Mentha pulegium L.: A Plant Underestimated for Its Toxicity to Be Recovered from the Perspective of the Circular Economy

Mentha Pulegium: A Plant with Several Medicinal Properties

The species Mentha Pulegium L. (M. pulegium L.) belongs to the family Lamiaceae, native to Europe, North Africa, and the Middle East, and the genus Mentha. It has been traditionally used in food, cosmetics, and medicines. It is a perennial, fragrant, well-liked, herbaceous plant that can grow up to half a meter tall. It is extensively used as a food flavoring, particularly for Moroccan traditional drinks. Chewing mint and M. pulegium, a relaxing and refreshing plant, can be used to treat hiccups and act as an anticonvulsant and nerve relaxant. Pennyroyal leaves that have been crushed have a pungent, spearmint-like scent. Pennyroyal is used to make herbal teas, which, while not proven to be harmful to healthy adults in small doses, are not recommended due to their liver toxicity. Infants and children can die if they consume it. Pennyroyal leaves, both fresh and dried, are particularly effective at repelling insects. Pennyroyal essential oil should never be taken internally because it is highly toxic, even in small doses, it can be fatal. This plant is used in traditional Moroccan medicine to treat a wide range of conditions, including influenza, rheumatism, migraine, infertility, ulcer, pain, gastrointestinal problems, fever, diabetes, obesity, mental and cardiac disorders, constipation, respiratory ailments, and cough. M. pulegium is a great candidate for contemporary therapeutic usage since it contains a wide variety of biologically active compounds, including terpenoids, flavonoids, alkaloids, tannins, and saponins in all its parts. Among the different parts used are the whole plant, the aerial part, the stem, and the leaves. More interestingly, the entire plant contains a variety of compounds including Pulegone, Isomenthone, Carvone, Menthofuran, Menthol, 1,8-Cineole, Piperitone, Piperitenone, Neomenthol, -humulene, and 3-octanol. Eriocitrin, Hesperidin, Narirutin, Luteolin, Isorhoifolin, Galic acid, and Rosmarinic acid are found in the leaves. p-hydroxybenzoic acid, Ferulic acid, Caffeic acid, Vanillic acid, Syringic acid, Protocatechuic acid, Cinnamic acid, Phloretic acid, o-coumaric acid, p-coumaric acid, Catechin, Epicatechin, Chrysin, Quercetin, Naringenin, Carvacrol are all found in the areal part. Alterporriol G, Atropisomer, Alterporriol H, Altersolanol K, Altersolanol L, Stemphypyrone, 6-O-methylalaternin, Macrosporin, Altersolanol A, Alterporriol E, Alterporriol D, Alterporriol A, Alterporriol B, and Altersolanol J are also found in the stem of fungus. Pulegone, Piperitone, p-Menthane-1,2,3- triol, β-elemenene, guanine (cis-), Carvacrol acetate, and Phenyl ethyl alcohol are all components of this plant's essential oils. Moreover, the study also sought to investigate and document all currently available evidence and information on the nutritional composition and therapeutic uses of this plant ornamental. Its pharmacological applications include antimicrobial, antioxidant, antihypertensive, antidiabetic, anti-inflammatory, antiproliferative, antifungal, anticancer, burn wound healing, antispasmodic, and hepatotoxicity. Finally, toxicological studies have revealed that while low doses of extracts of the plant M. pulegium are not toxic, however, its essential oils of it are extremely toxic. In order to evaluate future research needs and investigate its pharmacological applications through clinical trials, the current assessment focuses on the distribution, chemical composition, biological activities, and primary uses of the plant.

Origanum heracleoticum Essential Oils: Chemical Composition, Phytotoxic and Alpha-Amylase Inhibitory Activities

Many studies have demonstrated the herbicidal effects of several essential oils and their possible use as substitutes for chemical herbicides. Several enzymes play a very significant role in seed germination: among these, α-amylase could be involved in essential oil phytotoxic processes. The aims of this study were to compare the chemical composition of the essential oils of two ecotypes of O. heracleoticum growing in Cilento (Southern Italy) and to study their possible use as natural herbicide using Raphanus sativus, Sinapis arvensis and Lolium multiflorum seeds. Moreover, a possible inhibitory activity on the α-amylase enzyme extracted from germinating seeds was evaluated as a possible mechanism of action. Both oils, characterized by GC-MS, belonged to a carvacrol chemotype. The alpha-amylase activity was determined using DNSA (dinitrosalicylic acid) assay quantifying the reducing sugar produced. Furthermore, the essential oils demonstrated phytotoxicity at the highest dose tested, and an inhibitory effect on α-amylase, probably correlated with the phytotoxic effects, was registered. The oils showed interesting phytotoxic and alpha-amylase inhibitory activities, which deserve to be further investigated.

