Siderol Inhibits Proliferation of Glioblastoma Cells and Acts Synergistically with Temozolomide

Antineoplastic Activity of Methyl rosmarinate in Glioblastoma Cells

Glioblastoma (GMB) is a remarkably aggressive brain malignancy characterized by high mortality rates, despite continuous advances in therapeutic approaches. Compounds derived from plants are being studied for their potent medicinal properties in the quest for more efficient therapies. This study investigated the anti-glioma properties of Methyl rosmarinate, a hydroxycinnamic acid isolated from Thymus thracicus Velen, which has previously demonstrated anti-cancer activity in various cell lines. Human glioblastoma cell lines U87 and T98 were treated with Methyl rosmarinate to assess its effect on cell viability, cell cycle distribution and migratory capacity using Trypan blue assay, flow cytometry and scratch wound healing assay, respectively. The combinatorial effects of Methyl rosmarinate and temozolomide were also analyzed with CompoSyn software. According to the outcomes, Methyl rosmarinate significantly reduced cell viability, induced cell death by interfering in cell cycle checkpoints, and inhibited migration in both GMB cell lines. Notably, in U87 cells, the compound showed a synergistic impact with temozolomide, whereas in T98 cells, there was an antagonistic relationship. These results suggest that Methyl rosmarinate has potential anti-glioma properties; however, more in vivo research is needed.

Anti-Proliferative Activity of Ethylenediurea Derivatives with Alkyl and Oxygen-Containing Groups as Substituents

Background/Objectives: Natural cytokinins are a promising group of anti-tumor agents. In this work, we hypothesized that modification of the ethylenediurea moiety with alkyl and oxygen-containing groups could be a way to enhance the anti-proliferative properties of the molecule. Methods: Ten new analogs of ethylenediurea with these substitutions were tested for anti-proliferative activity in the human cancer cell lines MDA-MB-231 (breast cancer), A-375 (melanoma), and U-87 MG (glioblastoma) during 72 h of incubation using resazurin test and evaluated the substances receptor using molecular docking. Results: The compound with the carbamate link and ethylene substituent on the phenyl ring inhibited proliferation in these models by 70-90% without cytotoxic effects. The compound did not affect the viability of the immortalized fibroblast cell line Bj-5ta. The compound was also able to enhance the action of doxorubicin and temozolomide by about 20%. According to the molecular modeling data, the probable receptor target for the synthesized compound was the A2AR adenosine receptor. Conclusions: The results obtained on the ethylenediurea analogs with ethyl substituent in the aromatic ring are promising for the development of novel anticancer therapeutics.

New Esters of Ferrediol and Sideritriol in Sideritis clandestina subsp. peloponnesiaca: Characterization and Antiproliferative Activity

17-Isovalerate esters of ferrediol and sideritriol (compounds 1 and 5) and 17-(2-methylbutyrate) ferrediol (compound 2), which have not been earlier described, were isolated along with five known ent-15-kaurene diterpenes (siderol, sideridiol, sideroxol, eubotriol, and epi-candicandiol), one ent-beyerene (flavovirol), and one phytosterol (β-sitosterol) from the aerial parts of Sideritis clandestina subsp. peloponnesiaca (Boiss. & Heldr.) Baden that is a mountain tea species endemic to Northern Peloponnese in Greece. Compounds 1-5 exhibited weak antiproliferative activity against triple-negative MDA-MB-231 and Hs578T breast cancer cells. In MCF-7 breast cancer cells, compounds 1, 2, siderol, and sideridiol were equipotent to 5-fluorouracil (moderate antiproliferative activity).

Antioxidant properties of allium turcicum Özhatay & cowley plant extract, its effects on the proliferation and migration of cancer cells

Cancer is a type of non-communicable disease that is responsible for numerous deaths worldwide. Cancer incidence and mortality rates are on the rise due to a combination of factors, such as a growing population, aging, and poor dietary habits. The Allium turcicum Özhatay & Cowley plant is an endemic plant in the area where it grows and is consumed by the public due to its various benefits. This endemic plant, which generally grows in high-altitude regions, is sold in bunches because it is costly, mixed with rock salt, crushed into powder, and consumed as a spice. The cytotoxic and growth-inhibitory effects of A. turcicum Özhatay & Cowley herb extract on human glioblastoma U373 cells, human colorectal carcinoma cell HCT-116, and healthy HUVEC cell lines were determined by the MTT method. After 24 and 48 h of application, logIC50 values in HUVEC, HCT-116, and U373 cells were defined as 3.737, 3.765; 3.513, 3.696, 4.476, and 4.104 μg/mL, respectively. We conducted a cell migration experiment to study the A. turcicum Özhatay & Cowley Extract (ATÖCE) impact on cancer cells' metastatic behavior. Our findings indicate that ATÖCE has an inhibitory effect on the migration potential of the cells used in the study. We conducted experiments using DPPH, ABTS, CUPRAC, and total phenolic content to assess the antioxidant properties of ATÖCE. The findings from the antioxidant activity experiments revealed an activity level of 0.20 ± 0.046 at IC50. Additionally, the total phenolic content was measured to be 0.26 ± 0.044 mg GAE/g.

