Peppermint antioxidants revisited

Exploring the anti-inflammatory, sedative, antidiabetic, and antioxidant potential in in-vitro and in-vivo models and phenolic profiling of Atractylis aristata Batt

ETHNOPHARMACOLOGICAL RELEVANCE

Atractylis aristata batt., as an endemic plant from the Asteraceae family, holds a significant position in the Ahaggar region of southern Algeria's traditional medicine. The aerial parts of Atractylis aristata was used to cure inflammation, fever, and stomach disorders.

AIM OF THE STUDY

The objective of the present investigation was to ascertain the overall bioactive components and phytochemical components and examine the antioxidant, antidiabetic, anti-inflammatory, acute toxicity, and sedative properties of the crude extract obtained from the aerial portions of Atractylis aristata (AaME).

MATERIALS AND METHODS

The AaME's antioxidant activity was assessed by the use of pyrogallol autoxidation, (1,1 diphenyl-2-picrylhydrazyl) (DPPH), 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and reducing power (RP) techniques. 1 mg/mL of AaME was used to evaluate the antidiabetic activity by applying the enzyme α-amylase inhibitory power test. At the same time, the bovine serum albumin (BSA) denaturation method was employed to quantify the in vitro anti-inflammatory activity at different concentrations (1.5625, 0.78125, 0.390625, 0.1953125 and 0.09765625 mg/mL). In contrast, following the Organization for Economic Co-operation and Development (OECD) guideline No. 423, which covers acute oral toxicity testing protocols, the limit dosage test was employed to assess in vivo acute toxicity. At the dose of 0.08 mg/mL, the carrageenan-induced paw edema approach was used to assess the anti-inflammatory efficacy in vivo, and the sedative activity was carried out at the dose of 0.08 mg/mL using the measurement of the locomotor method. Different bioactive compounds were identified within AaME using LC-MS/MS and HPLC-UV analysis.

RESULTS

The acute toxicity study showed no fatalities or noticeable neurobehavioral consequences at the limit test; this led to their classification in Globally Harmonized System (GHS) category Five, as the OECD guideline No 423 recommended. At a concentration of 0.08 mg/mL (2000 mg/kg), AaME showed apparent inhibition of paw edema and a significant (p = 0.01227) reduction in locomotor activity compared to the control animals. Our findings showed that AaME exhibited considerable antioxidant (IC50 = 0.040 ± 0.003 mg/mL (DPPH), IC50 = 0.005 ± 5.77 × 10-5 mg/mL (ABTS), AEAC = 91.15 ± 3.921 mg (RP) and IR% = 23.81 ± 4.276 (Inhibition rate of pyrogallol) and rebuts antidiabetic activities (I% = 57.6241% ± 2.81772). Our findings revealed that the maximum percentage of BSA inhibition (70.84 ± 0.10%) was obtained at 1.562.5 mg/mL. Thus, the AaME phytochemical profile performed using phytochemical screening, HPLC-UV, and LC-MS/MS analysis demonstrated that A. aristata can be a valuable source of chemicals with biological activity for pharmaceutical manufacturers.

CONCLUSION

The phytochemical profiling, determined through HPLC-UV and LC-MS/MS applications, reveals this plant's therapeutic value. The aerial parts of Atractylis aristata contain bioactive molecules such as gallic acid, ascorbic acid, and quercetin, contributing to its significant antioxidant capabilities. Furthermore, identifying alizarin, the active compound responsible for its anti-inflammatory properties, could provide evidence supporting the anti-inflammatory capabilities of this subspecies.

Phytochemical analysis of carotenoid profile in Mentha piperita and Artemisia vulgaris: cytotoxicity in tumoral cells and evaluation of plasmid DNA cleavage

Several medicinal plants have been administered to cancer patients attributed to their anticarcinogenic and chemoprotective properties, in addition to lower toxicity compared to traditional therapies. The aim was to investigate the antioxidant properties and carotenoid composition of aqueous extracts of Mentha piperita or Artemisia vulgaris which were previously found to exert beneficial effects on human health through diet. aqueous extracts exhibited potent antioxidant activity. A diversity of carotenoids was identified in these extracts using HPLC-PDA-MS/MS. Both extracts contained predominantly all-trans-lutein as the main component within this class. In order to investigate antioxidant properties, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) techniques were used. The (3-4,5 dimethylthiazol-2, 5 diphenyl tetrazolium bromide) (MTT) and Crystal Violet assays assessed cellular cytotoxicity. Assessments of presence of reactive species were carried out following exposure of oral squamous cell carcinoma cell line (SCC-4) to various aqueous extracts of M piperita or A vulgaris utilizing dichlorofluorescein diacetate (DCFH-DA) and nitric oxide (NO) assays. Exposure to these extracts induced severe cytotoxic effects, which led to investigation of the biochemical and molecular mechanisms underlying this observed effect. Data demonstrated that both solutions induced oxidative stress and DNA damage, especially at higher concentrations using agarose gel subjected to electrophoresis. It is known that exposure to excess amounts of antioxidants results in a prooxidant effect which is beneficial in cancer therapy. Further, the extracts were found to reduce viability of SCC-4 in culture, indicating that this antitumoral activity may be of therapeutic importance and requires further study.

Effects of methomyl on the intestinal microbiome and hepatic transcriptome of tilapia, and the modifying effects of mint co-culture

Methomyl (MET) is an oxime carbamate insecticide that can contaminate aquatic systems resulting in toxicological effects. It can harm some fish species possibly through the anti-oxidative, phagosome pathway. Mint is one of the most widely herbal plants exhibiting antioxidant activities. In this study, we investigated the impact of MET on the antioxidant system of Oreochromis niloticus in presence of mint as a floating bed. Results revealed that the superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase, and glutathione S-transferase significantly decreased and the GSH content significantly increased in the intestine. The hepatic peroxisome proliferator-activated receptor (PPAR) signalling pathway, carbon metabolism, renal phosphoinositide 3-kinase (PI3K)-Akt, mitogen-activated protein kinase (MAPK) signalling pathway, and phagosomes were significantly affected. Upon long-term exposure, circadian rhythm and phagosomes were enriched in the liver and kidney. However, mint increased the enriched pathways of Toll-like receptor, PPAR, p53, NF-kappa B, MAPK, oestrogen, and B cell receptor signalling pathways. MET with different concentrations destroyed the balance of gut microbiota, mint decreased Verrucomicrobia and Akkermansia for the maintenance resulted from MET. Cetobacterium had a positive impact on total nitrogen (TN), chemical oxygen demand (CODMn), and glutathione reductase (GR), while Akkermansia had a positive impact on feed conversion ratio (FCR), SOD and CAT, and the abundance of both decreased due to MET exposure. High mint density removed more concentrations of nitrogen and phosphorus in the tilapia cultivation wastewater. Therefore, planting with mint can alleviate the toxicological effects produced by MET, shape the intestinal microbiota, and strengthen the connection between water quality and the metabolic parameters.

