Polyphenols from Citrus Tacle® Extract Endowed with HMGCR Inhibitory Activity: An Antihypercholesterolemia Natural Remedy.

Tacle® is a citrus fruit obtained from the crossbreeding of Clementine and Tarocco cultivars. This fruit retains a promising nutraceutical potential most likely due to a high content in polyphenols, among which the main constituents are the two glycosides naringin and hesperidin. Herein, we evaluated, through an in vitro assay, the capability of Tacle extracts to inhibit the hydroxymethylglutaryl-CoA reductase enzyme, which plays a key role in cholesterol biosynthesis. The results obtained spurred us to investigate whether the anti-enzymatic activity observed may be due to a direct interaction of aglycones naringenin and hesperetin with the enzyme catalytic site. Molecular docking simulations indicated that these two compounds are able to anchor to the protein with binding modes and affinities similar to those found for statins, which represent mainstream medications against hypercholesterolemia. The overall results showed an interesting nutraceutical potential of Tacle, suggesting that its extract could be used for dietary supplementation in the treatment of moderate hypercholesterolemia.

Essential Oils of Foeniculum vulgare subsp. piperitum and Their in Vitro Anti-Arthritic Potential.

Wild Foeniculum vulgare subsp. piperitum (C.Presl) Bég. flowers, fruits and leaves were extracted with steam distillation and obtained essential oils (EOs) were characterized using GC/MS. The study was designed to verify the potential effectiveness of fennel EOs in the treatment of inflammation and arthritis. Since tissue proteins denaturation is a major cause of arthritic diseases, fennel EOs and their main constituents were evaluated for their ability to inhibit the heat-induced proteins degradation using bovine serum albumin as a protein model. Moreover, the in vitro inhibitory effects of the three EOs on the pro-inflammatory mediator nitric oxide (NO) production were verified in LPS-stimulated RAW 264.7 cells. Estragole (28.81-33.40 %), anethole (24.16-27.40 %), fenchone (9.76-18.48 %), α-phellandrene (1.63-8.37 %) and limonene (5.54-6.05 %) were the major constituents. All the EOs showed a concentration-dependent biological activity, being the flower EO the most effective in inhibiting NO production (IC50 =232.2±11.3 µg/mL). The leaf EO showed a very good bovine serum albumin (BSA) anti-denaturation activity (IC50 =95.9±2.4 µg/mL). Moreover, four components were proved to be effective in protecting protein from heat-induced degradation, being α-phellandrene the most active compound (IC50 =73.2±1.9 µg/mL).

A Review of Biologically Active Natural Products from Mediterranean Wild Edible Plants: Benefits in the Treatment of Obesity and Its Related Disorders.

Wild foods constitute an essential component of people's diets around the world. According to the Food and Agriculture Organization (FAO), over 100 million people in the EU consume wild foods, while 65 million collect some form of wild food themselves. The Mediterranean basin is a biodiversity hotspot of wild edible species. Nowadays, due to the renewed interest in alimurgic plants and the recent findings on the beneficial role of their phytochemical constituents, these species have been defined as "new functional foods". Research on natural products has recently regained importance with the growing understanding of their biological significance. Botanical food supplements marketed for weight and fat loss in obese subjects will be one of the most important items in marketed nutraceuticals. The aim of this report was to review the phytochemical compounds of Mediterranean wild edible species and their therapeutic potential against obesity and its related disorders. Results on the in vitro and in vivo activity of the most interesting plant extracts and their bioactive components are presented and discussed. The most interesting discoveries on their mechanisms of action are reported as well. Overall, this contribution highlights the importance and beneficial health roles of wild edible species.

Leopoldia comosa prevents metabolic disorders in rats with high-fat diet-induced obesity.

