Compositional Analysis of Essential Oils from Two Mentha Species and in-Silico Studies on their Major Constituents towards Androgen Receptor

Background:

Polycystic ovarian syndrome (PCOS) is defined by excessive production and/or secretion of androgenic hormones in women. This disease has a complicated nature, so its control is difficult and challenging. Therefore, many women use complementary therapies to support medical treatment, one of which is the consumption of mint plants.

Objective:

This study aimed to characterize the chemical composition of peppermint (Mentha piperita L.) and spearmint (Mentha spicata L.) oils, to assess the binding of constituents of the oils to the androgen receptor as well as their pharmacokinetic features.

Methods:

The essential oils were isolated by water distillation and then analyzed using GC-MS and GC-FID. Thereafter, in silico binding studies were performed between the main volatile constituents and human androgen receptors using Autodock Vina. Besides, the pharmacokinetic properties of the selected compounds were evaluated using SwissADME.

Results:

GC analyses showed the presence of 19 and 23 constituents out of the total components (accounting for 94.7% and 97.6%, respectively) with carvone (73.0%), and menthone (33.1%) and menthol (29.3%) as the major compounds in spearmint and peppermint oils, respectively. Moreover, molecular docking studies revealed that carvone has the lowest binding energy to the androgen receptor. On the other hand, all tested compounds finally exhibited favorable pharmacokinetic parameters.

Conclusion:

The present study virtually indicated that the main volatile constituent in the spearmint oil, i.e., carvone, could probably cause a beneficial effect on PCOS.

Compositional Analysis and Antioxidant Activities of Thymus pubescens Essential Oil from Iran

BACKGROUND

The genus Thymus is one of the well-known members of the Lamiaceae, which comprises about 215 species. It is a polymorphic genus in this family. Therefore, possible differences in chemical composition among polymorphs may result in differences in their biological activities.

OBJECTIVE

This study was designed to specify chemical composition in order to assess antioxidant activities and to characterize active constituents of essential oil from Thymus pubescens.

METHODS

Essential oil was collected by hydrodistillation and was analyzed using GC-MS and GC-FID. Antioxidant activities were evaluated by ABTS radical cation scavenging and β-carotene bleaching inhibition methods. Detection and identification of antioxidant components were performed by TLC-bioautography assay using ABTS•+ reagent.

RESULTS

GC analyses indicated the presence of 39 components, accounting for 96.64% of total constituents, with thymol (38.67%), γ-terpinene (7.46%), and p-cymene (5.54%) as the main components. The IC50 values for antioxidant activities were equal to 1.15 (1.05 - 1.25) μg/mL and 0.45 (0.33 - 0.62) μg/mL for ABTS•+ scavenging and β-carotene bleaching inhibition tests, respectively. TLC-bioautograpgy of oil resulted in identification of thymol as the major antioxidant compound.

CONCLUSION

Essential oil exhibited very potent and significant antioxidant activities correlated well with increasing dose in vitro.

An efficient biotransformation of progesterone into 11α-hydroxyprogesterone by Rhizopus microsporus var. oligosporus

Rhizopus microsporus var. oligosporus is a fungus that belongs to the Mucoraceae family that is used for the preparation of some soy-fermented foods. Microbial biotransformation of progesterone by R. microsporus var. oligosporus afforded some monohydroxylated and dihydroxylated metabolites. The main product was purified using chromatographic methods and identified as 11α-hydroxyprogesterone on the basis of its spectroscopic features. Time course studies by high-performance thin-layer chromatography demonstrated that this fungi efficiently hydroxylated progesterone at the 11α-position for 3 days with a yield of 76.48%, but beyond this time, the microorganism transformed 11α-hydroxyprogesterone into dihydroxylated metabolites. 11α-Hydroxyprogesterone is widely used as a precursor in the synthesis of hydrocortisone and other steroidal anti-inflammatory agents.

