A validated high performance liquid chromatography method for the analysis of thymol and carvacrol in Thymus vulgaris L. volatile oil

Analytical Method for Quantifying Monoterpenoids (p-Cymene and Myrcene) in Nanoemulsions Using High-Performance Liquid Chromatography

BACKGROUND

Myrcene and cymene, aromatic monoterpenes found in plants and essential oils, possess distinctive aromatic qualities. However, their volatility and limited solubility pose challenges in precise handling and formulation. Meanwhile, nanoemulsions emerge as promising drug delivery systems, improving the bioavailability and stability of these active ingredients.

OBJECTIVE

This article aimed to develop an HPLC method for the quantification of two monoterpenoids, p-cymene and myrcene, in nanoemulsions.

METHOD

The method used a Phenomenex® Synergi™ Fusion-RP column (150 mm × 4.6 mm id, 4 μm particle size) on an HPLC system with isocratic elution. The mobile phase was composed of acetonitrile and water (60:40, v/v) and was validated in terms of specificity, linearity, accuracy, precision, robustness, and selectivity.

RESULTS

The method provided accurate and precise results with a correlation coefficient of 0.999 and RSD values of less than 2%. The method can be used for quality control of nanoemulsions containing these monoterpenoids and as a reference for future studies on their efficacy and stability.

CONCLUSIONS

The study demonstrates the feasibility of using HPLC for the quantification of monoterpenoids in nanoemulsions and its potential as a quality control tool for nanoemulsion-based drug delivery systems.

HIGHLIGHTS

The method's accuracy, precision, and reliability, as evidenced by high correlation coefficients and low RSD values, underscore its suitability for ensuring the consistent formulation of these monoterpenoid-containing nanoemulsions, while also serving as a reference point for future research endeavors in this field.

Carvacrol Encapsulation in Chitosan-Carboxymethylcellulose-Alginate Nanocarriers for Postharvest Tomato Protection

Advancements in polymer science and nanotechnology hold significant potential for addressing the increasing demands of food security, by enhancing the shelf life, barrier properties, and nutritional quality of harvested fruits and vegetables. In this context, biopolymer-based delivery systems present themselves as a promising strategy for encapsulating bioactive compounds, improving their absorption, stability, and functionality. This study provides an exploration of the synthesis, characterization, and postharvest protection applications of nanocarriers formed through the complexation of chitosan oligomers, carboxymethylcellulose, and alginate in a 2:2:1 molar ratio. This complexation process was facilitated by methacrylic anhydride and sodium tripolyphosphate as cross-linking agents. Characterization techniques employed include transmission electron microscopy, energy-dispersive X-ray spectroscopy, infrared spectroscopy, thermal analysis, and X-ray powder diffraction. The resulting hollow nanospheres, characterized by a monodisperse distribution and a mean diameter of 114 nm, exhibited efficient encapsulation of carvacrol, with a loading capacity of approximately 20%. Their suitability for phytopathogen control was assessed in vitro against three phytopathogens-Botrytis cinerea, Penicillium expansum, and Colletotrichum coccodes-revealing minimum inhibitory concentrations ranging from 23.3 to 31.3 μg·mL-1. This indicates a higher activity compared to non-encapsulated conventional fungicides. In ex situ tests for tomato (cv. 'Daniela') protection, higher doses (50-100 μg·mL-1, depending on the pathogen) were necessary to achieve high protection. Nevertheless, these doses remained practical for real-world applicability. The advantages of safety, coupled with the potential for a multi-target mode of action, further enhance the appeal of these nanocarriers.

Formulation, Evaluation and Optimization of Antimicrobial Potential of Herbal Cream Containing Allium sativum, Moringa oleifera Extracts and Thymus vulgaris Oil

BACKGROUND

Herbal preparations can be formed by combining several plant classes. One possible explanation for the effectiveness of combined medications is that the various mixtures with different mechanisms may add up to produce a more comprehensive therapeutic effect.

OBJECTIVE

This study aims to investigate the synergistic antibiotic potential of a cream containing three natural herbal extracts: Allium sativum, Moringa oleifera, and Thymus vulgaris. The efficacy of combining these plant extracts was compared to that of a standard antibiotic formulation (Polyfax).

METHODS

The herbal cream was formulated by using aqueous extracts of garlic (Allium sativum), moringa (Moringa oleifera) and essential oil of thyme (Thymus vulgaris). The study aimed to explore the therapeutic potential of these extracts against bacteria. P. aeruginosa, B. subtilis, E. coli, S. aureus, and S. pneumonia are commonly found in fresh wounds.

RESULTS

The results showed that garlic extract (5%) had the highest zone of inhibition, 14.26 ± 0.05 mm, and a combination of garlic (5%) and thyme (2%) exhibited a significant synergistic effect, with a 23.5 ± 0.05 mm zone of inhibition. High-performance liquid chromatography analysis revealed the presence of allicin, quercetin and thymol as potential therapeutic phytoconstituents. The formulated herbal cream had a soft texture, was easily spreadable, and had better stability and absorption than the standard polyfax. The topical application of the cream did not cause any skin reaction or allergy in mice. The in vivo wound healing effect of the herbal cream was investigated on an abrasion model of albino mice, and the results showed that the treatment group (46 ± 16.31%) had significant wound healing potential compared to the standard (64 ± 17.49%) and control groups (18 ± 3.74%).

