Comprehensive Modulation of Secondary Metabolites in Terpenoid-Accumulating Mentha spicata L. via UV Radiation.

In plants, secondary metabolites change in response to environmental conditions. These changes co-regulate resilience to stressful environmental conditions, plant growth and development, and interactions between plants and the wider ecosystem, while also affecting soil carbon storage and atmospheric and climatic conditions. The objective of this study was to determine the association between UV exposure and the contents of key metabolites, including amino acids, phenolics, flavonoids, terpenoids, carotenoids, tocopherols, and phytosterols. Mentha spicata plantlets were grown in tissue culture boxes for 30 days and then exposed to a low dose of broadband UV-B (291-315 nm; 2.8 kJm-2 biologically effective UV) enriched light for eight days. Metabolite contents were quantified either immediately after the final UV exposure, or after seven days of recovery under photosynthetically active radiation. It was found that UV promoted the production of flavonoids (1.8-fold) ahead of phenolic acids (unchanged). Furthermore, the majority of monoterpenes and sesquiterpenes, constituents of valuable mint essential oil, were significantly increased through UV treatment (up to 90-fold for α-linalool). In contrast, the contents of carotenoids and tocopherols did not increase following UV exposure. A comparison between plants sampled immediately after UV exposure and after seven days of recovery showed that there was an overall increase in the content of carotenoids, mono- and sesquiterpenes, phenolics, and amino acids following recovery, while the contents of sterols and tocopherols decreased. These UV-induced changes in metabolite profile may have important consequences for agriculture, ecology, and even the global climate, and they also provide an exciting opportunity to enhance crop value, facilitating the development of improved products with higher levels of essential oils and added benefits of enhanced flavour, colour, and bioactive content.

Insulin-Mimetic Activity of Herbal Extracts Identified with Large-Scale Total Internal Reflection Fluorescence Microscopy.

Diabetes mellitus is a spreading global pandemic. Type 2 diabetes mellitus (T2DM) is the predominant form of diabetes, in which a reduction in blood glucose uptake is caused by impaired glucose transporter 4 (GLUT4) translocation to the plasma membrane in adipose and muscle cells. Antihyperglycemic drugs play a pivotal role in ameliorating diabetes symptoms but often are associated with side effects. Hence, novel antidiabetic compounds and nutraceutical candidates are urgently needed. Phytogenic therapy can support the prevention and amelioration of impaired glucose homeostasis. Using total internal reflection fluorescence microscopy (TIRFM), 772 plant extracts of an open-access plant extract library were screened for their GLUT4 translocation activation potential, resulting in 9% positive hits. Based on commercial interest and TIRFM assay-based GLUT4 translocation activation, some of these extracts were selected, and their blood glucose-reducing effects in ovo were investigated using a modified hen's egg test (Gluc-HET). To identify the active plant part, some of the available candidate plants were prepared in-house from blossoms, leaves, stems, or roots and tested. Acacia catechu (catechu), Pulmonaria officinalis (lungwort), Mentha spicata (spearmint), and Saponaria officinalis (common soapwort) revealed their potentials as antidiabetic nutraceuticals, with common soapwort containing GLUT4 translocation-activating saponarin.

Chemical Characterization of the Essential Oil Compositions of Mentha spicata and M. longifolia ssp. cyprica from the Mediterranean Basin and Multivariate Statistical Analyses.

This present study aims to characterize the essential oil compositions of the aerial parts of M. spicata L. and endemic M. longifolia ssp. cyprica (Heinr. Braun) Harley by using GC-FID and GC/MS analyses simultaneously. In addition, it aims to perform multivariate statistical analysis by comparing with the existing literature, emphasizing the literature published within the last two decades, conducted on both species growing within the Mediterranean Basin. The major essential oil components of M. spicata were determined as carvone (67.8%) and limonene (10.6%), while the major compounds of M. longifolia ssp. cyprica essential oil were pulegone (64.8%) and 1,8-cineole (10.0%). As a result of statistical analysis, three clades were determined for M. spicata: a carvone-rich chemotype, a carvone/trans-carveol chemotype, and a pulegone/menthone chemotype, with the present study result belonging to the carvone-rich chemotype. Carvone was a primary determinant of chemotype, along with menthone, pulegone, and trans-carveol. In M. longifolia, the primary determinants of chemotype were identified as pulegone and menthone, with three chemotype clades being pulegone-rich, combined menthone/pulegone, and combined menthone/pulegone with caryophyllene enrichment. The primary determinants of chemotype were menthone, pulegone, and caryophyllene. The present study result belongs to pulegone-rich chemotype.