PURPOSE: Obesity is the main feature of a complex illness known as metabolic syndrome. Anti-obesogenic therapies are often associated with side effects and represent a high cost in conventional pharmacological approaches. New strategies based on natural remedies are under continuous investigation. Leopoldia comosa (L.) Parl. (L. comosa) is a spontaneous plant with diuretic, anti-inflammatory and antioxidant properties. Recently, a hypoglycemic activity mediated by inhibition of carbohydrate digestion has been identified. The aim of this study was to evaluate the effects of a diet supplemented with L. comosa extracts on a rat model of diet-induced obesity. METHODS: Leopoldia comosa bulb extracts were obtained using a dynamic extractor. Phytochemical properties and in vitro determination of the antioxidant activity and of the inhibitory effects on lipase and pancreatic amylase were performed. Rats were fed (12 weeks) a standard diet, or a high-fat diet (HFD), or an HFD plus L. comosa (20 or 60 mg/die) extracts. The metabolic and anthropometric parameters were recorded. RESULTS: Results indicated that L. comosa inhibited lipase and pancreatic amylase activities. In vivo data showed that the supplementation with both doses of L. comosa extracts counteracted the HFD-dependent effects. It reduced body weight, abdominal obesity and dyslipidemia, and improved glucose tolerance with a reduction of lipidic tissue hypertrophy and liver steatosis, as compared to HFD-fed rat. In liver, L. comosa reduced protein expression levels of PEPCK and G6Pase. CONCLUSION: We suggest that L. comosa extracts prevent obesity-dependent metabolic disorders. This paves the way for their therapeutic application as a natural anti-obesity drug.

Biological Properties and Bioactive Components of Allium cepa L.: Focus on Potential Benefits in the Treatment of Obesity and Related Comorbidities.

Common onion (Allium cepa L.) is one of the oldest cultivated plants, utilized worldwide as both vegetable and flavouring. This species is known to contain sulphur amino acids together with many vitamins and minerals. A variety of secondary metabolites, including flavonoids, phytosterols and saponins, have also been identified. Despite the predominant use of this plant as food, a wide range of beneficial effects have also been proved. Different biological properties, such as antioxidant, antimicrobial and antidiabetic, have been reported. The aim of this review is to provide an overview of the studies concerning the beneficial effects of this species against obesity and its related comorbidities, such as hyperlipidaemia, hypertension and diabetes. Both in vitro and in vivo results about onion dietary supplementation have been taken into account. Furthermore, this review examines the possible role of onion bioactive components in modulating or preventing weight-gain or related diseases, as well as the possible mechanisms behind their activity.

Identification by Molecular Docking ofHomoisoflavones from Leopoldia comosa as Ligands of Estrogen Receptors.

The physiological responses to estrogen hormones are mediated within specific tissues by at least two distinct receptors, ER and ER. Several natural and synthetic molecules show activity by interacting with these proteins. In particular, a number of vegetal compounds known as phytoestrogens shows estrogenic or anti-estrogenic activity. The majority of these compounds belongs to the isoflavones family and the most representative one, genistein, shows anti-proliferative effects on various hormone-sensitive cancer cells, including breast, ovarian and prostate cancer. In this work we describe the identification of structurally related homoisoflavones isolated from Leopoldia comosa (L.) Parl. (L. comosa), a perennial bulbous plant, potentially useful as hormonal substitutes or complements in cancer treatments. Two of these compounds have been selected as potential ligands of estrogen receptors (ERs) and the interaction with both isoforms of estrogen receptors have been investigated through molecular docking on their crystallographic structures. The results provide evidence of the binding of these compounds to the target receptors and their interactions with key residues of the active sites of the two proteins, and thus they could represent suitable leads for the development of novel tools for the dissection of ER signaling and the development of new pharmacological treatments in hormone-sensitive cancers.

Effects of Saponins on Lipid Metabolism: A Review of Potential Health Benefits in the Treatment of Obesity.

Obesity is one of the greatest public health problems. This complex condition has reached epidemic proportions in many parts of the world, and it constitutes a risk factor for several chronic disorders, such as hypertension, cardiovascular diseases and type 2 diabetes. In the last few decades, several studies dealt with the potential effects of natural products as new safe and effective tools for body weight control. Saponins are naturally-occurring surface-active glycosides, mainly produced by plants, whose structure consists of a sugar moiety linked to a hydrophobic aglycone (a steroid or a triterpene). Many pharmacological properties have been reported for these compounds, such as anti-inflammatory, immunostimulant, hypocholesterolemic, hypoglycemic, antifungal and cytotoxic activities. The aim of this review is to provide an overview of recent studies about the anti-obesity therapeutic potential of saponins isolated from medicinal plants. Results on the in vitro and in vivo activity of this class of phytochemicals are here presented and discussed. The most interesting findings about their possible mechanism of action and their potential health benefits in the treatment of obesity are reported, as well.