CONCLUSION

The formulated herbal cream was a better alternative to standard therapy, exhibiting promising healing and antimicrobial effects with significant compatibility and safety profile.

Thymus vulgaris ameliorates cough in children with asthma exacerbation: a randomized, triple-blind, placebo-controlled clinical trial

BACKGROUND

Asthma is one of the most common chronic respiratory diseases with inflammatory involvement and has a high burden worldwide. This study aimed to determine the effect of Thymus vulgaris (TV) on cough in children between 5 and 12 years old with mild to moderate asthma exacerbation.

METHODS

In this randomized, triple-blind clinical trial, 60 children between the ages of 5 and 12 with asthma exacerbations were randomly divided into two groups. The intervention group (n = 30) was given TV powder at a dose of 20 mg/kg every 8 hours, prepared as syrup, along with routine medical treatment for a week, and the control group (n = 30) received only routine medical treatment with placebo syrup. At the end of the week, clinical and laboratory symptoms, and spirometry data were re-recorded for both groups. Finally, the recorded factors were compared and statistically analyzed.

RESULTS

The results showed that after the intervention, activity-induced cough reduced, and difference was statistically significant between the two groups (p = 0.042), but the reduction in wheezing and breathlessness had no statistically significant difference. Spirometry data showed a significant difference in forced expiratory volume in 1 second (FEV1) between the two groups after intervention (p = 0.048), but this difference was not significant in FEV1/FVC (forced vital capacity), peak expiratory flow (PEF), and forced expiratory flow at 25-75% of the vital capacity (FEF25-75%).

CONCLUSION

The results show that TV syrup may be useful as an adjuvant treatment in children with asthma exacerbations.

Investigation of the prophylactic and therapeutic effectiveness of oral thyme extract in rats experimentally infected with cryptosporidium parvum

In this study, the prophylactic and therapeutic activities of thyme extract at different concentrations against experimental Cryptosporidium parvum infection in immunosuppressed rats were investigated. Thyme extract was prepared at four different concentrations (10%, 30%, 50%, and 100%) and administered as a single oral dose of 1 mL for evaluation of its prophylactic efficacy. Five consecutive days after infection was detected in all rats, therapeutic evaluations were also performed. According to the results obtained by daily counting of oocysts in stools, the prophylactic and therapeutic effects of thyme extract administration were significant in comparison to the control group (P˂0.01). Oocyst shedding continued in the control group at high numbers from the beginning to the end of the study, while oocyst counts in the prophylaxis groups remained low throughout the study. On the other hand, oocyst excretion rates were high in the therapeutic groups and decreased rapidly after thyme extract administration. At the end of the study, oocyst excretion had completely stopped for some rats administered thyme extract. There was no group in which oocyst shedding ceased for all rats. No significant differences were observed in the therapeutic or prophylaxis groups regarding the doses administered (P > 0.01). Renal and hepatic functions were monitored by measuring urea, creatinine, alanine transaminase, and aspartate transaminase levels ​​before and after thyme extract administration. As a result, it was concluded that oral thyme extract administration at the doses applied in this study is effective and safe in the prophylactic and therapeutic treatment of experimental cryptosporidiosis in rats.

Neuronal Differentiation and Outgrowth Effect of Thymol in Trachyspermum ammi Seed Extract via BDNF/TrkB Signaling Pathway in Prenatal Maternal Supplementation and Primary Hippocampal Culture

Reviving the neuronal functions in neurodegenerative disorders requires the promotion of neurite outgrowth. Thymol, which is a principal component of Trachyspermum ammi seed extract (TASE), is reported to have neuroprotective effects. However, the effects of thymol and TASE on neuronal differentiation and outgrowth are yet to be studied. This study is the first report investigating the neuronal growth and maturation effects of TASE and thymol. Pregnant mice were orally supplemented with TASE (250 and 500 mg/kg), thymol (50 and 100 mg/kg), vehicle, and positive controls. The supplementation significantly upregulated the expression of brain-derived neurotrophic factor (BDNF) and early neuritogenesis markers in the pups' brains at post-natal day 1 (P1). Similarly, the BDNF level was significantly upregulated in the P12 pups' brains. Furthermore, TASE (75 and 100 µg/mL) and thymol (10 and 20 µM) enhanced the neuronal polarity, early neurite arborization, and maturation of hippocampal neurons in a dose-dependent manner in primary hippocampal cultures. The stimulatory activities of TASE and thymol on neurite extension involved TrkB signaling, as evidenced by attenuation via ANA-12 (5 µM), which is a specific TrkB inhibitor. Moreover, TASE and thymol rescued the nocodazole-induced blunted neurite extension in primary hippocampal cultures, suggesting their role as a potent microtubule stabilizing agent. These findings demonstrate the potent capacities of TASE and thymol in promoting neuronal development and reconstruction of neuronal circuitry, which are often compromised in neurodegenerative diseases and acute brain injuries.

Liquid chromatography–mass spectrometry analysis of carvacrol in chicken tissues

Introduction

Carvacrol is an essential oil derived from oregano that is used as a natural additive to improve the efficiency of livestock nutrition. Residues of natural additives such as carvacrol should be monitored in food of animal origin to ensure consumer safety. The aim of this study was to appraise the quick, easy, cheap, effective, rugged and safe (QuEChERS) approach coupled with liquid chromatography and mass spectrometry as a means of carvacrol analysis in chicken tissue.