Effectiveness of Phosphate and Zinc Solubilizing Paenarthrobacter nitroguajacolicus P1 as Halotolerant Rhizobacterium with Growth-Promoting Activity on Pistacia vera L

Plant growth-promoting rhizobacteria (PGPR) are beneficial microorganisms to develop microbial fertilizers. Biofertilizers can accelerate plant growth and enhance crop yields. The current research aimed to isolate and identify rhizobacterium with plant growth-promoting activity in the rhizospheric region of pistachio trees in arid and salty region of Iran. In the present study, 26 bacterial isolates were isolated from the rhizospheric region of the pistachio trees. Plant growth-promoting characteristics of isolated bacteria, including the ability to solubilize phosphate and zinc, produce hydrolyzing enzymes, and hydrogen cyanide (HCN), as well as synthesize indole-3-acetic acid (IAA) were evaluated through in vitro assays. Based on these activities, five multifunctional bacterial strains designated P1, P10, P11, P17, and P19 were then applied and their effect was studied on the growth and physiological properties of Pistacia vera L. seedlings by pot experiments under normal conditions. Finally, the most efficient strain has been identified by analysis of the 16S rRNA gene sequence. According to the results, all the isolated bacteria exhibited considerable plant growth-promoting properties. They could produce amylase (n = 26, 2 ± 0.00-13 ± 0.42 mm), lipase (n = 24, 2 ± 0.00-9 ± 0.23 mm), protease (n = 20, 1 ± 0.00-17 ± 0.0 mm), indole-3-acetic acid (n = 26, ranging from 5.05 ± 0.08 to 11.5 ± 0.11 μg/mL) and HCN (n = 24). Six isolates showed significant growth at 20% w/v NaCl. Inoculation of P1, P17, and P19 increased chlorophyll, carotenoid, and phenolic content in treated Pistacia vera L. seedlings. P1 and P11 inoculated plants showed an enhanced level of anthocyanin and proline. These most effective strains were catalase and Gram-positive bacterium and showed antibiotic sensitivity. They can consider as halotolerant PGPR, due to the growth in the presence of NaCl (20% w/v). Finally, P1 inoculated plants exhibited higher levels of sugar content. This strain showed the most similarity (99.92%-1322 bp) to Paenarthrobacter nitroguajacolicus based on 16S rRNA gene sequence. Based on the results, Paenarthrobacter nitroguajacolicus P1 with multiple PGPR can be applied as a promising candidate in the soil-Pistacia vera L. system to improve their productivity and health by increasing available nutrient content, improving photosynthetic parameters, and producing phytohormones and HCN.

New Healthy Low-Sugar and Carotenoid-Enriched/High-Antioxidant Beverage: Study of Optimization and Physicochemical Properties

Lutein is a prominent biologically active carotenoid pigment with a polyene skeleton that has great benefits for human health. The study examined the synergistic effects of potentially functional components, including lutein carotenoid (LC), Mentha × Piperita extract (MPE), and Citrus × aurantifolia essential oil (CAEO), all three as bioactive components and antioxidants (AOs), on the physicochemical characteristics of a new low-sugar and carotenoid-enriched high-antioxidant beverage. Sucralose was utilized as a non-nutritive sweetener. Polynomial equations obtained by combined design methodology (CDM) were fitted to the experimental data of total phenolic and flavonoid contents (TPC and TFC, respectively) and antioxidant potential of the beverages using multiple regression analysis with R2 (determination coefficient) values of 0.87, 0.89, and 0.97, respectively. Estimated response values for the TPC, TFC, and antioxidant potential (determined as 2, 2-diphenyl-1-picrylhydrazyl radical (DPPH•) scavenging activity) of the optimum beverage formulation were 41.90 mg gallic acid equivalent (GAE) per L-1, 27.51 mg quercetin equivalent (QE) per L-1, and 34.06%, respectively, with a desirability value of 0.74. The potentially functional components had a synergistic effect on the antioxidant potential. This healthy beverage can have the potential to enhance health benefits and may have therapeutic potential for diabetic patients.

The mint versus Covid hypothesis

Recent lines of evidence suggest the intriguing hypothesis that consuming common culinary herbs of the mint family might help prevent or treat Covid. Individual citizens could easily explore the hypothesis using ordinary kitchen materials. I offer a philosophical framework to account for the puzzling lack of public health messaging about this interesting idea.

Kinetics of Microwave-Assisted Extraction Process Applied on Recovery of Peppermint Polyphenols: Experiments and Modeling

The aim of this work was to investigate the microwave-assisted extraction (MAE) kinetics of polyphenolic compounds from organic peppermint leaves. The phytochemicals of peppermint (Mentha piperita L.) are increasingly used in food technology due to their numerous biological activities. The processing of various plant materials by MAE and the production of high-quality extracts is becoming increasingly important. Therefore, the influence of microwave irradiation power (90, 180, 360, 600, and 800 W) on total extraction yield (Y), total polyphenols yield (TP), and flavonoid yield (TF) were investigated. Common empirical models (first-order, Peleg's hyperbolic, Elovich's logarithmic, and power-law model) were applied to the extraction process. The first-order kinetics model provided the best agreement with the experimental results in terms of statistical parameters (SS_er, R², and AARD). Therefore, the influences of irradiation power on the adjustable model parameters (k and C_eq) were investigated. It was found that irradiation power exerted a significant influence on k, while its influence on the asymptotic value of the response was negligible. The highest experimentally determined k (2.28 min^-1) was obtained at an irradiation power of 600 W, while the optimal irradiation power determined by the maximum fitting curve determination predicted the highest k (2.36 min^-1) at 665 W.

Dyeing of polyamide 6 fabric with new bio-colorant and bio-mordants

The present study investigates the natural dyeing of nylon fabric using the dragon's blood resin extract. Response surface methodology was used to optimize the process variables including pH (3-9), temperature (50-100 °C), concentration (10-50%owf), and time (30-90 min). From a visual point of view, diverse eco-friendly shades with a rather diverse color gamut of varied hue and tone were generated by applying a wide range of natural and eco-label mordants. The impact of 4 bio-mordants (including peppermint, mugworts (Artemisia), Dorema ammoniacum (DA) gum, and pomegranate rind), as well as 4 mineral mordants (alum, copper (II) sulfate, potassium dichromate, and iron (II) sulfate) on the color and fastness properties of the dyed nylon samples, was assessed. The concentration of the used mordants was 5%owf, and the dyeing experiments were conducted by applying the pre-mordanting technique. Measurement of the color strength (K/S) of the dyed fabric was done using a reflectance spectrophotometer. The dyed nylon fastness qualities and the colorimetric characteristics were then evaluated by applying the related standards. The results showed that the optimum conditions for obtaining the highest color strength were dye concentration = 50%owf, pH = 6, temperature = 100 °C, and dyeing tome = 60 min. The proposed ISO standards in relation to colorfastness displayed acceptable ratings for the color strength of dragon's blood resin dyed fabric while its treatment was done by applying bio-mordants in comparison to its metallic counterparts. Therefore, dragon's blood resin could be regarded as a promising eco-friendly natural colorant source for the purpose of sustainable nylon dyeing.

