Lippia Alba Essential Oil Research Articles

Antifungal Activity of Cyperus articulatus, Cyperus rotundus and Lippia alba Essential Oils against Aspergillus flavus Isolated from Peanut Seeds.

Aspergillus flavus is a cosmopolitan saprophytic fungus that infests several foodstuffs and is associated with adverse effects in humans. In Senegal, significant losses of groundnut production are mainly due to contamination caused by this species. This study evaluated in vitro antifungal activities of Cyperus articulatus, Cyperus rotundus and Lippia alba essential oils against A. flavus isolated from peanut seeds. Essential oils obtained by hydrodistillation of rhizomes of the two Cyperus species and leaves of L. alba were analyzed with GC-DIF and GC-MS. The essential oil yields from C. articulatus, C. rotundus and L. alba were 1.1%, 1.3% and 1.7%, respectively. These three samples had the following chemotypes: (i) mustakone (21.4%)/eudesma-4(15)-7-dien-1β-ol (8.8%)/caryophyllene oxide (5.9%), (ii) caryophyllene oxide (25.2%)/humulene epoxyde 2 (35.0%) and (iii) geranial (46.6%)/neral (34.6%). The three oils tested inhibited the growth of A. flavus at concentrations between 100 and 1000 ppm. The L. alba oil was the most effective with total clearance of A. flavus on PDA. For the essential oils of C. rotundus (93.65%) and C. articulatus (78.11%), the highest inhibition rates were obtained with a 1000 ppm dose. Thus, L. alba oil could be used safely as an effective protector of groundnuts against A. flavus.

Enhancing Selectivity and Inhibitory Effects of Chemotherapy Drugs Against Myelogenous Leukemia Cells with Lippia alba Essential Oil Enriched in Citral.

Acute myelogenous leukemia (AML) is one of the most lethal cancers, lacking a definitive curative therapy due to essential constraints related to the toxicity and efficacy of conventional treatments. This study explores the co-adjuvant potential of Lippia alba essential oils (EO) for enhancing the effectiveness and selectivity of two chemotherapy agents (cytarabine and clofarabine) against AML cells. EO derived from L. alba citral chemotype were produced using optimized and standardized environmental and extraction protocols. Rational fractionation techniques were employed to yield bioactive terpene-enriched fractions, guided by relative chemical composition and cytotoxic analysis. Pharmacological interactions were established between these fractions and cytarabine and clofarabine. The study comprehensively evaluated the cytotoxic, genotoxic, oxidative stress, and cell death phenotypes induced by therapies across AML (DA-3ER/GM/EVI1+) cells. The fraction rich in citral (F2) exhibited synergistic pharmacological interactions with the studied chemotherapies, intensifying their selective cytotoxic, genotoxic, and pro-oxidant effects. This shift favored transitioning from necrosis to a programmed cell death phenotype (apoptotic). The F2-clofarabine combination demonstrated remarkable synergistic anti-leukemic performance while preserving cell integrity in healthy cells. The observed selective antiproliferative effects may be attributed to the potential dual prooxidant/antioxidant behavior of citral in L. alba EO.

Antioxidant Properties of Lippia alba Essential Oil: A Potential Treatment for Oxidative Stress-Related Conditions in Plants and Cancer Cells.

Lippia alba (Mill.) N.E.Br. ex Britton and P. Wilson is used in folk medicine of Central and South America for its biological activities: i.e., antifungal, antibacterial, antiviral, and anti-inflammatory. Based on ethnopharmacological information and the increasing interest in this species, this work aimed to test a possible wide use of its essential oil (EO) in pharmaceutical and horticultural applications. Therefore, we focused the attention on the antioxidant activity of the oil as a possible tool to overcome the oxidative stress in both applications. For this purpose, we have chosen three aggressive breast cancer cell lines and two horticultural species (Solanum lycopersicum L. and Phaseolus acutifolius L.) that are very sensitive to salt stress. We determined the antioxidant activity of L. alba EO through the quantification of phenols and flavonoids. Regarding tomato and bean plants under salt stress, L. alba EO was used for the first time as a seed priming agent to enhance plant salt tolerance. In this case, the seed treatment enhanced the content of phenolic compounds, reduced power and scavenger activity, and decreased membrane lipid peroxidation, thus mitigating the oxidative stress induced by salt. While in breast cancer cells the EO treatment showed different responses according to the cell lines, i.e., in SUM149 and MDA-MB-231 the EO decreased proliferation and increased antioxidant activity and lipid peroxidation, showing high cytotoxic effects associated with the release of lactate dehydrogenase, vice versa no effect was observed in MDA-MB-468. Such antioxidant activity opens a new perspective about this essential oil as a possible tool to counteract proliferation in some cancer cell lines and in horticulture as a seed priming agent to protect from oxidative damage in crops sensitive to salinity.

