Toxic essential oils, part VI: Acute oral toxicity of lemon balm (Melissa officinalis L.) essential oil in BALB/c mice

The role of melatonin in preventing amiodarone-induced rat liver damage

Long-term exposure to amiodarone, an antiarrhythmic drug, can induce different organ damage, including liver. Cell damage included by amiodarone is a consequence of mitochondrial damage, reactive oxygen species production, and cell energy depletion leading to programmed cell death. In the present study, hepatoprotective potential of neurohormone melatonin (50 mg/kg/day) was evaluated in a chronic experimental model of liver damage induced by a 4-week application of amiodarone (70 mg/kg/day). The obtained results indicate that amiodarone induces an increase in xanthine oxidase activity, as well as the content of the lipid and protein oxidatively modified products and p53 levels. Microscopic analysis further corroborated the biochemical findings revealing hepatocyte degeneration, apoptosis, and occasional necrosis, with the activation of Kupffer cells. Coadministration of melatonin and amiodaron prevented an increase in certain damage associated parameters, due to its multiple targets. In conclusion, the application of melatonin together with amiodarone prevented an increase in tissue oxidative damage parameters and moderately prevented liver cell apoptosis, indicating that the damage of hepatocytes provoked by amiodarone supersedes the protective properties of melatonin in a given dose.

Therapeutic Potential of Essential Oils Against Ulcerative Colitis: A Review

Ulcerative colitis (UC) is a chronic non-sp ecific inflammatory disease of the colorectal mucosa. Researchers have associated UC onset with familial genetics, lifestyle behavior, inflammatory immune factors, intestinal microbiota, and the integrity of the intestinal mucosal barrier. The primary therapeutic interventions for UC consist of pharmacological management to control inflammation and promote mucosal healing and surgical interventions. The available drugs effectively control and decelerate the progression of UC in most patients; nonetheless, their long-term administration can exert adverse effects and influence the therapeutic effect. Plant essential oils (EOs) refer to a group of hydrophobic aromatic volatile substances. EOs have garnered considerable attention in both domestic and international research because of their anti-inflammatory, antibacterial, and antioxidant properties. They include peppermint, peppercorns, rosemary, and lavender, among others. Researchers have investigated the role of EOs in medicine and have elucidated their potential to mitigate the detrimental effects of UC through their anti-inflammatory, antioxidant, antidepressant, and anti-insomnia properties as well as their ability to regulate the intestinal flora. Furthermore, EOs exert minimal toxic adverse effects, further enhancing their appeal for therapeutic applications. However, these speculations are based on theoretical experiments, thereby warranting more clinical studies to confirm their effectiveness and safety. In this article, we aim to provide an overview of the advancements in utilizing natural medicine EOs for UC prevention and treatment. We will explore the potential pathogenesis of UC and examine the role of EOs therapy in basic research, quality stability, and management specification of inadequate EOs for UC treatment. We intend to offer novel insights into the use of EOs in UC prevention and management.

Toxicological safety evaluation of an aqueous lemon balm (Melissa officinalis) extract

Melissa officinalis (lemon balm) has a long history of safe use as an aromatic herb, flavoring, tea, food supplement, and traditional medicine. An aqueous extract of the leaves of M. officinalis is intended for use as a food ingredient, however the existing safety database does not contain any high quality toxicological studies to support safe consumer exposure. Therefore, a standard tier 1 genotoxicity battery (bacterial reverse mutation and in vitro mammalian cell micronucleus tests) and a 90-day repeated dose oral toxicity study in rats were conducted in accordance with GLP and OECD guidelines. The genotoxicity studies confirmed that aqueous lemon balm extract is not genotoxic at up to the highest concentrations tested (5000 μg/plate or 5000 μg/mL). A non-GLP 14-day dose range finding study was conducted prior to the 90-day study to confirm dietary administration of aqueous lemon balm extract at concentrations of 0, 0.5, 1.6, or 5.0%. The 90-day study was conducted using the established dietary concentrations and no test substance-related adverse effects on clinical, hematological, biochemical, macroscopic, or histopathologic parameters were reported. Thus, the no-observed-adverse-effect-level was determined to be at least 3046.1 and 3720.9 mg/kg body weight/day (the highest doses tested) for male and female rats, respectively.

Marrubiin Inhibits Peritoneal Inflammatory Response Induced by Carrageenan Application in C57 Mice

Marrubiin is a diterpene with a long history of a wide range of biological activities. In this study, the anti-inflammatory effects of marrubiin were investigated using several in vitro and in vivo assays. Marrubiin inhibited carrageenan-induced peritoneal inflammation by preventing inflammatory cell infiltration and peritoneal mast cell degranulation. The anti-inflammatory activity was further demonstrated by monitoring a set of biochemical parameters, showing that the peritoneal fluid of animals treated with marrubiin had lower levels of proteins and lower myeloperoxidase activity compared with the fluid of animals that were not treated. Marrubiin exerted the most pronounced cytotoxic activity towards peripheral mononuclear cells, being the main contributors to peritoneal inflammation. Additionally, a moderate lipoxygenase inhibition activity of marrubiin was observed.

