Phytocannabinoids possess anticancer properties, as established in vitro and in vivo. However, they are characterized by high lipophilicity. To improve the properties of cannabidiol (CBD), such as solubility, stability, and bioavailability, CBD inclusion complexes with cyclodextrins (CDs) might be employed, offering targeted, faster, and prolonged CBD release. The aim of the present study is to investigate the in vitro effects of CBD and its inclusion complexes in randomly methylated β-CD (RM-β-CD) and 2-hyroxypropyl-β-CD (HP-β-CD). The enhanced solubility of CBD upon complexation with CDs was examined by phase solubility study, and the structure of the inclusion complexes of CBD in 2,6-di-O-methyl-β-CD (DM-β-CD) and 2,3,6-tri-O-methyl-β-CD (TM-β-CD) was determined by X-ray crystallography. The structural investigation was complemented by molecular dynamics simulations. The cytotoxicity of CBD and its complexes with RM-β-CD and HP-β-CD was tested on two cell lines, the A172 glioblastoma and TE671 rhabdomyosarcoma cell lines. Methylated β-CDs exhibited the best inclusion ability for CBD. A dose-dependent effect of CBD on both cancer cell lines and improved efficacy of the CBD–CDs complexes were verified. Thus, cannabinoids may be considered in future clinical trials beyond their palliative use as possible inhibitors of cancer growth.

Crocus sativus L. has various pharmacological properties, known for over 3600 years. These properties are attributed mainly to biologically active substances, which belong to the terpenoid group and include crocins, picrocrocin and safranal. The aim of the current work was to examine the effects of crocins (CRCs) and their methyl ester derivate dimethylcrocetin (DMCRT) on glioblastoma and rhabdomyosarcoma cell lines, in terms of cytotoxicity and gene expression, implicated in proapoptotic and cell survival pathways. Cell cytotoxicity was assessed with Alamar Blue fluorescence assay after treatment with saffron carotenoids for 24, 48 and 72 h and concentrations ranging from 22.85 to 0.18 mg/mL for CRCs and 11.43 to 0.09 mg/mL for DMCRT. In addition, BAX, BID, BCL2, MYCN, SOD1, and GSTM1 gene expression was studied by qRT-PCR analysis. Both compounds demonstrated cytotoxic effects against glioblastoma and rhabdomyosarcoma cell lines, in a dose- and time-dependent manner. They induced apoptosis, via BAX and BID upregulation, MYCN and BCL-2, SOD1, GSTM1 downregulation. The current research denotes the possible anticancer properties of saffron carotenoids, which are considered safe phytochemicals, already tested in clinical trials for their health promoting properties.

Rosmarinus officinalis is a well-studied plant, known for its therapeutic properties. However, its biological activity against several diseases is not known in detail. The aim of this study is to present new data regarding the cytotoxic activity of a hydroethanolic extract of Rosmarinus officinalis on glioblastoma (A172) and rhabdomyosarcoma (TE671) cancer cell lines. The chemical composition of the extract is evaluated using liquid chromatography combined with time-of-flight mass spectrometry, alongside its total phenolic content and antioxidant activity. The extract showed a promising time- and dose-dependent cytotoxic activity against both cell lines. The lowest IC₅₀ values for both cell lines were calculated at 72 h after treatment and correspond to 0.249 ± 1.09 mg/mL for TE671 cell line and 0.577 ± 0.98 mg/mL for A172 cell line. The extract presented high phenolic content, equal to 35.65 ± 0.03 mg GAE/g of dry material as well as a strong antioxidant activity. The IC₅₀ values for the antioxidant assays were estimated at 12.8 ± 2.7 μg/mL (DPPH assay) and 6.98 ± 1.9 μg/mL (ABTS assay). The compound detected in abundance was carnosol, a phenolic diterpene, followed by the polyphenol rosmarinic acid, while the presence of phenolic compounds such as rhamnetin glucoside, hesperidin, cirsimaritin was notable. These preliminary results suggest that R. officinalis is a potential, alternative source of bioactive compounds to further examine for abilities against glioblastoma and rhabdomyosarcoma.