Inhibition of Cancer Cell Proliferation and Antiradical Effects of Decoction, Hydroalcoholic Extract, and Principal Constituents of Hemidesmus indicus R. Br.

Indian Sarsaparilla (Hemidesmus indicus R. Br.) is widely used in Indian traditional medicine. In the present work, we explored the effects of decoction, traditional Ayurvedic preparation, and hydroalcoholic extract, a phytocomplex more traditionally studied and commercialized as food supplement in western medicine, from the roots as possible source of chemicals with new functional potential linked to their nutritional uses. The antiproliferative and antioxidant properties were assayed. To test antiproliferative affects, different cancer cell lines, growing both as monolayers (CaCo2, MCF-7, A549, K562, MDA-MB-231, Jurkat, HepG2, and LoVo) and in suspension (K562 and Jurkat) were used. The decoction showed strong activity on HepG2 cells, while the hydroalcoholic extracts were active on HepG2, LoVo, MCF-7, K562, and Jurkat cell lines. Weak inhibition of cancer cell proliferation was observed for the principal constituents of the preparations: 2-hydroxy-4-methoxybenzaldehyde, 2-hydroxy-4-methoxybenzoic acid, and 3-hydroxy-4-methoxybenzaldehyde that were tested alone. The antiradical activity was tested with 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)diammonium salt tests and inhibition of nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 macrophages. Interesting result has also been obtained for hydroalcoholic extract regarding genoprotective potential (58.79% of inhibition at 37.5 µg/mL).

Hypericum perforatum: Influences of the habitat on chemical composition, photo-induced cytotoxicity, and antiradical activity.

CONTEXT: Hypericin, isolated from Hypericum perforatum L. and about another 300 Hypericum species (Guttiferae), is one of the most powerful photosensitizers found in nature. OBJECTIVE: The aim of this study was to assess the variability of chemical composition and biological activities of four H. perforatum samples, collected at different altitudes in the South Apennine of Italy. MATERIALS AND METHODS: MTT assay was used to evaluate the antiproliferative activity of different samples concentrations (0.6-100 µg/mL) after irradiation at 365 nm. The inhibition of nitric oxide production was evaluated after 24 h of incubation using the macrophage cell line RAW 264.7 and sample solutions ranging from 12.5 to 1000 µg/mL. Antioxidant activities were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and ß-carotene bleaching test (ranges were 12.5-1000 and 1-400 µg/mL, respectively). Chemical composition was evaluated through HPTLC, and different contents of hypericin and rutin have been observed. RESULTS: The most phototoxic sample was collected from Zumpano (no. 1 at 370 m), with IC50 values of 24.61 ± 0.02 µg/mL. Sample no. 1 showed also the best radical scavenging activity (IC50 value of 9.18 ± 0.03 µg/mL) and the best antioxidant activity (IC50 value of 10.04 ± 0.03 µg/mL after 30 min of incubation). Best activity of extract no. 1 was well in accordance with chemical data, including the phenolic total content and particular metabolome profile. DISCUSSION AND CONCLUSION: This paper confirms the usefulness in maintaining the exploration of H. perforatum activities, in order to confirm its potentiality as a multipurpose plant.

Phenolic Compounds from Tropea Red Onion as Dietary Agents for Protection against Heavy Metals Toxicity.