Investigating the effectiveness of iron nanoparticles synthesized by green synthesis method in chemoradiotherapy of colon cancer.

Current methods of colon cancer treatment, especially chemotherapy, require new treatment methods due to adverse side effects. One important area of interest in recent years is the use of nanoparticles as drug delivery vehicles since several studies have revealed that they can improve the target specificity of the treatment thus lowering the dosage of the drugs while preserving the effectiveness of the treatment thus reducing the side effects. The use of traditional medicine has also been a favorite topic of interest in recent years in medical research, especially cancer research. In this research work, the green synthesis of Fe nanoparticles was carried out using Mentha spicata extract and the synthesized nanoparticles were identified using FT-IR, XRD, FE-SEM and EDS techniques. Then the effect of Mentha spicata, Fe nanoparticles, and Mentha spicata -loaded Fe nanoparticles on LS174t colon cancer cells, and our result concluded that all three, especially Mentha spicata -loaded Fe nanoparticles, have great cytotoxic effects against LS174t cells, and exposure to radiotherapy just further intensified these results. The in vitro condition revealed alterations in the expression of pro-apoptotic BAX and anti-apoptotic Bcl2, suggesting a pro-apoptotic effect from all three components, particularly the Mentha spicata-loaded Fe nanoparticles. After further clinical trials, these nanoparticles can be used to treat colon cancer.

Dietary agents in the prevention of radiation-induced nausea and vomiting (RINV): review addressing the scientific observations, benefits, lacunae and future direction.

PURPOSE: Radiation-induced Nausea and Vomiting (RINV) is an important side effect and conservative estimates are that 50-80% of the patients undergoing curative radiotherapy (RT) will experience some sought of retching, nausea, and/or vomiting during the course of their treatment. Conventionally, antiemetic drugs like the 5-hydroxytryptamine receptor antagonists and steroids are the mainstay of treatment. However, the use of these agents, especially steroids, can cause side effects and thereby negate the proposed benefits. The antiemetic effects of Centella asiatica (Indian pennywort), Hippophae rhamnoides (Sea buckthorn), oil of Mentha spicata (Spearmint) and the rhizomes of Zingiber officinale (ginger) have been addressed. CONCLUSIONS: Results indicate that Indian pennywort, Sea buckthorn, Spearmint oil and ginger are beneficial in mitigating RINV. Also, of the four plants investigated in preclinical models of study, mint oil and ginger seem to be more useful and merit structured systematic translational studies to ascertain the benefit of these two agents.

Chemical composition and toxicity of commercial Mentha spicata and Eucalyptus citriodora essential oils on Culex quinquefasciatus and non-target insects.

Current vector control strategies based on synthetic chemicals are not eco-friendly against non-target organisms; hence, alternative approaches are highly required. Commercially purchased oil of Mentha spicata (Spearmint) and Eucalyptus citriodora (Citriodora) were examined against the medical pest Cx. quinquefasciatus (Say) and their non-toxicity on the aquatic species was evaluated. Chemical screening with gas chromatography coupled with mass spectrometry (GC-MS) analysis revealed a total of 14 and 11 compounds in Citriodora and Spearmint oils, respectively, with the highest peak (%) at carvone (70.44%) and isopulegol (30.4%). The larvicidal activity on the fourth instar larvae of Cx. quinquefasciatus showed dose-dependent mortality and significance at a 100 ppm concentration 48 h post-treatment with Citriodora (76.4%, P ≤ 0.001) and Spearmint (100%, P ≤ 0.001). Additionally, the photomicrograph of the fourth instar larvae revealed significant physical abnormalities in the head and midgut tissues post-exposure to Spearmint and Citriodora oils. Moreover, the histological assay revealed severe damage in the epithelial cells and gut lumen 2 to 24 h post-treatment. The repellency percentage of adult Culex mosquitoes was prominent across both oils at 150 ppm 210 min post-exposure. Non-target toxicity on the aquatic predator showed both essential oils (Spearmint oil (17.2%) and Citriodora oil (15.2%)) are safer at the maximum treatment (200 ppm) compared to temephos (75.4% at 1 ppm). The in silico screening of phyto-compounds derived by both essential oils with BeeTox (online server) showed no contact toxicity to the honey bee Apis mellifera. Overall, the present research revealed that Spearmint and Citriodora essential oils and their active phyto-compounds were toxic to Cx. quinquefasciatus and harmless to the aquatic predator and honey bee.