Baeyer-Villiger oxidation of progesterone by Aspergillus sojae PTCC 5196

Microbial transformations are capable of producing steroid substances difficult to synthesize by chemical methods. Strains belonging to the genus Aspergillus are effective facilitators of microbial biotransformations due to their enzymatic diversity. In this study, the biotransformation of progesterone by the fungus Aspergillus sojae (A. sojae) PTCC 5196 was examined. Analysis of the bioconversion process revealed that progesterone was converted to testololactone through a three-step pathway (17β-acetyl side chain cleavage, 17β-hydroxyl oxidation, and oxygenative lactonization of 17-ketone), indicating the presence of Baeyer-Villiger monooxygenase (BVMO) activity in the fungal strain. GC analysis confirmed the production of testololactone with a yield of 99% in 24 h. Faster testololactone production was induced in the presence of both C-21 (progesterone) and C-19 (androstenedione, testosterone, and dehydroepiandrosterone [DHEA]) steroid substances. Due to the high biotransformation rate observed in the present study, A. sojae may be a novel and promising candidate in the production of testololactone.

Effect-Directed Analysis for the Antioxidant Compound in Salvia verticillata

Salvia genus is one of the largest genera of the Lamiaceae family. Its species have been used for a wide variety of disorders in the local traditional medicine systems. Therefore, the genus has been the subject of several phytochemical and biological studies. The aim of the study was to identify the major antioxidant compound(s) from the methanol extract of Salvia verticillata using activity-guided fractionation. The crude extract showed strong antioxidant activities in DPPH and β-carotene/linoleic acid tests. The ethyl acetate fraction also exhibited a potent free radical scavenging activity compared to the other fractions. Further fractionation and purification of the ethyl acetate fraction using chromatography methods yielded a compound with high antioxidant capacity. The isolated active compound was determined as chrysoeriol. It showed a dose-dependent free radical scavenging activity with an IC50 (DPPH scavenging) value of 93.32 (80.23 - 108.57) mM.

Biotransformation of Progesterone by Whole Cells of Filamentous Fungi Aspergillus brasiliensis

Microbial steroid biotransformations have found a wide-reaching application for the production of more precious and functionalized compounds due to their high regio-and stereo selectivity. In this study, the possibility of using filamentous fungi Aspergillus brasiliensiscells in the biotransformation of progesterone, a C-21 steroid hormone was studied for the first time. The fungal strain was inoculated into the transformation medium supplemented with progesterone as a substrate. Biotransformation of this steroid for 7 days afforded 3 different hydroxylated metabolites: 11α-hydroxy progesterone; 14α-hydroxyprogesteroneand21-hydroxyprogesterone. The metabolites were separated by thin layer chromatography. Structure determinations of the metabolites were performed by comparing NMR, MS and IR spectra of the starting compound with those of metabolites. These results may be of industrial importance because the metabolites can be used as precursor of some steroid drugs.

Fungal transformation of androsta-1,4-diene-3,17-dione by Aspergillus brasiliensis

BACKGROUND

The biotransformation of steroids by fungal biocatalysts has been recognized for many years. There are numerous fungi of the genus Aspergillus which have been shown to transform different steroid substances. The possibility of using filamentous fungi Aspergillus brasiliensis cells in the biotransformation of androsta-1,4-diene-3,17-dione, was evaluated.

METHODS

The fungal strain was inoculated into the transformation medium which supplemented with androstadienedione as a substrate and fermentation continued for 5 days. The metabolites were extracted and isolated by thin layer chromatography. The structures of these metabolites were elucidated using (1)H-NMR, broadband decoupled (13)C-NMR, EI Mass and IR spectroscopies.

RESULTS

The fermentation yielded one reduced product: 17β-hydroxyandrost-1,4-dien-3-one and two hydroxylated metabolites: 11α-hydroxyandrost-1,4-diene-3,17-dione and 12β-hydroxyandrost-1,4-diene-3,17-dione.

CONCLUSIONS

The results obtained in this study show that A. brasiliendsis could be considered as a biocatalyst for producing important derivatives from androstadienedione.