Evaluation and estimation of diuretic activity of the linalyl acetate in the rats

This study aimed to explore the diuretic activity of linalyl acetate (LA). LA is an essential oil, it is an integral phyto-constituent of various plants. In this study, acute and chronic diuretic activities were explored by measuring the levels of different electrolytes and pH in the urine of experimental rats. Rats were divided into five groups. The control group was given 10 mg/kg normal saline, the treated group was given 10 mg/kg furosemide, and the remaining 3 groups received different doses of LA including 25, 50, and 75 mg/kg through intraperitoneal route, to determine its diuretic potential. Urine volume for acute diuretic activity was measured for 6 hours however for chronic diuretic activity was measured for 6 days. For a comparative study of LA with a control group and treated group with reference drug, diuretic index was used. Moreover, the underlying mechanism of the diuretic activity was also explored by comparing atropine, L-NAME, and indomethacin. The results of each group with 6 rats in each group were obtained by ± standard error of the mean of every group. Analysis of Variance (ANOVA) was used for statistical analysis. Results revealed that the LA 75 mg/kg dose showed comparable results as of furosemide. Moreover, this study revealed the involvement of muscarinic receptors to produce diuresis in comparison with atropine with very little involvement of prostanoids and no effect on NO pathway induced by indomethacin and L-NAME respectively. It is concluded that LA possess anti-diuretic potential. Muscarinic receptors might be involved in producing diuretic effects.

Essential oils as green promising alternatives to chemical preservatives for agri-food products: New insight into molecular mechanism, toxicity assessment, and safety profile

Microbial food spoilage caused by food-borne bacteria, molds, and associated toxic chemicals significantly alters the nutritional quality of food products and makes them unpalatable to the consumer. In view of potential adverse effects (resistance development, residual toxicity, and negative effects on consumer health) of some of the currently used preservative agents and consumer preferences towards safe, minimally processed, and chemical-free products, food industries are looking for natural alternatives to the chemical preservatives. In this context, essential oils (EOs) showed broad-range antimicrobial effectiveness, low toxicity, and diverse mechanisms of action, and could be considered promising natural plant-based antimicrobials. The existing technical barriers related to the screening of plants, extraction methods, characterization, dose optimization, and unpredicted mechanism of toxicity in the food system, could be overcome using recent scientific and technological advancements, especially bioinformatics, nanotechnology, and mathematical approaches. The review focused on the potential antimicrobial efficacy of EOs against food-borne microbes and the role of recent scientific technology and social networking platform in addressing the major obstacles with EOs-based antimicrobial agents. In addition, a detailed mechanistic understanding of the antimicrobial efficacy of EOs, safety profile, and risk assessment using bioinformatics approaches are summarized to explore their potential application as food preservatives.

Application of chitosan and other biopolymers based edible coatings containing essential oils as green and innovative strategy for preservation of perishable food products: A review

Deterioration of perishable foods due to fungal contamination and lipid peroxidation are the most threatened concern to food industry. Different chemical preservatives have been used to overcome these constrains; however their repetitive use has been cautioned owing to their negative impact after consumption. Therefore, attention has been paid to essential oils (EOs) because of their natural origin and proven antifungal and antioxidant activities. Many EO-based formulations have been in use but their industrial-scale application is still limited, possibly due to its poor solubility, vulnerability towards oxidation, and aroma effect on treated foods. In this sense, active food packaging using biopolymers could be considered as promising approach. The biopolymers can enhance the stability and effectiveness of EOs through controlled release, thus minimizes the deterioration of foods caused by fungal pathogens and oxidation without compromising their sensory properties. This review gives a concise appraisal on latest advances in active food packaging, particularly developed from natural polymers (chitosan, cellulose, cyclodextrins etc.), characteristics of biopolymers, and current status of EOs. Then, different packaging and their effectiveness against fungal pathogens, lipid-oxidation, and sensory properties with recent previous works has been discussed. Finally, effort was made to highlights their safety and commercialization aspects towards market solutions.