Examining the varied concentrations of Mentha spicata and Ocimum basilicum affect the synthesis of AgNPs that restrict the development of bacteria.

This work examined the effects of varied concentrations of Ocimum basilicum and Mentha spicata aqueous extracts in order to determine the concentration that has the strongest antibacterial impact through the green synthesis technique of silver nanoparticles (AgNPs). In order to synthesize AgNPs using the reduction method, different quantities of reducing and stabilizing agents: (a) 0.75 mM Ocimum basilicum and 0.25 mM Mentha spicata; (b) 0.5 Mentha spicata and 0.5 mM Ocimum basilicum; and (c) 0.25 mM Ocimum basilicum and 0.75 mM Mentha spicata were utilized. X-ray Diffraction (XRD), and UV-vis spectra were used to analyze AgNPs' crystal structure and shape. The antibacterial potency of E. coli ATCC 35218 was investigated utilizing AgNPs employing the well diffusion, MBC, MIC, and the time-kill curve. Ocimum basilicum water solution's dark yellow hue denotes the completion of the AgNPs' synthesis. As the aqueous Ocimum basilicum solution concentration increases between 0.25 and 0.75 mM, the AgNPs' UV spectra show a gradually increasing absorption. This, in turn, caused the nanoparticle size to alter from 73.57 to 89.05 nm and the wavelength to change from 468 to 474 nm. The experiments also revealed that the nanoparticles had a significantly antibacterial activity against E. coli, of the sample prepared with 1 mM Ocimum basilicum. Based on the synthesis of AgNPs, it has been shown that an aqueous extract of Ocimum basilicum outperforms Mentha spicata as a powerful reducing agent and stabilizing agent for the production AgNPs in various sizes. This is true regardless of the solvent content.

Effects of Harvest Time and Hydrodistillation Time on Yield, Composition, and Antioxidant Activity of Mint Essential Oil.

In this study, we assessed the effects of different harvest times (9 a.m., 1 p.m., and 5 p.m.) and hydrodistillation times (60, 90, and 120 min) on the yield, chemical composition, and antioxidant activity of the spearmint (Mentha spicata L.) essential oil (EO) sourced from the Amazon region. EO yield was ≥1.55% and was not significantly influenced (p ≥ 0.05) by the different harvest times and hydrodistillation times. Thirty-one different organic compounds were identified, of which menthol (91.56-95.68%), menthone (0.6-2.72%), and isomenthone (0.55-1.46%) were the major constituents. The highest menthol content in the EO was obtained from samples collected at 9 a.m., with a hydrodistillation time of 60-90 min, compared to other harvest and hydrodistillation times. This suggests that exposure to sun and light, which is greater at harvest times of 1 p.m. and 5 p.m., decreased the menthol content and altered the chemical composition of Mentha EO. Furthermore, the sample harvested at 9 a.m. and hydrodistilled for 60 min showed the highest antioxidant activity (61.67 equivalent mg of Trolox per g of EO), indicating that antioxidant activity is strongly affected by light exposure and the contact duration of the sample with boiling water during hydrodistillation.

Enhancement of the anti-microbial activity of Mentha spicata essential oil on storage by glycerosomes.