Pedoclimatic Conditions Influence the Morphological, Phytochemical and Biological Features of Mentha pulegium L

In this study, Mentha pulegium leaves and flowers harvested in three different Sicilian areas were investigated from a micromorphological, phytochemical and biological point of view. Light and scanning electron microscopy showed the presence of spherocrystalline masses of diosmin both in the leaf epidermal cells and in thin flower petals. Two different chemotypes were identified (I, kaempferide/rosmarinic acid; II, jaceidin isomer A). Phytochemical screening identified plant from collection site II as the richest in total phenolics (16.74 g GAE/100 g DE) and that from collection site I as the richest in flavonoids (46.56 g RE/100 g DE). Seventy-seven metabolites were identified both in flower and leaf extracts. Plant from site II showed the best antioxidant (0.90-83.72 µg/mL) and anti-inflammatory (27.44-196.31 µg/mL) activity expressed as half-maximal inhibitory concentration (IC₅₀) evaluated by DPPH, TEAC, FRAP, ORAC, BSA denaturation and protease inhibition assays. These data were also corroborated by in vitro cell-based assays on lymphocytes and erythrocytes. Moreover, plant of site II showed the best antiangiogenic properties (IC₅₀ 33.43-33.60 µg/mL) in vivo on a chick chorioallantoic membrane. In conclusion, pedoclimatic conditions influence the chemotype and the biological activity of M. pulegium, with chemotype I showing the most promising biological properties.

Mentha: Nutritional and Health Attributes to Treat Various Ailments Including Cardiovascular Diseases

A poor diet, resulting in malnutrition, is a critical challenge that leads to a variety of metabolic disorders, including obesity, diabetes, and cardiovascular diseases. Mentha species are famous as therapeutic herbs and have long served as herbal medicine. Recently, the demand for its products, such as herbal drugs, medicines, and natural herbal formulations, has increased significantly. However, the available literature lacks a thorough overview of Mentha phytochemicals' effects for reducing malnutritional risks against cardiovascular diseases. In this context, we aimed to review the recent advances of Mentha phytochemicals and future challenges for reducing malnutritional risks in cardiovascular patients. Current studies indicated that Mentha species phytochemicals possess unique antimicrobial, antidiabetic, cytotoxic, and antioxidant potential, which can be used as herbal medicine directly or indirectly (such as food ingredients) and are effective in controlling and curing cardiovascular diseases. The presence of aromatic and flavor compounds of Mentha species greatly enhance the nutritional values of the food. Further interdisciplinary investigations are pivotal to explore main volatile compounds, synergistic actions of phytochemicals, organoleptic effects, and stability of Mentha sp. phytochemicals.

Molecular Interaction Studies and Phytochemical Characterization of Mentha pulegium L. Constituents with Multiple Biological Utilities as Antioxidant, Antimicrobial, Anticancer and Anti-Hemolytic Agents