Melatonin as a Promising Anti-Inflammatory Agent in an In Vivo Animal Model of Sepsis-Induced Rat Liver Damage

Melatonin (MLT), earlier described as an effective anti-inflammatory agent, could be a beneficial adjunctive drug for sepsis treatment. This study aimed to determine the effects of MLT application in lipopolysaccharide (LPS)-induced sepsis in Wistar rats by determining the levels of liver tissue pro-inflammatory cytokines (TNF-α, IL-6) and NF-κB as well as hematological parameters indicating the state of sepsis. Additionally, an immunohistological analysis of CD14 molecule expression was conducted. Our research demonstrated that treatment with MLT prevented an LPS-induced increase in pro-inflammatory cytokines TNF-α and IL-6 and NF-κB levels, and in the neutrophil to lymphocyte ratio (NLR). On the other hand, MLT prevented a decrease in the blood lymphocyte number induced by LPS administration. Also, treatment with MLT decreased the liver tissue expression of the CD14 molecule observed after sepsis induction. In summary, in rats with LPS-induced sepsis, MLT was shown to be a significant anti-inflammatory agent with the potential to change the liver's immunological marker expression, thus ameliorating liver function.

Antinociceptive and anti-inflammatory activities of essential oil of the leaves of Amburana cearensis (Allemão) A.C. Smith. from the semi-arid region of Northeastern Brazil

ETHNOPHARMACOLOGICAL RELEVANCE

Amburana cearensis (Allemão) A.C. Smith is a medicinal plant with wide distribution in South America, popularly known in Brazil as "cumaru" or "amburana de cheiro". In folk medicine, in the semi-arid region of Northeastern Brazil, infusions, teas and decoctions of leaves of Amburana cearensis have their practical use for treating fever, gastrointestinal disorders, inflammation, and inflammation pain. However, none of the ethnopharmacological properties has been scientifically evaluated using volatile compounds obtained from its leaves (essential oil).

AIM OF THE STUDY

This study investigated the chemical composition, acute oral toxicity, and antinociceptive and anti-inflammatory activities of the essential oil from the leaves of A. cearensis.

MATERIAL AND METHODS

The acute toxicity of the essential oil was investigated in mice. The antinociceptive effect was evaluated using the formalin test and, abdominal writhing induced by acetic acid, being investigated the possible mechanisms of action involved in antinociception. The acute anti-inflammatory effect was investigated through models of carrageenan-induced peritonitis, yeast-induced pyrexia, and carrageenan- and histamine-induced paw inflammation.

RESULTS

No acute toxicity was observed at doses up to 2000 mg/kg; p.o. The antinociceptive effect was statistically equal to morphine. In the formalin assay, the oil showed analgesic activity in the neurogenic and inflammatory phases, having as mechanisms the cholinergic, adenosinergic system, and ATP-sensitive potassium channels (K-ATP). In peritonitis, a reduction in TNF-α and IL-1β levels and leukocyte migration were observed. The antipyretic effect was statistically superior to dipyrone. The reduction in paw edema was statistically superior to the standard in both models.

CONCLUSION

The results obtained not only support the traditional use of the species in inflammatory conditions and pain in folk medicine but also demonstrate that this is a rich source of phytocomponents such as germacrone, which can be used as a natural and sustainable therapeutic agent with industrial applications.

Evaluation of 28-day repeated doses oral toxicity of essential oil from Psidium glaziovianum Kiaersk leaves on various biological parameters in Swiss mice

Only a small number of the many medicinally important species in the genus Psidium L. have had their safety assessed. Psidium glaziovianum, a plant native to Brazil, is reported to exert antinociceptive and anti-inflammatory effects; however, there are no apparent reports of long-term safety following administering of repeated doses. The aim of this study was to examine the effects of 28-day oral of treatment at 250, 500 or 1,000 mg/kg Psidium glaziovianum essential oil (PgEO) on behavioral and physiological parameters in male and female Swiss mice. First, PgEO was chemically characterized by gas chromatography mass spectrometry (GC-MS). The following parameters were examined: motor activity, body temperature, blood glucose, urine, hematology, biochemistry, histology, and oxidative stress. Characterization of PgEO revealed 48 components which were dominated by sesquiterpenes 1,8-cineol (24.29%), α-pinene (19.73%) and β-pinene (17.31%). Data showed that PgEO treatment in mice increased activities of antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) without markedly affecting body weight, hematological or biochemical parameters, as well as water or food consumption. Administration of PgEO in repeated daily dosages over 28 days did not significantly alter exploratory or locomotor activities. Based upon our findings, PgEO administration daily for 28 days, exhibited low toxicity and absence of effects on the nervous system. Data demonstrated that PgEO produced hypoglycemic and antioxidant actions which need to be considered in safety assessment.