Material and Methods

A 5 ± 0.05 g portion of plasma, lung, muscle and liver was mixed for 15 min with 5 mL of 1-butanol and 20 mL of water, then centrifuged. A 0.5 mL volume from the top layer was transferred, then 60 mg of octadecylsilane sorbent, 30 mg of primary and secondary amine and 200 mg of MgSO₄ were added. The extract was mixed and centrifuged. The top layer was filtered and then transferred to an autosampler vial for analysis by high-performance liquid chromatography–tandem mass spectrometry.

Results

The limit of detection was calculated at 0.06 μg g⁻¹ and the limit of quantification was 0.2 μg g⁻¹, with relative standard deviation repeatability and reproducibility below <20%.

Conclusion

The validation results showed that this method could be a good alternative to determination of carvacrol by gas chromatography and is suitable for carvacrol analysis in different matrices.

Implementation of an Analytical Method for Spectrophotometric Evaluation of Total Phenolic Content in Essential Oils

Over the past decade, there has been growing interest in polyphenols’ research since these compounds, as antioxidants, have several health benefits, such as preventing neurodegenerative diseases, inflammation, cancer, cardiovascular diseases, and type 2 diabetes. This study implements an analytical method to assess the total phenolic content (TPC) in essential oils using Folin–Ciocalteu’s phenol reagent and quantifies the individual phenolic compounds by liquid chromatography. Thus, the research design and methodology included: (1) extraction of essential oil from dried thyme leaves by hydrodistillation; (2) spectrophotometric measurement of TPC by Folin–Ciocalteu method; and (3) identification and quantification of individual phenolic compounds by high-performance liquid chromatography-diode array detection/electrospray ionization mass spectrometry (HPLC-DAD-ESI-MS). Results revealed a TPC of 22.62 ± 0.482 mg GAE/100 µL and a polyphenolic profile characterized by phenolic acids (52.1%), flavonoids (16.1%), and other polyphenols (31.8%). Thymol, salvianolic acid A, and rosmarinic acid were the major compounds of thyme essential oil. The proposed analytical procedure has an acceptable level of repeatability, reproducibility, linearity, LOD (limit of detection), and LOQ (limit of quantification).

Determination of Thymol in Commercial Formulation, Essential Oils, Traditional, and Ultrasound-Based Extracts of Thymus vulgaris and Origanum vulgare Using a Greener HPTLC Approach

In the literature, greener analytical approaches for determining thymol in its commercial formulations, plant-based phytopharmaceuticals, and biological fluids are scarce. As a result, the goal of this study is to develop and validate a normal-phase "high-performance thin-layer chromatography (HPTLC)" method for determining thymol in commercial formulations, essential oils, traditional extracts (TE), and ultrasound-based extracts (UBE) of Thymus vulgaris and Origanum vulgare obtained from various geographical regions. The greener mobile phase for thymol analysis was a binary combination of cyclohexane and ethyl acetate (85:15, v/v). The derivatized densitometric analysis of thymol was carried out under visible mode at 530 nm utilizing anisaldehyde-sulfuric acid as a derivatizing/visualizing agent. In the 10-2000 ng/band range, the greener normal-phase HPTLC method was linear. Furthermore, for thymol analysis, the proposed analytical approach was simple, quick, inexpensive, accurate, precise, robust, sensitive, and greener. The thymol contents in commercial formulation were computed as 7.61% w/w. In general, the thymol contents were maximum in essential oils of T. vulgaris and O. vulgare compared to the other sample matrices studied. The thymol contents of TE of T. vulgaris and O. vulgare of different geographical regions were significantly low compared to their UBE extract. Using 12 distinct components of green analytical chemistry, the overall "analytical GREEnness (AGREE)" scale for the proposed analytical approach was computed 0.79, showing the good greener nature of the proposed analytical approach. Overall, the greener normal-phase HPTLC technique was found to be reliable for determining thymol in commercial formulations and plant-based phytopharmaceuticals.

Hydrophobic Chitosan Nanoparticles Loaded with Carvacrol against Pseudomonas aeruginosa Biofilms

Pseudomonas aeruginosa infections have become more challenging to treat and eradicate due to their ability to form biofilms. This study aimed to produce hydrophobic nanoparticles by grafting 11-carbon and three-carbon alkyl chains to a chitosan polymer as a platform to carry and deliver carvacrol for improving its antibacterial and antibiofilm properties. Carvacrol–chitosan nanoparticles showed ζ potential values of 10.5–14.4 mV, a size of 140.3–166.6 nm, and an encapsulation efficiency of 25.1–68.8%. Hydrophobic nanoparticles reduced 46–53% of the biomass and viable cells (7–25%) within P. aeruginosa biofilms. Diffusion of nanoparticles through the bacterial biofilm showed a higher penetration of nanoparticles created with 11-carbon chain chitosan than those formulated with unmodified chitosan. The interaction of nanoparticles with a 50:50 w/w phospholipid mixture at the air–water interface was studied, and values suggested that viscoelasticity and fluidity properties were modified. The modified nanoparticles significantly reduced viable P. aeruginosa in biofilms (0.078–2.0 log CFU·cm⁻²) and swarming motility (40–60%). Furthermore, the formulated nanoparticles reduced the quorum sensing in Chromobacterium violaceum. This study revealed that modifying the chitosan polarity to synthesize more hydrophobic nanoparticles could be an effective treatment against P. aeruginosa biofilms to decrease its virulence and pathogenicity, mainly by increasing their ability to interact with the membrane phospholipids and penetrate preformed biofilms.