Small Brown Planthopper Nymph Infestation Regulates Plant Defenses by Affecting Secondary Metabolite Biosynthesis in Rice

The small brown planthopper (SBPH, Laodelphax striatellus) is one of the most destructive insect pests in rice (Oryza sativa), which is the world's major grain crop. The dynamic changes in the rice transcriptome and metabolome in response to planthopper female adult feeding and oviposition have been reported. However, the effects of nymph feeding remain unclear. In this study, we found that pre-infestation with SBPH nymphs increased the susceptibility of rice plants to SBPH infestation. We used a combination of broadly targeted metabolomic and transcriptomic studies to investigate the rice metabolites altered by SBPH feeding. We observed that SBPH feeding induced significant changes in 92 metabolites, including 56 defense-related secondary metabolites (34 flavonoids, 17 alkaloids, and 5 phenolic acids). Notably, there were more downregulated metabolites than upregulated metabolites. Additionally, nymph feeding significantly increased the accumulation of seven phenolamines and three phenolic acids but decreased the levels of most flavonoids. In SBPH-infested groups, 29 differentially accumulated flavonoids were downregulated, and this effect was more pronounced with infestation time. The findings of this study indicate that SBPH nymph feeding suppresses flavonoid biosynthesis in rice, resulting in increased susceptibility to SBPH infestation.

Obtaining poly (lactic acid) nanofibers encapsulated with peppermint essential oil as potential packaging via solution-blow-spinning

The development of active packaging based on biodegradable material and incorporating active compounds, such as essential oil, is a new technique to ensure food safety without harming the environment. In this study, nanofiber mats of poly (lactic acid)/ polyethylene glycol (PLA/PEG) blend incorporated with peppermint essential oil (PO) at different ratios (5-20 % v/w) were produced by solution-blow-spinning (SBS) for potential packaging application. Electron microscopy showed a cylindrical and interlaced morphology for PLA/PEG/PO and a significant increase in the diameter (139-192 nm) of the nanofibers by increasing PO content. All nanofibers showed high thermal stability (278-345 °C) suitable for use in the food industry. Nuclear magnetic resonance (¹³C NMR) spectrum confirmed PO in the nanofibers after SBS. ATR-FTIR spectral analysis supported the chemical composition of the nanofiber mats. PO addition led to obtaining hydrophobic nanofibers, enhancing the contact angle to 122° and decreasing water vapor permeability (60 % reduction compared to the PLA/PEG (3.0 g.mm.kPa^-1.h^-1.m^-2). Although the PLA/PEG/20%PO nanofibers did not show halo formation in 24 h, they effectively extended the strawberries' shelf-life at 25 °C, evidencing PO release over time. It also reduced weight loss (2.5 % and 0.3 % weight loss after 5 days for PLA/PEG and PLA/PEG/20%PO, respectively) and increased firmness (8-12 N) for strawberries packed with the nanofiber mats. It is suggested that PLA/PEG films incorporating PO may be used as an active, environmentally friendly packaging material.

Effect of Oil Type on Spatial Partition of Resveratrol in the Aqueous Phase, the Protein Interface and the Oil Phase of O/W Emulsions Stabilized by Whey Protein and Caseinate

Oil-in-water emulsions contain the inner oil phase, the protein membrane at the interface and the aqueous phase. In this study, the spatial partition of resveratrol was investigated in sunflower oil, fish oil, medium-chain triglyceride (MCT) and peppermint oil emulsions stabilized by native whey protein isolate (WPI), heat-denatured WPI and sodium caseinate. Resveratrol was added in the aqueous phase of emulsions and its partition was analyzed in term of resveratrol solubility in bulk oil and in the aqueous phase of protein, protein concentration and interfacial protein. The final concentrations of resveratrol in the aqueous phase were basically greater than those in the oil phase of fish oil, sunflower oil and MCT oil emulsions, while the final concentrations of resveratrol in the oil phase were greater than those in the aqueous phase of peppermint oil emulsions. The difference in the interfacial partition of resveratrol and proteins increased as the polyphenol solubility in bulk oil increased. Resveratrol solubility in the oil phase drove its transfer from the aqueous phase into the oil phase in all emulsions, except that the interfacial protein also contributed to the transfer in fish oil emulsions. The oil–water interface provided the microenvironment for the enrichment of resveratrol by proteins.

Essential Oils from Apiaceae, Asteraceae, Cupressaceae and Lamiaceae Families Grown in Serbia: Comparative Chemical Profiling with In Vitro Antioxidant Activity

The aim of the present study was to investigate the chemical profile and antioxidant activity of essential oils obtained from the most commonly grown plant species in Serbia. Aromatic and medicinal plants from Lamiaceae (Mentha x Piperita, Ocimum basilicum, Origanum majorana, Origanum vulgare, Salvia officinalis, Satureja hortensis, Satureja montana and Thymus vulgaris), Asteraceae (Ehinacea purpurea and Matricaria chamomilla), Apiaceae (Anethum graveolens, Carum carvi, Foeniculum vulgare, Petroselinum crispum and Pimpinella anisum) and Cupressaceae (Juniperus comunis) were selected as raw material for essential oils (EOs)' isolation. Hydrodistillation (HD) was used for the isolation of EOs while they were evaluated in terms of yield and terpenoid profiles by GC-MS. In vitro radical scavenging DPPH and ABTS⁺ radical activities were carried out for all EOs. Finally, a principal component analysis (PCA) was performed with the experimental results of the composition and antioxidant activity of the EOs, which showed a clear distinction between the selected plant species for the aforementioned responses. This work represents a screening tool for the selection of other EO candidates for further processing by emerging extraction techniques and the use of EOs as natural additives for meat products.

Development of a Novel Low-Calorie Lime Juice-Based Prebiotic Beverage Using a Combined Design Optimization Methodology

A novel lime-juice based low-calorie functional beverage was developed by using D-optimal combined design optimization. For the preparation of the beverage, the following functional ingredients were used: lime juice, lime peel essential oil (LEO) as a flavoring agent and bioactive component, sucralose as a low-calorie sweetener, an inulin/polydextrose (I/P) mixture as prebiotic fibers, pectin as a thickening agent and soluble dietary fiber, lutein as a carotenoid colorant and antioxidant, and peppermint extract (ME) as a flavoring agent and bioactive component. A combined design consisting of one mixture factor (LEO/ME ratio), one numeric factor (lutein concentration), and one categoric factor (presence or absence of prebiotics) was used for optimizing the functional beverage based on the sensory quality. Regression models were adequately fitted to the data of sensory acceptance with a determination coefficient >90%. The sample containing a mixture of prebiotics, 2:3 (v/v) ratio of LEO: ME, and 3 mg/100 mL lutein was selected as the best formulation among the six optimal beverages which was suggested by Design-Expert software. This final optimum sample showed the highest total phenolic (44.22 mg gallic acid equivalents/L) and flavonoid (25.49 mg quercetin equivalents/L) contents, and its antioxidant activity (as 2,2-diphenyl-1-picrylhydrazyl radical (DPPH^•) scavenging) was 38.30%. The newly designed beverage has the potential to promote health benefits and in therapeutic applications.

