Anti- Candida albicans activity of some Iranian plants used in traditional medicine

Unveiling the mechanism of essential oil action against skin pathogens: from ancient wisdom to modern science

Essential oils are among the most well-known phyto-compounds, and since ancient times, they have been utilized in medicine. Over 100 essential oils have been identified and utilized as therapies for various skin infections and related ailments. While numerous commercial medicines are available in different dosage forms to treat skin diseases, the persisting issues include their side effects, toxicity, and low efficacy. As a result, researchers are seeking novel classes of compounds as substitutes for synthetic drugs, aiming for minimal side effects, no toxicity, and high efficacy. Essential oils have shown promising antimicrobial activity against skin-associated pathogens. This review presents essential knowledge and scientific information regarding essential oil's antimicrobial capabilities against microorganisms that cause skin infections. Essential oils mechanisms against different pathogens have also been explored. Many essential oils exhibit promising activity against various microbes, which has been qualitatively assessed using the agar disc diffusion experiment, followed by determining the minimum inhibitory concentration for quantitative evaluation. It has been observed that Staphylococcus aureus and Candida albicans have been extensively researched in the context of skin-related infections and their antimicrobial activity, including established modes of action. In contrast, other skin pathogens such as Staphylococcus epidermidis, Streptococcus pyogens, Propionibacterium acnes, and Malassezia furfur have received less attention or neglected. This review report provides an updated understanding of the mechanisms of action of various essential oils with antimicrobial properties. This review explores the anti-infectious activity and mode of action of essential against distinct skin pathogens. Such knowledge can be valuable in treating skin infections and related ailments.

Evaluation of Yield, Chemical Profile, and Antimicrobial Activity of Teucrium polium L. Essential Oil Used in Iranian Folk Medicine

Teucrium polium L. is used to treat many diseases like abdominal pains, indigestion, colds, and reproductive system diseases in Iranian folk medicine. This study was designed to investigate the yield, chemical profile of essential oil, and antibacterial and antifungal activity of this species. The flowering aerial parts of T. polium were collected from the Margh region of Kashan, Iran. The essential oil of the plant was extracted and separated using the Clevenger apparatus and analyzed using gas chromatography-mass spectrometry (GC-MS). The antimicrobial activity of the essential oil against a variety of standard microbial strains was investigated with the Agar well-diffusion method and determination of the lowest growth inhibitory and lethal concentration (MIC and MBC). The results showed that the yield of T. polium essential oil (TPEO) was 0.5778%. Based on the results of GC-MS, 76 compounds (99.3%) were identified in the TPEO, of which α-pinene (9.67%), β-caryophyllene (8.07%), β-pinene (5.04%), nerolidol (4.94%), and oleic acid (4.57%) were the dominant components. The results of antimicrobial tests showed that the TPEO on Staphylococcus aureus created the largest zone of inhibition (~ 14.29 mm). The dominant inhibitory activity of this essential oil was against Gram-negative bacteria Escherichia coli (~ 9.00 mm), which was almost similar to rifampin (~ 11 mm). It seems that the predominance of terpenoid and acidic compounds of the essential oil is one of the possible factors of the anti-bacterial activity of this essential oil. Therefore, the TPEO may be a promising and potential strategy to inhibit some bacterial strains.

Antimicrobial and Toxic Effects of Boswellia serrata Roxb. and Mentha piperita Linn. Essential Oils on Vaginal Inhabitants

Commercial essential oils (EOs) of incense, Boswellia serrata Roxb, and mint, Mentha piperita L., were investigated against vaginal bacterial and Candida albicans isolates for antimicrobial potential and safety use. The antimicrobial activity of EOs was investigated through a double-dilution micro-plate assay. A brine shrimp assay was used for the determination of toxicity, while the determination of the chemical composition of EOs was carried out using GS-MS. Obtained minimal inhibitory (MIC) and minimal bactericidal concentration (MBC) point to the activity of mint essential oil (EO) against the multi-resistant P. aeruginosa isolate (MIC/MBC at 6.25 µL/mL), while MIC and MBC values for other isolates were reached at higher concentrations (25-50 µL/mL). According to the toxicity assay, the incense EO reached the LC₅₀ value at 3.07 µL/mL, while mint EO showed higher toxicity at lower concentrations (0.5 µL/mL) and the LC₅₀ could not be determined. The highest antimicrobial potential was obtained for incense against P. aeruginosa. Although the toxicity assay showed high toxicity of mint EO to the eggs of aquatic crustaceans Artemia salina, further testing of EO toxicity is proposed, for example on healthy cell-lines. According to the GC/MS spectrometry, the most represented components of mint EO were the oxygenated hydrocarbons L-menthone (20.86%) and menthol (31.86%), and they could be proposed for further antimicrobial and toxicity investigation.

Antifungal Properties of Zataria multiflora on Candida species: A Systematic Review

BACKGROUND AND PURPOSE

Candida infections have increased significantly in the antimicrobial resistance era, and synthetic antifungal drugs have limitations. The present work aimed to review the antifungal properties of Zataria multiflora (Z. multiflora) as an herbal remedy.

METHOD

PubMed, Scopus, ScienceDirect, Web of Science, SID, Civilica, and Magiran databases were searched for the antifungal activity on in vitro, in vivo, dental biofilm, and clinical studies of Z. multiflora on Candida species.