Predictions of the Biological Effects of Several Acyclic Monoterpenes as Chemical Constituents of Essential Oils Extracted from Plants

Acyclic terpenes are biologically active natural products having applicability in medicine, pharmacy, cosmetics and other practices. Consequently, humans are exposed to these chemicals, and it is necessary to assess their pharmacokinetics profiles and possible toxicity. The present study considers a computational approach to predict both the biological and toxicological effects of nine acyclic monoterpenes: beta-myrcene, beta-ocimene, citronellal, citrolellol, citronellyl acetate, geranial, geraniol, linalool and linalyl acetate. The outcomes of the study emphasize that the investigated compounds are usually safe for humans, they do not lead to hepatotoxicity, cardiotoxicity, mutagenicity, carcinogenicity and endocrine disruption, and usually do not have an inhibitory potential against the cytochromes involved in the metabolism of xenobiotics, excepting CYP2B6. The inhibition of CYP2B6 should be further analyzed as this enzyme is involved in both the metabolism of several common drugs and in the activation of some procarcinogens. Skin and eye irritation, toxicity through respiration and skin-sensitization potential are the possible harmful effects revealed by the investigated compounds. These outcomes underline the necessity of in vivo studies regarding the pharmacokinetics and toxicological properties of acyclic monoterpenes so as to better establish the clinical relevance of their use.

The potential of lemon balm (Melissa officinalis L.) essential oil as an anti-anxiety agent - is the citronellal the activity carrier?

ETHNOPHARMACOLOGICAL RELEVANCE

Among the fewest drugs discovered are those belonging to the class of anxiolytics. Although some drug targets for anxiety disorders are established, it is hard to modify and selectively choose the active principle for those targets. Thus, the ethnomedical approach to treating anxiety disorders remains one of the most prevalent ways for (self)managing the symptoms. Melissa officinalis L. (lemon balm) has been extensively used as an ethnomedicinal remedy for the treatment of different psyche-related symptoms, especially dose related to restlessness.

AIM OF THE STUDY

This work aimed to evaluate the anxiolytic activity, in several in vivo models, of the essential oil extracted from Melissa officinalis (MO) and its main constituent citronellal, a widespread plant utilized for managing anxiety.

MATERIALS AND METHODS

In the present study several animal models were used to assess MO anxiolytic potential in mice. The effect of the MO essential oil applied in doses ranging from 12.5 to 100 mg/kg was estimated in light/dark, hole board, and marble burying tests. In parallel doses of citronellal corresponding to the ones in the MO essential oil were applied to animals to determine if this is the activity carrier.

RESULTS

The results indicate that the MO essential oil exerts anxiolytic potential in all three experimental settings by significantly altering the traced parameters. The effects of citronellal are somewhat inconclusive and should not be interpreted only as anxiolytic but rather as a combination of anti-anxiety and motor-inhibiting effects.

CONCLUSIONS

In conclusion, we could say that the results of the present study provide a base for future mechanistic studies that would evaluate the activity of M. officinalis essential oil on various neurotransmitter systems involved in the generation, propagation, and maintenance of anxiety.

Melissa Officinalis L. aqueous extract pretreatment decreases methotrexate-induced hepatotoxicity at lower dose and increases 99mTc-phytate liver uptake, as a probe of liver toxicity assessment, in rats

OBJECTIVE

Hepatotoxicity remains amongst the restricting factors of Methotrexate (MTX)-associated cancer therapy, especially in high doses of chemo-drugs or prolonged treatment. Due to the known protective effects of Melissa officinalis (M. officinalis), the aqueous extract of this plant was evaluated to ameliorate MTX-associated hepatotoxicity in rats.

METHODS

Adult female Wistar rats were received or not M. officinalis aqueous extract at doses of 100 mg/kg (for 14 and 24 consecutive days) and 2 g/kg (for 14 consecutive days) by gavage technique. MTX (20 mg/kg) was intraperitoneally injected on the 10th- and 20th-day post-M. officinalis treatment. 24 h after the last day of treatment, ^99mTc-phytate was intravenously injected through the tail of rats. Animals were killed at 20 min after radiocolloid injection, and vital tissues including the liver and spleen were isolated, weighed, and their radioactivity was counted. As well, ^99mTc-phytate scintigraphy and histopathology of the liver were performed for higher accuracy.

RESULT

A significant increase in liver radioactivity was detected in M. officinalis+MTX receiving groups compared with the MTX rats which were more robust at a dose of 100 mg/kg for 14 days. Also, a significant reduction in liver radioactivity was evident with M. officinalis extract at a dose of 2 g/kg for 14 days in comparison with the control group, this reduction was not significant at the lower dose of 100 mg/kg. Gamma scintigraphy and histopathological examinations confirmed the hepatoprotective effect of M. officinalis vs MTX-induced liver injury in rats.