Mentha spicata essential oil (EO) is isolated from the aerial parts of Mentha spicata L. with pronounced antibacterial effects as food preservative in food industry. Nevertheless, its application in the clinical industry and food is significantly restricted by its poor water solubility and physicochemical instability. Glycerosomes of this EO were prepared to enhance its anti-microbial stability. The EO was encapsulated in the glycerosomes and characterized for its physical properties. The optimized EO-loaded glycerosomes displayed entrapment efficiency of 93.2 ± 7.5%, release efficiency of 75.4 ± 6.1%, the particle size of 276 nm, and zeta potential of - 30.4 mV. Scanning electron microscopy (SEM) image showed spherical morphology of the glycerosomes. EO release from optimized formulation of glycerosomes best fitted with a first-order kinetic model. Compared with free EO, EO-loaded glycerosomes showed better storage stability. The results indicated that the incorporation of EO in glycerosomes possessed sustained release properties and significantly enhanced antibacterial effects in storage.

Evaluating the Effect of pH, Temperature and Concentration on Antioxidant and Antibacterial Potential of Spectroscopically, Spectrophotometrically and Microscopically Characterized Mentha Spicata Capped Silver Nanoparticles.

The use of traditional plants has been tremendously increased due to their higher biological impact, minimal side effects, and comparatively low cost. Moreover, the emergence of antibacterial resistance is also shifting the scientific community to reconsider herbal remedies which provide relatively safer, cheap and biologically tolerable solutions. The present research was designed to fabricate the Mentha spicata conjugated silver nanoparticles (Me-AgNPs). Furthermore, the assessment of the bactericidal potential of Me-AgNPs against various bacterial strains was another motive behind this study. Fabricated NPs were characterized with the help of the UV-Visible spectrophotometric analysis, Fourier transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM). Me-AgNPs showed a significant zone of inhibition (23 ± 0.2 mm) at 8 mg/mL against Staphylococcus aureus and a 4.0 ± 0.2 mm zone of growth inhibition at 2 mg/mL against Aeromonas veronii. The stability of Me-AgNPs was assessed at various pH (4, 7 and 11) and temperatures (25 °C, 4 °C, 37 °C, 75 °C). The significant zones of inhibition (11.3 ± 0.3 mm, 8.3 ± 0.3mm, 14.3 ± 0.3 mm, and 7.6 ± 0.2 mm) were observed at pH 11 against Escherichia coli, Staphylococcus aureus, Bacillus subtilis, and Klebsiella pneumoniae, respectively. Growth inhibition zones (14.0 ± 0.5 mm and 13.0 ± 0.5 mm) were also determined against B. subtilis and S. aureus at 25 °C. DPPH bioassay was conducted to find the antioxidant properties of Me-AgNPs. The highest (38.66 ± 0.2%) free radical scavenging activity was shown by Me-AgNPs at 4 mg/mL. Present study results concluded that biogenic Me-AgNPs have bactericidal as well as anti-oxidative potential. Moreover, these green synthesized Me-AgNPs could maintain their potency and stability at a wide range of pH and temperature.

Interactions of Chitosan-coated Green Synthesized Silver Nanoparticles using Mentha spicata and Standard Antibiotics against Bacterial Pathogens.

BACKGROUND: Infectious diseases are caused by various multidrug-resistant pathogenic bacteria and in recent scenarios, nanoparticles have been used as innovative antimicrobial agents. AIMS: This current research aimed to evaluate the bactericidal effect of chitosan-coated green synthesized silver nanoparticles using aqueous extract of Mentha spicata (MSaqu) against bacterial pathogens, i.e., Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Serratia marcescens, Staphylococcus aureus, and Streptococcus pyogenes. METHODS: Synthesis and characterization of silver nanoparticles (MSAgNPs) were carried out via atomic absorption spectrometer and Fourier-transform infrared spectroscopy. Agar well and agar disc diffusion methods were used to assess the antibacterial and synergistic effect of chitosanmediated biogenic silver nanoparticles and standard antibiotics. Three types of interactions, i.e., antagonistic (↓), synergistic (↑), and additive (¥) were observed. RESULTS: Synergistic effect was recorded against Pseudomonas aeruginosa (8.5±0.25 mm↑), Serratia marcescens (19.0±1.0 mm↑), and Klebsiela pneumonia (8.5±0.25 mm↑), an additive effect was exhibited by Escherichia coli (9.0±0.0 mm¥), Streptococcus pyogenes (10.0±0.0 mm¥), and Staphylococcus aureus (7.5±0.25 mm↓) and they showed antagonistic effects when chitosan-coated silver nanoparticles (CLMSAgNPs) were applied compared to chitosan, MSaqu, and MSAgNPs. Interesting antibacterial results were recorded when chitosan-coated Mentha spicata extract and silver nanoparticles were applied along with antibiotics. The synergistic effects of chitosan-coated silver nanoparticles (CLMSAgNPs) + K were recorded against E. coli (14.5±0.25 mm). The synergistic effects of chitosan-coated silver nanoparticles (CLMSAgNPs) + AML were recorded against E. coli (5.5±0.0 mm), S. pyogenes (10.0±0.0 mm), K. pneumonia (5.5±0.0 mm), and S. aureus (4.0±0.0 mm). The synergistic effects of chitosan-coated silver nanoparticles (CLMSAgNPs) + NOR were recorded against E. coli (16.0±0.0 mm), P. aeruginosa (19.0±0.0 mm), S. marcescens (19.5±0.25 mm), S. pyogenes (11.5.0±0.25 mm), K. pneumonia (23.0±0.0 mm), and S. aureus (8.5±0.25 mm). CONCLUSION: Current findings concluded that chitosan-coated biogenic silver nanoparticles have potential bactericidal effects against infectious pathogens and could be used as forthcoming antibacterial agents.

