part of the plant most used for the production were the leaves. In addition, the essential oil showed strong antibacterial activity against most of the bacteria tested.

Can Plant Materials Be Valuable in the Treatment of Periodontal Diseases? Practical Review.

Periodontal diseases are one of the most significant challenges in dental health. It is estimated that only a few percent of the worldwide population have entirely healthy teeth, and according to WHO, oral diseases may affect up to 3.5 billion people worldwide. One of the most serious oral diseases is periodontitis, an inflammatory disease affecting periodontal tissues, caused by pathogenic bacteria and environmental factors such as the ageing population, abuse of tobacco products, and lack of adequate oral hygiene due low public awareness. Plant materials are widely and successfully used in the management of many conditions, including periodontitis. Plant materials for periodontitis exhibit antibacterial, anti-inflammatory, antioxidant activities and affect the periodontium structure. Numerous studies demonstrate the advantages of phytotherapy for periodontitis relief and indicate the usefulness of Baikal skullcap root, Pomegranate fruit peel and root cortex, Tea leaves, Chamomile flowers, Magnolia bark, Blackberry leaves and fruits, Cranberry fruits and Lippia sidoides essential oil. This review aims to analyze the use and applicability of selected plant materials in periodontitis management since it is of paramount importance to evaluate the evidence of the traditionally used plant materials in light of continuously growing interest in phytotherapy and its adjuvant role in the treatment of periodontitis.

Dietary supplementation with essential oils of Lippia sidoides, Ocimum gratissimum and Zingiber officinale on the growth and hemato-immunological parameters of Colossoma macropomum challenged with Aeromonas hydrophila

This study aimed to evaluate the effects of essential oil (EO) of Lippia sidoides, Ocimum gratissimum, and Zingiber officinale in the diet of tambaqui (Colossoma macropomum) growth, hematological and immunological parameters. The survival rate was also calculated after challenge with Aeromonas hydrophila. Seven diets containing 32 % crude protein were formulated as follows: control (0 g/kg of EO), 0.625 and 1.25 g/kg of L. sidoides EO; 1.25 and 5.0 g/kg of O. gratissimum EO; 1.25 and 5.0 g/kg of Z. officinale EO, in triplicate. Tambaqui fed diets supplemented with EO of L. sidoides, O. gratissimum, and Z. officinale did not present significant differences in the growth parameters. After 30 and 60 days of feeding, performance and hematological parameters were evaluated. Reductions in total thrombocytes number occurred after 30 days of feeding with 1.25 g/kg and 5.0 g/kg O. gratissimum EO. After 60 days of feeding, fish were challenged with A. hydrophila (1.6 × 108 UFC mL−1) and were observed for 10 days. Fish fed with diets supplemented with L. sidoides EO at 0.625 g/kg and 1.25 g/kg showed a higher nonspecific immune response through the increased respiratory activity of leukocytes after challenge. Additionally, there was a decrease in plasma glucose levels and no alteration of the total protein levels. Moreover, after the challenge, the highest survival rate occurred among fish fed 0.625 g/kg L. sidoides EO, while treatments with O. gratissimum and Z. officinale EO did not affect fish survival. This is the first report of L. sidoides EO in tambaqui diets. More studies are warranted to adjust the concentration and periods of treatment regarding diets supplemented with L. sidoides EO or thymol in treatment of bacterial fish diseases.

Potential source of ecofriendly insecticides: Essential oil induces avoidance and cause lower impairment on the activity of a stingless bee than organosynthetic insecticides, in laboratory