CONCLUSION

In conclusion, we highlighted the liver uptake of ^99mTc-phytate as a valuable method for assessment of liver toxicity and addressed that M. officinalis pretreatment (100 mg/kg for 14 days) ameliorates the MTX-associated hepatotoxicity in rats; however, M. officinalis itself induces liver toxicity at higher doses.

Acute and sub-acute toxicity evaluation of dihydro-p-coumaric acid isolated from leaves of Tithonia diversifolia Hemsl. A. Gray in BALB/c mice

In present study, the acute and sub-acute toxicities of Dihydro-p-coumaric acid isolated from the leaves of Tithonia diversifolia (Hemsl.) A. Gray was studied for safety issues in mammals. For acute toxicity tests, isolated compound was administered orally in both male and female BALB/c mice at the doses of 200, 800, and 1,600 mg/kg body weight for 7 days. In sub-acute toxicity study 50 and 500 mg/kg bw of the compound was orally administered for 14 days. Toxicity induced behavioural changes, haematological parameters, biochemical markers and histopathological sections were studied after Dihydro-p-coumaric acid administration. The vital organs like heart, kidney, uterus and testis revealed no adverse effects at doses of upto 1,600 mg/kg bw and 500 mg/kg bw. Slight hepatotoxicity was however demonstrated by ALT and AST assay but histopathological section did not concur as much. The study demonstrated insignificant difference in the percentage of feed intake, water intake, weight gain, haematological parameters and histopathological changes, with no toxicity signs and mortality. Dihydro-p-coumaric acid can be regarded as safe in both acute and sub-acute toxicity assay in both sexes. This indicates Dihydro-p-coumaric acid as a viable alternative to synthetic pesticides.

Melissa officinalis L. as a Sprout Suppressor in Solanum tuberosum L. and an Alternative to Synthetic Pesticides

The goal of this research was to screen plant essential oils (EOs) as sprout inhibitors or suppressors in potato (Solanum tuberosum L.). Three controlled environment experiments were conducted to screen 18 EOs and several pure compounds as sprout inhibitors. The EOs were applied using the wicked method on potato cv. Gala in 19 L plastic containers. The results indicated that Melissa officinalis L. EO inhibited sprouting, while Coriandrum sativum L. seed oil and the EO blend of Lavandula angustifolia Mill. and Salvia sclarea L. suppressed sprouting. The EOs of interest were analyzed using gas chromatography coupled to mass spectrometry (GC-MS) and/or a flame ionization detector (GC-FID); the detailed chemical profiles are provided. The M. officinalis EO was fractionated into seven fractions, and these were tested on minitubers. We identified two fractions (F and A) that suppressed potato sprouting better than the whole oil. The GC-MS-FID analyses of M. officinalis EO fraction A identified myrcene, Z-ocimene, E-ocimene, trans-caryophyllene, and α-humulene as the main constituents, while the main constituents of fraction F were α-terpineol, β-citronellol, and geraniol. The pure isolated compounds, together with the major compound in M. officinalis EO (citral), were tested for sprout suppression on three potato cultivars (Ranger Russet, Terra Rosa, and Dakota TrailBlazer), which revealed that β-citronellol reduced the sprout length and the number of sprouts in all three cultivars, while citral and (+)-α-terpineol reduced the sprout length and the number of sprouts in Ranger Russet relative to the two controls in all three cultivars. Myrcene had a stimulating effect on the number of sprouts in Cv. Terra Rosa. However, none of the pure compounds suppressed sprouting completely or were comparable to the EO of M. officinalis.

Lemon Balm (Melissa officinalis) Essential Oil Moderately Affects Strychnine-Induced and Pentylenetetrazol-Induced Convulsions —In Silico and In Vivo Studies

Epileptic seizures are a consequence of uncontrolled neuronal discharge and demand urgent and prolonged treatment. Due to a lack of potent and low-risk drugs that could prevent seizures, efforts are underway to discover new drugs, and plant metabolites are often considered valuable candidates in this search. Lemon balm ( Melissa officinalis L., Lamiaceae) is a world-renowned medicinal plant affecting central nervous system function. In this study, we aimed to examine whether the results from in silico modeling of the interactions of major lemon balm essential oil constituents with GABAA and glycine receptors correspond to in vivo results of the convulsions in mice induced by the application of either pentylenetetrazol (GABAA antagonistic) or strychnine (glycine receptor antagonist). While molecular docking experiments of essential oil constituents to the two receptors demonstrated the possibility of ligand–receptor interactions, no binding poses were scored highly, and as the in vivo effect of the essential oil on convulsions seems to be only moderate, the results of the in silico study seem not to contradict results obtained by in vivo models. Thus, we can say that molecular docking might be a useful tool in initial screening for active constituents of natural product mixtures and the potential prediction of their activity in models in vivo.