RESULTS

Overall, 33 articles evaluated the effect of Z. multiflora on Candida species and classified them into four groups, as follows in vitro (23), dental biofilm (6), in vivo (2), and clinical studies (3). All studies considered Z. multiflora effective in reducing or even inhibiting the growth of Candida species. NoMFC significant differences were seen in the effect of Z. multiflora on susceptible Candida compared to the resistant groups of Candida in the studies. It was also influential in inhibiting C. parapsilosis, C. glabrata, C. krusei, C. kefyer, and C. zeylanoides.

CONCLUSION

Considering the side effects and resistance of current antifungal drugs as well as the benefits of using herbal medicines, such as lower cost, less likely to develop drug resistance, the absence of side effects, and toxicity compared with chemical ones, it is possible as a powerful alternative to replace or combine with the current antifungal for Candida infection therapy along with other therapies.

In vitro phytochemical analysis and antibacterial and antifungal efficacy assessment of ethanolic and aqueous extracts of Rumex nervosus leaves against selected bacteria and fungi

Background and Aim

Scientists are interested in identifying natural antibiotic substitutes that are effective against drug-resistant pathogenic microbes and spoilage fungi to counter pathogens and reduce the major public health problem of antibiotic residues in animal products. This study aimed to evaluate the antimicrobial activity of Rumex nervosus leaves (RNLs) as a medicinal herb against four bacterial and two fungal strains using absolute ethanol, 50% ethanol, and aqueous extracts.

Materials and Methods

The antimicrobial activities of various RNL extracts against selected microbes were evaluated using the disk diffusion antibiotic susceptibility test, minimum inhibitory concentrations (MICs), minimum bactericidal concentrations (MBCs), minimum fungicidal concentrations, and the poisoned food technique.

Results

The absolute ethanol RNL extract showed the best bacteriostatic/bactericidal activity against Salmonella Typhimurium, Escherichia coli, and Staphylococcus aureus (MIC/MBC: 0.20/0.40, 0.20/0.40, and 0.32/0.65 mg/mL, respectively). The diameter of the zone of inhibition was larger (p < 0.05) for the 100% ethanol RNL extract (8.17 mm) against Salmonella Typhimurium, the 50% ethanol-RNL extract (11.5 mm) against E. coli, and the aqueous RNL extract (14.0 mm) against S. aureus than for any other bacterial isolate. The aqueous RNL extract strongly (p < 0.0001) inhibited the mycelial growth of Aspergillus fumigatus (100%) and Aspergillus niger (81.4%) compared with the control.

Conclusion

The results of this study suggest that RNL is a promising new natural antimicrobial agent for food preservation. To date, most research on the antimicrobial properties of natural herbs has been conducted in vitro, with few exceptions in vivo and intervention-based research.

Susceptibility of Fluconazole-Resistant Candida albicans to Thyme Essential Oil

Candida spp. is the most common microbial pathogen in fungal infections. There has been a tremendous increase in cases of candidiasis, especially among critically ill non-neutropenic patients. Candida albicans’ isolates were procured from the Prince Sultan Military Hospital, Riyadh, KSA. The isolates were characterized for their identification using CHROMagar, carbohydrate metabolism, germ tube formation, and RAPD-PCR techniques. The essential oil of Thymus vulgaris was obtained by hydro-distillation and characterized to decipher the major bioactive phytoconstituents. The antifungal activity of the thyme essential oil (TEO) was evaluated against fluconazole-resistant C. albicans isolates. The major phytocomponents identified by GC/MS were thymol (68.1%) followed by γ-terpinene (8.9%), cymol (7.7%), caryophyllene (1.1%), linalool (1.4%). The TEO successfully reduced the growth of C. albicans isolates. At very low doses, the TEO proved to be fungi static and fungicidal. TEO also effectively inhibited the germ tube formation and budging of fungal pathogens. The time kill assays have shown that TEO was more effective against drug resistant clinical isolates than fluconazole. This study provides an array of experimental evidence regarding the therapeutic efficacy of TEO against the drug-resistant clinical isolates of C. albicans. The findings may be used in the development of a new antifungal agent accordingly.

A review of ethnobotany, phytochemistry, antimicrobial pharmacology and toxicology of Nigella sativa L

Nigella sativa L. is one of the most extensively used traditional medicinal plants. This widely studied plant is known to display diverse pharmacological actions, including antimicrobial activities. Current literature has documented its multi-target mode of antimicrobial actions. N. sativa or its bioactive compounds, such as thymoquinone, can induce oxidative stress, cell apoptosis (by producing reactive oxygen species), increase membrane permeability, inhibit efflux pumps, and impose strong biocidal actions. Despite its well-documented antimicrobial efficacy in the experimental model, to the best of our knowledge its antimicrobial mechanisms highlighting the multi-targeting properties have yet to be well discussed. Is N. sativa or thymoquinone a valuable lead compound for therapeutic development for infectious diseases? Are N. sativa's bioactive compounds potential antimicrobial agents or able to overcome antimicrobial resistance? This review aims to discuss the antimicrobial pharmacology of N. sativa-based treatments. Additionally, it provides a holistic overview of the ethnobotany, ethnopharmacology, and phytochemistry of N. sativa.

