Stefkov, GJoshe

Preferred name

Stefkov, GJoshe

Official Name

Stefkov, GJoshe

Main Affiliation

gstefkov@yahoo.com

Now showing 1 - 10 of 12

Some of the metrics are blocked by your
consent settings
Differentiation of Cannabis seeds employing digital morphological screening and infrared spectroscopy coupled with multivariate modeling
(Elsevier, 2024-05-01)
;
;
;
Trajkovska, Ana
;
Cultivation of Cannabis for medicinal purposes primarily relies on seed propagation with expected variations in yield, cannabinoid content, growth rate and seed material non-uniformity. This study aims to employ digital methods for morphological analysis and infrared spectroscopy, combining them with multivariate analysis to characterize and differentiate Cannabis seeds. Morphological traits of 100 seeds from both commercial Cannabis specimens and wild-growing local varieties were analyzed using the high-throughput phenotyping software in addition to their collected infrared spectra in the mid-IR region. Subsequently, a chemometrics approach by means of Principal Component Analysis (PCA), Hierarchical Cluster Analysis (HCA), and Partial Least Square-Discriminatory Analysis (PLS-DA) was applied. The statistical indicators of the PLS-DA model (R2X=0.99, R2Y=0.63, Q2=0.64) demonstrate strong predictive capabilities for the differentiation of Cannabis seed specimens based on morphological attributes. The score scatter plot clearly shows a distinct grouping pattern, primarily driven by seed size. Wild-type seeds predominantly cluster into group 1, characterized by smaller diameters, while commercial seeds cluster into group 2. By analysing spectral data, in contrast to the expected differentiation based on secondary metabolites (cannabinoids) in the seeds, differentiation was based on the macronutrient profile with characteristic bands at 3275 cm−1, 2921 cm−1, 2852 cm−1, 1743 cm−1, 1630 cm−1, 1532 cm−1, 1459 cm−1, 1239 cm−1, 1157 cm−1, 1094 cm−1, 1018 cm−1, identified as the most distinctive spectral features. The PCA model (R2X=0.88 and Q2=0.85) was composed of 5 principal components explaining 88% of the spectral variations. The loading plot of the PLS-DA model reveals the distinctive spectral features for both groups (lipid and carbohydrate bands - group 2 samples, protein and water content - group 1 samples). The developed models have the potential for application for rapid screening of quality parameters of Cannabis seeds and their differentiation.
Some of the metrics are blocked by your
consent settings
Determination of phenolic compounds in methanolic extracts of flowering stems and rosette leaves of Sideritis raeseri
(Macedonian Pharmaceutical Association, 2022)
Qazimi, Bujar
;
;
;
Dragusha, Shpend
;
Ejupi, Valon
Some of the metrics are blocked by your
consent settings
Headspace screening: A novel approach for fast quality assessment of the essential oil from culinary sage
(Elsevier BV, 2016-07)
;
;
;
;
Some of the metrics are blocked by your
consent settings
Cytotoxic screening of selected Cannabis cultivars using brine shrimp lethality assay
(Macedonian Pharmaceutical Association, 2022-12-31)
Zhivikj, Zoran
;
Shutevska, Kristina
;
Bajatovska, Ana Marija
;
Sofronievska, Sevda
;
Some of the metrics are blocked by your
consent settings
Cannabinoid production in various Cannabis sativa L. in vitro cultures
(Springer Nature, 2025-01-02)
Ana Trajkovska;
;
Oliver Tusevski;
;
;
;
Iskra Davkova;
The main goal of this study was to develop an efficient micropropagation protocol for cannabis (Cannabis sativa L.) and to summarize the influence of plant growth regulators on cannabinoid production in various in vitro cultures. Three in vitro culture lines were obtained during cannabis micropropagation and referred to calli, shoots, and plantlets. Shoot multiplication was examined on apical segments isolated from in vitro seedlings and cultivated on solid MS/B5 medium supplemented with various concentrations (0.05-1.0 mg·L− 1) of thidiazuron (TDZ). Callogenesis was induced from leaf explants of seedlings in the presence of 1.0 mg·L− 1 TDZ and 0.5 mg·L− 1 1-naphthaleneacetic acid (NAA), while