Revisiting the Effect of 3 Sesquiterpenoids From Conocephalum conicum (Snake Liverwort) on Rat Spleen Lymphocyte Viability and Membrane Functioning

Previously 3 sesquiterpenoids from Conocephalum conicum (L.) Dum. (Conocephalaceae) were found to modulate lymphocyte response to different stimuli, suggesting their immunomodulatory potential. Herein we evaluated the impact of low concentrations of these sesquiterpenoids on rat splenocyte viability and membrane permeability, as well as lactate dehydrogenase (LDH) activity, in order to, possibly, shed light on their mechanism of action. After a 24 h incubation of splenocytes with the sesquiterpenoids (from 10−8 to 10−6 M), MTT and trypan blue (TB) assays, as well as histochemical staining for LDH, were performed. The tested compounds were shown not to reduce the ability of cells to metabolize MTT; however, cell membrane permeability to TB was altered, suggesting that a certain percentage of cells were dead. Histochemical staining for LDH presence releveled that only 2, out of the 3 sesquiterpenoids, decreased the staining intensity, indicating either LDH leakage or its inhibition. In conclusion, having in mind the already proven modulatory potential of the tested sesquiterpenoids, the present results suggest that through the changes in the cell membrane function and leakage/inhibition of LDH in unaltered immune cells, some of the tested compounds could be considered promising candidates for further research as anticancer agents.

Histological Study for Median lethal Dose (LD50) of Eucalyptus Oil Administrated Orally in ( Mice mus musculus)

Eucalyptus oil is used in a wide range of medicinal and other uses, and the current study aims to estimate the median lethal dose LD50 of eucalyptus oil of Eucalyptus camaldulensis and estimate the pathological effect of eucalyptus oil in mice. Eucalyptus oil was obtained in the study by extracting the leaves of the plant Eucalyptus camaldulensis using hydrodistillation. Toxicity testing was performed by dividing mice into groups that you treated with different doses of eucalyptus oil 1200, 1600, 2000, and 2400 mg/kg. The current study showed that the average lethal dose, the LD50, was 1820 mg/kg. The study suggested the emergence of clinical signs in mice when consuming eucalyptus oil in high doses, such as slow movement, suffocation, and convulsion, compared with the control group and the group that administered a lower dose, It was observed that high doses of eucalyptus oil could cause damage to the lung, liver, kidneys, and heart, as the lung was the organ most affected by the oil, followed by the liver, kidneys, and then the heart, and it was less affected by eucalyptus oil, and this indicates that eucalyptus oil, when administered orally in high doses, causes clear toxicity effects. Eucalyptus oil is a safe medicine for external use. Keywords. Eucalyptus oil, LD50; Administrated; Lung; Liver; Heart; Kidney; Mice.

Lemon balm (Melissa officinalis L.) essential oil and citronellal modulate anxiety-related symptoms - In vitro and in vivo studies

ETHNOPHARMACOLOGICAL RELEVANCE

Besides psyche-related symptoms, patients with anxiety disorders can have a large number of somatic symptoms as well. Although the treatment of these disorders is mainly focused on resolving their mental component, one cannot neglect the need for the treatment of accompanying somatic symptoms. Melissa officinalis L. (lemon balm), in various formulations, has been extensively used as an ethnomedicinal remedy for the treatment of different psyche-related symptoms, and its use is considered relatively safe.

AIM OF THE STUDY

In the present study, the activity of M. officinalis (MO) essential oil was evaluated in several in vitro and in vivo models mimicking or involving anxiety-related somatic symptoms.

MATERIALS AND METHODS

To address the effect of MO essential oil on the gastrointestinal and heart-related symptoms accompanying anxiety disorders, in vitro models were utilized that follow the function of the isolated mouse ileum and atria tissues, respectively, after exposure to MO essential oil. Effects of MO essential oil on BALB/c mice motor activity was estimated using the open field, rota-rod, and horizontal wire tests. Additionally, the essential oil was assayed for its potential in inhibiting acetylcholinesterase activity.

RESULTS

The performance of mice treated with 25 mg/kg of the oil showed a statistically significant decrease in the motor impairment arising from acute anxiety (open field test), while there was a prolonged latency and a reduction of the frequency of falling from a rotating rod and/or a horizontal wire (signs of muscle weakness/spasms). Concentrations of the essential oil higher than 1 μg/mL were found to inhibit both spontaneous and induced ileum contractions. Moreover, the essential oil and citronellal were found to decrease isolated mouse atria contraction frequency, as well as contraction force. However, the oil was found to be a very weak acetylcholinesterase inhibitor.