Prenatal developmental toxicity study of herbal tea of Moringa stenopetala and Mentha spicata leaves formulation in Wistar rats.

Background: Moringa stenopetala and Mentha spicata have long been used to treat diabetes, hypertension, asthma, and other ailments. Herbal tea of M. stenopetala and Mentha spicata leaves formulation showed better antidiabetic and antihypertensive activities. This study investigated the prenatal developmental toxicity potential of the herbal tea of M. stenopetala and M. spicata leaves blend in rats. Methods: Wistar pregnant rats were randomly distributed into four groups (n = 8). Group I (control) dams received distilled water. Group II-IV dams were treated with 559.36, 1118.72, and 2237.44 mg/kg of herbal tea of M. stenopetala and Mentha spicata leaves formulations, respectively, during days 5-19 of gestation. Maternal mortality, clinical signs, body weight changes, and food consumption were recorded. On gestation day 20, cesarean sections were performed, and maternal parameters of systemic toxicity (e.g., body weight, serum biochemistry, organ weight, and macro-pathology) as well as reproductive toxicity (e.g., number of corpora lutea, implantations, resorptions (early/late), pre/postimplantation losses, number of fetuses (live/dead), and fetal body weights, length, and their sex ratio) were evaluated. Fetuses were further examined for external, soft tissue, and skeletal alterations. Results: No herbal tea-related maternal deaths or overt toxic symptoms were observed. The measured maternal systemic and reproductive toxicity parameters showed no herbal tea-associated significant alterations at any dosage levels. Moreover, there were no overt toxic effects of the herbal tea on the fetal external, visceral, or skeletal prenatal growth and development. Conclusion: The study findings demonstrated that the herbal tea of M. stenopetala and M. spicata leaves blend could be relatively safe/low toxic to pregnant rats and developing fetuses. The no-observed-adverse-effect level (NOAEL) of herbal tea for maternal toxicity, fetotoxicity, and teratogenicity in rats is estimated to be > 2237.44 mg/kg/day.

Subchronic toxicity study of herbal tea of Moringa stenopetala (Baker f.) Cudof. and Mentha spicata L. leaves formulation in Wistar albino rats.