Analyses of the essential oil from Bunium persicum fruit and its antioxidant constituents

This study was aimed to analyze and identify the antioxidant constituents of the essential oil of Bunium persicum (Apiaceae) fruit. The essential oil was obtained by hydrodistillation and analyses by GC-FID and GC-MS. The essential oil was tested for antioxidant capacity in DPPH radical scavenging and linoleic acid/β-carotene assays. The TLC-bioautography method based on DPPH radical assay and GC analyses were carried out to characterize the major antioxidant compounds in the essential oil. GC analyses showed the presence of sixteen compounds with p-cymene (31.1%), cuminaldehyde (22.2%), and γ-terpinene (11.4%) as the main components in the essential oil. The oil exhibited good radical scavenging [IC50 (DPPH·) = 4.47 (3.96 - 5.05) mg/mL] and antilipid peroxidation [IC50 (β-carotene bleaching) = 0.22 (0.16 - 0.31) mg/mL] activities. The TLC tests resulted in identification of cuminaldehyde, p-cymene-7-ol, and cuminyl acetate as the main constituents of the active oil fraction.

Bioassay-Guided Separation of an α-Amylase Inhibitor Anthocyanin from Vaccinium arctostaphylos Berries

Vaccinium arctostaphylos is a traditional medicinal plant in Iran used for the treatment of diabetes mellitus. In our search for antidiabetic compounds from natural sources, we found that the extract obtained from V. arctostaphylos berries showed an inhibitory effect on pancreatic α-amylase in vitro [IC50 = 1.91 (1.89 -1.94) mg/mL]. The activity-guided purification of the extract led to the isolation of malvidin-3-O-β-glucoside as an α-amylase inhibitor. The compound demonstrated a dose-dependent enzyme inihibitory activity [IC50 = 0.329 (0.316 - 0.342) mM].

Chemical Composition of the Fixed and Volatile Oils of Nigella sativa L. from Iran

The chemical composition of the extracted fixed oil (total fatty acid composition) and volatile oil of Nigella sativa L. seeds grown in Iran were determined by GC and GC/MS. Eight fatty acids (99.5%) and thirty- two compounds (86.7%) have been identified in the fixed and volatile oils, respectively. The main fatty acids of the fixed oil were linoleic acid (55.6%), oleic acid (23.4%), and palmitic acid (12.5%). The major compounds of the volatile oil were trans-anethole (38.3%), p-cymene (14.8%), limonene (4.3%), and carvone (4.0%).

TLC-Bioautography and GC-MS Analyses for Detection and Identification of Antioxidant Constituents of Trachyspermum copticum Essential Oil

The present work was designed to study the antioxidant activity and to identify the main active components of the essential oil of ajowan (Trachyspermum copticum) fruit. GC and GC-MS analyses of the essential oil showed the presence of eight compounds. The main constituents of the oil were thymol (43.7%), p-cymene (26.8%), and γ-terpinene (24.9%). The antioxidant and free radical scavenging activities of ajowan oil was evaluated by using ABTS(•+) and β-carotene bleaching assays. The oil exhibited a considerable dose-dependent antioxidant activity. Antioxidant activity guided fractionation of the oil was carried out by TLC-bioautography method based on the DPPH(•) assay to screen and separate the main active constituents. The bioautography screening and fractionation resulted in the separation of the main antioxidant compound which was identified as thymol.

Bioactivity-Guided Separation of an α-Amylase Inhibitor Flavonoid from Salvia virgata

It is now believed that the inhibition of carbohydrate hydrolyzing enzymes (CHEs) in the digestive tract can significantly prolong the overall carbohydrate digestion time and decrease the postprandial hyperglycemia after a meal. Therefore, inhibitors of CHEs can be useful therapeutic approaches in the management of diabetes mellitus, especially in the type 2, and complications associated with the disease. In our previous study, the ethanol extract of the aerial parts of Salvia virgata showed an inhibitory effect on pancreatic α-amylase in-vitro. Bioassay-guided fractionation of the extract using the α-amylase inhibitory assay led to the isolation and identification of an active flavone compound, chrysoeriol. The compound concentration dependently inhibited the α-amylase activity with an IC50 value of 1.27 (1.21-1.33) mM.