The present study aims to highlight the cell protective effect of Tropea red onion (TRO) hydroalcoholic extract and some of its components against "non-essential" heavy metals. For this purpose, the cytoprotective roles of cyanidin, cyanidin-3-O-glucoside and quercetin against Cd, Hg and Pb and of TRO extract against Hg and Pb have been investigated, and data are reported here. To the best of our knowledge, this is the first detailed evaluation of the protective effect against cell damage induced by "non-essential" heavy metals through the simultaneous administration of cyanidin, cyanidin-3-O-glucoside and quercetin with CdCl2, HgCl2 or PbCl2 and the TRO extract against HgCl2 and PbCl2. Present data are also compared with our previous results from the TRO extract against Cd. The antioxidant capacity of the extract was also determined by the ferric reducing antioxidant power (FRAP) and the bovine brain peroxidation assay. Both of the assays indicated a good antioxidant capacity of the extract. Cell viability and the impact on necrotic cell death were examined by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) test and lactate dehydrogenase (LDH) release assay. After 24 h of exposure, Caco-2 cell viability decreased by approximately 50% at 0.25 µM for Cd, Hg and Pb and, after 72 h, the ranking order of "non-essential" heavy metal toxicity on cell viability was PbCl2 > CdCl2 > HgCl2. Cell viability was assessed by treating the cells with the biomolecules at doses of 25, 50 and 100 µg/mL for 24 and 72 h. The same analysis was carried out on Caco-2 cells treated with combinations of TRO extract, cyanidin, cyanidin-3-O-glucoside, or quercetin and "non-essential" heavy metals. Treatments with the bioactive metabolites did not significantly improve cell viability. The identical treatment of Caco-2 cells produced instead LDH release, suggesting a decrease in cell viability. Consistently with the finding that TRO extract showed a good antioxidant activity, we suggest that its higher cytotoxicity, compared to that of the individual assayed phytochemicals, may be derived by the combined antioxidant and chelating properties of all the molecules present in the extract. Therefore, from all the acquired experimental evidence, it appears that the TRO extract may be a better promising protective agent against the toxic effect of Cd, Hg and Pb compared to its bioactive metabolites.

Molecular Docking Studies and In Vitro Activity of Paliurus spina-christi Mill Extracts as Pancreatic Lipase Inhibitors.

Obesity is a risk factor for the onset of chronic diseases. One of the most promising approaches to treating obesity consists of reducing dietary fat absorption using extracts from plants because they contain phenolic compounds, especially flavonoids. Paliurus spina-christi, belonging to the Rhamnaceae family, is one of the five species belonging to the Paliurus genus. Herein, the aerial parts of the plant were extracted with methanol through the pressurized cyclic solid-liquid extraction using the Naviglio extractor®. The extracts were analyzed with High Performance Thin Layer Chromatography and investigated for their in vitro biological potential. The phytochemical analysis revealed that rutin has been shown to be the most abundant flavonoid component. The best antiradical activity was observed for the fruit extract with an IC50 value of 53.41 ± 1.24 µg/mL. This extract also has a better inhibitory capacity on lipid peroxidation evaluated at a different time of incubation. Potent lipase inhibitor activity of the extract from fruits was also demonstrated with in vitro experiments. This property can be attributed to a direct interaction of main components of P. spina-christi extract with the human pancreatic enzyme as demonstrated by the results of molecular docking experiments conducted on the crystallographic structures of lipase.

Use of Essential Oils to Counteract the Phenomena of Antimicrobial Resistance in Livestock Species.

Antimicrobial resistance is an increasingly widespread phenomenon that is of particular concern because of the possible consequences in the years to come. The dynamics leading to the resistance of microbial strains are diverse, but certainly include the incorrect use of veterinary drugs both in terms of dosage and timing of administration. Moreover, the drug is often administered in the absence of a diagnosis. Many active ingredients in pharmaceutical formulations are, therefore, losing their efficacy. In this situation, it is imperative to seek alternative treatment solutions. Essential oils are mixtures of compounds with different pharmacological properties. They have been shown to possess the antibacterial, anti-parasitic, antiviral, and regulatory properties of numerous metabolic processes. The abundance of molecules they contain makes it difficult for treated microbial species to develop pharmacological resistance. Given their natural origin, they are environmentally friendly and show little or no toxicity to higher animals. There are several published studies on the use of essential oils as antimicrobials, but the present literature has not been adequately summarized in a manuscript. This review aims to shed light on the results achieved by the scientific community regarding the use of essential oils to treat the main agents of bacterial infection of veterinary interest in livestock. The Google Scholar, PubMed, SciELO, and SCOPUS databases were used for the search and selection of studies. The manuscript aims to lay the foundations for a new strategy of veterinary drug use that is more environmentally friendly and less prone to the emergence of drug resistance phenomena.