In vitro and in silico analyses of Lippia alba (Verbenaceae) essential oil as an inhibitor of dengue virus and platelet activation

ABSTRACT Dengue virus (DENV) causes millions of infections each year, and there are currently no approved antivirals. Essential oils could serve as potential candidates for developing plant-based dengue treatments. Lippia alba (Mill.) N.E. Brown essential oil (LAEO) was selected to investigate the mode of antiviral action and its effect on activated platelets. Binding affinities of 20 LAEO compounds and platelet proteins were investigated through docking analyses. LAEO showed a potent virucidal effect (IC50, 2.1 to 5.1 μg/mL) against all DENV serotypes. LAEO reduced P-selectin (from 61% to 18%) and increased survival (from 71% to 97%) in DENV-2- and DENV NS1-stimulated human platelets. Sesquiterpene hydrocarbons showed the highest binding affinities (from −7.3 to −8.0 kcal/mol) with platelet innate immune receptors such as TLR2/1, TLR4/MD-2 and αIIbβ3 integrin. The data provide a first step towards defining the potential of LAEO as a candidate for developing phytotherapeutics for dengue.

Lippia alba essential oil: A powerful and valuable antinociceptive and anti-inflammatory medicinal plant from Brazil

Ethnopharmacological relevanceIn Brazilian popular medicine, Lippia alba leaves are used in teas to treat pain and inflammatory diseases. Aim of the studyto evaluate the chemical composition, antinociceptive, and anti-inflammatory activities of Lippia alba essential oil and its major compound geraniol. Material and methodsLippia alba leaves were collected in Pará state, Brazil. The leaf essential oil was obtained using a modified Clevenger-type extractor. Then, the oil was analyzed by GC and GC-MS analyses. To evaluate the toxicity of LaEO and geraniol, the doses of 50, 300, and 2000 mg/kg were used in a mouse model. For antinociception tests, abdominal contortion, hot plate, and formalin tests were used; all groups were treated with LaEO and geraniol at doses of 25, 50, and 100 mg/kg; and to evaluate inflammation using the ear edema model. ResultsThe constituents identified in the highest content were oxygenated monoterpenes: geraniol (37.5%), geranial (6.7%) and neral (3.8%). The animals treated with LaEO and geraniol demonstrated atypical behaviors with aspects of lethargy and drowsiness, characteristics of animals in a state of sedation; the relative weights showed no significant difference compared to the controls. In the abdominal contortion test, LaEO at 25 mg/kg, 50 mg/kg doses, and 100 mg/kg reduced the number of contortions, representing a percentage reduction of 84.64%, 81.23%, and 66.21% respectively. In the hot plate test, LaEO and geraniol increased the latency time at doses of 25, 50, and 100 mg/kg in all test periods; there was no statistical difference between LaEO and geraniol. In the first phase of the formalin test, only doses of 25 mg/kg and 100 mg/kg of LaEO showed significant activity, reducing the latency time by 53.40% and 58.90%. LaEO at doses of 25 mg/kg and 100 mg/kg reduced the size of the edema, demonstrating an anti-inflammatory activity of 59.38% (25 mg/kg) and 50% (100 mg/kg). ConclusionLippia alba essential oil and geraniol showed central/peripheral analgesic and anti-inflammatory potential and can be used as an alternative or complementary treatment to conventional drugs. More studies are needed to evaluate its action mechanisms and its analgesic effects.