CONCLUSION

The modulation of anxiety-related symptoms by the oil was found not to be mediated through the inhibition of the acetylcholinesterase, nonetheless, the mechanistic studies involving the ileum and cardiac tissues, revealed that the activity of MO and citronellal might be related to the modification of either voltage-gated Ca²⁺ channels or muscarinic receptors. Mice locomotion, balance, and muscle strength were not impacted by the essential oil; however, its main constituent, citronellal, was found to exert a certain degree of muscle function inhibition. All these results suggest that the activity of MO essential oil arises from synergistic and/or antagonistic interactions of its constituents, and is not completely dependent on the oil's main constituent.

Chemical Composition and Preliminary Toxicity Evaluation of the Essential Oil from Peperomia circinnata Link var. circinnata. (Piperaceae) in Artemia salina Leach

Peperomia Ruiz and Pav, the second largest genus of the Piperaceae, has over the years shown potential biological activities. In this sense, the present work aimed to carry out a seasonal and circadian study on the chemical composition of Peperomia circinata essential oils and aromas, as well as to evaluate the preliminary toxicity in Artemia salina Leach and carry out an in silico study on the interaction mechanism. The chemical composition was characterized by gas chromatography (GC/MS and GC-FID). In the seasonal study the essential oil yields had a variation of 1.2–7.9%, and in the circadian study the variation was 1.5–5.6%. The major compounds in the seasonal study were β-phellandrene and elemicin, in the circadian they were β-phellandrene and myrcene, and the aroma was characterized by the presence of β-phellandrene. The multivariate analysis showed that the period and time of collection influenced the essential oil and aroma chemical composition. The highest toxicity value was observed for the essential oil obtained from the dry material, collected in July with a value of 14.45 ± 0.25 μg·mL⁻¹, the in silico study showed that the major compounds may be related to potential biological activity demonstrated by the present study.

The effects of lemon balm (Melissa officinalis L.) on depression and anxiety in clinical trials: A systematic review and meta-analysis

A systematic review and a meta-analytic approach were considered to investigate the effects of lemon balm as a medicinal herb on anxiety and depression in clinical trials and its side effects. All randomized clinical trials published up to October 30, 2020 that examined lemon balm in patients with symptoms of depression or anxiety, with acute or chronic manifestations, were searched in 12 online databases. Statistical analysis was performed using RevMan software. Continuous data were analyzed using standardized mean differences. Statistical heterogeneity was assessed using Chi² , I² , and p value tests. Based on meta-analysis results, lemon balm significantly improved mean anxiety and depression scores compared with the placebo (SMD: -0.98; 95% CI: -1.63 to -0.33; p = 0.003), (SMD: -0.47; 95% CI: -0.73 to -0.21; p = 0.0005) respectively, without serious side effects. Current evidence suggests that lemon balm may be effective in improving anxiety and depressive symptoms, particularly in the acute setting. Due to the high level of heterogeneity between studies, results should be interpreted with caution. The small number of clinical trials and differences between their methods were the limitations of the present study. Further high-quality studies are needed to firmly establish the clinical efficacy of the lemon balm.

Backhousia citriodora F. Muell. (Lemon Myrtle), an Unrivalled Source of Citral

Lemon oils are amongst the highest volume and most frequently traded of the flavor and fragrance essential oils. Citronellal and citral are considered the key components responsible for the lemon note with citral (neral + geranial) preferred. Of the myriad of sources of citral, the Australian myrtaceous tree, Lemon Myrtle, Backhousia citriodora F. Muell. (Myrtaceae), is considered superior. This review examines the history, the natural occurrence, the cultivation, the taxonomy, the chemistry, the biological activity, the toxicology, the standardisation and the commercialisation of Backhousia citriodora especially in relation to its essential oil.

Melissa officinalis L. as a Nutritional Strategy for Cardioprotection

This review aimed to provide a summary on the traditional uses, phytochemistry, and pharmacological activities in the cardiovascular system and cardiotoxicity of Melissa officinalis (MO), with the special emphasis on the protective mechanisms in different cardiovascular pathologies. MO is a perennial aromatic herb commonly known as lemon balm, honey balm, or bee balm, which belongs to Lamiaceae family. Active components are mainly located in the leaves or essential oil and include volatile compounds, terpenoid (monoterpenes, sesquiterpenes, triterpenes), and polyphenolic compounds [rosmarinic acid (RA), caffeic acid, protocatechuic acid, quercitrin, rhamnocitrin, luteolin]. For centuries, MO has been traditionally used as a remedy for memory, cognition, anxiety, depression, and heart palpitations. Up until now, several beneficial cardiovascular effects of MO, in the form of extracts (aqueous, alcoholic, and hydroalcoholic), essential oil, and isolated compounds, have been confirmed in preclinical animal studies, such as antiarrhythmogenic, negative chronotropic and dromotropic, hypotensive, vasorelaxant, and infarct size-reducing effects. Nonetheless, MO effects on heart palpitations are the only ones confirmed in human subjects. The main mechanisms proposed for the cardiovascular effects of this plant are antioxidant free radical-scavenging properties of MO polyphenols, amelioration of oxidative stress, anti-inflammatory effects, activation of M2 and antagonism of β1 receptors in the heart, blockage of voltage-dependent Ca²⁺ channels, stimulation of endothelial nitric oxide synthesis, prevention of fibrotic changes, etc. Additionally, the main active ingredient of MO-RA, per se, has shown substantial cardiovascular effects. Because of the vastness of encouraging data from animal studies, this plant, as well as the main ingredient RA, should be considered and investigated further as a tool for cardioprotection and adjuvant therapy in patients suffering from cardiovascular diseases.

