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.

Study of embryotoxicity of mentha piperita L. during organogenesis in balb/c mice / Estudio de la embriotoxicidad de mentha piperita L. durante la organogénesis en ratones balb/c

Mentha piperita (Labiatae), commonly known as peppermint is a native Iranian herb which is used in folk medicine for various purposes. This study was carried out to reveal the teratogenic effect of Mentha piperita on mice fetuses. In this experimental study, pregnant Balb/c mice divided to four groups. Case group received 600 (treatment I) and 1200 (treatment II) mg/kg/day the hydroalcoholic extract of Mentha piperita during 6-15 of gestational days and one control group received normal saline during GD6-GD15 by gavages and other control group did not receive any matter during 6-15 of gestational days. Mice sacrificed at GD18 and embryos were collected. Macroscopic observation was done by stereomicroscope. 20 fetuses of each group were stained by Alizarin red-S and Alcian blue staining method. The Mean weight of fetuses decreased in treatment groups rather than control (P<0.05) but CRL there was no significant difference between treatments and controls groups. In the treatment I (600 mg/kg/day) and treatment II (1200 mg/kg/day), normal saline and control group, no gross congenital malformations were observed in fetuses. Treated fetuses also had no delayed bone ossification as determined by Alizarin red-S and Alcian blue staining method. This study showed that the hydroalcoholic extract of Mentha piperita (600 and 1200 mg/kg/day) has no teratogenic effect in mice fetuses if used continuously during embryonic period.

Mentha piperita (Labiatae), comúnmente conocida como menta, es una hierba nativa de Irán, que se utiliza en la medicina tradicional para diversos fines. Este estudio fue realizado para descubrir el efecto teratogénico de la Mentha piperita en fetos de ratones. Los ratones Balb/c preñadas fueron divididas en cuatro grupos. Los grupos recibieron 600 (tratamiento I) y 1200 (tratamiento II) mg/kg/día del extracto hidroalcohólico de Mentha piperita durante los días 6-15 de gestación (DG), mientras que un grupo control recibió solución salina normal durante los DG 6-15 vía oral y otro grupo control sano no recibió substancia durante los DG 6-15. Los ratones fueron sacrificados el DG 18, recolectando los fetos. Se realizó la observación macroscópica mediante un estereomicroscopio. 20 fetos de cada grupo se tiñeron por el método de rojo de alizarina-S y azul de Alcián. La media de peso de los fetos disminuyó más en los grupos de tratamientos que los controles (p <0,05), pero CRL no presentó diferencias significativas entre los tratamientos y los grupos control. En los fetos del grupos tratamiento I (600 mg/kg/día), tratamiento II (1200 mg/kg/día), solución salina normal y control no se observó ninguna malformación congénita grave. Los fetos tratados tampoco tuvieron osificación ósea retrasada según lo determinado por el método de rojo de alizarina-S y azul de Alcián. Este estudio mostró que el extracto hidroalcohólico de Mentha piperita (600 y 1200 mg/kg/día) no tiene efectos teratogénicos en fetos de ratones al ser utilizado continuamente durante el período embrionario.

Efficacy of five volatile oils and their mixtures against the mealybug, Icerya seychellarum seychellarum (Westw.) infesting Sago palm, Cycas revoluta in Alexandria, Egypt.

Five tested plant volatile oils and their mixtures were evaluated for controlling the Margarodid, Icerya seychellarum seychellarum (Westw.) on growing Sago palms in Antoniades public gardens, Alexandria, Egypt. The tested volatile oils at concentration rates of 0.5, 1 and 1.5 % (v/v) were as follows: Camphor 20%; Dill 20%; Rose 30%; Peppermint 20% and Clove 30% (v/v). Their mixtures were Camphor/Peppermint; Camphor/Rose; at a rate of 1:1 Camphor/Rose/ Peppermint at 1:1:2 and Camphor/Rose/Dill at 2:1:1. The calculated results as general mean of residual reduction percent for the whole inspection periods of the test indicated that the superior volatile oils in reducing mealybugs were both Camphor and Rose, followed by Dill, Peppermint and the least efficient was Clove volatile oil. The evaluated volatile oils mixtures showed that each of Camphor/Rose/Peppermint, Camphor/Rose, and Camphor/Peppermint mixtures occupied a higher rank of efficiency against the treated mealybugs.

Giardia lamblia: the effects of extracts and fractions from Mentha x piperita Lin. (Lamiaceae) on trophozoites.

Giardia lamblia is a parasite that causes giardiasis in humans and other mammals. The common treatment includes different classes of drugs, which were described to produce unpleasant side effects. Mentha x piperita, popularly known as peppermint, is a plant that is frequently used in the popular medicine to treat gastrointestinal symptoms. We examined the effects of crude extracts and fractions from peppermint against G. lamblia (ATCC 30888) on the basis of trophozoite growth, morphology and adherence studies. The methanolic, dichloromethane and hexanic extracts presented IC(50) values of 0.8, 2.5 and 9.0microg/ml after 48h of incubation, respectively. The aqueous extract showed no effect against the trophozoites with an IC(50)>100microg/ml. The aqueous fraction presented a moderate activity with an IC(50) of 45.5microg/ml. The dichloromethane fraction showed the best antigiardial activity, with an IC(50) of 0.75microg/ml after 48h of incubation. The morphological and adhesion assays showed that this fraction caused several alterations on plasma membrane surface of the parasite and inhibited the adhesion of G. lamblia trophozoites. Cytotoxic assays showed that Mentha x piperita presented no toxic effects on the intestinal cell line IEC-6. Our results demonstrated antigiardial activity of Mentha x piperita, indicating its potential value as therapeutic agent against G. lamblia infections.

Modulatory effects of Mentha piperita on lung tumor incidence, genotoxicity, and oxidative stress in benzo[a]pyrene-treated Swiss albino mice.

Mentha piperita or peppermint is currently used for alleviating nausea, flatulence, and vomiting. In the present investigation, we evaluated the chemopreventive, antigenotoxic, and antioxidative effects of an aqueous extract of Mentha piperita leaves. One-day-old Swiss albino mice were treated with a single subcutaneous injection of 0.5 mg benzo[a]pyrene (BP) and then given either water or a Mentha extract (ME; 1 g/kg body weight) by gavage starting at 3 weeks of age (weaning). The mice were killed at 9 weeks of age and tested for lung tumor incidence (chemoprevention); bone marrow micronucleus and chromosome aberration frequency (antigenotoxicity); and levels of liver and lung sulfhydral groups, superoxide dismutase (SOD) and catalase (CAT) activity, and lipid peroxidation (LPO) (antioxidative properties). The ME treatment resulted in a significant reduction in the number of lung adenomas from an incidence of 67.92% in animals given only BP to 26.31%, an inhibition of 61.26%. Tumor multiplicity was 1.22 in the BP-alone group and 1.15 in the BP + ME group. In addition, compared with the animals in the BP-alone group, ME reduced the frequency of chromosomal aberrations and micronuclei in bone marrow cells and decreased the levels of LPO and increased reduced glutathione content, and SOD and CAT activities in liver as well as lung. The results of this study indicate that ME is chemopreventive and antigenotoxic when given subsequent to an initiating dose of BP in newborn Swiss albino mice. The chemopreventive action and antigenotoxic effects observed in the present study may be due to the antioxidative properties of ME.