Symbiotic association of microalgae and plants in a deep water culture system

In this study, microalgae culture (Chlorella vulgaris) and mint seedlings (Mentha spp.) were combined in a hydroponic system to improve plant growth. Mint seedlings were grown both in microalgae-containing and in microalgae-free trial groups, and both groups were subjected to aerated and non-aerated conditions to show the effect of aeration and microalgae co-cultivation on the mint weight and height. The plant quality was also determined with color measurements of the mint leaves. The increase in the weight of the plants was the highest in microalgae-containing and aerated group (0.47 g) and the lowest in microalgae-free and non-aerated group (0.22 g). On the other hand, the variation in the plant height was not significant between the groups, the growth was lateral. The best quality mint leaves were also produced in microalgae-containing and aerated group. Our results have revealed the symbiotic life of the mint plant placed in the hydroponic system with microalgae and demonstrated improved mint growth and quality. This co-cultivation system is also potentially more environmentally friendly compared to growing microalgae and mint independently because of lower cost of aeration and mixing for microalgae cultivation, higher nutrient consumption efficiency, and reduced nutrient outflow.

Application of insecticides on peppermint (Mentha × piperita L.) induces lignin accumulation in leaves by consuming phenolic acids and thus potentially deteriorates quality

Irrational use of pesticides may lead to physiological and metabolic disorders in different crops. However, there are limited investigations on impacts of insecticides on physiology and biochemistry, secondary metabolic pathways, and associated quality of medicinal plants such as peppermint (Mentha × piperita L.). In this study, target metabolites in peppermint were monitored following foliar spraying of five insecticides: imidacloprid, pyriproxyfen, acetamiprid, chlorantraniliprole, and chlorfenapyr. Compared with the control, all insecticide treatments caused a significant loss of soluble protein (decreased by 22.3-38.7%) in peppermint leaves. Insecticides induced an increase in the levels of phytohormones jasmonic acid and abscisic acid in response to these chemical stresses. Among them, imidacloprid increased jasmonic acid by 388.3%, and pyriproxyfen increased abscisic acid by 98.8%. The contents of phenylpropanoid metabolites, including rutin, quercetin, apigenin, caffeic acid, 4-hydroxybenzoic acid, ferulic acid, syringic acid, and sinapic acid showed a decreasing trend, with pyriproxyfen decreasing the levels of quercetin and 4-hydroxybenzoic acid by 78.8% and 72.6%, respectively. Combined with correlation analysis, the content of lignin in leaves shows different degrees of negative correlations with several phenolic acids. It could be inferred that insecticides may trigger plant defense mechanisms that accumulate lignin (increased by 24.6-49.1%) in leaves by consuming phenolic acids to barricade absorption of insecticides. Through constructing networks between phytohormones and secondary metabolites, peppermint may regulate the contents of caffeic acid, 4-hydroxybenzoic acid, and sinapic acid by the antagonistic effect between salicylic acid and abscisic acid in response to insecticidal stresses. Principal component analysis and systemic cluster analysis revealed that the most pronounced changes in physiological indexes and metabolites were caused by the pyriproxyfen treatment. In conclusion, this study improves our understanding of the mechanism by which insecticides affect plant physiological and metabolic processes, thus potentially altering the quality and therapeutic value of peppermint as an example.

The Influence of Microwave Treatments on Bioactive Compounds and Antioxidant Capacity of Mentha piperita L

Microwave extraction is becoming a popular option in many fields, especially for bioactive compounds from medicinal plants. This paper addresses the application of microwaves in the process of extracting bioactive compounds (phenols, flavonoids, chlorophyll) from peppermint with antioxidant capacity in order to highlight the influence of the microwave field on the quality of the final product in comparison with the control samples. The Mentha piperita L. is a rich source of phenols. The total phenol content after applying the MW treatments significant increased and varied between 25.000 ± 1.992 and 391.687 ± 20.537 mg GAE/100 g dw compared to the untreated sample (8.089 ± 2.745 mg GAE/100 g dw). The same trend was also recorded in the case of the flavonoid and pigment content in peppermint leaves following the application of microwave treatments. The obtained results were investigated using chemometric multivariate analysis. The main purpose of our research was to compare the possibilities of total or partial substitution of conventional extraction technologies with the microwave extraction technology, and also to highlight the existing differences in the amount of total phenols and flavonoids extracted from peppermint plants in different processing conditions. Through microwave processing, a significant increase in polyphenolic compounds is obtained.

Effect of methomyl on water quality, growth performance and antioxidant system in liver of GIFT (Oreochromis niloticus) in the presence of peppermint (Mentha haplocalyx Briq.) as a floating bed

This study was conducted to investigate the effect of methomyl (MET) on water quality, growth and antioxidant system of genetically improved farmed tilapia (GIFT, Oreochromis niloticus) in the presence of peppermint as a floating bed. The concentration of NH3-N, NO2--N, NO3--N and TP in T3 (with 200 g wet peppermint) was significantly lower (P < 0.05) than that in T2 (100 g), T1 (50 g) and control, and the nutrient removal rates were 61.90%, 31.59%, 59.86% and 45.92% in 20 days, respectively. Juveniles GIFT (5.1 ± 0.2 g) were exposed to sub-lethal concentrations of 0.2, 2.0, 20 and 200 µg/L of MET for 45 days. After 6 weeks of a feeding trial, percentage weight gain (PWG), specific growth rate (SGR) and feed conversion ratio (FCR) were significantly decreased in 0.2, 2.0, 20 µg/L MET groups respectively and increased in the 200 µg/L MET group. Compared with the control, no significant changes in superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) were detected in the 0.2 µg/L group. The significant increase in activities of SOD, CAT and GPx was accompanied by a diminution in reduced glutathione (GSH) levels resulting with tilapia exposed to 2.0, 20, or 200 µg/L for 45 days. The highest rates observed in SOD, CAT, GPx were 157.63%, 164.05% and 167.46% of the control respectively, and the lowest inhibition rate in GSH was 66.42% of the control. Peppermint as a floating bed can alleviate the adverse effects of MET, such as growth retardation and oxidative stress.

Measurement of Naringin from Citrus Fruits by High-Performance Liquid Chromatography - a Review

Naringin is a flavonoid found primarily in citrus species with especially high concentrations being present in grapefruit (Citrus paradisi), bitter orange (Citrus aurantium), and pomelo (Citrus grandis). Because of its many positive effects on human health, naringin has been the focus of increasing attention in recent years. Recently, conventional extraction methods have been commonly replaced with unconventional methods, such as ultrasound-assisted extraction (UAE) and other, more eco-friendly extraction methods requiring little-to-no environmentally harmful solvents or significantly less energy. Naringin analysis is most commonly done via high-performance liquid chromatography (HPLC), and ultrahigh-performance liquid chromatography (UHPLC) coupled with a mass spectrometer (MS) or a photodiode array (DAD) detector. The aim of this review is to provide an overview of recent trends developments in the extraction, sample preparation, and liquid chromatographic analysis of the compound originating from citrus fruits or their products.