The negative effect of insecticides on bees has been reported as one of the factors associated with the decline in population of these pollinators. Thus, the aim of this study was to evaluate the response of the stingless bee Nannotrigona aff. testaceicornis (Lepeletier, 1836) to a promising source of new insecticide molecules obtained from Lippia sidoides (rosemary pepper) essential oil (EO) and its major compounds (thymol, ρ-cymene, and (E)-caryophyllene), comparing them to commercial insecticides (organosynthetic: imidacloprid, deltamethrin and semisynthetic: spinetoram). For this, stingless bees were exposed by contact with these compounds to evaluate the lethal and sublethal (locomotion and flight orientation) toxicity. The L. sidoides EO and its major compounds have low lethal toxicity to forager worker bees (N. aff. testaceicornis). The organosynthetics imidacloprid (LD50 =0.00146 µgbee−1) and deltamethrin (LD50 =0.0096 µg bee−1) were about 209,589 and 31,875 times more toxic, respectively, than the least toxic natural compound, (E)-caryophyllene (LD50 =306 µgbee−1). Locomotion ability and flight orientation were little affected by spinetoram and by L. sidoides EO and its major compounds, however, were greatly reduced by the imidacloprid and deltamethrin insecticides. Besides shows low lethal and sublethal toxicity, the bioinsecticides were also avoided by the forager bees. Individuals treated with the L. sidoides EO and thymol were avoided by the untreated bees. Therefore, the natural products studied here were promising due to their recognized effectiveness against pest insects and greater safety to bees N. aff. testaceicornis.

Development of Chlorhexidine Digluconate and Lippia sidoides Essential Oil Loaded in Microemulsion for Disinfection of Dental Root Canals: Substantivity Profile and Antimicrobial Activity.

The dental intracanal disinfection is crucial to achieve the success of endodontic treatment, avoiding the maintenance of endodontic infections. Chlorhexidine digluconate can act as an irrigating agent for it. However, it can cause tissue irritation in high concentrations. Therefore, combinations with other antimicrobial agents and more efficient therapeutic alternatives are studied, which make it possible to administer drugs more safely and with minimal adverse effects. Thus, the objective of this study was the development of a microemulsion containing chlorhexidine digluconate and essential oil of Lippia sidoides to be used for disinfection of dental root canals and to evaluate its profile of substantivity and antimicrobial activity. The microemulsions were obtained through phase diagrams, using the spontaneous formation method. We completed a physical-chemical characterization and evaluate the stability of the microemulsions, in addition to the substantivity profile in a bovine root dentin model, and in vitro antibacterial effect on Enterococcus faecalis. A method for quantifying chlorhexidine was developed using UV-Vis spectroscopy. The microemulsions showed acid pH, conductivity above 1.3 μScm-1, and dispersion index similar to water. The microemulsions showed antimicrobial inhibition halos similar to the commercial gel conventionally used, but with four times more substantivity to dentinal tissues. Microemulsions were obtained as a therapeutic alternative to formulations available on the market, presenting themselves as a system with great potential for the administration of drugs for disinfection of root canals.

Factors Affecting the Retention Efficiency and Physicochemical Properties of Spray Dried Lipid Nanoparticles Loaded with Lippia sidoides Essential Oil.

Essential oils (EOs) are widely used in various industrial sectors but can present several instability problems when exposed to environmental factors. Encapsulation technologies are effective solutions to improve EOs properties and stability. Currently, the encapsulation in lipid nanoparticles has received significant attention, due to the several recognized advantages over conventional systems. The study aimed to investigate the influence of the lipid matrix composition and spray-drying process on the physicochemical properties of the lipid-based nanoparticles loaded with Lippia sidoides EO and their retention efficiency for the oil. The obtained spray-dried products were characterized by determination of flow properties (Carr Index: from 25.0% to 47.93%, and Hausner ratio: from 1.25 to 1.38), moisture (from 3.78% to 5.20%), water activity (<0.5), and powder morphology. Zeta potential, mean particle size and polydispersity index, of the redispersed dried product, fell between −25.9 mV and −30.9 mV, 525.3 nm and 1143 nm, and 0.425 and 0.652, respectively; showing slight differences with the results obtained prior to spray-drying (from −16.4 mV to −31.6 mV; 147 nm to 1531 nm; and 0.459 to 0.729). Thymol retention in the dried products was significantly lower than the values determined for the liquid formulations and was affected by the drying of nanoparticles.