Ultrasonic-Assisted Thymol and Carvacrol Extraction from Za’atar Leaves Using Cold-Pressed Sesame Oil

Thymol and carvacrol found in Origanum syriacum “Za’atar” plant leaves have triggered interest among researchers for their natural antimicrobial and antifungal properties. However, their applications in modern pharmaceutical and cosmetic industries as natural preservatives remain challenging. In this research, extraction of thymol and carvacrol from Za’atar leaves has been investigated using the ultrasonic-assisted method and the use of sesame oil as the primary extraction solvent compared with other vegetable oils including sunflower and olive oils. In addition, a high-performance liquid chromatography (HPLC) analytical method was developed by using a C8 column and 0.05% trifluoroacetic acid as a buffering agent. The method was validated for specificity, linearity, repeatability, accuracy, and robustness for the analysis of the content of the two terpenes thymol and carvacrol in different Za’atar extracts. Using the validated analytical method, thymol and carvacrol content results revealed the best vegetable oil for extraction. Results showed that sesame oil had the highest content of thymol and carvacrol, followed by sunflower oil, and the least amount obtained by using olive oil. A consistent extraction result opens an opportunity for application in the pharmaceutical and cosmetic industries. For this reason, the essential extraction key parameters that influence the final content of thymol and carvacrol were evaluated. The highest impact originated from the quality and volume of sesame oil. Cold-pressed sesame oil resulted in a 23% higher content of thymol and decreased amount of carvacrol. It was found that wetting the Za’atar leaves powder with sesame oil was enough for extraction; any additional sesame oil volume dilutes the extracted sample. The second impact was the Za’atar cultivation conditions; less than 10% difference of thymol and carvacrol content was observed within Za’atar of Hebron origin. Finally, the origin of sesame seeds used for sesame oil production had the least impact.

Ultrasonic-Assisted Thymol and Carvacrol Extraction from Za’atar Leaves Using Cold-Pressed Sesame Oil

Thymol and carvacrol found in Origanum syriacum “Za’atar” plant leaves have triggered interest among researchers for their natural antimicrobial and antifungal properties. However, their applications in modern pharmaceutical and cosmetic industries as natural preservatives remain challenging. In this research, extraction of thymol and carvacrol from Za’atar leaves has been investigated using the ultrasonic-assisted method and the use of sesame oil as the primary extraction solvent compared with other vegetable oils including sunflower and olive oils. In addition, a high-performance liquid chromatography (HPLC) analytical method was developed by using a C8 column and 0.05% trifluoroacetic acid as a buffering agent. The method was validated for specificity, linearity, repeatability, accuracy, and robustness for the analysis of the content of the two terpenes thymol and carvacrol in different Za’atar extracts. Using the validated analytical method, thymol and carvacrol content results revealed the best vegetable oil for extraction. Results showed that sesame oil had the highest content of thymol and carvacrol, followed by sunflower oil, and the least amount obtained by using olive oil. A consistent extraction result opens an opportunity for application in the pharmaceutical and cosmetic industries. For this reason, the essential extraction key parameters that influence the final content of thymol and carvacrol were evaluated. The highest impact originated from the quality and volume of sesame oil. Cold-pressed sesame oil resulted in a 23% higher content of thymol and decreased amount of carvacrol. It was found that wetting the Za’atar leaves powder with sesame oil was enough for extraction; any additional sesame oil volume dilutes the extracted sample. The second impact was the Za’atar cultivation conditions; less than 10% difference of thymol and carvacrol content was observed within Za’atar of Hebron origin. Finally, the origin of sesame seeds used for sesame oil production had the least impact.

Voltammetric Determination of Isopropylmethylphenols in Herbal Spices

Thymol and carvacrol—the components of herbal spices—are known for their broad biological activity as antimicrobials and antioxidants. For this reason, it is important to develop new methods for their determination in plant material. A simple, rapid, and sensitive method for determination of total content of these analytes in herbal spices using differential pulse voltammetry (DPV) has been developed. The basis of the research is the oxidation process of isopropylmethylphenols on a platinum microelectrode in glacial acetic acid containing acetonitrile (20%, v/v) and 0.1 mol L⁻¹ sodium perchlorate as the supporting electrolyte. Linear voltammetric responses for thymol and carvacrol were obtained in a wide concentration range from 0.39–1105 and 0.47–640 µg mL⁻¹, with a low detection limit of 0.04 and 0.05 µg mL⁻¹, respectively. The analysis was performed using the multiple standard addition method. The results of the voltammetric determination are in good agreement with the data of the standard chromatographic method. To the best of our knowledge, this is the first presentation of an electrochemical procedure to determine these compounds in these environmental and electrode materials.