Enhancing the nitric oxide inhibitory activity using a combination of plant essential oils and mixture design approach.

The synergistic effects of essential oils (EOs) from three aromatic plant species, Foeniculum vulgare subsp. piperitum (C.Presl) Bég. (FV), Origanum heracleoticum L. (OH) and Lavandula austroapennina N.G.Passal., Tundis & Upson. (LA), were evaluated for their inhibitory properties on nitric oxide production in RAW 264.7 macrophages stimulated with lipopolysaccharide (LPS). We utilized a Design of Experiments (DoE) methodology to optimize a formulation by combining three Essential Oils (EOs), while simultaneously taking into account two response variables, maximization of NO inhibition with minimum cytotoxicity. The optimal blend of components was predicted, and the statistical outcome's efficacy was experimentally verified. The combination corresponding to 87.7 % FV, 12.3 % LA and 0.0 % OH showed high inhibitory effect (76.3 %) with negligible cytotoxicity (4.5 %). This research provides new information on the interactions among fennel, oregano and lavender essential oils and shows how they can synergistically inhibit in vitro LPS-induced NO production.

Bergamot Polyphenolic Fraction for the Control of Flupyradifurone-Induced Poisoning in Honeybees.

Flupyradifurone (FLU) is a butenolide insecticide that has come onto the market relatively recently. It is used in agriculture to control aphids, psyllids, and whiteflies. Toxicity studies have decreed its low toxicity to honeybees. However, recent research has challenged these claims; oral exposure to the pesticide can lead to behavioral abnormalities and in the worst cases, lethal phenomena. Compounds with antioxidant activity, such as flavonoids and polyphenols, have been shown to protect against the toxic effects of pesticides. The aim of this research was to evaluate the possible protective effect of the bergamot polyphenolic fraction (BPF) against behavioral abnormalities and lethality induced by toxic doses of FLU orally administered to honeybees under laboratory conditions. Honeybees were assigned to experimental groups in which two toxic doses of FLU, 50 mg/L and 100 mg/L were administered. In other replicates, three doses (1, 2 and 5 mg/kg) of the bergamot polyphenolic fraction (BPF) were added to the above toxic doses. In the experimental groups intoxicated with FLU at the highest dose tested, all caged subjects (20 individuals) died within the second day of administration. The survival probability of the groups to which the BPF was added was compared to that of the groups to which only the toxic doses of FLU were administered. The mortality rate in the BPF groups was statistically lower (p < 0.05) than in the intoxicated groups; in addition, a lower percentage of individuals exhibited behavioral abnormalities. According to this research, the ingestion of the BPF attenuates the harmful effects of FLU. Further studies are needed before proposing BPF incorporation into the honeybees' diet, but there already seem to be beneficial effects associated with its intake.

Antioxidant Activity and Seasonal Variations in the Composition of Insoluble Fiber from the Cladodes of Opuntia ficus-indica (L.) Miller: Development of New Extraction Procedures to Improve Fiber Yield.