Effects of Lippia sidoides Cham. (Verbenaceae) essential oils on the honey bees, Apis mellifera (Apidae: Hymenoptera), foraging

The use of plant essential oils has been adopted as less hazardous to the environment and human health than synthetic insecticides used for the control of insects that transmit diseases. Despite of exerting insecticidal activities against several insect disease vectors, the potential impacts on non-target organisms exerted by essential oils extracted from Lippia sidoides (Cham.) have not received adequate attention. Here, we evaluated the susceptibility and potential changes in consumption rates of honey bees, Apis mellifera (L.), when exposed to essential oils extracted from L. sidoides. Was exposed forager bees to honey syrup (50% v/v) containing L. sidoides essential oil for 5 h. After this exposure period, the bees received regular honey syrup for another 19 h period. Six essential oil concentrations was used, namely 1.0, 1.5, 2.0, 2.5, 3.0 and 3.5 µL of essential oil/mL of syrup, and evaluated the syrup consumption and bees mortality in both periods (at the 5th and 24th h). The results reveal that independent of the essential oil concentration, the forager bees fed significantly less on L. sidoides essential oil-containing honey syrup. However, feeding on L. sidoides essential oil-containing honey syrup did not cause significant mortality when compared with bees that were not exposed to the essential oils. Thus, the results demonstrate that L. sidoides essential oils exhibited adequate selectivity against honey bees.

English

Research institutions have emphasized alternative disease control agents because they represent a great option with beneficial effects on human and animal health and ecosystem balance. Despite the studies already done on botanical fungicides, their effective use requires knowledge about the applicability of natural products to different production systems. The main objective of this study is to evaluate the efficacy of essential oils of Ocimum pupuraceus L., Cymbopogon nardus (L.) Rendle, Cymbopogon citratus (DC.) Stapf, and Lippia sidoides Cham. on the inhibition of mycelial growth and germination of conidia of B. maydis. The other objectives of this study were to perform gas chromatographic and phytotoxicity analyses, and test the control of bipolaris leaf spot using essential oils of L. sidoides applied as a preventive and curative agent. Among the treatments studied, the essential oil of L. sidoides is effective in inhibiting mycelial growth and conidial germination at the concentrations of 5 and 1%, respectively. The main constituent of the oil is thymol (92.68%). The concentration range 0.75-3% of L. sidoides essential oil is phytotoxic to maize plants. Lower values of the area under the progress curve of bipolaris leaf spot are observed at concentrations 0.1-0.5%, when the essential oil was applied as a preventive agent prior to the colonization of plant tissues by the pathogen. The application of the oil as a curative to plants with the disease also shows efficacy at the concentration 0.1%, reducing the severity by more than 54%. These results demonstrate the potential effects of L. sidoides essential oil on preventive and curative control of bipolaris leaf spot in maize and mycelial growth. Key words: Medicinal plants, alternative control, phytopathogens, Zea mays, Bipolaris maydis, Lippia sidoides.

Physiological and pharmacokinetic responses in neotropical Piaractus mesopotamicus to the essential oil from Lippia sidoides (Verbenaceae) as an anesthetic

The goal of the study was to evaluate Lippia sidoides essential oil as an anesthetic for the tropical fish pacu Piaractus mesopotamicus. The physiological and pharmacokinetic responses were evaluated during fish handling. Fish were exposed to different concentrations of the essential oil (20, 30, 40, 50, 60, and 70 mg L−1) to determine the induction times to anesthesia. The hematological parameters were determined in fish exposed to different concentrations of the essential oil (20 and 70 mg L−1), which were enough to induce light and deep anesthesia in 10 min. For pharmacokinetics purposes, blood samples were collected after exposure to the essential oil (70 mg L−1) for 10 min at different depuration times (0, 15, and 30 min, 1, 2, 4, 6, 8, 24, and 48 h). Thymol was the major essential oil compound in Lippia sidoides, at 61.12%. All physiological parameters returned to control values in 24 h. Distribution and elimination of the major compound in the blood plasma were fast, being 64.31% in 1 h. The distribution constant of the essential oil was 7.59 µg h−1 (k) in the organism. Therefore, when the plasmatic concentration of thymol was reduced, this constant decreased to 0.44 µg h−1(k). The AUC value was 38.05 µg h−1, the initial half-life during the distribution stage (T1/2 α) was 0.09 h and the elimination half-life (T1/2β) was 1.59 h. Fish survival was 100% even 20 days after the experiments. Therefore, Lippia sidoides essential oil may be considered a safe anesthetic for tropical fish.