Nanovesicles Loaded with Origanum onites and Satureja thymbra Essential Oils and Their Activity against Food-Borne Pathogens and Spoilage Microorganisms

Food poisoning is a common cause of illness and death in developing countries. Essential oils (EOs) could be effective and safe natural preservatives to prevent and control bacterial contamination of foods. However, their high sensitivity and strong flavor limit their application and biological effectiveness. The aim of this study was firstly the chemical analysis and the antimicrobial evaluation of the EOs of Origanum onites L. and Satureja thymbra L. obtained from Symi island (Greece), and, secondly, the formulation of propylene glycol-nanovesicles loaded with these EOs to improve their antimicrobial properties. The EOs were analyzed by GC-MS and their chemical contents are presented herein. Different nanovesicles were formulated with small average sizes, high homogeneity, and optimal ζ-potential. Microscopic observation confirmed their small and spherical shape. Antibacterial and antifungal activities of the formulated EOs were evaluated against food-borne pathogens and spoilage microorganisms compared to pure EOs. Propylene glycol-nanovesicles loaded with O. onites EO were found to be the most active formulation against all tested strains. Additionally, in vitro studies on the HaCaT cell line showed that nanovesicles encapsulated with EOs had no toxic effect. The present study revealed that both EOs can be used as alternative sanitizers and preservatives in the food industry, and that their formulation in nanovesicles can provide a suitable approach as food-grade delivery system.

Development and Characterization of Monoolein-Based Liposomes of Carvacrol, Cinnamaldehyde, Citral, or Thymol with Anti-Candida Activities

There is an increasing need for novel drugs and new strategies for the therapy of invasive candidiasis. This study aimed to develop and characterize liposome-based nanoparticles of carvacrol, cinnamaldehyde, citral, and thymol with anti-Candida activities. Dioctadecyldimethylammonium bromide- and monoolein-based liposomes in a 1:2 molar ratio were prepared using a lipid-film hydration method. Liposomes were assembled with equal volumes of liposomal stock dispersion and stock solutions of carvacrol, cinnamaldehyde, citral, or thymol in dimethyl sulfoxide. Cytotoxicity was tested on RAW 264.7 macrophages. In vitro antifungal activity of liposomes with phytocompounds was evaluated according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) methodology using clinical isolates of Candida albicans, Candida auris, Candida dubliniensis, and Candida tropicalis Finally, the ability of macrophage cells to kill Candida isolates after addition of phytocompounds and their nanoparticles was determined. Nanoparticles with 64 μg/ml of cinnamaldehyde, 256 μg/ml of citral, and 128 μg/ml of thymol had the best characteristics among the formulations tested. The highest encapsulation efficiencies were achieved with citral (78% to 83%) and carvacrol (66% to 71%) liposomes. Carvacrol and thymol in liposome-based nanoparticles were nontoxic regardless of the concentration. Moreover, carvacrol and thymol maintained their antifungal activity after encapsulation, and there was a significant reduction (∼41%) of yeast survival when macrophages were incubated with carvacrol or thymol liposomes. In conclusion, carvacrol and thymol liposomes possess high stability, low cytotoxicity, and antifungal activity that act synergistically with macrophages.

Natural Antibiotic Oregano in Hydroxyapatite-Coated Titanium Reduces Osteoclastic Bone Resorption for Orthopedic and Dental Applications

Traditional infection prevention and treatment methods include synthetic antibiotics, which can cause severe adverse side effects. Carvacrol and thymol are biologically active monoterpenoid extractants from oregano leaves with antibiotic capabilities; however, little is known regarding their effects on bone tissue engineering. The objective of this work is to understand their effects on osteogenesis, specifically with osteoblast and osteoclast cells, from surface-modified Ti6Al4V with plasma sprayed hydroxyapatite (HA) coatings. This system is an alternative to cemented implants to aid in bone healing. Results reveal that full carvacrol release from the HA matrix is successful in aqueous environments and modulation of release kinetics can also be made using polycaprolactone (PCL) and polyethylene glycol (PEG) polymers. From HA-pressed disc samples in physiological pH, full carvacrol release is achieved in 10 days using PCL/PEG, about 95% release in 50 days using no polymer, and 60% in 50 days when using a PCL coating. Without polymer, full carvacrol release is achieved after 3 days from HA coatings in both physiological pH and acidic pH, mimicking the post-surgery environment. The release is assessed as a diffusion-based mechanism in phosphate-buffered saline but degradation-based mechanism in acetate buffer solution. Carvacrol and thymol show bacterial inhibition of Staphylococcus epidermidis and no cytotoxic effects on osteoblast proliferation in vitro. Carvacrol and thymol also induce a significant 7% reduction in osteoclast tartrate-resistant acid phosphatase (TRAP) activity, caused by poorly attached cellular morphologies, leading to an approximately 65% reduction in osteoclast resorption pit formation. Our goal is to demonstrate a natural medicinal system that can support bone healing while providing infection prevention and reducing costly revision surgeries for orthopedic and dental applications.

Ultrasound Assisted Dispersive Solid Phase Microextraction of Thymol and Carvacrol in Pharmaceutical Products Using Graphene Oxide as an Adsorbent Prior to Analysis by High Performance Liquid Chromatography

Background:

Thymol and carvacrol are the most important dietary constituents in thyme species. These two active compounds are used for the standardization of pharmaceutical compounds.

Objective:

In this work, a simple and reliable ultrasonic assisted dispersive solid phase microextraction method (USA-DSPME) coupled with high performance liquid chromatography-ultra violet detection system was developed to determine thymol and carvacrol in pharmaceutical syrups. The efficiency of SPME sorbent was examined through several sorbents and finally Graphene Oxide (GO) was applied for extraction of the analytes. Method: The efficiency of GO was compared with three reduced forms of GO adsorbents as well. Several effective factors on the extraction performance were investigated.