Green Synthesis of Silver Nanoparticles Using Extract of Artemisia absinthium L., Humulus lupulus L. and Thymus vulgaris L., Physico-Chemical Characterization, Antimicrobial and Antioxidant Activity

The novelty of this study is twofold: AgNPs were obtained and characterized using Artemisia absinthium (A. absinthium), Humulus lupulus (H. lupulus), and Thymus vulgaris (T. vulgaris) plants extracts; moreover, a green and environmentally friendly approach for the synthesis of silver nanoparticles (AgNPs) using aqueous extracts was developed. This paper discusses new approaches about the synthesis of AgNPs. T. vulgaris, H. lupulus, and A. absinthium, which are renewable and common plants, perfect as reducing, stabilizing, and capping agent for green synthesis of silver nanoparticles (AgNPs). The extracts and synthesized AgNPs were characterized by various physico-chemical, phytochemical, morphological scanning electron microscope (SEM/EDS) and transmission electron microscope scanning (TEM), and antibacterial activity. The antioxidant activity of extracts and AgNPs were also assessed by 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+), 2,2-diphenyl-1-picrylhydrazyl (DPPH•), cupric reducing antioxidant capacity (CUPRAC), ferric reducing antioxidant power (FRAP), and trifluoperazine dihydrochloride (TFPH•) scavenging assays. Extracts/AgNPs showed significant antioxidant activity in all cases. A. absinthium/AgNPs, H. lupulus/AgNPs, and T. vulgaris /AgNPs displayed activities against DPPH• (0.14 ± 0.00; 0.11 ± 0.00 and 0.14 ± 0.00 mmol/g), ABTS•+ (0.55 ± 0.05; 0.86 ± 0.05 and 0.55 ± 0.05 mmol/g), respectively. TEM analysis confirmed the average particle size, it estimated t A. absinthium/AgNPs–46 nm, H. lupulus/AgNPs size of synthesized particles was 42 nm and T. vulgaris/AgNPs–48 nm. SEM analysis revealed that T. vulgaris/AgNPs showed in solitary cases as snowflake-like, branched, but in a general spheric shape, H. lupulus/AgNPs were wedge-shaped, and A. absinthium/AgNPs were the spherical shape of the synthesized AgNPs. EDS analysis confirmed the purity of the synthesized AgNPs with a strong signal at 3.2 keV. A. absinthium/AgNPs, H. lupulus/AgNPs, and T. vulgaris/AgNPs exhibited higher antibacterial activity against all tested bacterial strains compared to their respective pure extracts. It is concluded that AgNPs synthesized in extracts have a broad range of biological applications, which can be used as an eco-friendly material without having negative effects on the environment.

Relationships of irrigation water and soil physical and chemical characteristics with yield, chemical composition and antimicrobial activity of Damask rose essential oil

Damask rose (Rosa damascena Mill.) is an aromatic medicinal plant rich in bioactive compounds with high value in the food, pharmaceutical and cosmetic industries. Knowledge of the factors affecting the quantitative and qualitative properties of the compounds in its essential oil (EO) and the bioactivity of this EO is important in optimizing Damask rose cultivation and production. This research studied, for the first time, the effects of irrigation water and soil chemical and physical characteristics on the EO yield of this important commercial species and on it chemical composition and antimicrobial activity. The results showed the significant effect of crop cultivation site on yield, chemical composition and inhibition zone diameter (IZD) at the 1% significance level. The highest EO yield (~0.0266%), which belonged to the Noushabad site (EON), resulted from the increased soil electrical conductivity (EC) and the higher sand, gypsum and lime contents and irrigation water salinity. Analysis of the chemical composition of the EOs showed that their main compounds at all three crop sites were citronellol, nonadecane, heneicosane and geraniol. The EO obtained from the Yazdel site (EOY) had the highest contents of citronellol and geraniol (~29.05% and ~6.85%) that were directly correlated with soil potassium and phosphorus contents and inversely correlated with soil acidity and EC and its lime, nitrogen, and organic carbon contents. Antimicrobial assays indicated that the EO extracted from the Sefidshahr site (EOS), which had the largest inhibition zone diameter (~14.67 mm) for Aspergillus brasiliensis (IZD~14.67 mm) and the lowest MIC (~31.25 μg/mL) for Staphylococcus aureus and Pseudomonas aeruginosa, exhibited efficacy similar to that of rifampin, probably due to the dominance of the alkanes in it. The EOY and EOS also exhibited the strongest inhibitory and lethal activity against Candida albicans (MIC and MBC <15.63 μg/mL for EOY and MIC and MBC = 62.5 μg/mL for EOS), which were six and four times stronger than those of nystatin, respectively. Therefore, the selected EOs can act as a potentially promising strategy for fighting microbial strains.

Chemotype of damask rose with oleic acid (9 octadecenoic acid) and its antimicrobial effectiveness

Essential oils are natural products that have great antimicrobial potential value against many fungi and bacteria. Rosa damascena Mill. is one of the most important aromatic species of the Rosaceae family from which essential oil and economically valuable products can be obtained. The present study was designed to investigate the major compositions of the essential oil of this plant in Isfahan region of Iran and to identify its antibacterial and antifungal effects against 11 microorganisms causing human diseases and food spoilage. The essential oil was extracted by using the Clevenger apparatus and was analyzed by gas chromatography-mass spectrometry (GC-MS) technique. Its antimicrobial activity was evaluated by well diffusion, minimum inhibitory concentration (MIC) and minimum bactericide concentration (MBC). The results showed that the most important compounds of the essential oil were nonadecane (24.72%), heneicosane (19.325%), oleic acid (17.63%), and citronellol (12.61%). The results also showed that the highest inhibition zone of rose essential oil was against Aspergillus brasiliensis (15.00 ± 0.00 mm) and had a significant effect on Klebsiella pneumoniae (~ 8.00 mm). Also the rose oil had a significant inhibition and lethal effect against Candida albicans (MIC and MBC ~ 125 μg/mL), which is equivalent to the nystatin antibiotic (~ 125 μg/mL). Therefore, the essential oil of Damask rose can be considered as an alternative natural product for the prevention and treatment of fungal diseases in humans and against food spoilage as well.