Risk assessment of in vitro cytotoxicity, antioxidant and antimicrobial activities of Mentha piperita L. essential oil

The objective of this study was to determine the chemical composition as well as antioxidant, antibacterial, and cytotoxic properties of the essential oil of Mentha piperita L. (peppermint). Fifteen chemical constituents were identified in the essential oil, for a total of 99.99% of the compounds. The essential oil exhibited antimicrobial activity against two Gram-positive bacteria Staphylococcus aureus and Listeria monocytogenes. The minimum inhibitory concentration (MIC) of essential oil of Mentha piperita L. for Staphylococcus aureus and Listeria monocytogenes was 1.84 μg/ml, whereas the minimum bactericidal concentration (MBC) values were 3.7 and 7.43 μg/ml, respectively. The oil displayed potent antioxidant activity inhibiting up to approximately73% of 2,2'-azinothiobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals. In the cytotoxicity assay, the highest essential oil concentration (100 μg/ml) resulted in viability of approximately 90% human epidermal keratinocyte (HaCaT) cells. With respect to antitumor activity in C6 rat glioma cells, there was significant reduction in cell viability: 56-74% in 24 hr, and 71-77% in 48 hr. Data suggest that in presence of the essential oil of Mentha piperita L. antioxidant, antibacterial, antitumor and non-cytotoxic properties were noted.

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

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

Optimizing growing conditions for hydroponic farming of selected medicinal and aromatic plants

This work presents a pipeline for optimizing semi-hydroponic growth conditions and analyzes the impact on the growth and metabolism in three Mentha species (M. arvensis, M. x piperita, or M. spicata) and three Ocimum basilicum genotypes (́Chládek červená́, ́Litrá, or ́Máneś). The plant growth and the content- of nitrogen-containing compounds, phenolics, and terpenoids were determined under different nitrate concentrations and salt stress. Different responses were observed among genotypes for both species. ́Chládek červená́ had the best growth under low nitrate, with lower histamine and higher flavonoid levels. Mentha x piperita was the best mint species performing under low nitrate and salt stress. Altogether, we demonstrate that a combination of phenomics and metabolomics is ideal to identify the optimal growth conditions for these plants and the chemical markers associated with these conditions. Besides, we showed that both primary and secondary metabolites can be good markers for classifying both species.

Peppermint leaves hydrodistillation by-products: bioactive properties and incorporation into ice cream formulations

Distillation by-products of peppermint have not been considered for the valorization of bioactive compounds. In this study, by-products of peppermint after hydrodistillation, hydrosol and distilled leaves, were investigated followed by the most effective fraction was incorporated into ice cream formulations in order to improve the health promoting effects including antioxidant and α-glucosidase inhibition capacities of the ice creams. Distilled leaves of peppermint were subjected to sequential extraction by ethyl acetate and ethanol. HPLC analyses of eriocitrin and total phenolic analysis indicated that hydrosol contained significant amount of phenolics after 2 h hydrodistillation. Extending hydrodistillation from 1 to 2 h had insignificant effects on phenolic content. Distilled leaves of peppermint had extract yield of 7.39 and 7.19 g/100 mL in 1 and 2 h ethyl acetate extraction, respectively. The predominant phenolic of peppermint (eriocitrin) was 917.5 mg/L in hydrosol after 1 h distillation. Four h distillation of peppermint resulted in decrease in the amount of eriocitrin, however, hydrosol contained valuable amount of phenolics (840.1 mg/L). Hydrosols displayed higher antioxidant capacity in all tested methods than distilled leaves. Hydrosols, at equal amount of phenolics, had higher α-glucosidase inhibition capacity (5.92 µg/mL) than ethyl acetate extract (14.62 µg/mL) and ethanol extract (17.04 µg/mL) of deodorized leaves. Hydrosols were spray dried with the aid of maltodextrin in order to increase drying yield and incorporate the spray dried hydrosol (SDH) into ice cream formulations. Among others, ice cream incorporated with 0.5% of SDH was accepted by the panelists without damaging sensorial properties of ice cream.

Peppermint extract inhibits protein aggregation

The extracts of 7 herbs were screened and compared for their functional ability to inhibit the aggregation of trypsin as an appropriate model protein for in vitro fibrillation in aqueous ethanol at pH 7.0. Turbidity measurements, total phenolic content determination, aggregation kinetics, Congo red binding assay as well as transmission electron microscopy were used to analyse the inhibition of amyloid fibril formation. This correlated with the total phenolic content of the herb extracts. The peppermint extract proved to be the most potent anti-amyloidogenic agent. Results showed that the peppermint extract exerted dose-dependent inhibitory effect on trypsin fibril formation.

Mint Oil, ɤ-Tocopherol, and Whole Yeast Cell in Sow Diets Enhance Offspring Performance in the Postweaning Period

Times of high metabolic activity in gestation and lactation, as well as periods of stress at weaning, can lead to greater incidences of oxidative stress in the dam and offspring during the suckling and postweaning period. Oxidative stress is an imbalance between prooxidant molecules and the antioxidant defense system that can negatively impact growth and/or reproductive performance. The objective of this research was to evaluate the effectiveness of whole yeast cell, peppermint oil, and ɤ-tocopherol in gestation and lactation on maternal oxidative status and offspring growth from birth to market. In study 1, 45 sows and gilts were assigned to one of four diets [control diet (CON), control + whole yeast cell (YC), control + mint oil top dress (MO), and control + yeast cell and mint oil top dress (YCMO)] provided from d110 of gestation through to weaning. A total of 481 weaned offspring were randomly allotted to pens balanced by weight and litter within maternal treatment and received the same dietary treatment as the sow for 35 days postwean in a four-phase feeding regimen. In study 2, 53 sows and gilts were allotted to four diet regimens similar to study 1 [CON, YC, MO, and control + ɤ-tocopherol (GT)] from d5 postbreeding to weaning. At weaning, 605 piglets were randomly allotted to pens, balanced by weight and litter within maternal treatment and fed a common diet for 126 days postwean in a nine-phase feeding regimen. Maternal dietary treatment did not impact sow body weight, piglet birth weight, and litter size in either study. In study 1, piglets from YC sows were heavier (p < 0.05) at weaning than CON animals. In the postwean period, overall daily gain was greater (p < 0.05) for CON-fed pigs than YCMO pigs, with overall feed intake greater (p < 0.05) for YCMO- than MO-fed pigs, resulting in lower (p < 0.05) Gain to Feed (G:F) in YCMO-fed pigs. In study 1, glutathione content in milk tended to be lower (p < 0.10) in MO than in YCMO sows. In study 2, piglets from GT-fed sows tended to be heavier (p < 0.10) at weaning than YC piglets. Lightweight pigs from CON sows tended to be lighter (p < 0.10) than pigs from all other treatment groups at weaning and day (d) 29 postwean. Lightweight MO and GT pigs were heavier at d42 (p < 0.05) than CON and YC pigs. At d70 postwean, GT pigs tended to be heavier than CON pigs. Lightweight MO pigs had greater gain (p < 0.05) during the finishing period than all other treatment groups. With respect to sow oxidative status in study 2, glutathione content in colostrum and d4 and 14 milk samples did not differ by maternal treatment. Superoxide dismutase activity in sow sera, colostrum, and milk did not differ between diets in either study. Whole yeast cell and ɤ-tocopherol supplementation in sow lactation diets resulted in heavier offspring. However, pre- and postnatal exposure to mint oil benefited lightweight pigs up to market weight.