Results:

Under the optimized conditions for the GO sorbent, inter and intra-day relative standard deviations (RSDs, n = 3) and the Limits of Detections (LODs) were lower than 5.0% and 0.02 μg/ml, respectively. Moreover, good linear ranges were observed in wide concentration ranges with R-squared larger than 0.9961 for both thymol and carvacrol.

Conclusion:

The present method is reliable and simple for determination of carvacrol and thymol in pharmaceutical products.

Combination of bioactive phytochemicals and synthetic anthelmintics: In vivo and in vitro assessment of the albendazole-thymol association

The search of novel strategies for anthelmintic control is a crucial need considering the widespread increase in resistant parasitic populations in livestock. Bioactive phytochemicals may contribute to improve parasite control by enhancing the effect of existing anthelmintic drugs. The aim of the current work was to evaluate the in vivo and in vitro pharmaco-chemical interaction and the in vivo efficacy of the combination of albendazole (ABZ) with thymol (TML) in lambs naturally infected with resistant gastrointestinal nematodes. Thirty (30) lambs were allocated into three experimental groups. Each group was treated orally with either ABZ (5 mg/kg), TML (150 mg/kg, twice every 24 h) or the co-administration of both compounds. Blood samples were collected between 0 and 51 h post-treatment and TML, ABZ and its metabolites were measured by HPLC. Individual faecal samples were collected at days -1 and 14 post-treatment to perform the faecal egg count reduction test. Additionally, the effect of TML on the sulphoreduction and sulphonation of ABZ sulphoxide was assessed in vitro using ruminal content and liver microsomes, respectively. The metabolism of TML in the ruminal content was very low and the monoterpene exhibited a low degree of association with the particulate phase of the ruminal content. No changes in the pharmacokinetic behavior of ABZ sulphoxide were observed in the presence of the natural product (TML). In contrast, the ABZ sulphone Cmax and AUC were lower (P 0.002 and 0.001 respectively) in the co-administered animals (0.16 ± 0.07 μg/mL and 3.63 ± 1.21 μg.h/mL) compared with those that received ABZ alone (0.45 ± 0.15 μg/mL and 9.50 ± 2.84 μg.h/mL). TML was detected in the bloodstream between 1 and 48 h post-treatment, which indicates the time of target nematodes being exposed to the bioactive monoterpene. However, the in vivo efficacy of TML was 0% and the presence of this terpene did not increase the efficacy of ABZ. The presence of TML significantly inhibited the ruminal sulphoreduction (P 0.001) and the hepatic sulphonation (P 0.001) of ABZ sulphoxide. These observations point out that in vivo pharmaco-parasitological studies are relevant to corroborate the adverse kinetic/metabolic interactions and the efficacy of bioactive natural products combined with synthetic anthelmintics.

Impact of ripening inhibitors on molecular transport of antimicrobial components from essential oil nanoemulsions

The objective of this study was to provide insights into the mechanisms involved in the mass transport of antimicrobial compounds from essential oil nanoemulsions to bacterial cell membranes. Origanum oil-in-water nanoemulsions were produced using spontaneous emulsification by titrating a mixture of essential oil, ripening inhibitor, and surfactant (Tween 80) into 5 mM sodium citrate buffer (pH 3.5). Stable nanoemulsions containing relatively small droplets (d < 60 nm) were produced using this low-energy method. The nature of the ripening inhibitor used in the oil phase of the nanoemulsions affected the antimicrobial activity of the nanoemulsions: corn (LCT) > medium-chain triglycerides (MCT). Differences in antimicrobial activity were attributed to the differences in the rate of transfer of hydrophobic antimicrobial constituents from the nanoemulsion to the MCT emulsion, which was used to mimic the hydrophobic region of the bacterial cell membranes. Each antimicrobial nanoemulsion was separated from the MCT emulsion by a dialysis tubing. Dialysis tubing with two different pore sizes was used, one excluding nanoemulsion droplet and micelle delivery, allowing the delivery of antimicrobial compounds only through the aqueous phase and the other by both the aqueous phase and micelles. For origanum oil nanoemulsions, the delivery of all antimicrobial agents occurred more efficiently when micelles were present.

Evaluation of the Impact of Varied Carvacrol Concentrations on Salmonella Recovery in Oregano and How Corn Oil Can Minimize the Effect of Carvacrol during Preenrichment

Phenolic compounds, like carvacrol, in oregano interfere with the detection of foodborne pathogens such as Salmonella enterica. Carvacrol concentration varies based on plant cultivars and growth region. Six oregano cultivars were used to compare the impact of carvacrol concentration on Salmonella and to evaluate the effectiveness of corn oil to help increase Salmonella survival for detection. The results of Agilent 1200 series high-performance liquid chromatography analysis showed that carvacrol concentration in the six oregano cultivars ranged from 64 to 11,200 ppm. Oregano samples were artificially contaminated with S. enterica and were preenriched in Trypticase soy broth with or without 2% (v/v) corn oil. After 18 to 24 h at 37°C, aliquots were transferred to selective enrichment broths. Salmonella was recovered onto xylose lysine Tergitol 4 agar. Six Salmonella serovars were compared, and recovery varied based on carvacrol concentration and serovar. Samples with higher concentrations of carvacrol showed Salmonella recovery only when they were preenriched with corn oil. Based on metagenomic analysis, the microflora associated with the oregano also varied per cultivar. The results show that, as carvacrol levels increased, Salmonella survival decreased. However, the addition of corn oil to the preenrichment broth can minimize the antimicrobial effects of the phenolic compounds, thus allowing for increased detection of Salmonella from oregano cultivars.