Background: Moringa stenopetala (Baker f.) Cudof. and Mentha spicata L. are widely used in the traditional system of medicine for the treatment of diabetes, hypertension, digestive problems and various disorders. The leaves formulation of M. stenopetala and M. spicata herbal tea showed better antidiabetic and antihypertensive effects in rodent models. However, its long-term safety profile has not been investigated yet. Thus, this study investigated the subchronic (90 days) oral toxicity of the leaves formulation of M. stenopetala and M. spicata herbal tea in Wistar albino rats. Methods: Four groups of rats (n = 10, with 5/sex/group) were randomly assigned into a control (vehicle) group and three test groups (559.36, 1118.72 and 2237.44 mg/kg, respectively). The three test groups received the herbal tea of M. stenopetala and M. spicata leaves blend daily for 90 days. The control group received distilled water. During the treatment period, clinical signs were observed daily, and food consumption and body weight changes of the rats were measured weekly. At the end of the experiment, macro-pathological, hematological and biochemical parameters were evaluated. Furthermore, histopathology of liver, kidney, heart, stomach and pancreas were examined. Results: Subchronic oral administration of the herbal tea of M. stenopetala and M. spicata leaves blend did not result in death or significant toxicity signs in the treated group rats. Moreover, the herbal tea caused no significant changes on body weight, food intake, organ weight, hematological and biochemical parameters in either sex. However, the serum AST, CK and LDH levels were significantly elevated in rats treated with 2237.44 mg/kg of herbal tea in both sexes. There was no significant alteration in the histology of organs, only minor lesions in the liver, kidney and pancreas were observed. Conclusion: The study results indicate that the herbal tea of M. stenopetala and M. spicata leaves blend is relatively safe/low toxic to rats in subchronic exposure. However, further preclinical (chronic, teratogenic, reproductive and developmental toxicity) studies in animals are required in order to have sufficient safety and toxicity profiles for its use in humans.

Impact of Foliar Application of Amino Acids on Essential Oil Content, Odor Profile, and Flavonoid Content of Different Mint Varieties in Field Conditions.

Mint is an industrial plant that is a good source of essential oil and many phenolic compounds that have several positive benefits to human health and can be used to prevent the development of many diseases. The aim of this research was to investigate the possibility of increasing essential oil and flavonoid content, changing the chemical composition of these compounds in different mint cultivars under foliar application with precursors (phenylalanine, tryptophan, and tyrosine) at two concentrations, 100 and 200 mg L-1, to enable the possibilities for wider use of these plants when they are grown in field conditions. Spraying with phenylalanine at 100 mg L-1 concentration increased essential oil content in Mentha piperita 'Granada' plants by 0.53 percentage units. Foliar application with tyrosine solutions at 100 mg L-1 concentration most effectively influenced the essential oil odor profile Mentha spicata 'Crispa'. The highest number of total flavonoids was in Mentha piperita 'Swiss' sprayed with tyrosine at 100 mg L-1 concentration. The flavonoid content depended on the mint cultivar, amino acids, and their concentration. The results showed that the effect of amino acid solutions on different secondary metabolites' quantitative and qualitative composition differed depending on the mint cultivar; therefore, amino acids and their concentrations must be selected based on the cultivar they are targeting.

Biosynthesis and characterization of iron oxide nanoparticles from Mentha spicata and screening its combating potential against Phytophthora infestans.

Plant pathogens cause serious diseases to agricultural crops which lead to food insecurity in the world. To combat plant pathogens, various strategies have been developed including the use of agrochemicals. The overuse of these chemicals is now leading to the pesticide-resistant capability of pathogens. To overcome this problem, modern nanobiotechnology offers the production of alternative nano drugs. In this study, we used Mentha spicata for the synthesis of iron oxide nanoparticles using the green synthesis method. The synthesis of Fe2O3 NPs was confirmed through various characterizations. UV-Vis analysis detected a characteristic absorbance at the spectral range of 272 nm. The SEM micrographic analysis at various magnifications displayed circular or rod-shaped nanoparticles with a size ranging from 21 to 82 nm. The elemental EDX characterization showed intense peaks with a weight percent of 57, 34.93, and 8.07 for Fe, O, and, Cl respectively. TGA analysis showed that weight loss at 44-182, 500, and 660°C with no further modification indicates the thermal stability of iron oxide nanoparticles. FTIR spectrum of uncalined detects various bands at 3331, 1625, and 1,437 cm-1 for the hydroxyl group. After calcination two bands at 527 and 434 cm-1 were observed for Fe-O. The antimicrobial in vitro study showed maximum growth inhibition of Phytophthora infestans by the concentration of 100 µg ml-1 of Fe2O3-PE and Fe2O3 NPs. Therefore, this study resulted that bio-stable iron oxide nanoparticles can be used as alternative antimicrobial agents.

Phytochemical screening, cytotoxicity assessment and evaluation of in vitro antiplasmodial and in vivo antimalarial activities of Mentha spicata L. methanolic leaf extract.