LC-ESI-QTOF-MS/MS Characterisation of Phenolics in Herbal Tea Infusion and Their Antioxidant Potential

Ginger (Zingiber officinale R.), lemon (Citrus limon L.) and mint (Mentha sp.) are commonly consumed medicinal plants that have been of interest due to their health benefits and purported antioxidant capacities. This study was conducted on the premise that no previous study has been performed to elucidate the antioxidant and phenolic profile of the ginger, lemon and mint herbal tea infusion (GLMT). The aim of the study was to investigate and characterise the phenolic contents of ginger, lemon, mint and GLMT, as well as determine their antioxidant potential. Mint recorded the highest total phenolic content, TPC (14.35 ± 0.19 mg gallic acid equivalent/g) and 2,2′-azino-bis(3-e-thylbenzothiazoline-6-sulfonic acid), ABTS (24.25 ± 2.18 mg ascorbic acid equivalent/g) antioxidant activity. GLMT recorded the highest antioxidant activity in the reducing power assay, RPA (1.01 ± 0.04 mg ascorbic acid equivalent/g) and hydroxyl radical scavenging assay, •OH-RSA (0.77 ± 0.08 mg ascorbic acid equivalent/g). Correlation analysis showed that phenolic content positively correlated with the antioxidant activity. Venn diagram analysis revealed that mint contained a high proportion of exclusive phenolic compounds. Liquid chromatography coupled with electrospray ionisation and quadrupole time of flight tandem mass spectrometry (LC-ESI-QTOF-MS/MS) characterised a total of 73 phenolic compounds, out of which 11, 31 and 49 were found in ginger, lemon and mint respectively. These characterised phenolic compounds include phenolic acids (24), flavonoids (35), other phenolic compounds (9), lignans (4) and stilbene (1). High-performance liquid chromatography photometric diode array (HPLC-PDA) quantification showed that GLMT does contain a relatively high concentration of phenolic compounds. This study presented the phenolic profile and antioxidant potential of GLMT and its ingredients, which may increase the confidence in developing GLMT into functional food products or nutraceuticals.

A simple method to determine antioxidant status in aromatic plants subjected to drought stress

Drought is a major environmental stress factor that affects the growth and development of plants. All plants have to maintain the reactive oxygen species within certain levels for normal cellular homeostasis by means of their antioxidant systems, which can be classified as enzymatic and non-enzymatic. Plants under drought stress generate an excess production of reactive oxygen species. At high concentrations, this can be detrimental by producing damage to the protein structures and inhibiting enzymes, as well as oxidizing macromolecules, which may eventually lead to cell death. There has been increasing attention paid to the antioxidant capacity of aromatic/medicinal plants, with a high antioxidant content having been reported in some plant extracts, such as in Mentha piperita (peppermint). Peppermint plants cultivated under drought stress also present high levels of phenolic compounds, peroxidase enzyme activity and lipid peroxidation of membranes. A simple and inexpensive laboratory class is proposed for teaching some mechanisms that plants have evolved to avoid reactive oxygen species damage. The series of lab experiments described is aimed at demonstrating the antioxidant status in aromatic plants subjected to drought stress, by measuring total phenolic compound content (non-enzymatic antioxidant compound), peroxidase activity (enzymatic antioxidant) and malondialdehyde, as convenient biomarkers for lipid peroxidation. The proposed class will be carried out by undergraduate students of the advanced biochemistry course, as part of our biology and agronomy studies. The experiment presented is intended to be used as a vehicle to emphasize the concepts that students have learned in their lectures. This lab exercise to be carried out by the students has dual goals: to apply a methodology only learned superficially on previous courses, and also to increase their understanding of how plants developed resistance mechanisms in order to tolerate drought stress.

Investigation of yield, phytochemical composition, and photosynthetic pigments in different mint ecotypes under salinity stress

Salinity stress is one of the main limiting factors of medicinal plant growth and may affect their characteristics and chemical composition. In order to evaluate the response of different species of Iranian mint to salinity stress, an experiment was designed in greenhouse conditions. In this experiment, six Iranian mint species were cultivated in pots under different salinity stress including 0, 2.5, 5, and 7.5 dS/m. The chlorophyll indices (a, b, total, and a/b ratio), carotenoids, total anthocyanin, total phenolic and flavonoid content, antioxidant activity, dry matter yield, and essential oil content were measured in two different harvest stages. Salinity stress affected various measured traits. The results showed that despite the negative effect of salinity stress on photosynthetic pigments, in some ecotypes and species, photosynthetic pigments were not affected by salinity stress. The amount of total phenolic content, total flavonoid content, and total anthocyanin increased in response to salinity stress. The dry matter decreased under salinity stress, but the content of essential oil increased as a result of salinity stress increment. The results of PCA biplot showed that the E16 and E18 ecotypes were separated by a large distance. Among the various ecotypes, E18 had the most desirable traits which can be recognized as a salt-tolerant ecotype. Also, piperita species was the best among the species in all salinity stress levels.

Phenolic Compounds and Biological Activity of Selected Mentha Species

Mentha species are widely used as food, medicine, spices, and flavoring agents. Thus, chemical composition is an important parameter for assessing the quality of mints. In general, the contents of menthol, menthone, eucalyptol, and limonene comprise one of the major parameters for assessing the quality of commercially important mints. Building further on the phytochemical characterization of the quality of Mentha species, this work was focused on the composition of phenolic compounds in methanolic extracts. Thirteen Mentha species were grown under the same environmental conditions, and their methanolic extracts were subjected to the LC-MS/MS (liquid chromatography-tandem mass spectrometry) profiling of phenolics and the testing their biological activities, i.e., antioxidant and tyrosinase inhibition activities, which are important features for the cosmetic industry. The total phenolic content (TPC) ranged from 14.81 ± 1.09 mg GAE (gallic acid equivalents)/g for Mentha cervina to 58.93. ± 8.39 mg GAE/g for Mentha suaveolens. The antioxidant activity of examined Mentha related with the content of the phenolic compounds and ranged from 22.79 ± 1.85 to 106.04 ± 3.26 mg TE (Trolox equivalents)/g for M. cervina and Mentha x villosa, respectively. Additionally, Mentha pulegium (123.89 ± 5.64 mg KAE (kojic acid equivalents)/g) and Mentha x piperita (102.82 ± 15.16 mg KAE/g) showed a strong inhibition of the enzyme tyrosinase, which is related to skin hyperpigmentation. The most abundant compound in all samples was rosmarinic acid, ranging from 1363.38 ± 8323 to 2557.08 ± 64.21 μg/g. In general, the levels of phenolic acids in all examined mint extracts did not significantly differ. On the contrary, the levels of flavonoids varied within the species, especially in the case of hesperidin (from 0.73 ± 0.02 to 109. 39 ± 2.01 μg/g), luteolin (from 1.84 ± 0.11 to 31.03 ± 0.16 μg/g), and kaempferol (from 1.30 ± 0.17 to 33.68 ± 0.81 μg/g). Overall results indicated that all examined mints possess significant amounts of phenolic compounds that are responsible for antioxidant activity and, to some extent, for tyrosinase inhibition activity. Phenolics also proved to be adequate compounds, together with terpenoids, for the characterization of Mentha sp. Additionally, citrus-scented Mentha x villosa could be selected as a good candidate for the food and pharmaceutical industry, especially due its chemical composition and easy cultivation, even in winter continental conditions.