further biomass production was evaluated upon TDZ (0.5-2.0 mg·L− 1). The shoot regenerative potential was assessed on various concentrations (0.1-1.0 mg·L− 1) of indole-3-butyric acid (IBA). The HPLC-DAD analysis of cannabinoids revealed that cannabidiolic acid (CBDA), cannabidiol (CBD), cannabinol (CBN), ∆9-tetrahydrocannabinol (∆9-THC), and ∆9-tetrahydrocannabinolic acid (∆9-THCA) were the main identified cannabinoids in calli, shoots and regenerated plantlets. The superior production of Δ9-THC was observed in multiple shoots cultured on 0.05 mg·L− 1 TDZ (49.23 mg·g− 1), callus cultures treated with 1.0 mg·L− 1 TDZ (3.92 µg·g− 1), as well in plantlets regenerated on hormone-free medium (80.1 mg·g− 1). The Δ9-THC content in the leaves of 6-month-old regenerated plantlets was significantly higher (1.6-fold) than that of the mother plant. Cannabinoid contents in the inflorescences of the mother plant were higher or even comparable to those observed for acclimatized plantlets. In conclusion, cannabis in vitro cultures could be proposed as promising systems for cannabinoid production.
Some of the metrics are blocked by your
consent settings
Assessment of cytotoxic impact of wild grown Lavandula angustifolia essential oil encapsulated in liposomes and nanoemulsions on DU145 cancer cell line
(Marmara University Press, 2024-12)
Mimoza BASHOLLI-SALIHU
;
Aida LOSHAJ-SHALA
;
Art ÇUNAKU
;
Venesa LUPÇI
;
Ufuk BAǦCI
The cytotoxic activity of free and nanoencapsulated essential oil of Lavandula angustifolia (LEO) was evaluated in this study. The aim was to produce different nanoformulations (NF) of LEO to improve the physicochemical properties of NF and the cytotoxic activity of LEO in the DU145 cancer cell line. Essential oil-based liposomes (LEO-Lipoid S100, -Ph 85G, and -Ph 90H) and nanoemulsions (LEO-NE) were prepared by ethanol injection method and high-pressure homogenization, respectively. LEO demonstrates measurable in vitro cytotoxic activity against the DU145 cell line (IC50 75 μg/mL). NE and Ph90H LS significantly enhanced its cytotoxic activity, while LEOLipoid S100 LS and LEO-Ph 85G LS showed no significant difference. LEO-Ph 90H LS and LEO-NE demonstrate stable nanosystems and enhanced cytotoxic potential against the DU-145 cancer cell line, suggesting promising therapeutic benefits for future application. Further studies involving in vivo experiments are necessary to validate and extend these findings.
Some of the metrics are blocked by your
consent settings
Freeze dried Salvia officinalis methanolic extract incorporated into nanostructured lipid carriers for Alzheimer’s disease treatment
(2019-04-11)
Markova, Elena
;
Kostovska, Monika
;
Taneska, Lea
;
Mihailova, Ljubica
;
Shalabalija, Dushko
Some of the metrics are blocked by your
consent settings
Chitosan-pectine microparticles loaded with sage extract for extending shell-life of sausages
(2018-05-20)
;
;
;
;
Some of the metrics are blocked by your
consent settings
Approved indications for cannabis-based preparations
(The International Organization of Scientific Research, 2021-09)
Tijana Serafimovska
;
;
;
Marija Darkovska Serafimovska
;
In traditional medicine, cannabis-based preparations have been used for a thousand of years for treatment of various diseases. The clinical use of cannabis-based preparations is limited due to legal and ethical reasons, and therefore there is a lack of data for the therapeutic potential of cannabinoids. By searching the FDA site, we identified three approved cannabis-based medicines for treatment of anorexia, nausea and vomiting caused by chemotherapy and two particularly severe forms of child epilepsy (Lennox-Gastaut and Dravet's syndrome). By searching the EMA site, we identify only one cannabis-based medicine authorized for use in the European Union – Epidyolex. But, EMA recognized possible positive therapeutic outcome of three cannabinoids (cannabidiol, cannabinol-9-carboxylic acid (resunab and lenabasum) and cannabidivarin) for which by the European Commission was granted status "Orphan designation" for 12 different indications: treatment of: tuberous sclerosis, West