Examination of the antioxidant effects of linalool and Lippia alba essential oil in the Pacific whiteleg shrimp, Litopenaeus vannamei, subjected to eyestalk ablation

Essential oils are considered to have the ability to minimize the effects of stress during handling in aquatic animals. This study evaluated the anesthetic effects of Lippia alba essential oil and its major compound, linalool, on the antioxidant responses of eyestalk-ablated female shrimp Litopenaeus vannamei. Female shrimp were divided into the following treatments: pure seawater (control), ethanol (9000 μL L−1 of ethanol), 750 μL L−1 of Lippia alba essential oil, 1000 μL L−1 of Lippia alba essential oil, 350 μL L−1 of linalool, and 500 μL L−1 of linalool. The shrimp were sedated for 3 min. The eyestalks were then ablated unilaterally by cauterization (cutting the eyestalk with hot scissors). Biochemical variables were analyzed in the gill, muscle, and hepatopancreas. The antioxidant capacity against peroxyl radicals in the group that received 750 μL L−1 of Lippia alba essential oil was significantly higher in the hepatopancreas and muscle than in the control group, whereas the ethanol group had a higher antioxidant capacity in the gills and muscle than the control group. An increase in the total antioxidant capacity in the hepatopancreas and muscle was observed in the 750 μL L−1 Lippia alba essential oil group, but not in the ethanol group, relative to the control group. A significant reduction in lipid peroxidation in the gills was observed in females treated with 500 μL L−1 of linalool compared to the ethanol group. Linalool and Lippia alba essential oil contributed to the improvement in the antioxidant defense systems of shrimp gills. Overall, the obtained results suggest that exposure to Lippia alba essential oil and linalool may activate certain components of the antioxidant system that exist in the gills and scavenge peroxyl radicals; this in turn may help maintain homeostasis and improve the welfare of eyestalk-ablated female shrimp.

Biological effects of Lippia alba essential oil against Anopheles gambiae and Aedes aegypti

The management of mosquito resistance to chemical insecticides and the biting behaviour of some species are motivating the search for complementary and/or alternative control methods. The use of plants is increasingly considered as a sustainable biological solution for vector control. The aim of this study was to evaluate the biological effects of the essential oil (EO) of Lippia alba harvested in Abidjan (Côte d’Ivoire) against Anopheles gambiae and Aedes aegypti mosquitoes. Phytochemical compounds were identified by GC–MS. Knockdown and mortality were determined according to the WHO test tube protocol. Contact irritancy was assessed by observing the movement of mosquitoes from a treated WHO tube to a second untreated tube. Non-contact repellency was assessed using a standardised high-throughput screening system (HITSS). Blood meal inhibition was assessed using a membrane feeding assay treated with EO. The EO was identified as the citral chemotype. The EO gave 100% KD60 in both species at a concentration of 1%. Mortalities of 100% were recorded with An. gambiae and Ae. aegypti at concentrations of 1% and 5% respectively. The highest proportions of females escaping during the contact irritancy test were 100% for An. gambiae at 1% concentration and 94% for Ae. aegypti at 2.5% concentration. The 1% concentration produced the highest proportions of repelled mosquitoes in the non-contact repellency tests: 76.8% (An. gambiae) and 68.5% (Ae. aegypti). The blood meal inhibition rate at a dose of 10% was 98.4% in Ae. aegypti but only 15.5% in An. gambiae. The citral chemotype of L. alba EO has promising biological effects in both species that make it a potentially good candidate for its use in mosquito control. The results obtained in this study encourage the further evaluation of L. alba EOs from other localities and of different chemotypes, under laboratory and field conditions.

Pharmacological Screening of Species from the Lippia genus, Content in Terpenes and Phenylpropanoids, and their Vasorelaxing Effects on Human Umbilical Artery

Naturally occurring bioactive compounds have a plethora of biological effects. In this study, we examined a pharmacological screening of natural products on the human umbilical artery (HUA). HUA preparations were used to follow contractions by KCl (60 mM) and tested at different concentrations (1-5000 μg/mL and μM) of the Lippia alba (EOLa) and Lippia origanoides (EOLo) essential oils, terpenes (citral, limonene perilic alcohol) and phenylpropanoids (eugenol, methyl eugenol). Discussion/Results: The reduction corresponded to approximately 100%, except for limonene (80±1.2 %). When evaluating the concentration of the natural product that promotes 50 % relaxation of the HUA contracted by KCL, EC50 values were: 424.3 μg/mL (EOLa); 468.7±6.7 μg/mL (EOLo); 264.2 ± 8.2 μM (citral); 677.8±5.4 μM (limonene); 186.3±6.4 μM (peryl alcohol); 986.4±7.9 μM (eugenol); and 279.1±4.4 μM (methyl-eugenol). Perillyl alcohol had a lower EC50 (consequently it has a higher pharmacological potency). The plant extracts have a promising vasorelaxing effect in HUAs, paving the way for future investigations: as applications in diseases related to these vessels, such as preeclampsia.