Utilization of Grape Seed Flour for Antimicrobial Lipopeptide Production by Bacillus amyloliquefaciens C5 Strain

An endophytic Bacillus amyloliquefaciens strain called C5, able to produce biosurfactant lipopeptides with a broad antibacterial activity spectrum, has been isolated from the roots of olive tree. Optimization of antibacterial activity was undertaken using grape seed flour (GSF) substrate at 0.02, 0.2, and 2% (w/v) in M9 medium. Strain C5 exhibited optimal growth and antimicrobial activity (MIC value of 60 μg/ml) when incubated in the presence of 0.2% GSF while lipopeptide production culminated at 2% GSF. Thin layer chromatography analysis of lipopeptide extract revealed the presence of at least three active spots at Rf 0.35, 0.59, and 0.72 at 0.2% GSF. Data were similar to those obtained in LB-rich medium. MALDI-TOF/MS analysis of lipopeptide extract obtained from 0.2% GSF substrate revealed the presence of surfactin and bacillomycin D. These results show that GSF could be used as a low-cost culture medium supplement for optimizing the production of biosurfactants by strain C5.

Comparing the effectiveness of Salvia officinalis, clotrimazole and their combination on vulvovaginal candidiasis: A randomized, controlled clinical trial

AIM

To determine the effect of vaginal tablet of Salvia officinalis, alone and in combination with Clotrimazole, on the recovery of Vulvovaginal candidiasis.

METHODS

In this triple-blind randomized controlled trial, 111 participants were randomly assigned into three groups of 37 patients using block randomization with block sizes of 6 and 9, and allocation ratio of 1:1:1: 100 mg vaginal tablet of Clotrimazole and Placebo (CP), 400 mg vaginal tablet of S. officinalis and Placebo (SP), and vaginal tablet of S. officinalis and Clotrimazole (SC), once daily for 7 days. On the seventh day after the treatment was ended up, Vulvovaginal candidiasis were examined by vaginal symptoms and wet test, and if positive, they were examined by culture in chrome agar Candida medium.

RESULTS

Socio-demographic characteristics was similar (P > 0.05). Thirty-six, 36 and 35 patients, respectively in CP, SC and SP groups recruited in the study. The frequency of a positive wet test confirmed by Sabrodextrose agar medium 7 days after treatment was significantly lower in SC group than the reference group of CP (adjusted odds ratio = 0.09, 95% confidence interval: 0.93-0.932, P = 0.043). There was no significant difference between SP and CP group (P = 0.071, 95% confidence interval: 0.032-1.151, adjusted odds ratio = 0.192). Also, there was no significant difference between the three groups in terms of vaginal symptoms at the baseline (P > 0.05), however the statistical differences were indicated after the intervention in cheesy discharge, pruritus and Vulvovaginal edema (P < 0.05.(.

CONCLUSION

S. officinalis in the form of vaginal tablet, alone and when combined with Clotrimazole, can treat the Vulvovaginal Candidiasis.

Antifungal activity of essential oils extract from Origanum floribundum Munby, Rosmarinus officinalis L. and Thymus ciliatus Desf. against Candida albicans isolated from bovine clinical mastitis

OBJECTIVE

The aim of this study is to limit the antibiotic use in mastitis treatment and to find other alternatives. The antifungal activity of the essential oils from Origanum floribundum Munby., Rosmarinus officinalis L. and Thymus ciliatus Desf. is studied in the present work against a Candida albicans reference strain and ten C. albicans isolated strains from bovine clinical mastitis.

MATERIALS AND METHODS

Essential oils were extracted by hydrodistillation technique using Clevenger apparatus. Their chromatographic analysis was performed with a Gas Chromatograph/Mass Spectrometer (GC/MS). Antifungal activities of essential oils were investigated by macrobroth method of dilution in tubes to determine the Minimum Inhibitory Concentrations (MIC 80%).

RESULTS

Analysis of the essential oil showed chemical profile dominated by thymol (50.47 and 62.41%) and P-cymene (24.22 and 15.51%) in the oregano and the thyme respectively, 1, 8-cineol (31.50%) and α-pinene (18.33%) in Rosemary. The three essential oils revealed highly effective anticandidal activity, with an MIC of 80% values ranged from 15.02 to 31.08μg/mL.

CONCLUSION

These results suggest that essential oils studied can be real alternatives in the control of mastitis fungi but deserving studies more in-depth and detailed on their application in vivo.

The anti-dermatophyte activity of Zataria multiflora essential oils

OBJECTIVE

Dermtophytes are a group of pathogenic fungi and the major cause of dermatophytosis in humans and animals. Fighting dermatophytes by natural essential oils is one important issue in new researches.

MATERIALS AND METHODS

In this investigation, we evaluated the anti-dermatophyte activities of three samples of Z. multiflora essential oils against dermatophytes along with analysis of chemical compositions of the essential oils and their anti-elastase activities on elastase production in dermatophytes.

RESULTS

Carvacrol (1.5-34.4%), thymol (25.8-41.2%), carvacrol methyl ether (1.9-28.3%) and p-cymene (2.3-8.3%) were the main components of Z. multiflora essential oils. Z. multiflora essential oils (100ppm) inhibited the mycelium growth of dermatophytes (6±1.7-47.0±1.4%) and had the minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) values of 0.03-0.25μl/ml against dermatophytes. Essential oils inhibited elastase produced in dermatophytes and pure porcine elastase.