Xanthones Content in Swertia multicaulis D. Don from Nepal

The medicinal plant Swertia multicaulis D. Don was collected in Rasuwa District (Nepal) and the xanthone content of its ethyl acetate extracts was studied. The total amount of xanthones in S. multicaulis determined by HPLC reaches almost 13 g of xanthones per 1 kg of dry matter. The identification of xanthones in S. multicaulis was achieved by a combination of HPLC, LC–MS and LC–NMR. The final assignment of the individual chemical structures was provided by NMR, supported by preparative HPLC. In eight chromatographic peaks, four major xanthones were identified—1,3-dihydroxy-5,8-dimethoxyxanthone, 1-hydroxy-3,5,8-trimethoxyxanthone, bellidifolin (1,5,8-tri-hydroxy-3-methoxyxanthone), and decussatin (1-hydroxy-3,7,8-trimethoxyxanthone).

Formulation of an aloe-based product according to Iranian traditional medicine and development of its analysis method

BACKGROUND

Currently, people are more interested to traditional medicine. The traditional formulations should be converted to modern drug delivery systems to be more acceptable for the patients. In the present investigation, a poly herbal medicine "Ayarij-e-Faiqra" (AF) based on Iranian traditional medicine (ITM) has been formulated and its quality control parameters have been developed.

METHODS

The main ingredients of AF including barks of Cinnamomum zeylanicum Blume and Cinnamomum cassia J. Presl, the rhizomes of Nardostachys jatamansi DC., the fruits of Piper cubeba L.f., the flowers of Rosa damascena Herrm., the oleo gum resin of Pistacia terebinthus L. and Aloe spp. dried juice were powdered and used for preparing seven tablet formulations of the herbal mixture. Flowability of the different formulated powders was examined and the best formulations were selected (F6&F7). The tablets were prepared from the selected formulations compared according to the physical characteristics and finally, F7 was selected and coated. Physicochemical characters of core and coated AF tablets were determined and the HPLC method for quantitation of aloin as a marker of tablets was selected and verified according to selectivity, linearity, precision, recovery, LOD and LOQ.

RESULTS

The results showed that core and coated AF tablets were in agreement with USP requirements for herbal drugs. They had acceptable appearance, disintegration time, friability, hardness, dissolution behavior, weight variation and content uniformity. The amount of aloin in tablets was found 123.1 mg/tab. The HPLC method for aloin determination in AF tablets was verified according to selectivity, linearity (5-500 μg/ml, r²:0.9999), precision (RSD: 1.62%), recovery (108.0%), LOD & LOQ (0.0053 & 0.0161 μg/ml).

CONCLUSIONS

The formulated tablets could be a good substitute for powder and capsules of AF in ITM clinics with a feasible and precise method for its quality control. Ayarij-e-Faiqra formulation.

Development of a validated HPLC method for the simultaneous determination of flavonoids in Cuscuta chinensis Lam. by ultra-violet detection

BACKGROUND

Cuscuta species known as dodder, have been used in traditional medicine of eastern and southern Asian countries as liver and kidney tonic. Flavonoids are considered as the main biologically active constituents in Cuscuta plants especially in C. chinensis Lam.

OBJECTIVE

In the present study, a fast, simple and reliable method for the simultaneous determination and quantization of C. chinensis flavonols including hyperoside, rutin, isorhamnetin and kaempferol has been developed.

MATERIALS AND METHODS

The chromatographic separation was carried out on a reversed phase ACE 5 C18 with eluting at a flow rate of 1 ml/min using a gradient with O-phosphoric acid 0.25% : acetonitrile for 42 min. UV spectra were collected across the range of 200-900 nm, extracting 360 nm for the chromatograms. The method was validated according to linearity, selectivity, precision, recovery, LOD and LOQ.

RESULTS

The method was selective for determination of rutin, hyperoside, isorhamnetin and kampferol. The calibration graphs of flavonols were linear with r2 > 0.999. RSDs% of intra- and inter-day precisions were found 1.3&3.4 for rutin, 1.5&2.8 for hyperoside, 1.3&3.3 for isorhamnetin and 1.7 & 2.9 for kaempferol which were satisfactory. LODs and LOQs were calculated as 1.73 & 8.19 for rutin, 0.09 & 4.19 for hyperoside, 2.09 & 6.3 for isorhamnetin and 0.18 & 0.56 for kaempferol. The recovery averages of above-mentioned flavonols were 90.3%, 97.4%, 98.7% and 90.0%, respectively.

CONCLUSION

The simplicity of the method makes it highly valuable for quality control of C. chinensis according to quantization of flavonols.

Comparative study of rosmarinic acid content in some plants of Labiatae family

BACKGROUND

Plants of Labiatae are used in traditional medicine and phytotherapy. Rosmarinic acid (RA) is a phenolic compound which is found in many genus of Labiatae and exhibits important biological activities.