Citral-rich fractions of Lippia alba essential oils as immunoresponsive and anti-Candida albicans additives for collagen membranes in guided bone regeneration.

The aim of this study was to optimize the immunoresponsive and anti-Candida albicans (C. albicans) properties of guided bone regeneration-resorbable membranes (collagen) using additives based on synergistic mixtures of chlorhexidine with terpene-enriched fractions from Lippia alba essential oils (EO). The anti-C. albicans activity of the fractions (individually or combined with chlorhexidine) was evaluated using planktonic and sessile cultures. J774A.1 murine macrophage cells were used to determine the cytotoxicity and immunoresponsive effects of the therapies. The anti-planktonic and anti-sessile performance of chlorhexidine on C. albicans was improved 2- to 4-fold by supplementation with citral-rich fractions. On macrophages, this fraction also exhibited a potentially cytoprotective action against the toxic effects of chlorhexidine, minimizing damage to the cell membrane, mitochondrial membrane potential, and nuclear integrity. Macrophages growing on collagen-membrane fragments and stimulated with the citral fraction (alone or with chlorhexidine) showed a significant increase in releasing the osteogenic cytokine TNF-α and enhancing the IL-4. This combined therapy appears as a promising platform for the development of a prophylactic or therapeutic biocidal solution that can optimize the pharmacological characteristics of chlorhexidine (epithelium tolerance and anti-C. albicans consolidation on surfaces), as well as potentiating the immunoresponsive properties of collagen membranes.

Mycorrhization changes the antioxidant response and chemical profile of Lippia alba (Verbenaceae) essential oil under salinity conditions

Mycorrhization changes the antioxidant response and chemical profile of Lippia alba (Verbenaceae) essential oil under salinity conditions

In vitro anthelmintic activity of Lippia alba essential oil chemotypes against Haemonchus contortus

The aim of the present study was to evaluate the effects of the essential oils of Lippia alba chemotypes carvone and citral on H. contortus. Chemical characterization was performed by means of gas chromatography coupled to mass spectrometry (GC/MS). The anthelmintic effects of the essential oils were assessed through the egg hatch test (EHT) and the adult worm motility test (AWMT) using a multidrug-resistant H. contortus Kokstad isolate. Confocal laser scanning microscopy (CLSM) of eggs and adults of H. contortus and scanning electron microscopy (SEM) of adults were performed after treatment with oils for qualitative observations of their effects. The carvone chemotype of L. alba (LaCV) presented 70% carvone, and the citral chemotype of L. alba (LaCT) presented 29.4% geranial and 20.4% neral, respectively. In the EHT, the EC50 values of LaCV and LaCT were 0.2 and 0.3 mg/mL, respectively. In AWMT, after 12 h of exposure to 2 mg/mL LaCV and 2 mg/mL LaCT, 100% of adult nematodes were immobile. CLSM showed changes in larval motility inside the egg caused by LaCV, while LaCT promoted changes in larval formation. In adults exposed to both chemotypes, alterations in the anterior portion of the oesophagus were observed. In SEM, morphological changes were observed in the buccal capsule and in the medial portion of H. contortus adults. It is concluded that the two essential oils of L. alba, the chemotypes carvone and citral, caused morphological changes and inhibited the hatching of eggs and the motility of adult H. contortus nematodes.