Control of Rhizopus stolonifer in strawberries by the combination of essential oil with carboxymethylcellulose

Strawberry has a limiting postharvest shelf life, especially because of soft rot. The antifungal activity of the essential oils (EOs) of Eucalyptus staigeriana, Lippia sidoides and Pimenta pseudocaryophyllus was tested in vitro against plant pathogen Rhizopus stolonifer. The chemical composition of the EO with the highest activity and its effects on pathogen morphology were verified. The in vivo antifungal activity of this EO associated with carboxymethylcellulose (CMC) coating, in preventive and curative applications, was also evaluated. L. sidoides EO presented the highest in vitro antifungal activity. The analysis of the chemical composition of this EO showed a prevalence of the compound thymol and the scanning and transmission electron microscopy showed that L. sidoides EO was able to cause damage to the cell wall and the intracellular components of the pathogen. Strawberries treated with L. sidoides EO associated with CMC presented a reduction in disease severity, especially when treated in a curative way.

Lippia sidoides essential oil encapsulated in lipid nanosystem as an anti-Candida agent

Essential oils (EOs) have high importance in various industrial sectors, due to their wide range of confirmed biological activity, such as antibacterial, antiviral, antifungal, antiparasitic, insecticide, analgesic, anti-inflammatory, and so on. The main components of essential oils belong to the classes of monoterpenes, diterpenes, and sesquiterpenes, compounds generally sensitive to oxygen, light, heat, and moisture. These substances may undergo irreversible changes when in contact with other materials or external agents, without adequate protection. In this way, micro and nanoencapsulation technologies arise as a viable and effective solution, since they furnish protection against instability problems, change product solubility, release of the bioactive substances, and might enhance the biological activity. In this study, essential oil (EO) of Lippia sidoides Cham. (L. sidoides) was loaded in lipid-based systems through emulsification by phase inversion. Gelucire® 50/13, stearic acid or Compritol® 888 ATO (solid lipids) and oleic acid or Labrasol® (liquid lipids) comprised the lipid phase, while Poloxamer® 188 or a combination of Tween® 80 and Span® 80 were the surfactants used. Twelve formulations were prepared, and their stability examined by visual inspection. Accelerated stability tests were carried out with the formulations containing Gelucire® 50/13, which appeared more stable. Formulations were characterised by the determination of the droplet size (214.4–423.2 nm), polydispersity index (around 0.3) and ζ-potential (−40.6 to −23.0). The antifungal activity against Candida albicans of the lipid base compositions loaded with L. sidoides EO, pure EO, and its major compound, thymol, was evaluated. The lipid-based formulations and the pure EO exhibited potent activity against this yeast, exhibiting Minimum Inhibitory Concentration (MIC) between 156 and 312 μg/mL. This study contributes to the development of an effective approach to enhance the essential oil stability and to form promising antimicrobial systems, which can be used in the most diverse sectors of the industry.

Antifungal activity of essential oils associated with carboxymethylcellulose against Colletotrichum acutatum in strawberries

The antifungal activity of the essential oils (EOs) of Eucalyptus staigeriana, Lippia sidoides and Pimenta pseudocaryophyllus was evaluated in vitro, by direct contact and by exposure to volatiles, against Colletotrichum acutatum, an important pathogen of strawberry. The chemical composition of the EO with the highest activity and its effects on the morphology of the pathogen were verified. The in vivo antifungal activity of this EO associated with carboxymethylcellulose (CMC) coating, in preventive and curative applications, was also evaluated. L. sidoides EO presented the highest antifungal activity in vitro, being more efficient by direct contact than by volatilization. This EO has a predominance of the compound thymol and was able to cause dehydration and rupture of the pathogen hyphae. In vivo, strawberries treated with CMC associated with L. sidoides EO presented a reduction in disease severity, when treated in a curative way. Thus, the association of L. sidoides EO with CMC can be a potential alternative for the control of this disease.