Evaluation of the antioxidant capacity and phenolic content of three Thymus species

Thymus species are known to have significant amounts of phenolic and flavonoid compounds and exhibit strong antioxidant activities. This work was designed to evaluate the antioxidant activities of three endemic Iranian Thymus species (including T. daenensis, T. kotschyanus, and T. pubescens) in different test systems [namely DPPH() (2,2'-diphenyl-1-picrylhydrazyl), ABTS(+) [2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid], and linoleic acid/β-carotene bleaching assays] to determine the total phenolic and flavonoid contents of the species (assayed by colorimetric techniques) and to study the possible composition-activity relationship. All the tested plants exhibited concentration-dependent antioxidant and free radical scavenging activities. T. pubescens showed the highest free radical scavenging activities in both DPPH() and ABTS(+) methods, while T. daenensis and T. kotschyanus were the most active species in the β-carotene bleaching inhibition test. Alternatively, T. pubescens exhibited a significantly higher level of the total flavonoid content compared with those of the other species, while no significant statistically differences were found among the tested plants regarding the total phenolic content. In addition, significant correlations were found between the flavonoid content and DPPH()/ABTS(+) radical scavenging activities, but not between the β-carotene bleaching inhibition system and the flavonoid content.

Enzyme Assay Guided Isolation of an α-Amylase Inhibitor Flavonoid from Vaccinium arctostaphylos Leaves

The management of postprandial hyperglycemia is an important strategy in the control of diabetes mellitus and complications associated with the disease, especially in the diabetes type 2. Therefore, inhibitors of carbohydrate hydrolyzing enzymes can be useful in the treatment of diabetes and medicinal plants can offer an attractive strategy for the purpose. Vaccinium arctostaphylos leaves are considered useful for the treatment of diabetes mellitus in some countries. In our research for antidiabetic compounds from natural sources, we found that the methanol extract of the leaves of V. arctostaphylos displayed a potent inhibitory activity on pancreatic α-amylase activity (IC50 = 0.53 (0.53 - 0.54) mg/mL). The bioassay-guided fractionation of the extract resulted in the isolation of quercetin as an active α-amylase inhibitor. Quercetin showed a dose-dependent inhibitory effect with IC50 value 0.17 (0.16 - 0.17) mM.

Diuretic effect of powdered Cerasus avium (cherry) tails on healthy volunteers

In this study, the diuretic activity of powdered cherry stalk was evaluated in 13 healthy volunteers by means of their water balance. In addition to biochemical parameters, such as urinary electrolyte concentration, osmolality and any adverse reaction were determined. The capsules of cherry stalks were administered at an equivalent dose of 2.0 grams of the plant per person. Urinary biochemical determination was made of concentration of electrolytes (sodium, potassium, chloride and calcium), urinary volume and osmolality by standard laboratory procedures. Statistical evaluation was performed by Student's-t and Wilcoxon rank tests. After administration of cherry stalk, the mean of urine calcium, sodium, chloride, and urine volume increased, but the amount of urine potassium and urine osmolality did not change. No adverse reaction was observed. Powdered C. avium stalk increased mild urine volume confirming thus the claimed diuretic effect of the herb. Administration of cherry stalk caused urinary sodium and chloride rising less than loop diuretics but higher than the others. Because of rising calcium excretion, it should be used with cautious in those with urolithiasis.

Screening of antioxidant properties of seven Umbelliferae fruits from Iran

Antioxidative activities (IC(50)) of ethanol extracts from seven Umbelliferae fruits (Bunium persicum, Coriandrum sativum, Cuminum cyminum, Foeniculum vulgare, Heracleum persicum, Pimpinella anisum and Trachyspermum copticum) have been studied by the DPPH (2,2'-diphenyl-1-picrylhydrazyl) radical scavenging test. All the studied extracts showed antioxidant capability and P. anisum extract exhibited the strongest activity. The scavenging activity of the extracts in decreasing order was: P. anisum> T. copticum> C. cyminum> F. vulgare > or = B. persicum > or = C. sativum> H. persicum. The extracts were also investigated regarding their total flavonoid contents by the AlCl3 technique. The decreasing order of the flavonoid content of the extracts was: C. cyminum > T. copticum> P. anisum > or = H. persicum > or = B. persicum > or = F. vulgare > or = C. sativum. However, a favorable correlation was not found between the antioxidant activity and the total flavonoid content of the extracts. As well, the most active extract (i.e. P. anisum) was partitioned with n-hexane, chloroform and ethyl acetate to yield three organic fractions together with the remaining aqueous fraction. The antioxidative activities (IP%) and flavonoid contents of the fractions were also determined. The ethyl acetate fraction exhibited the highest activity and content. A positive correlation was found between the antioxidant potency and flavonoid content of the fractions.