MATERIALS AND METHODS

In this investigation, RA contents of 29 species of Labiatae named Salvia officinalis, Salvia limbata, Salvia virgata, Salvia hypoleuca, Salvia macrosiphon, Salvia choloroleuca, Melissa officinalis, Origanum vulgare, Lavandula angustifolia, Rosmarinus officinalis, Thymus daenensis, Thymus citriodorous, Thymus pubescens, Thymus vulgaris, Zataria multiflora, Mentha piperita, Mentha pulegium, Mentha longifolia, Mentha spicata, Mentha aquatica, Mentha crispa, Perovskia artemisoides, Zhumeria majdae, Satureja hortensis, Satureja khuzistanica, Satureja bachtiarica, Satureja atropatana, Satureja mutica and Satureja macrantha were determined by using high-performance liquid chromatographic method.

RESULTS

The results showed that RA content in different species of Labiatae was 0.0-58.5 mg g(-1) of dried plants. The highest amount of RA was found in Mentha species especially M. spicata.

CONCLUSION

M. spicata can be considered as a new source of rosmarinic acid .

Analgesic and Antiinflammatory Activities of the Aqueous Extract from Plectranthus amboinicus (Lour.) Spreng. Both In Vitro and In Vivo

Plectranthus amboinicus (Lour.) Spreng. is a native Labiatae plant of Taiwan. The plants are commonly used in Chinese folk medicine for the treatment of cough, fever, sore throats, mumps, and mosquito bite. The aim of this study was to investigate the analgesic and antiinflammatory properties of the aqueous extract from Plectranthus amboinicus (PA) in vivo and in vitro. PA inhibited pain induced by acetic acid and formalin, and inflammation induced by carrageenan. The anti-inflammatory effect of PA was related to modulating antioxidant enzymes' activities in the liver and decreasing the Malondialdehyde (MDA) level and the production of tumor necrosis factor alpha (TNF-α), and cyclooxygenase2 (COX-2) in edema-paw tissue in mice. In vitro studies show that PA inhibited the proinflammatory mediators in RAW 264.7 cells stimulated with lipopolysaccharide (LPS). PA blocked the degradation of IκB-α and nuclear translocation of NF-κB p65 subunit. Finally, the amount of carvacrol in the aqueous extract of PA was 1.88 mg/g extract. Our findings suggest that PA has analgesic and anti-inflammatory activities. These effects were mediated by inhibiting the proinflammatory mediators through blocking NF-κB activation. Meanwhile, the effects observed in this study provide evidence for folkloric uses of Plectranthus amboinicus (Lour.) Spreng. in relieving pain and inflammation.

The alteration of components in the fermented Hwangryunhaedok-tang and its neuroprotective activity

BACKGROUND

Hwangryunhaedok-tang is a traditional herbal prescription that has sedative activity, hypotensive and anti-bacterial effects.

OBJECTIVE

In this study, we investigated the alteration of contents of components in Hwangryunhaedok-tang, antioxidant activity and neuroprotective activity by fermentation with Lactobacillus acidophilus KFRI 128.

MATERIALS AND METHODS

Contents of three marker compounds (geniposide, berberine and palmatine) and unknown compounds in the Hwangryunhaedok-tang (HR) and the fermented Hwangryunhaedok-tang (FHR) were measured and compared using the established high-performance liqued chromatograph coupled with a photodiode (HPLC-DAD) method. The antioxidant activity of HR and FHR were determined by DPPH free radical and hydrogen peroxide (H(2)O(2)) scavenging assay. Also, the neuroprotective activities of HR and FHR against glutamate-induced oxidative stress in a mouse hippocampal cell line (HT22) were evaluated by MTT assay.

RESULTS

The contents of geniposide and palmatine were decreased but the content of berberine was increased in the FHR. And the contents of unknown compounds (1), (2), (3), (4) and (5) in the HR were altered by fermentation. Electron donating activity (EDA, %) value of FHR was higher than HR for DPPH radical scavenging activity and H2O2 scavenging activity, respectively. In the MTT assay, FHR showed more potent neuroprotective activity than HR by 513.90%.

CONCLUSION

The FHR using microorganism could convert compounds in HR and enhance the antioxidant and neuroprotective activity.

A Validated HPTLC-Densitometric Method for Assay of Aucubin in Vitexagnus-castusL

Vitexagnus-castusL. is a medicinal plant which is used in several dosage forms for women hormonal disorders and standardized according to the iridoids or flavonoids content. Aucubin, an iridoid glycoside, considered as a marker in some formulations. In this research, a thin layer chromatographic method with densitometric detection has been developed for quantitative determination of aucubin in chaste tree fruits. Chromatographic separation was performed using silica gel high performance thin-layer chromatography (HPTLC) plates with ethyl acetate-methanol-water 77 : 15 : 8 as mobile phase. Chromatograms were visualized using p-dimethylaminobenzaldehyde as reagent. Aucubin RF-value was about 0.5 and spots were scanned at 580 nm through a mercury lamp. By using this method, the amount of aucubin was found 43.5 mg/100 g of dried plant fruits. The method was validated for selectivity, linearity (r(2) = 0.997, 20-100 μg/mL), precision (intra-day < 4.9, inter-day < 7.2) and accuracy measured via determination of recovery (95-98%). The limit of detection and limit of quantization were found 6.6 and 20 μg/mL, respectively. This methodology was found to be precise with respect to the validation parameters. It is simple and convenient and could be applicable to the routine determination of aucubin in different Vitexagnus-castusL. samples.