Antimicrobial activity of some essential oils against Streptococcus agalactiae, an important pathogen for fish farming in Brazil

ABSTRACTThe antimicrobial activity of the essential oils from Lippia alba, Lippia sidoides, Mentha piperita, Ocimum gratissimum and Zingiber officinale was tested against Streptococcus agalactiae. The major compounds in the oils, identified by gas chromatography and mass spectrometry (GC/MS), were geranial (25.4%), neral (16.6%) and caryophyllene oxide (16.0%) in L. alba; thymol (76.6%), p-cymene (6.3%) and β-caryophyllene (5.0%) in L. sidoides; menthol (30.5%), menthyl acetate (14.6%), pulegone (14.2%) and menthone (12.9%) in M. piperita; eugenol (43.3%), 1,8-cineole (28.2%) and β-selinene (5.5%) in O. gratissimum; and geranial (23.2%), neral (16.7%) and 1,8-cineole (15.8%) in Z. officinale. All essential oils evaluated showed bactericidal action against S. agalactiae with minimum inhibitory concentration (MIC) ranging from 312.5–2,500 μg mL−1 and minimum bactericidal concentration (MBC) ranging from 416.7–2,500 μg mL−1. In this study, L. sidoides essential oil showed the better results against S. agalactiae.

Antidepressant-Like Effect of Lippia sidoides CHAM (Verbenaceae) Essential Oil and Its Major Compound Thymol in Mice.

Depression is a common disease affecting more than 300 million people worldwide. Since Lippia sidoides has shown central nervous system effects in previous works, we aimed to investigate the effect of L. sidoides essential oil and its major compound, thymol on a corticosterone-induced depression model in mice. Male mice (20⁻25 g) received corticosterone (20 mg/kg, subcutaneously), once a day for 22 days. From the 16th day on, mice were grouped to receive either corticosterone or L. sidoides essential oil (100 and 200 mg/kg), or thymol (25 and 50 mg/kg) or fluoxetine (35 mg/kg) by gavage. The forced swimming test, tail suspension, open field, elevated plus maze and sucrose preference tests were performed from the 19th to 22nd day. Data were analyzed by ANOVA followed by the Student-Newman-Keuls as a post hoc test and the results were considered significant when p < 0.05. It was shown that L. sidoides essential oil, thymol and fluoxetine decreased the immobility time in the tail suspension and forced swimming tests and none of these altered locomotor activity in the open field test. However, the drugs increased the amount of grooming. In the elevated plus maze, all drugs increased the number of entries and the time of permanence in the open arms. In the sucrose preference test, the L. sidoides essential oil, thymol and fluoxetine reversed anhedonia. These results suggest that the thymol and L. sidoides essential oil have an antidepressant-like effect, similar to fluoxetine. However, future studies should be encouraged to enhance understanding of the effects of essential oil and thymol for the treatment of depression.

Carboxymethylcellulose coating associated with essential oil can increase papaya shelf life

Abstract The use of essential oils (EO) associated with coatings in the post-harvest treatment of papaya is a little studied alternative to avoid post-harvest losses. Therefore, the antifungal activity of Eucalyptus staigeriana, Lippia sidoides and Pimenta pseudocaryophyllus essential oils (EOs) was tested in vitro against Colletotrichum gloesporiodes, the causal agent of anthracnose in papaya. The EO with the highest activity was evaluated regarding its chemical composition, in vivo activity and its effects on papayas post-harvest quality, when associated with a carboxymethylcellulose coating. L. sidoides EO presented the highest in vitro antifungal activity, with thymol as the predominant compound in its composition. In vivo, the fruit treated with CMC associated with L. sidoides EO presented a reduction in disease severity and maintained post-harvest parameters, besides slowing the appearance of rot and shriveling in the fruit on the ninth day of storage, whereas in the control and treatment with only CMC, this behavior occurred on the fifth and seventh days, respectively. Thus, the association of L. sidoides EO with CMC was effective in the rise of papayas shelf life, preserving their post-harvest characteristics for nine days, indicating that this treatment can be considered a viable alternative for the extension of the fruit commercialization period.