Opuntia ficus-indica (L.) Miller is a plant belonging to the Cactaceae family adapted to live in environments characterized by long periods of drought and arid or desert climates. This plant is characterized by an aerial part composed of structures transformed by branches, called "cladodes", which are essential to reduce excessive perspiration of water and appear covered with thorns. The composition of the cladodes includes water, polysaccharides, fiber, proteins, vitamins, fatty acids, sterols, polyphenols, and minerals. The main purposes of this scientific work are (a) to compare the insoluble fiber (IF) extracted from the cladodes of O. ficus-indica belonging to the same plant but collected in different seasonal periods (winter and summer) and develop new extraction protocols that are able to improve the yield obtained and (b) evaluate the antioxidant potential of the fiber and study possible variations as a result of the extraction protocol chosen. The first objective was achieved (1) by measuring the amount of IF extracted from cladodes harvested in winter and summer (CW and CS, respectively) and (2) by modifying three variables involved in the fiber extraction protocol. To achieve the second objective, the following experiments were carried out: (1) measurement of the antioxidant potential of IF in CW and CS; (2) measurement of cellular reactive oxygen species; (3) measurement of the activity of some antioxidant enzymes; and (4) comparison of the polyphenol content in CW and CS. In conclusion, the results obtained showed that the IF extraction process can be improved, achieving a uniform yield regardless of seasonality; the antioxidant effect may vary depending on the extraction protocol.

Hive Products: Composition, Pharmacological Properties, and Therapeutic Applications.

Beekeeping provides products with nutraceutical and pharmaceutical characteristics. These products are characterized by abundance of bioactive compounds. For different reasons, honey, royal jelly, propolis, venom, and pollen are beneficial to humans and animals and could be used as therapeutics. The pharmacological action of these products is related to many of their constituents. The main bioactive components of honey include oligosaccharides, methylglyoxal, royal jelly proteins (MRJPs), and phenolics compounds. Royal jelly contains jelleins, royalisin peptides, MRJPs, and derivatives of hydroxy-decenoic acid, particularly 10-hydroxy-2-decenoic acid (10-HDA), which possess antibacterial, anti-inflammatory, immunomodulatory, neuromodulatory, metabolic syndrome-preventing, and anti-aging properties. Propolis has a plethora of activities that are referable to compounds such as caffeic acid phenethyl ester. Peptides found in bee venom include phospholipase A2, apamin, and melittin. In addition to being vitamin-rich, bee pollen also includes unsaturated fatty acids, sterols, and phenolics compounds that express antiatherosclerotic, antidiabetic, and anti-inflammatory properties. Therefore, the constituents of hive products are particular and different. All of these constituents have been investigated for their properties in numerous research studies. This review aims to provide a thorough screening of the bioactive chemicals found in honeybee products and their beneficial biological effects. The manuscript may provide impetus to the branch of unconventional medicine that goes by the name of apitherapy.

Rapid solid-liquid dynamic extraction of Cachrys pungens Jan ex Guss. aerial parts: influence on the photobiological and antioxidant properties.

Cachrys pungens Jan ex Guss. (Apiaceae) is a perennial plant native to Italy and Northwestern Africa. This species is known for its content in furanocoumarins, and the methanolic extract obtained with maceration previously demonstrated significant phototoxicity on 375 melanoma cells. Here, in order to better explain the biological effects, the apoptotic responses on melanoma cancer cell line were verified. The aerial parts were extracted with methanol through an innovative solid-liquid extraction technology, the Naviglio extractor®, and the raw extract was tested for its photobiological properties on human melanoma C32 cells irradiated with UVA light. The in vitro antioxidant potential was assessed as well. The sample exerted a concentration-dependent photocytotoxic activity (IC50 value = 3.00 ± 0.16 µg/mL). In line with these evidences, in C32-treated cells subjected to UV irradiation, further data have reported an up-regulation of p53 and PARP, both proteins involved in apoptotic response and DNA repair.

In vitro antioxidant and anti-denaturation effects of Buglossoides purpurocaerulea (L.) I. M. Johnst. fruit extract.

Fruits from Buglossoides purpurocaerulea (L.) I. M. Johnst. were extracted with methanol through maceration. The phytochemical composition of obtained raw extract was investigated with gas chromatography-mass spectrometry (GC-MS) and high-performance thin layer chromatography (HPTLC) analyses. The total phenolic and flavonoid contents were also quantified and in vitro antioxidant activity was assessed using the DPPH assay and the ß-carotene bleaching test. In order to verify the anti-arthritic potential, the raw extract was evaluated for its anti-denaturation effect on heat-treated bovine serum albumin (BSA), chosen as a protein model. Linoleic and α-linolenic acids were the most abundant identified apolar constituents. HPTLC analyses allowed the identification of rosmarinic acid. The sample showed a concentration-dependent antioxidant activity and it was also proven to be effective in preventing the heat-induced denaturation of BSA, with an IC50 value equal to 15.7 ± 0.5 µg/mL.