ETHNOPHARMACOLOGICAL RELEVANCE: Malaria causes extensive morbidity and mortality, and the decreasing efficacy of artemisinin and its partner drugs has posed a serious concern. Therefore, it is important to identify new antimalarials, and the natural compounds from plants provide a promising platform. Mentha spicata L. representing the Lamiaceae family has been used in traditional medicine for various diseases including malaria. AIM OF THE STUDY: This study was aimed at evaluating the antiplasmodial activity of M. spicata methanolic leaf extract using Plasmodium falciparum (Pf) cultures (Pf3D7 and artemisinin (ART)-resistant PfCam3.IR539T strains) and antimalarial activity using Plasmodium berghei (Pb)-infected mice. Dry leaf powder and methanolic leaf extract were examined for in vivo antimalarial activity and the efficacy of oral versus parenteral administration was compared. MATERIALS AND METHODS: Leaves of M. spicata were collected and extracted using 70% methanol in water (v/v). [3H]-hypoxanthine incorporation assays and Giemsa-stained smears were used to assess the in vitro antiplasmodial activity of M. spicata methanolic extract against Pf3D7 and ART-resistant PfCam3.IR539T strains. Cytotoxicity was evaluated in HeLa and HEK-293T cell lines using MTT assays. Hemolysis assays were performed using red blood cells (RBCs). In vivo antimalarial activities of M. spicata dry leaf powder and methanolic leaf extract were examined in P. berghei-infected mice by Rane's curative test and Peters' 4-day suppressive test. RESULTS: Phytochemical screening of M. spicata methanolic leaf extract indicated the presence of reducing sugars, phenolic compounds, flavonoids, glycosides, sterols, saponins, alkaloids, coumarins, tannins, carbohydrates, and proteins. In vitro studies carried out using Pf cultures showed that M. spicata methanolic leaf extract had significant antiplasmodial activity against Pf3D7 cultures with a 50% inhibitory concentration (IC50) of 57.99 ± 2.82 µg/ml. The extract was also effective against ART-resistant PfCam3.IR539T strain with an IC50 of 71.23 ± 3.85 µg/ml. The extract did not show significant in vitro cytotoxicity, hemolysis, and in vivo toxicity. In vivo studies performed using Pb-infected mice treated with M. spicata dry leaf powder and methanolic leaf extract showed ∼50% inhibition in parasite growth at 1500 mg/kg and 1000 mg/kg doses, respectively. There was also a significant delay in the mortality of treated mice. Parenteral administration was found to be appropriate for the in vivo treatment. CONCLUSIONS: Our in vitro and in vivo findings from Pf and Pb parasites suggested the therapeutic potential of M. spicata leaf extract as an antimalarial. M. spicata leaf extract could also inhibit the growth of ART-resistant Pf strain. Further studies on fractionation and active component analysis of M. spicata leaf extract would be required to identify the bioactive phytochemicals having pharmaceutical and therapeutic values. Such efforts would help us in developing new antimalarials to combat malaria.

Soil Amendments with Spearmint, Peppermint and Rosemary Enhance the Community of Free-Living Nematodes and Improve Soil Quality, While Having Strikingly Different Effects on Plant Growth.

Sustainable farming practices aim to replace agrochemicals with plant-based alternatives to increase productivity and soil quality. To evaluate the potential use of aromatic plants as soil amendments in tomato seedbeds, in a greenhouse experiment, we used spearmint, peppermint, and rosemary, separately, as soil amendments, in pots sown with tomato, and studied their effect on seedling growth, soil nutrients, and the soil nematode community in terms of trophic and functional structure, metabolic footprint, and genera composition. Non-amended soil was used in the control pots. We further explored the dynamics of the plant-soil-nematode interactions by using aromatic plants at different stages of decomposition (0, 28, and 56 days). Incorporating aromatic plants into the soil led to the proliferation of free-living nematodes, especially of the opportunistic kind, resulting in vigorous and enriched soil. This was more pronounced in the case of the spearmint and peppermint, which also increased the tomato growth. The high soil nutritional status and enhanced plant growth were most prominent when the aromatic plants were left for 28 days to decompose in the soil before sowing. Compared with the mint plants, the rosemary had similar, yet less intense, effects on the soil community, but completely inhibited the growth of the tomato seedlings. Therefore, it is not recommended for use as a soil amendment in tomato seedbeds.