Effect of irrigation depth on biomass production and metabolic profile of Lippia alba (linalool chemotype) essential oil

Water is a limiting factor in agricultural production. In the cultivation of aromatic plants, abiotic factors, such as water deficit, influence the yield and composition of essential oils. Lippia alba, linalool chemotype, is an aromatic species originally from South America in domestication, and it can be used in the cosmetics industry to develop natural products, such as flavorings, fragrances, and perfumes. So far, the effect of water deficit on the agronomic characteristics and the species' essential oil composition has not been evaluated. In this work, total aerial dry matter production, total leaf dry matter production, essential oil production, and chemical composition of the essential oil from the leaves of selected clones of L. alba were evaluated under four different irrigation depths, using an organic production system during four cutting cycles of 90 days. Nineteen compounds were detected in the essential oil of L. alba. The irrigation treatments altered the relative proportions of the compounds linalool, geranial, β-elemene, and germacrene D. The highest total biomass production of the aerial part was obtained with the 125% of the reference evapotranspiration (ET0) at 180 (second cut) and 270 (third cut) days after formation pruning. The irrigation depths of 100% and mainly the 125% ET0 at 180 days (second cut) favored the total dry matter production of leaves in Lippia alba, chemotype linalool, and the essential oil production. In general, a moderate water deficit generated an adjustment in the use of water resources with increased the essential oil production, in particular the linalool compound.

Eugenol and Lippia alba essential oils as effective anesthetics for the Amazonian freshwater stingray Potamotrygon wallacei (Chondrichthyes, Potamotrygonidae)

This study assessed the potential of eugenol and the essential oil of Lippia alba (EOLA) in providing suitable anesthetic induction and recovery times, and their consequent effects on the blood and respiratory physiology, as well as the gill architecture of an Amazonian freshwater stingray, Potamotrygon wallacei, shortly after reaching the recovery and 48 h later. Juveniles of P. wallacei were exposed to increasing concentrations of eugenol (75, 100, 125, and 150 µL L-1) and EOLA (150, 175, 200, and 225 µL L-1) in an immersion bath. Anesthetic induction was found to be faster with the use of eugenol compared to EOLA. On the other hand, the stingrays anesthetized with eugenol displayed a longer recovery time than those exposed to EOLA. The highest concentrations of eugenol caused moderate to severe histological changes in the gills. No significant changes were found for hematocrit and plasma energy metabolites in the stingrays anesthetized with all concentrations of both eugenol and EOLA shortly after reaching the recovery from the ansthesia, when compared to those recovered after 48h. Investigations regarding the potential use of these natural anesthetics are unprecedented for freshwater stingray species, and 200 μL L-1 EOLA is recommended as the most suitable anesthetic for use in juveniles of P. wallacei.

Immunomodulation and Antioxidant Activities as Possible Trypanocidal and Cardioprotective Mechanisms of Major Terpenes from Lippia alba Essential Oils in an Experimental Model of Chronic Chagas Disease.

In the late phase of Trypanosoma cruzi infection, parasite persistence and an exaggerated immune response accompanied by oxidative stress play a crucial role in the genesis of Chronic Chagasic Cardiomyopathy (CCC). Current treatments (Benznidazole (BNZ) and Nifurtimox) can effect only the elimination of the parasite, but are ineffective for late stage treatment and for preventing heart damage and disease progression. In vivo trypanocidal and cardioprotective activity has been reported for Lippia alba essential oils (EOs), ascribed to their two major terpenes, limonene and caryophyllene oxide. To investigate the role of antioxidant and immunomodulatory mechanisms behind these properties, chronic-T. cruzi-infected rats were treated with oral synergistic mixtures of the aforementioned EOs. For this purpose, the EOs were optimized through limonene-enrichment fractioning and by the addition of exogenous caryophyllene oxide (LIMOX) and used alone or in combined therapy with subtherapeutic doses of BNZ (LIMOXBNZ). Clinical, toxicity, inflammatory, oxidative, and parasitological (qPCR) parameters were assessed in cardiac tissue. These therapies demonstrated meaningful antioxidant and immunomodulatory activity on markers involved in CCC pathogenesis (IFN-γ, TNF-α, IL-4, IL-10, and iNOS), which could explain their significant trypanocidal properties and their noteworthy role in preventing, and even reversing, the progression of cardiac damage in chronic Chagas disease.