CONCLUSION

Z. multiflora essential oils can be used as natural anti-dermatophyte agent for fighting dermatophytes in further preclinical and clinical studies.

Fungicidal efficacy of various honeys against fluconazole-resistant Candida species isolated from HIV+ patients with candidiasis

OBJECTIVE

Honey is well known to possess a broad spectrum of activity against medically important organisms. The purpose of this study was to assess the antifungal activity of different honeys against 40 fluconazole (FLU) resistant Candida species, including Candida albicans (C. albicans), Candida glabrata, Candida krusei and Candida tropicalis.

MATERIALS AND METHODS

Three honey samples were collected from northern (Mazandaran, A), southern (Hormozgan, B) and central (Lorestan, C) regions of Iran. A microdilution technique based on the CLSI, M27-A2 protocol was employed to compare the susceptibility of honeys "A", "B" and "C" against different pathogenic Candida isolates.

RESULTS

The results showed that different Candida isolates were resistant to FLU, ranging from 64μg/mL to 512μg/mL. All of the honeys tested had antifungal activities against FLU-resistant Candida species, ranging from 20% to 56.25% (v/v) and 25% to 56.25% (v/v) for minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs), respectively. Honey "A" (MIC: 31.59%, v/v) showed higher anti-Candida activity than honey "B" (MIC: 35.99%, v/v) and honey "C" (MIC: 39.2%, v/v). No statistically significant differences were observed among the mean MIC values of the honey samples (P>0.05). The order of overall susceptibility of Candida species to honey samples were; C. krusei>C. glabrata>C. tropicalis>C. albicans (P>0.05). In addition, the mean MICs of Candida strains isolated from the nail, vagina and oral cavity were 33.68%, 36.44% and 39.89%, respectively, and were not significantly different (P>0.05).

CONCLUSION

Overall, varying susceptibilities to the anti-Candida properties of different honeys were observed with four FLU-resistant species of Candida. Further research is needed to assess the efficacy of honey as an inhibitor of candidal growth in clinical trials.

Biological Activities of Essential Oils: From Plant Chemoecology to Traditional Healing Systems

Essential oils are complex mixtures of hydrocarbons and their oxygenated derivatives arising from two different isoprenoid pathways. Essential oils are produced by glandular trichomes and other secretory structures, specialized secretory tissues mainly diffused onto the surface of plant organs, particularly flowers and leaves, thus exerting a pivotal ecological role in plant. In addition, essential oils have been used, since ancient times, in many different traditional healing systems all over the world, because of their biological activities. Many preclinical studies have documented antimicrobial, antioxidant, anti-inflammatory and anticancer activities of essential oils in a number of cell and animal models, also elucidating their mechanism of action and pharmacological targets, though the paucity of in human studies limits the potential of essential oils as effective and safe phytotherapeutic agents. More well-designed clinical trials are needed in order to ascertain the real efficacy and safety of these plant products.

Evaluation of antioxidant and antifungal properties of the traditional plants against foodborne fungal pathogens

OBJECTIVE

To determine the antioxidant and antifungal activities of the essential oils from five aromatic herbs, including Thymus vulgaris, Chamaemelum nobile, Ziziphora clinopodioides, Zingiber officinale and Cuminum cyminum, against different Aspergillus and Penicillium species.

METHODS

The oils were subjected to screening for their possible antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The susceptibility test for the oils was carried out in terms of minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) using microdilution method.

RESULTS

The values of the essential oils in DPPH assay were as follows: T. vulgaris (450.11±5.23 μg/mL), Ch. nobile (602.73±4.8 μg/mL), Ziz. clinopodioides (1238.82±9.3 μg/mL), Cu. cyminum (1255.52±8.92 μg/mL) and Zin. officinale (5595.06±8.24 μg/mL). Our findings also indicated a strong activity against tested fungi for the oil of T. vulgaris (1250 μg/mL), followed by Cu. cyminum (1416 μg/mL), Zin. officinale (1833 μg/mL), Ziz. clinopodioides (2166 μg/mL) and Ch. nobile (3750 μg/mL). This study confirmed the excellent antifungal and antioxidant properties of the essential oils, especially T. vulgaris, against foodborne pathogenic fungi.

CONCLUSION

Owing to their strong protective features, these oils could be used in ethno-medicine as preventers of lipid peroxidation and cellular damage, and in food industries as preservers of foodstuffs against spoilage fungi. Also, they could be the candidates to develop new antibiotics and disinfectants to control infective agents.

Antioxidant and antidiabetic activities of 11 herbal plants from Hyrcania region, Iran

In the present study, 2,2-diphenyl-1-picrylhydrazyl radical scavenging, α-amylase and α-glucosidase inhibition activities, and total phenolic contents of n-hexane, ethyl acetate, and methanol extracts of various parts of Allium paradoxum, Buxus hyrcana, Convolvulus persicus, Eryngium caucasicum, Heracleum persicum, Pimpinella affinis, Parrotia persica, Primula heterochroma, Pyrus boissieriana, Ruscus hyrcanus, and Smilax excelsa were investigated. These plants, which mostly serve as food flavoring, were collected from Hyrcania region, Sari, Iran. Some extracts of H. persicum, S. excels, P. boissieriana, P. persica, and P. heterochroma exhibited significant antidiabetic activities in α-amylase and α-glucosidase assays, more effective than acarbose (concentrations that cause 50% inhibition = 75.7 μg/mL and 6.1 μg/mL against α-amylase and α-glucosidase, respectively). Also, C. persicus, P. boissieriana, and P. heterochroma showed strong antioxidant activities, compared with butylated hydroxytoluene (concentration that causes 50% inhibition = 16.7 μg/mL). In conclusion, this study can recommend these plants as good candidates for further investigations to find potent antidiabetic natural products or probable lead compounds. Statistical analysis showed significant correlation between the 2,2-diphenyl-1-picrylhydrazyl scavenging activity and total phenolic contents (r = 0.711, p < 0.001).