Spearmint (Mentha spicata L.) Phytochemical Profile: Impact of Pre/Post-Harvest Processing and Extractive Recovery.

The purpose of this study was to chemically compare samples of Mentha spicata (marketing byproducts, production byproducts, and export material), cultivated in the open field and under greenhouse, using an integrated approach by HPLC/DAD and GC/MS analysis. The presence of phenolic compounds was higher in the marketing byproducts cultivated in the open field. Marketing byproducts also had the highest amount of carvone. For this reason, this byproduct was selected as a candidate for the development of natural ingredients. With the best selected material, the optimization of simultaneous high-intensity ultrasound-assisted extraction processes was proposed for the recovery of the compounds of interest. This extraction was defined by Peleg's equation and polynomial regression analysis. Modeling showed that the factors amplitude, time, and solvent were found to be significant in the recovery process (p < 0.005). The maximum amount of compounds was obtained using 90% amplitude for 5 min and ethanol/water mixture (80:20) for extraction to simultaneously obtain phenolic and terpenoid compounds. This system obtained the highest amount of monoterpenoid and sesquiterpenoid compounds from the essential oil of M. spicata (64.93% vs. 84.55%). Thus, with an efficient and eco-friendly method, it was possible to optimize the extraction of compounds in M. spicata as a starting point for the use of its byproducts.

Chemical Compounds Emitted from Mentha spicata Repel Aromia bungii Females.

Aromia bungii (Coleoptera: Cerambycidae) is an economically important wood-boring insect pest of stone fruit trees, particularly Prunus persica, in China. It has entered Japan and several European countries as an invasive species in recent years. It is difficult to control because of the cryptic feeding behaviour of larvae beneath the bark. Identification of repellent constituents from non-host plants has potential for use in management strategies against this beetle. Mentha spicata is cultivated extensively in Hebei Province (China) as a medicinal plant. Firstly, antennal responses of female A. bungii to M. spicata volatiles were evaluated by coupled gas chromatography-electroantennograms (GC-EAD), and then the EAD-active components were tested in semi-field trials. The results showed that A. bungii females were significantly repelled by myrcene, (S)-(+)-carvone, (E)-ß-caryophyllene, and borneol compared with the control. The presence of myrcene (100 µL; 90% purity), (S)-(+)-carvone (200 µL; 96% purity), (E)-ß-caryophyllene (500 µL; 98.5% purity), and borneol (800 µL; 80% purity) significantly reduced the perching rates of A. bungii females on both peach logs and leaves. Considering cost and commercial availability, we suggest that myrcene, (S)-(+)-carvone, and (E)-ß-caryophyllene could be promising repellents against A. bungii females in the field.

Biochemical Characterization, Antifungal Activity, and Relative Gene Expression of Two Mentha Essential Oils Controlling Fusarium oxysporum, the Causal Agent of Lycopersicon esculentum Root Rot.

Tomato (Lycopersicon esculentum Mill.) is important food in daily human diets. Root rot disease by Fusarium oxysporum caused huge losses in tomato quality and yield annually. The extensive use of synthetic and chemical fungicides has environmental risks and health problems. Recent studies have pointed out the use of medicinal plant essential oils (EOs) and extracts for controlling fungal diseases. In the current research, Mentha spicata and Mentha longifolia EOs were used in different concentrations to control F. oxysporum. Many active compounds are present in these two EOs such as: thymol, adapic acid, menthol and menthyl acetate. These compounds possess antifungal effect through malformation and degradation of the fungal cell wall. The relative expression levels of distinctly upregulated defense-related WRKY genes (WRKY1, WRKY4, WRKY33 and WRKY53) in seedling root were evaluated as a plant-specific transcription factor (TF) group in different response pathways of abiotic stress. Results showed significant expression levels of WRKY, WRKY53, WRKY33, WRKY1 and WRKY4 genes. An upregulation was observed in defense-related genes such as chitinase and defensin in roots by application EOs under pathogen condition. In conclusion, M. spicata and M. longifolia EOs can be used effectively to control this plant pathogen as sustainable and eco-friendly botanical fungicides.