syndrome, Drave's syndrome, Lennox-Gastaut's syndrome, graft-versus-host disease, perinatal asphyxia, glioma, systemic sclerosis, cystic fibrosis, dermatomyositis, Rett syndrome and fragile X syndrome. The adverse effects of cannabis preparations are primarily due to THC, which has psychotropic effects and used in higher doses can cause certain central nervous system (CNS) disorders. Chronic use of THC may cause an excessive hyperemetic syndrome, which is always weaker than the side effects that cause hemotherapy. For many patients who do not respond adequate to conventional therapy, cannabis preparations are the only possible option evenif cannabinoids are less potent than conventional therapy.
Some of the metrics are blocked by your
consent settings
Mid-infrared spectroscopy as process analytical technology tool for estimation of THC and CBD content in Cannabis flowers and extracts
(Elsevier BV, 2021-04-15)
;
;
;
Stefov, Stefan
;
Huck, Christian W
Tetrahydrocannabinol (THC) and cannabidiol (CBD) are the most notable Cannabis components with pharmacological activity and their content in the plant flowers and extracts are considered as critical quality parameters. The new Medical Cannabis industry needs to adopt the quality standards of the pharmaceutical industry, however, the variability of phytocannabinoids content in the plant material often exerts an issue in the inconsistency of the finished product quality parameters. Sampling problems and sample representativeness is a major limitation in the end-point testing, particularly when the expected variation of the product quality parameters is high. Therefore, there is an obvious need for the introduction of Process Analytical Technology (PAT) for continuous monitoring of the critical quality parameters throughout the production processes. Infrared spectroscopy is a promising analytical technique that is consistent with the PAT requirements and its implementation depends on the advances in instrumentation and chemometrics that will facilitate the qualitative and quantitative aspects of the technique. Our present work aims in highlighting the potential of mid-infrared (MIR) spectroscopy as PAT in the quantification of the main phytocannabinoids (THC and CBD), considered as critical quality/material parameters in the production of Cannabis plant and extract. A detailed assignment of the bands related to the molecules of interest (THC, CBD) was performed, the spectral features of the decarboxylation of native flowers were identified, and the specified bands for the acid forms (THCA, CBDA) were assigned and thoroughly explained. Further, multivariate models were constructed for the prediction of both THC and CBD content in extract and flower samples from various origins, and their prediction ability was tested on a separate sample set. Savitskzy-Golay smoothing and the second derivative of the native MIR spectra (1800-400 cm-1 region) resulted in best-fit parameters. The PLS models presented satisfactory R2Y and RMSEP of 0.95 and 3.79% for THC, 0.99 and 1.44% for CBD in the Cannabis extract samples, respectively. Similar statistical indicators were noted for the Partial least-squares (PLS) models for THC and CBD prediction of decarboxylated Cannabis flowers (R2Y and RMSEP were 0.99 and 2.32% for THC, 0.99 and 1.33% for CBD respectively). The VIP plots of all models demonstrated that the THC and CBD distinctive band regions bared the highest importance for predicting the content of the molecules of interest in the respected PLS models. The complexity of the sample (plant tissue or plant extract), the variability of the samples regarding their origin and horticultural maturity, as well as the non-uniformity of the plant material and the flower-ATR crystal contact (in the case of Cannabis flowers) were governing the accuracy descriptors. Taking into account the presented results, ATR-MIR should be considered as a promising PAT tool for THC and CBD content estimation, in terms of critical material and quality parameters for Cannabis flowers and extracts.

Stefkov, GJoshe

Filters

Settings

Sort By

Results per page