Maternal Reproductive Toxicity of Some Essential Oils and Their Constituents

Even though several plants can improve the female reproductive function, the use of herbs, herbal preparations, or essential oils during pregnancy is questionable. This review is focused on the effects of some essential oils and their constituents on the female reproductive system during pregnancy and on the development of the fetus. The major concerns include causing abortion, reproductive hormone modulation, maternal toxicity, teratogenicity, and embryo-fetotoxicity. This work summarizes the important studies on the reproductive effects of essential oil constituents anethole, apiole, citral, camphor, thymoquinone, trans-sabinyl acetate, methyl salicylate, thujone, pulegone, β-elemene, β-eudesmol, and costus lactone, among others.

Nanoencapsulation of essential oils and their bioactive constituents: A novel strategy to control mycotoxin contamination in food system

Spoilage of food by mycotoxigenic fungi poses a serious risk to food security throughout the world. In view of the negative effects of synthetic preservatives, essential oils (EOs) and their bioactive constituents are gaining momentum as suitable substitute to ensure food safety by controlling mycotoxins. However, despite their proven preservative potential against mycotoxins, the use of EOs/bioactive constituents in real food system is still restricted due to instability caused by abiotic factors and negative impact on organoleptic attributes after direct application. Nanoencapsulation in this regard could be a promising approach to address these problems, since the process can increase the stability of EOs/bioactive constituents, barricades their loss and considerably prevent their interaction with food matrices, thus preserving their original organoleptic qualities. The aim of this review is to provide wider and up-to-date overview on recent advances in nanoencapsulation of EOs/bioactive constituents with the objective to control mycotoxin contamination in food system. Further, the information on polymer characteristics, nanoencapsulation techniques, factors affecting the nanoencapsulation, applications of nanoencapsulated formulations, and characterization along with the study on their release kinetics and impacts on organoleptic attributes of food are discussed. Finally, the safety aspects of nanoencapsulated formulations for their safe utilization are also explored.

Artemisia annua, a Traditional Plant Brought to Light

Traditional remedies have been used for thousand years for the prevention and treatment of infectious diseases, particularly in developing countries. Of growing interest, the plant Artemisia annua, known for its malarial properties, has been studied for its numerous biological activities including metabolic, anti-tumor, anti-microbial and immunomodulatory properties. Artemisia annua is very rich in secondary metabolites such as monoterpenes, sesquiterpenes and phenolic compounds, of which the biological properties have been extensively studied. The purpose of this review is to gather and describe the data concerning the main chemical components produced by Artemisia annua and to describe the state of the art about the biological activities reported for this plant and its compounds beyond malaria.

Caffeic acid phenethyl ester attenuates changes in pancreatic tissue damage biomarkers induced by cisplatin

Application of cisplatin (CP) for the treatment of different cancers is known to cause pancreatitis through an increase in reactive oxygen species production and promotion of inflammation. Caffeic acid phenethyl ester (CAPE), the main activity carrier of propolis extracts, was previously found to possess numerous beneficial properties. This study aims to determine for the first time the potential of CAPE in preventing CP-induced pancreatic tissue damage by studying the changes occurring on both biochemical and microscopic levels. The levels of serum α-amylase and a panel of pancreatic tissue biomarkers related to tissue injury (reduced glutathione, xanthine oxidase, malondialdehyde, and protein carbonylated concentration) and inflammation (myeloperoxidase, nitric oxide, and umor necrosis factor alpha) were studied in male Wistar rats treated with either CP alone or with CP and CAPE. Additionally, microscopic analysis of pancreatic tissue would be conducted as well. Application of CAPE together with CP statistically significantly prevented the disturbance in all here-studied pancreatic tissue damage and inflammation-related biomarkers. The changes in pancreas biochemical status was followed by morphological disturbance. The results of the present study suggest that CAPE could act as a protective agent in pancreatic damage that arises after CP application.