Antimicrobial Activities of the Combined Use of Cuminum Cyminum L. Essential Oil, Nisin and Storage Temperature Against Salmonella typhimurium and Staphylococcus aureus In Vitro

Background:

Foodborne diseases are considered as major health problems in different countries. Concerns over the safety of some chemical preservatives and negative consumer reactions to them have prompted interest in natural alternatives for the maintenance or extension of food shelf life. In this respect, the combination of a plant essential oil and nisin has used for controlling the growth of foodborne pathogens as natural food preservative using the mathematical model.

Objectives:

The purpose of this study was to determine the effect of different concentrations of Cuminum cyminum L. essential oil (0, 15, 30 and 45 µL/100 mL) and nisin (0, 0.5 and 1.5 µg/mL) combination at different temperatures (10, 25 and 35°C) on growth of Salmonella typhimurium and Staphylococcus aureus in the Brain-Heart Infusion (BHI) broth model. The concentrations of 0 µL/100 mL for essential oil and 0 µg/mL for nisin imply the negative control.

Materials and Methods:

A multivariate variance experiment was performed. To assess the effect of essential oil, nisin and the incubation temperature on growth probability (log P%) of S. typhimurium and S. aureus, four concentrations of C. cyminum L. essential oil (0, 15, 30 and 45 µL/100 mL), three concentrations of nisin (0, 0.5 and 1.5 µg/mL) and three storage temperatures (10, 25 and 35°C) were considered.

Results:

The growth of S. typhimurium was significantly decreased by the concentration of essential oil ≥ 30 µL/100 mL in combination with nisin ≥ 0.5 µg/mL at temperature = 10°C (P < 0.05). Also, in combination of the essential oil ≥ 15 µL/100 mL and nisin ≥ 0.5 µg/mL at temperature ≤ 25°C, the growth of S. aureus was significantly reduced (P < 0.05).

Conclusions:

These results indicate that the combination of essential oil and nisin inhibits the growth of S. typhimurium and S. aureus bacteria and there is the possibility of using them as substitutes for chemical food preservatives. Moreover, the model (log P%) in this study can be a good tool for the reduction of microbiological hazards in food industry.

Immunomodulatory effects of Ziziphora tenuior L. extract on the dendritic cells

Background

Ziziphora tenuior L. (Kakuti in Persian) is used in traditional medicine for treatment of gastrointestinal disorders as carminative and analgesic plant. The other usages of this plant are included treatment of diarrhea and nausea. Therefore in the present study we evaluated the immunomodulatory effects of the ethanolic extract of this plant on the dendritic cells (DCs).

Results

Ziziphora tenuior L. extract significantly (p = 0.002) increased the level of surface expression of CD40 as an important co-stimulatory marker on DCs compared to the control. However this extract did not change CD86 and MHC-II molecules, so it could promote DCs phenotypic maturation. Treatment of DCs with the extract resulted in slightly increased of the production of (IL-12); however, this change was not significant. In addition, the ability of treated DCs to stimulate allogenic T cells proliferation and cytokines secretion was examined in the co-cuture of these cells with T cells in mixed lymphocyte reaction (MLR). Z. tenuior L. at the 100 μg/ml concentration inhibited the proliferation of allogenic T cells and also significantly (P < 0.001) increased the level of IL-10. Moreover, the extract at 10–100 μg/ml concentration caused slightly increase in IFN-γ production and decreased IL-4 cytokines but these changes were not significant.

Conclusions

These findings indicated that Z. tenuior L. extract can modulate immune response by induction of CD40 expression on DCs and cytokine production; whereas it can inhibit T cell stimulating activity of DCs in high concentration. These findings possibly in part explain the traditional use of this plant in treatment of immune-mediated disorders. However future studies are needed.

In vitro inhibition of herpes simplex virus type 1 replication by Mentha suaveolens essential oil and its main component piperitenone oxide

Several essential oils exert in vitro activity against bacteria and viruses and, among these latter, herpes simplex virus type 1 (HSV-1) is known to develop resistance to commonly used antiviral agents. Thus, the effects of the essential oil derived from Mentha suaveolens (EOMS) and its active principle piperitenone oxide (PEO) were tested in in vitro experimental model of infection with HSV-1. The 50% inhibitory concentration (IC50) was determined at 5.1μg/ml and 1.4μg/ml for EOMS and PEO, respectively. Australian tea tree oil (TTO) was used as control, revealing an IC50 of 13.2μg/ml. Moreover, a synergistic action against HSV-1 was observed when each oil was added in combination with acyclovir. In order to find out the mechanism of action, EOMS, PEO and TTO were added to the cells at different times during the virus life-cycle. Results obtained by yield reduction assay indicated that the antiviral activity of both compounds was principally due to an effect after viral adsorption. Indeed, no reduction of virus yield was observed when cells were treated during viral adsorption or pre-treated before viral infection. In particular, PEO exerted a strong inhibitory effect by interfering with a late step of HSV-1 life-cycle. HSV-1 infection is known to induce a pro-oxidative state with depletion of the main intracellular antioxidant glutathione and this redox change in the cell is important for viral replication. Interestingly, the treatment with PEO corrected this deficit, thus suggesting that the compound could interfere with some redox-sensitive cellular pathways exploited for viral replication. Overall our data suggest that both EOMS and PEO could be considered good candidates for novel anti-HSV-1 strategies, and need further exploration to better characterize the targets underlying their inhibition.