Multiple biological functions of Mentha pulegium extract were evaluated in the current work. Phytochemical components of the M. pulegium extract were detected by Gas Chromatography-Mass Spectrometry (GC-MS) and High-performance liquid chromatography (HPLC). Moreover, M. pulegium extract was estimated for antioxidant potential by 2,2-Diphenyl-1-picryl-hydrazyl-hydrate (DPPH) free radical scavenging, antimicrobial activity by well diffusion, and anticoagulant activity via prothrombin time (PT) and activated partial thromboplastin time (APTT). GC-MS analysis detected compounds including cholesterol margarate, stigmast-5-en-3-ol, 19-nor-4-androstenediol, androstan-17-one, pulegone-1,2-epoxide, isochiapin B, dotriacontane, hexadecanoic acid and neophytadiene. Chrysoeriol (15.36 µg/mL) was followed by kaempferol (11.14 µg/mL) and 7-OH flavone (10.14 µg/mL), catechin (4.11 µg/mL), hisperdin (3.05 µg/mL), and luteolin (2.36 µg/mL) were detected by HPLC as flavonoids, in addition to ferulic (13.19 µg/mL), cinnamic (12.69 µg/mL), caffeic (11.45 µg/mL), pyrogallol (9.36 µg/mL), p-coumaric (5.06 µg/mL) and salicylic (4.17 µg/mL) as phenolics. Antioxidant activity was detected with IC50 18 µg/mL, hemolysis inhibition was recorded as 79.8% at 1000 μg/mL, and PT and APTT were at 21.5 s and 49.5 s, respectively, at 50 μg/mL of M. pulegium extract. The acute toxicity of M. pulegium extract was recorded against PC3 (IC50 97.99 µg/mL) and MCF7 (IC50 80.21 µg/mL). Antimicrobial activity of M. pulegium extract was documented against Bacillus subtilis, Escherichia coli, Pseudomonasaureus, Candida albicans, Pseudomonas aeruginosa, but not against black fungus Mucor circinelloides. Molecular docking was applied using MOE (Molecular Operating Environment) to explain the biological activity of neophytadiene, luteolin, chrysoeriol and kaempferol. These compounds could be suitable for the development of novel pharmacological agents for treatment of cancer and bacterial infections.

Chemical composition and antimicrobial activity of essential oils from Mentha pulegium and Rosmarinus officinalis against multidrug-resistant microbes and their acute toxicity study

This article aimed to study the antimicrobial activity, chemical composition, and acute oral toxicity of essential oils (EOs) of Mentha pulegium and Rosmarinus officinalis, two aromatic and medicinal plants widely used in the traditional Moroccan pharmacopeia. The average content of EOs was 3.2 and 2.5% for M. pulegium and R. officinalis, respectively. The chemical characterization showed a richness in some compounds identified by gas chromatography coupled with mass spectrometry (GC/MS): R(+)-Pulegone (45.48%), Menthone (14.2%), Piperitone (8.15%), and Isomenthone (7.18%) in M. pulegium and 1,8-Cineole (46.32%), Camphene (13.4%), and α-Pinene (9.52%) in R. officinalis. These metabolites showed a significant antimicrobial effect against the tested strains (bacteria and yeasts isolated from the hospital environment) compared to synthetic antibiotics that seem to be ineffective against resistant microorganisms. Based on lethal concentration LD50 >5,000 mg/kg (body weight), the oil was found to be marginally safe according to OECD guidelines and can be further explored (bio-product with low risk).

Enantiomer-Selective Characterization of the Adsorption, Dissipation, and Phytotoxicity of the Plant Monoterpene Pulegone in Soils

Plant monoterpenes have received attention for their ecological functions and as potential surrogates for synthetic herbicides, but very little is known about the processes that govern their behavior in the soil environment, and even less about the possible enantioselectivity in the functions and environmental behavior of chiral monoterpenes. We characterized the adsorption and dissipation of the two enantiomers of the chiral monoterpene pulegone in different soils, and their phytotoxicity to different plant species through Petri dish and soil bioassays. R- and S-pulegone displayed a low-to-moderate non-enantioselective adsorption on the soils that involved weak interaction mechanisms. Soil incubation experiments indicated that, once in the soil, R- and S-pulegone are expected to suffer rapid volatilization and scarcely enantioselective, biodegradation losses. In Petri dishes, the phytotoxicity of pulegone and its enantioselectivity to Lactuca sativa, Hordeum vulgare, and Eruca sativa was species-dependent. Lactuca sativa was the most sensitive species and showed higher susceptibility to S- than to R-pulegone. Biodegradation and volatilization losses greatly reduced the phytotoxic activity of S-pulegone applied to soil, but the addition of a highly-adsorptive organoclay stabilized the monoterpene and increased its phytotoxic effect. Stabilization by adsorption may represent an important mechanism by which the bioactivity of plant monoterpenes in soils can be increased.