Eriocitrin attenuates ischemia reperfusion-induced oxidative stress and inflammation in rats with acute kidney injury by regulating the dual-specificity phosphatase 14 (DUSP14)-mediated Nrf2 and nuclear factor-κB (NF-κB) pathways

Background

Ischemia reperfusion (IR)-induced acute kidney injury (AKI) is accompanied by increased inflammatory response and oxidative stress. Eriocitrin is a flavonoid that is mainly derived from lemon or citrate juice. It exhibits various pharmacological effects and is known to have antioxidant and anti-steatotic benefits. However, research on the effect of eriocitrin against IR-induced oxidative stress and inflammation in AKI is limited.

Methods

In this study, an OGD/R of HK-2 cell in vitro and rat model of AKI in vivo were constructed. Then the cell or rats were treated with eriocitrin at different doses (60, 30, 10 mg/kg). The levels of apoptotic were detected by flow cytometry. Inflammatory and oxidative stress factors in supernatant in vitro and tissue in vivo. Meanwhile, Western blot was used to detect the change of dual-specificity phosphatase 14 (DUSP14), Nrf2 and nuclear factor-κB (NF-κB).

Results

Eriocitrin attenuated apoptosis of the human renal tubular epithelial cell line HK-2 mediated by oxygen glucose deprivation/reperfusion via the repression of inflammation and oxidative stress in a dose-dependent manner. Eriocitrin also enhanced the levels of dual-specificity phosphatase 14 (DUSP14) and Nrf2, and decreased NF-κB phosphorylation. Furthermore, the in vivo experiments indicated that eriocitrin dose-dependently alleviated IR-induced AKI and apoptosis in rats. By elevating DUSP14, eriocitrin promoted the expression of Nrf2 and inactivated NF-κB, thereby downregulating inflammation and oxidative stress. Moreover, inhibiting DUSP14 expression with protein tyrosine phosphatase (PTP) inhibitor IV reversed the kidney-protective effects of Eriocitrin.

Conclusions

Eriocitrin protected IR-induced AKI by attenuating oxidative stress and inflammation via elevating DUSP14, thereby providing a theoretical basis for the treatment of IR-induced AKI.

Tomato pomace extract and organic peppermint essential oil as effective sodium nitrite replacement in cooked pork sausages

The effect of supercritical fluid extract of tomato pomace (TP) and essential oil of organic peppermint (PM) on pH, color, residual nitrite content, lipid oxidation (TBARS value) and total plate count (TPC) of cooked pork sausages produced with 50 mg/kg of sodium nitrite was investigated. Five batches were produced: T1: 100 mg/kg of sodium nitrite; T2: 50 mg of sodium nitrite; T3: 50 mg of sodium nitrite and 0.150 µL/g TP; T4: 50 mg of sodium nitrite, 0.075 µL/g TP and 0.075 µL/g PM; T5: 50 mg of sodium nitrite and 0.150 µL/g PM. The lowest residual nitrite content and TBARS value were observed in treatment T4. The inclusion of TP increased redness of cooked pork sausages. TPC was the lowest in treatment T5. The results of this study showed that the addition of TP and PM enhanced quality of cooked sausages produced with reduced level of sodium nitrite.

Proficient dye removal from water using biogenic silver nanoparticles prepared through solid-state synthetic route

An environmentally benign, one-pot and highly scalable method was presented to produce biogenic silver nanoparticles (Ag NPs) using the solid-state synthetic route. Four plant-derived candidate bio-reductants (i.e., Datura stramonium, Papaver orientale, Mentha piperita, and Cannabis sativa) were investigated to compare the efficiency of solid-state route and typical solution method. M. piperita was selected as the best plant resource to produce totally pure and uniform Ag NPs (average diameter of 15 nm) without any aggregation. The purity and size of biogenic Ag NPs, were tailored by adjusting the M. piperita leaf powder/silver nitrate weight ratio and temperature. The as-synthesized Ag NPs were effectively utilized as an eco-friendly nanoadsorbent in water remediation to remove a model dye (i.e., crystal violet). The key factors affecting on the sorption process (i.e., nanoadsorbent dosage, temperature, pH, dye initial concentration, and shaking time) were investigated. The pseudo-second-order kinetic model was well fitted to the sorption process and at the optimum sorption conditions, based on the Langmuir model, the adsorption capacity was found to be 704.7 mg/g. The current, cost effective and feasible method could be considered as an applicable strategy to produce green, reusable and proficient Ag NPs as nanoadsorbents for removal of dyes from contaminated water.

Preliminary study of the production of metabolites from in vitro cultures of C. ensiformis

BACKGROUND

Canavalia ensiformis is a legume native to Central and South America that has historically been a source of protein. Its main proteins, urease, and lectin have been extensively studied and are examples of bioactive compounds. In this work, the effect of pH and light effects on the growth of C. ensiformis were analyzed. Also, the bioactive compounds such as phenols, carotenoids, chlorophyll a/b, and the growth of callus biomass of C. ensiformis from the effect of different types of light treatments (red, blue and mixture) were evaluated. Likewise, the antioxidative activity of C. ensiformis extracts were studied and related to the production of bioactive compounds. For this, a culture of calluses obtained from seeds were carried out. For the light experiments, polypropylene boxes with red, blue, combination (1/3, 3/1 and 1/1 R-B, respectively) lights and white LED were used as control. In each treatment, three glass containers with 25 ml of MS salts containing 0.25 g of fresh callus were seeded.

RESULTS

The results have shown that the pH of the culture medium notably affects the increase in callogenic biomass. It shows that the pH of 5.5 shows better results in the callogenic growth of C. ensiformis with an average increase of 1.3051 g (198.04%), regarding the initial weight. It was found that the pH 5.5 and the 1/3 R-B LED combination had higher production of bioactive compounds and better antioxidant activity. At the same time, the red-light treatment was least effective.

CONCLUSIONS

It was possible to find the ideal conditions of important growth under conditions of pH and light of C. ensiformis. Likewise, it is evaluated whether the production of compounds of interest, such as phenolic compounds and carotenoids, occurs under these conditions. The highest production of calluses occurs in the 1/3 R-B LED combined light treatment, which showed a significant increase in biomass, followed by B. From this study, it could be demonstrated that C. ensiformis produces compounds such as phenols and carotenoids in vitro culture that are essential for the antioxidant activity of the plant.