In vitro free radical scavenging activity of five Salvia species

The radical scavenging activity of ethanolic extracts from five Salvia species including S. hypoleuca Benth., S. reuterana Boiss., S. verticillata L., S. virgata Jacq. and S. officinalis L. (as the reference plant with well documented free radical scavenging and antioxidant properties) was evaluated in vitro with the spectrophotometric method based on the reduction of the stable DPPH free radical. All the extracts showed radical scavenging activity, especially S. verticillata [IC50=23.53 (20.56-26.93) microg ml(-1)] and S. virgata [IC50=27.01 (24.08-30.29) microg ml(-1)] were found to be the most active species. Furthermore, the extracts were investigated regarding their total flavonoid content (TFC) by AlCl3 reagent. The extracts S. hypoleuca (TFC=53.16+/-1.95 microg mg(-1)) and S. reuterana (TFC=46.97+/-4.43 microg mg(-1)) had the highest content of flavonoid. However, a favourable correlation was not found between the radical scavenging potency and the total flavonoid content. This study suggests that S. verticillata and S. virgata are the possible sources of natural radical scavengers.

Antimicrobial activity and main chemical composition of two smoke condensates from Peganum harmala seeds

The smoke of Peganum harmala seeds is traditionally used in Iran as a disinfectant agent. The aim of this study was to determine the antimicrobial activity of two smoke condensates from Peganum harmala seeds. Furthermore the composition of smoke preparations was studied using gas chromatography and mass spectroscopy analysis. The most prevalent compound detected in a dichloromethane extract was harmine. Standard harmine as well as the dichloromethane extract showed antimicrobial activity against all test strains. Harmine was not detected in an n-hexane extract and we did not observe antimicrobial activity from this smoke preparation at the tested concentrations.

Volatile constituents of the flower and fruit oils of Pittosporum tobira (Thunb.) Ait. grown in Iran

The volatile components of the flower and fruit oils from Pittosporum tobira (Thunb.) Ait. grown in Iran, obtained through hydrodistillation, were analyzed by GC/MS. Sixteen compounds (representing 90.7% of the oil) and seventeen constituents (representing 89.9% of the oil) were identified in the flower and fruit oils, respectively. While the flower oil contained a-pinene (38.6%), n-nonane (11.8%), (E)-nerolidol (9.0%) and (E)-beta-ocimene (7.7%), the fruit oil contained a-pinene (30.2%), n-nonane (12.2%), germacrene-D (12.0%), a-cubebene (7.6%) and beta-cubebene (5.1%) as the main compounds.

Antibacterial activity of Pulicaria dysenterica extracts

Aqueous, methanolic and chloroformic extracts of Pulicaria dysenterica aerial parts were tested for their antibacterial activity using the disc-diffusion assay technique. The methanolic extract was found to be the most effective extract against three out of six tested bacteria. All of the extracts were active against Vibrio cholera.

Anatomical study on Vaccinium arctostaphylos L

Vaccinium arctostaphylos L. (Ericaceae), locally named Qaraqat, is widely used in Iranian folk medicine as antidiabetic and antihypertensive agents. The anatomical study on the different organs of the plant was performed to give a clear standard for identification of the drug. Various diagnostic elements such as particular cells, rubiaceous stomata, covering and glandular trichomes, Ca-oxalate crystals were found in different parts.

Volatile constituents of the fruit and leaf oils of Thuja orientalis L. grown in Iran

The composition of the hydrodistilled essential oils from the fruits and leaves of Thuja orientalis L. grown in Iran was analyzed by GC/MS. Nineteen and twenty-eight compounds have been identified in the volatile oils of the fruit and leaf, respectively. While the fruit oil contained alpha-pinene (52.4%), delta-3-carene (14.2%), alpha-cedrol (6.5%) and beta-phellandrene (5.1%), the leaf oil contained alpha-pinene (21.9%), alpha-cedrol (20.3%), delta-3-carene (10.5%) and limonen (7.2%) as the main components.