Phytochemical Composition and Pharmacological Efficacy Evaluation of Calamintha nepeta, Calamintha sylvatica, Lavandula austroapennina and Mentha piperita Essential Oils for the Control of Honeybee (Apis mellifera) Varroosis.

Varroa destructor is currently considered the parasite that causes the greatest damage and economic losses to honeybee farms. Its presence is often associated with that of viral and bacterial pathogens, which ultimately leads to colony collapse. Careful control of the parasitic load is therefore necessary to avoid the onset of these events. Although chemical treatments are often in easily and quickly administered formulations, in recent years, there have been increasingly frequent reports of the onset of drug resistance phenomena, which must lead to reconsidering their use. Furthermore, chemical compounds can easily accumulate in the food matrices of the hive, with possible risks for the final consumer. In such a condition, it is imperative to find alternative treatment solutions. Essential oils (EOs) prove to be promising candidates due to their good efficacy and good environmental biodegradability. In this study, the acaricidal efficacy of the EOs of Calamintha sylvatica Bromf., Calamintha nepeta Savi, Lavandula austroapennina N.G. Passal. Tundis & Upson and Mentha piperita L., extracted from botanical species belonging to the Lamiaceae family, was evaluated. The test chosen for the evaluation was residual toxicity by contact. The examined EOs were diluted in Acetone to a concentration of 2, 1 and 0.5 mg/mL. At the highest concentration, the EOs demonstrated an acaricidal activity equal to 52% for C. nepeta, 60% for C. sylvatica, 80% for L. austroapennina and 68% for M. piperita. Of the EOs tested, therefore, Lavender proves to be a good candidate for subsequent evaluations in semi-field and field studies.

Chemical Profile of Essential Oils of Selected Lamiaceae Plants and In Vitro Activity for Varroosis Control in Honeybees (Apis mellifera).

The most significant ectoparasitic mite of honeybees, Varroa destructor, has a detrimental effect on bee health and honey output. The principal strategy used by the control programs is the application of synthetic acaricides. All of this has resulted in drug resistance, which is now a major worry for beekeeping. As a result, research on alternate products and techniques for mite management is now required. The aim of this study was to determine whether essential oils (EOs) extracted from botanical species of Lamiacae, typical of the Calabria region of Southern Italy, could reduce the population of the mite V. destructor. Among the best-known genera of the Lamiaceae family are oregano, rosemary and thyme, whose EOs were employed in this study. By steam distillation, the EOs were extracted from Origanum vulgare subsp. viridulum (Martrin-Donos) Nyman, Thymus capitatus Hoffmanns. and Link, Thymus longicaulis C.Presl and Salvia rosmarinus Schleid. plant species harvested directly on the Calabrian territory in their balsamic time. Each EO went to the test in vitro (contact toxicity) against V. destructor. Fifty adult female mites, five for each EO and the positive and negative control, were used in each experimental replicate. The positive controls comprised five individuals treated to Amitraz dilute in acetone, and the negative controls included five individuals exposed to acetone alone. To create the working solution to be tested (50 µL/tube), the EOs were diluted (0.5 mg/mL, 1 mg/mL, 2 mg/mL and 4 mg/mL) in HPLC-grade acetone. After 1 h of exposure, mite mortality was manually assessed. Origanum vulgare subsp. viridulum, Thymus capitatus and Thymus longicaulis were the EOs with the highest levels of efficiency at 2 mg/mL, neutralizing (dead + inactivated), 94%, 92% and 94% of parasites, respectively. Salvia rosmarinus EO gave a lower efficacy, resulting in a percentage of 38%. Interestingly, no adverse effects were highlighted in toxicity tests on honeybees. These results show that these OEs of the Lamiaceae family have antiparasitic action on V. destructor. Therefore, they could be used, individually or combined, to exploit the synergistic effect for a more sustainable control of this parasite mite in honeybee farms.