Antifungal activities and chemical composition of some medicinal plants

The use of and search for drugs and dietary supplements derived from plants have accelerated in recent years. Ethnopharmacologists, botanists, microbiologists and natural-products scientists are combing the earth for phytochemicals and leads, which could be developed for treatment of infectious diseases. The aim of this study was to investigate the antifungal activities of the essential oils of some medicinal plants such as Stachys pubescens, Thymus kotschyanus, Thymus daenensis and Bupleurum falcatum against Fusarium oxysporum, Aspergillus flavus and Alternaria alternata. The essential oils were used to evaluate their MICs and MFCs compared to the amphotricin B as a standard drug. The essential oils were also analyzed by GC/MS. Essential oils isolated from the S. pubescens, T. kotschyanus and B. falcatum showed strong antifungal activities. The essential oil of T. daenensis exhibited a moderate activity against the selected fungi in comparison with the other plants' essential oils. In addition, the results showed that 26, 23, 22 and 15 components were identified from the essential oils of T. kotschyanus, S. pubescens, T. daenensis and B. falcatum, respectively. These oils exhibited a noticeable antifungal activity against the selected fungi. Regarding obtained results and that natural antimicrobial substances are inexpensive and have fewer side effects, they convey potential for implementation in fungal pathogenic systems.

Antifungal activity of phenolic compounds identified in flowers from North Eastern Portugal against Candida species

ABSTRACT: 

Aim: To evaluate the antifungal effect of gallic acid, catechin, luteolin and quercetin, phenolic compounds identified from flowers of North Eastern Portugal, against Candida planktonic and biofilm cells. Materials & methods: The MICs were determined in Candida planktonic cells and the effect of phenolic compounds on Candida biofilms was assessed through quantification of colony-forming units. Results: MIC values demonstrated that gallic acid presented the highest effect against all Candida species. Catechin showed a similar effect against Candida albicans American Type Culture Collection (ATCC) 90028 cells. In addition, gallic acid and quercetin had demonstrated only a minimal effect against Candida species biofilms. Conclusion: Gallic acid affected the growth of the different planktonic Candida species in all concentrations used; still, catechin showed a similar effect against C. albicans ATCC 90028 and Candida glabrata ATCC 2001 cells. In addition, only gallic acid and quercetin demonstrated a slight effect against all Candida species biofilms.

Analysis and in vitro anti-Candida antifungal activity of Cuminum cyminum and Salvadora persica herbs extracts against pathogenic Candida strains

OBJECTIVE

The in vitro antifungal activities of essential oil from Cuminum cyminum (C. cyminum) and alcoholic extract from Salvadora persica (S. persica) were investigated in order to evaluate their efficacy against C. albicans ATCC 14053, C. dubliniensis ATCC CD60, C. glabrata ATCC 90030, C. krusei ATCC 6258 and C. parapsilosis ATCC 22019.

METHODS

The essential oil was obtained by hydrodistillation in a Clevenger apparatus and analyzed by gas chromatography/mass spectroscopy (GC/MS). The disc diffusion and broth macrodilution methods were used as antifungal susceptibility tests.

RESULTS

The GC/MS analysis allowed 17 components to be determined; the main constituents of C. cyminum essential oil were α-pinene (30%), limonene (21%) and 1,8-cineole (18.5%). C. cyminum oil had a broad-spectrum antifungal activity against different pathogenic Candida species. Inhibition zone values ranged from 7 to 50mm for C. cyminum and 0 to 10mm for S. persica against the organisms tested. The best minimal inhibitory concentration (MIC) of C. cyminum oil was associated with C. albicans and C. dubliniensis (289 mg/L) and the MICs of S. persica extract were 4.9 mg/mL and 20mg/mL against C. albicans and C. dubliniensis, respectively.

CONCLUSION

The results suggested the potential substitution of the antifungal chemicals by C. cyminum essential oil and S. persica alcoholic extract as natural inhibitors to control the growth of the most important pathogenic Candida species and alternative therapies for candidiasis.

Development of a Validated HPLC/Photodiode Array Method for the Determination of Isomenthone in the Aerial Parts of Ziziphora tenuior L

BACKGROUND

Ziziphora tenuior L. known as Kakuti in Persian, is used in traditional medicine for fever, dysentery, uterus infection and as an analgesic. It is used also in the treatment of gastrointestinal disorders as carminative, or remedy of diarrhea or nausea. Major components of plant essential oil including pulegone, isomenthone, thymol, menthone, and piperitone are suggested to be responsible for the mentioned medicinal properties.

OBJECTIVES

In the present study, a normal high performance liquid chromatography (HPLC)/photodiode array validated method for quantification of isomenthone, one of the major constituents of Ziziphora, was established for the first time with a simple, rapid and accurate method.