Anxiolytic-like Effect of Essential Oils Extracted from Lippia alba and Lippia citriodora

Introduction: Essential oils from natural plants are widely use around the world to relief mental conditions. The aim of this investigation was to determine the anxiolytic-like effect of essential oils extracted from Lippia alba and Lippia citriodora. Methods: The oil was extracted by hydro-distillation for 3 hours using a modified Clevenger-type apparatus and then chemical composition was investigated by gas chromatography analysis (GC) and gas chromatography-mass spectrometry (GC-MS). Moreover, a randomized experimental trial was conducted, where 95 participants were divided into 3 groups, comprising a waiting list control group and two experimental groups treated with essential oils by inhalation. The anxiety index was evaluated by State-Trait Anxiety Inventory (STAI). Measures were taken two times: pretest and posttest. Results: chemical analysis showed that carvone was the main component (64.5%) for Lippia alba essential oil and geranial (39.8%) for Lippia citriodora. State and Trait anxiety scores showed a decrease in posttest study phase in comparison with pretest in all experimental groups (p<0.05). Cohen's D and Hedges’ G scores show a large size effect in state anxiety for experimental group treated with Lippia alba while moderate changes were found for the rest of variables in all experimental groups. Conclusion: the essential oils extracted from Lippia alba and Lippia citriodora may be useful as a mean to counteract anxiety, specifically state anxiety showing short-terms benefits.

Lippia alba essential oil improves water quality during transport and accelerates the recovery of Potamotrygon wallacei from the transport-induced stress

The current work investigated whether the long transport could impact the water quality, the response to stress, the antioxidant defense system in cururu stingray (Potamotrygon wallacei) liver, and how a recovery process could affect them. Furthermore, it also examined the effects of the Lippia alba essential oil (EOLA) on these transport-induced changes. For this purpose, the cururu stingray (n = 30) were transported in plastic bags (from 3 to 4 specimens, each bag) in the absence or presence of EOLA at 10 μL/L from Manaus (Amazonas, Brazil) to Santa Maria (Rio Grande do Sul, Brazil) for about 32 h. A set of cururu stingray was sampled immediately at the arrival (n = 5 for each condition, without or with EOLA). The remaining individuals were kept for 24 h (n = 5 for each condition, without or with EOLA) and 48 h (n = 5 for each condition, without or with EOLA) to assess their recovery from the trip. After it, they were anesthetized for blood collection, and then, euthanized for liver removal. A set of cururu stingray was sampled before starting the transport protocol (n = 5). Water samples were collected during all steps for monitoring its quality. First of all, when the transport was carried out in the absence of EOLA, it resulted in higher ammonia levels in water linked to a hyperglycemic response, and an impairment in the glutathione-related antioxidant system characterized by decreased total glutathione, and catalytic subunit of glutamate cysteine ligase levels as well as glutathione S-transferase, and glucose-6-phosphate-dehydrogenase activities, thus leading the cururu stingray liver to lipid peroxidation at its arrival. The EOLA, in turn, avoided most transport-induced changes at the arrival. Furthermore, it also helped the antioxidant system to retrieve its optimal function in the liver after 48 h recovery, speeding up the recovery process that could take more than 48 h when transport was completed in the absence of this additive. Therefore, the addition of EOLA to the transport water at 10 μL/L is highly advisable when transporting cururu stingray for more than 30 h.

Acaricidal and ovicidal properties of Lippia alba essential oil and its chemical constituents against red spider mite, Oligonychus coffeae Nietner (Acari: Tetranychidae) infesting tea crops

The red spider mite, Oligonychus coffeae Nietner (Acari: Tetranychidae), is a prevalent mite pest damages tea crops. The present study evaluated the efficacy of L. alba essential oil against O. coffeae. GC and GC-MS analysis of L. alba essential oil revealed geraniol (52.19%) and neral (34.13%) as major compounds. The L. alba essential oil applied at 1500 ppm exhibited 100% mortality of treated mites 48 h after exposure through fumigant toxicity method, while 99% ovicidal activity of essential oil was achieved at 1000 ppm. Similarly, in fumigant bioassay LC50 value against O. coffeae was 87.75 ppm for geraniol and 103.49 ppm for neral at 72 h after exposure. The findings suggest that L. alba essential oil and its major constituents geraniol and neral could be used as eco-friendly acaricide, and can be incorporated as one of the components in IPM after multi-location field trials.