Antioxidant and enzyme-inhibitory activity of peppermint extracts and essential oils obtained by conventional and emerging extraction techniques

Peppermint is widely used medicinal plant with distinguished bioactive potential, therefore, the aim of present work was to develop novel peppermint extracts with high activity by application of traditional and emerging separation techniques. Conventional hydrodistillation and microwave-assisted hydrodistillation (MWHD) were applied for recovery of essential oil (EO), while organic solvent extraction using Soxhlet apparatus, microwave-assisted and ultrasound-assisted process and supercritical fluid extraction (SFE) were applied for non-selective recovery of peppermint lipophilic extracts. Extracts were characterized in terms of terpenoids profile with special emphasis on content of major compounds (mentol, menthone, isomenthol and eucalyptol). Antioxidant activity (DPPH, ABTS, CUPRAC, FRAP, chelating and phosphomolybdenum assay) and enzyme-inhibitory assays (acetylcholinesterase, butyrylcholinesterase, tyrosinase, amylase and glucosidase inhibition) were used for screening of peppermint bioactivity. MWHD was recognized as alternative for traditional process in EO recovery, while SFE extracts were useful for green production of solvent-free peppermint extracts rich in terpenoids and other lipophilic bioactives.

Potential Role of Phenolic Extracts of Mentha in Managing Oxidative Stress and Alzheimer's Disease

With an increase in the longevity and thus the proportion of the elderly, especially in developed nations, there is a rise in pathological conditions that accompany ageing, such as neurodegenerative disorders. Alzheimer’s disease (AD) is a neurodegenerative disease characterized by progressive cognitive and memory decline. The pathophysiology of the disease is poorly understood, with several factors contributing to its development, such as oxidative stress, neuroinflammation, cholinergic neuronal apoptotic death, and the accumulation of abnormal proteins in the brain. Current medications are only palliative and cannot stop or reverse the progression of the disease. Recent clinical trials of synthetic compounds for the treatment of AD have failed because of their adverse effects or lack of efficacy. Thus, there is impetus behind the search for drugs from natural origins, in addition to the discovery of novel, conventional therapeutics. Mints have been used traditionally for conditions relevant to the central nervous system. Recent studies showed that mint extracts and/or their phenolic constituents have a neuroprotective potential and can target multiple events of AD. In this review, we provide evidence of the potential role of mint extracts and their derivatives as possible sources of treatments in managing AD. Some of the molecular pathways implicated in the development of AD are reviewed, with focus on apoptosis and some redox pathways, pointing to mechanisms that may be modulated for the treatment of AD, and the need for future research invoking knowledge of these pathways is highlighted.

Peppermint Essential Oil Toxicity to the Pear Psylla (Hemiptera: Psyllidae) and Potential Applications in the Field

Chinese pear psylla (Cacopsylla chinensis Yang et Li) is a serious orchard pest that causes declines in fruit quality through feeding damage and the spread of pathogens. The rapid development of chemical pesticide resistance has become a severe problem in controlling pear psylla. Thus, the development of natural pesticides to replace conventional chemical pesticides is urgently needed. Here, we found that the essential oil of peppermint (Mentha haplocalyx Briq. [Lamiales: Labiatae]) is an ideal agent for controlling pear psylla based on experiments in the laboratory and the field. The major constituents of peppermint essential oil were found including menthol (49.73%), menthone (30.52%), α-pinene (3.60%), and α-terpineol (3.81%). This oil and chemicals in it performed serious contact toxicity against the winter-form adults and nymphs of pear psylla, yielding LD50 values of 2.54, 10.71, 2.77, 5.85, and 12.58 μg/adult and 1.91, 9.56, 2.18, 4.98, and 12.07 μg/nymph, respectively. Furthermore, the essential oil strongly repelled the adults of pear psylla with 78% repellence at the highest concentration tested in a Y-tube olfactometer in the laboratory. The combined effect of the two factors made peppermint essential oil a natural pesticide, which achieved a maximum reduction of round to 80.9% in winter-form adult population and round to 67.0% in nymph population at the concentration of 4.0 ml/L in the field. Additionally, it had no effect on the natural enemies of pear psylla in the field. Therefore, peppermint essential oil has potential as an alternative to chemical pesticides for pest control in integrated pest management programs in pear orchards.

Analysis of Polyphenolic Composition of a Herbal Medicinal Product-Peppermint Tincture

The pharmacological activity of peppermint leaf (Menthae piperitae folium) for medical use is mainly attributed to the presence of essential oil, which, according to the European Pharmacopoeia (Ph. Eur.), should constitute not less than 12 mL/kg of raw material. The content of polyphenols in peppermint-based preparations, except peppermint leaf dry extract, has not yet been considered as an essential parameter in the pharmacopeial assessment of peppermint quality. This study concerns the evaluation of the presence of representatives of polyphenolic compounds in 23 commercial peppermint tinctures (ethanolic extracts) purchased in pharmacies in Poland. The non-volatile polyphenolic fraction was investigated, and the presence of flavonoids and phenolic acids was quantified. High performance liquid chromatography coupled with a diode-array detector (HPLC-DAD) and an electrospray ionization mass spectrometer (U(H)PLC-ESI-MS) were used in the experiment. The study showed that eriocitrin, luteolin-7-O-rutinoside, and rosmarinic acid were the main polyphenolic components of the peppermint tinctures, as previously reported for peppermint leaf. Despite this, the research shows the extremely diverse content of the mentioned compounds in analyzed commercial medicinal products. In light of these results, it seems that the pharmacopeial assessment for the peppermint leaf (Ph. Eur.) and peppermint tincture (Polish Pharmacopoeia (FP)) requires correction and supplementation.

Improving Phenolic Total Content and Monoterpene in Mentha x piperita by Using Salicylic Acid or Methyl Jasmonate Combined with Rhizobacteria Inoculation

The effects of plant inoculation with plant growth-promoting rhizobacteria (PGPR) and those resulting from the exogenous application of salicylic acid (SA) or methyl jasmonte (MeJA) on total phenolic content (TPC) and monoterpenes in Mentha x piperita plants were investigated. Although the PGPR inoculation response has been studied for many plant species, the combination of PGPR and exogenous phytohormones has not been investigated in aromatic plant species. The exogenous application of SA produced an increase in TPC that, in general, was of a similar level when applied alone as when combined with PGPR. This increase in TPC was correlated with an increase in the activity of the enzyme phenylalanine ammonia lyase (PAL). Also, the application of MeJA at different concentrations in combination with inoculation with PGPR produced an increase in TPC, which was more relevant at 4 mM, with a synergism effect being observed. With respect to the main monoterpene concentrations present in peppermint essential oil (EO), it was observed that SA or MeJA application produced a significant increase similar to that of the combination with rhizobacteria. However, when plants were exposed to 2 mM MeJA and inoculated, an important increase was produced in the concentration on menthol, pulegone, linalool, limonene, and menthone concentrations. Rhizobacteria inoculation, the treatment with SA and MeJA, and the combination of both were found to affect the amount of the main monoterpenes present in the EO of M. piperita. For this reason, the expressions of genes related to the biosynthesis of monoterpene were evaluated, with this expression being positively affected by MeJA application and PGPR inoculation, but was not modified by SA application. Our results demonstrate that MeJA or SA application combined with inoculation with PGPR constitutes an advantageous management practice for improving the production of secondary metabolites from M. piperita.