MATERIALS AND METHODS

HPLC analysis was done on a Waters system, equipped with 515 HPLC pump and waters 2996 photodiode array detector. The column was a Nova-Pak Silica (3.9 × 150 mm), and Empower software was used for the determination of the compounds and processing the data. The method was validated according to USP 32 requirements.

RESULTS

A SELECTIVE METHOD FOR THE RESOLUTION OF ISOMENTHONE FROM TWO NEAREST PEAKS, THYMOL, AND CARVACROL WAS OBTAINED WITH GRADIENT SYSTEM OF HEXANE (A), AND HEXANE: ethyl acetate (9:1) (B), starting with A: B (100:0) for 2 minutes, then 0-20% B in 5 minutes, A:B (80:20) for 5 minutes, then 20-30% B in 3 minutes, 30-100% B for 5 minutes, A:B (0:100) for 4 minutes following with equilibrating for 10 minutes. The flow rate was 1 mL/min at 22˚C and the injection volume for the standards and the samples was 20 μL. The retention time for isomenthone was found to be 7.45 minutes. The regression equation was y = 143235x - 2433 with the correlation co-factor R(2) = 0.9992 and the percent recovery of 65.4 ± 3.85%. The sample obtained from 5 g of Z. teniour dried powder in 6 mL extract was standardized to contain 1.14 ± 0.030 μL/mL isomenthone which is equivalent to % 1.37 μL/g of the dried powdered plant. Limit of detection (LOD) and Limit of Quantification (LOQ) were 0.037, and 0.122 µL/mL determined by using the formula based on the signal to noise ratio.

CONCLUSIONS

Due to this fact that plant extracts may cause irreversible damages to the capillary GC columns, using validated HPLC method for the analysis of these compounds in cruse plant extracts is recommended.

Evaluation of the antifungal activity of Zataria multiflora, Geranium herbarium, and Eucalyptus camaldolensis essential oils on Saprolegnia parasitica-infected rainbow trout (Oncorhynchus mykiss) eggs

The purpose of the present study was to evaluate and assess the capability of Zataria multiflora, Geranium herbarium, and Eucalyptus camaldolensis essential oils in treating Saprolegnia parasitica-infected rainbow (Oncorhynchus mykiss) trout eggs. A total of 150 infected eggs were collected and plated on glucose-pepton agar at 24°C for 2 weeks. The antifungal assay of essential oils against S. parasitica was determined by a macrodilution broth technique. The eggs were treated with essential oils at concentrations of 1, 5, 10, 25, 50, and 100 ppm daily with three repetitions until the eyed eggs stage. Of 150 eggs examined, S. parasitica (54.3%), Saprolegnia spp. (45%), and Fusarium solani (0.7%) were isolated. The minimum inhibitory concentrations of Z. multiflora, E. camaldolensis, and G. herbarium essential oils against S. parasitica were 0.9, 2.3, and 4.8 ppm, respectively. Zataria multiflora and E. camaldolensis at concentrations of 25, 50, and 100 ppm, and G. herbarium at concentration of 100 ppm had significant differences in comparison with negative control (p<0.05). The results revealed that malachite green, followed by Z. multiflora, E. camaldolensis, and G. herbarium treated eggs had remained the most number of final eyed eggs after treatment. The highest final larvae rates belonged to malachite green, E. camaldolensis, Z. multiflora, and G. herbarium, respectively. The most hatching rates were recorded with malachite green (22%), and then Z. multiflora (11%), E. camaldolensis (7%), G. herbarium (3%), and negative control (1%). Zataria multiflora and E. camaldolensis were more effective than G. herbarium for the treatment of S. parasitica-infected rainbow trout eggs in aquaculture environment.

Inhibition of aflatoxin production and growth of Aspergillus parasiticus by Cuminum cyminum, Ziziphora clinopodioides, and Nigella sativa essential oils

Aflatoxins are highly toxic and carcinogenic metabolites produced by Aspergillus parasiticus on food and agricultural commodities. Natural products may control the production of aflatoxins. The aims of this study were to evaluate the effects of the essential oils (EOs) of Cuminum cyminum, Ziziphora clinopodioides, and Nigella sativa on growth and aflatoxins production by A. parasiticus. Minimal inhibitory concentrations (MICs) and minimal fungicidal concentrations (MFCs) of the EOs were determined and compared with each other. Determination of aflatoxins (AFB(1), AFB(2), AFG(1), and AFG(2)) was performed by immunoaffinity column extraction using reverse phase-high performance liquid chromatography. The major oil components were α-pinene (30%) in C. cyminum, pulegone (37%) in Z. clinopodioides, and trans-anthol (38.9%) in N. sativa oils. In broth microdilution method, C. cyminum oil exhibited the strongest activity (MIC(90): 1.6; MFC: 3.5 mg/mL), followed by Z. clinopodioides (MIC(90): 2.1; MFC: 5.5 mg/mL) and N. sativa (MIC(90): 2.75; MFC: 6.25 mg/mL) oils against A. parasiticus (p<0.05). Aflatoxin production was inhibited at 0.25 mg/mL of C. cyminum and Z. clinopodioides oils, of which that of C. cyminum was a stronger inhibitor. C. cyminum EO caused significant reductions in values of 94.2% for AFB(1), 100% for AFB(2), 98.9% for AFG(1), 100% for AFG(2), and 97.5% for total aflatoxin. It is concluded that the EOs of C. cyminum, Z. clinopodioides, and N. sativa could be used as natural inhibitors in foods at low concentrations to protect from fungal and toxin contaminations by A. parasiticus.