The present study identifies the phytochemical profile of a hydroalcoholic extract derived from Smilax aspera leaves and stems, estimates its antioxidant capacity and evaluates its cytotoxic activity against glioblastoma (A172 cell line) and rhabdomyosarcoma (TE671 cell line). Chemical analysis of leaves and stems was performed with liquid chromatography analysis combined with a quadrupole time-of-flight high-resolution mass spectrometry (LC/Q-TOF/HRMS). The antioxidant activity of the extract was evaluated with the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and the 2,2′-azinobis[3-ethylbenzthiazoline-6-acid)] (ABTS) assays. Cell viability was examined using the alamar blue assay. Most of the compounds tentatively identified belonged to the flavonoids family, with rutin being the most abundant, followed by luteolin. The extract showed potent antioxidant activity which corresponded to 13.9 ± 1.91 μg/mL (DPPH assay) and 6.27 ± 1.7 μg/mL (ABTS assay), expressed as IC₅₀ values. The extract inhibited the proliferation of cancer cells. The lowest IC₅₀ value for A172 cells was observed 48 h after treatment and was calculated at 0.482 ± 0.98 mg/mL while for the TE671 cell line the lowest IC₅₀ value was 0.629 ± 1.31 mg/mL, calculated 72 h after treatment. Considering the high biological value of flavonoids as health defense promoters, S. aspera leaves and stems can be an important natural source to consider as they may provide important health benefits.

Antigen screening for the SARS-CoV-2 S1 spike protein is among the most promising tools for the mass monitoring of asymptomatic carriers of the virus, especially in limited resource environments. Herewith, we report on the possible use of the angiotensin-converting enzyme 2 (ACE2), the natural receptor and entry point of the virus, as a biorecognition element for the detection of the S1 antigen combined with an established bioelectric biosensor based on membrane-engineered cells. The working principle of our approach is based on the measurable change of the electric potential of membrane-engineered mammalian cells bearing ACE2 after attachment of the respective viral protein. We demonstrate that sensitive and selective detection of the S1 antigen is feasible in just three min, with a limit of detection of 20 fg/mL. In a preliminary clinical application, positive patient-derived samples were identified with a 87.9% score compared to RT-PCR. No cross-reactivity was observed against a wide range of nucleocapsid protein concentrations. The novel biosensor is embedded in a commercially ready-to-use testing platform, complete with the consumable immobilized cell–electrode interface and a portable read-out device operable through smartphone or tablet. In addition, the possible application of the system for the high throughput screening of potential pharmacological inhibitors of the ACE2 receptor-S1 RBD interaction is discussed.

Natural plant extracts are an important source of antitumor agents, and still provide promising approaches for discovering new drugs. Crocus sativus (saffron) is endowed with anticancer, differentiating, antioxidant and genoprotective properties. Its pharmacological properties are attributed to biologically active substances, crocins (CRCs) which are hydrophilic carotenoids. They are glycosy-esters of the amphiphilic natural carotenoid crocetin (CRT), which exhibits extensive distribution and penetration through lipid bilayers. The hemisynthetic derivate dimethylcrocetin (DMCRT) is similar to CRT and is soluble in many organic solvents. With regards to safety, saffron and its constituents are considered practically non-toxic substances. The current research aims to study the in vitro cytotoxic effect of the natural carotenoids CRCs and DMCRT on a medulloblastoma cell line. CRCs are diluted to nuclease and protease free water and DMCRT to 10% DMSO. For the biological assays TE-671 medulloblastoma cells are incubated in 96-well plates at a range of concentrations of CRCs (0.18-22.85 mg/ml) and DMCRT (0.18-11.43 mg/ml) for 24, 48 and 72 hours. Analysis of cell viability is performed with Alamar Blue and MTT viability assays. CRCs manifest a cytotoxic effect in a dose and time-dependent manner (p<0.001 for exposed cells to any concentration at 24, 48 and 72 hours versus cells not exposed); as their concentration increases, cell viability is reduced for all time points. For the same concentration, as the time of exposure increases, the inhibitory effect is increased. The antiproliferative effect of DMCRT is less pronounced, observed only at concentrations higher than 5.71 mg/ml at 24 and 48 hours and higher than 1.43 mg/ml at 72 hours, whereas for lower concentrations the effect is not statistically significant. IC50 values for each time point are calculated as 3.230, 2.14 and 1.72 mg/ml for CRCs and 5.9, 5.6 and 3.712 mg/ml for DMCRT at 24, 48, and 72 hours, respectively. The results of our study could afford the basis of research, regarding the use of natural carotenoids as an alternative solution to the toxicity of retinoids, especially for the vulnerable pediatric population and during pregnancy, while retaining the anticancer properties of retinoids. Acknowledgements The research is co-financed through the Program ‘Support for researchers with an emphasis on young researchers-cycle B ‘ (MIS 5048464) AND The Foundation for Education and European Culture (IPEP).