In vitroanthelminthic activity ofLippia albaessential oil combined with silk fibroin against monogeneans ofColossoma macropomum(Serrasalmidae)

Essential oils have bioactive compounds that can be used against monogeneans and have low solubility in aqueous medium. This study investigated the in vitro anthelmintic efficacy of Lippia alba essential oil (320, 450, 550 and 640 mg/L) combined with a silk fibroin and isopropanol solution used as solvent in the control of monogeneans collected of gills from Colossoma macropomum (Cuvier, 1018). In vitro efficacy of 100% against Anacanthorus spathulatus (Kritsky, Thatcher & Kayton, 1979), Notozothecium janauachensis (Belmont-Jégu, Domingues & Martins, 2004) and Mymarothecium boegeri (Cohen & Kohn,2005) was observed after 15 min of exposure to 640 mg/L of L. alba EO combined with silk fibroin solution, while 100% efficacy with exposure to 450 and 550 mg/L occurred after 2 and 1 h respectively. Structural changes to the tegument of the parasites exposed to L. alba EO combined with silk fibroin solution were observed with scanning electron microscopy. Therefore, the silk fibroin solution has potential as a solvent of essential oils and increased the anthelmintic effect of L. alba essential oil; thus, it should be tested in vivo for controlling and treating infections by monogeneans.

In vivo protection against chagasic cardiomyopathy progression using trypanocidal fractions from Lippia alba (Verbenaceae) essential oils

The present study reports the trypanocidal and cardioprotective properties of fractions derived from Lippia alba (Verbenaceae family) essential oils (EOs), in a murine model of chronic Chagas disease (ChD). This infection represents one of the most serious public health problems in Latin American countries, without an effective therapy for chronic infection and its eventual cardiac complications. In the model established herein, the therapeutic scheme which involved 30 oral and daily doses of OxiLim (a mix composed by fractions enriched in citral, caryophyllene oxide, and limonene) was not toxic and exhibited trypanocidal activity comparable to benznidazole (assessed by parasitic DNA quantification - qPCR); but with an additional protective effects against cardiomyopathy progression. This last finding was confirmed by both echocardiography (reduction in the maximum diameter of the cardiac silhouette), and heart histopathology (tissue recovery, abundant fibroblasts, and mild separation of cardiac fibers). Conversely, rats treated only with benznidazole showed a significant increase in cardiac diameter with severe fiber dilation, angiogenesis, and high diversity of immune infiltrate. This research reports a highly trypanocidal (similar to benznidazole) therapeutic scheme based on L. alba essential oil fractions (OxiLim), which also exhibits a positive cardioprotective effect in the course of chronic chagasic cardiomyopathy, in rats.

Antiviral activity on the Zika virus and larvicidal activity on the Aedes spp. of Lippia alba essential oil and β-caryophyllene

Lippia alba is a species widely used in folk medicine for various health treatments. Essential oil from L. alba and its major compound β-caryophyllene were examined for its antiviral activity against Zika virus (ZIKV) in vitro and in silico. In addition, the larvicidal activity on the Aedes aegypti and Aedes albopictus larvae of the third instar was investigated. Anti-zika activity of these products was determined at different stages of ZIKV infection and replication cycle. Selectivity Index value (SI) was determined as the ratio of cytotoxic concentration 50 (CC50) to inhibitory concentration 50 (IC50) for each compound. Molecular docking assay was carried to identify the interaction between β-caryophyllene and ZIKV enzymes (NS1, NS2B-NS3 and NS5). Essential oils were analyzed by gas chromatography-mass spectrometry (GC-MS), whose extraction yield was 3.31 %. L. alba essential oil showed lower cytotoxicity on the vero cells, with CC50 = 1789.9, when compared with the β-caryophyllene (CC50 = 390.8). Essential oil exhibited a greater antiviral effect in the assays of virucidal activity (IC50 = 32.2 μg/mL) and post-treatment (IC50 = 54.1 μg/mL), with SI values of 55.6 and 33.1, respectively. β-caryophyllene inhibits the replication of ZIKV replication in the early stages of the viral cycle (IC50 = 74.4 μg/mL), whose SI was 5.2. Of all the investigated samples, only β-caryophyllene exhibited a larvicidal effect on the A. albopictus larvae (LC50 = 73.4 ± 1.68 μg/mL). Molecular docking confimed the antiviral activity of β-caryophyllene showing interactions with amino acid residues from the target sites of NS2B-NS3 and in greater numbers with NS5.