Iloperidone and Temozolomide Synergistically Inhibit Growth, Migration and Enhance Apoptosis in Glioblastoma Cells

Glioblastoma (GBM) is a fatal astrocytic glioma with poor prognosis and treatment resistance. Repurposing potential FDA-approved drugs like anti-psychotics can address the concerns in a timely and cost-effective manner. Epidemiological studies have shown that patients with schizophrenic using anti-psychotics have a low incidence of GBM. Therefore, we aimed to investigate the therapeutic potential of atypical anti-psychotic Iloperidone (ILO) alone and in combination with Temozolomide (TMZ) against GBM. The study assessed the growth inhibitory effect of ILO, TMZ, and their combination (ILO + TMZ) on U-87MG and T-98G cell lines using an MTT assay. The drug interaction coefficient (CDI) was determined, and doses with synergistic effects were used for subsequent experiments, including migratory, invasion, and TUNEL assays. The expressions of DRD2, β-catenin, Dvl2, Twist, and Slug were assessed by RTq-PCR, whereas the β-catenin protein expression was also determined by immunocytochemistry. ILO (p < 0.05) and TMZ (p < 0.01) significantly inhibited the growth of U-87MG cells at all tested doses. The combination of 60 µM of both drugs showed synergistic activity with CDI < 1. The inhibition of migration and apoptosis was more pronounced in the case of combination treatment (p < 0.001). Inhibition of the invading cells was also found to be significant in ILO- and combination-treated groups (p < 0.001). ILO and combination treatment also significantly downregulated the expression of DRD2, while TMZ upregulated the expression (p < 0.001). The expressions of β-catenin (p < 0.001), Dvl2 (p < 0.001), Twist (p < 0.001), and Slug (p < 0.001) were also significantly downregulated in all treatment groups as compared to the vehicle control. The data suggest that ILO possesses strong growth inhibitory activity, possibly due to its effect on DRD2 and β-catenin expression and has the potential to be repurposed against GBM.

A review of natural products and small-molecule therapeutics acting on central nervous system malignancies: Approaches for drug development, targeting pathways, clinical trials, and challenges

In 2021, the World Health Organization released the fifth edition of the central nervous system (CNS) tumor classification. This classification uses histopathology and molecular pathogenesis to group tumors into more biologically and molecularly defined entities. The prognosis of brain cancer, particularly malignant tumors, has remained poor worldwide, approximately 308,102 new cases of brain and other CNS tumors were diagnosed in the year 2020, with an estimated 251,329 deaths. The cost and time-consuming nature of studies to find new anticancer agents makes it necessary to have well-designed studies. In the present study, the pathways that can be targeted for drug development are discussed in detail. Some of the important cellular origins, signaling, and pathways involved in the efficacy of bioactive molecules against CNS tumorigenesis or progression, as well as prognosis and common approaches for treatment of different types of brain tumors, are reviewed. Moreover, different study tools, including cell lines, in vitro, in vivo, and clinical trial challenges, are discussed. In addition, in this article, natural products as one of the most important sources for finding new chemotherapeutics were reviewed and over 700 reported molecules with efficacy against CNS cancer cells are gathered and classified according to their structure. Based on the clinical trials that have been registered, very few of these natural or semi-synthetic derivatives have been studied in humans. The review can help researchers understand the involved mechanisms and design new goal-oriented studies for drug development against CNS malignancies.

Antineoplastic Activity of 9″-Lithospermic Acid Methyl Ester in Glioblastoma Cells

To date, many potent compounds have been found which are derived from plants and herbs and possess anticancer properties due to their antioxidant effects. 9″-Lithospermic acid methyl ester is an effective natural compound derived from the Thymus thracicus Velen. It has been proven that this compound has substantial properties in different diseases, but its effects in cancer have not been thoroughly evaluated. The aim of this work was to study the effects of 9″-Lithospermic acid methyl ester (9″-methyl lithospermate) in U87 and T98 glioblastoma cell lines. Its effects on cellular viability were assessed via Trypan Blue and Crystal Violet stains, the cell cycle analysis through flow cytometry, and cell migration by employing the scratch wound healing assay. The results demonstrated that 9″-methyl lithospermate was able to inhibit cellular proliferation, induce cellular death, and inhibit cell migration. Furthermore, these results were intensified by the addition of temozolomide, the most prominent chemotherapeutic drug in glioblastoma tumors. Further studies are needed to reproduce these findings in animal models and investigate if 9″-lithospermic acid methyl ester represents a potential new therapeutic addition for gliomas.

Antioxidant and Antitumor Potential of Micropropagated Balkan Endemic Sideritis scardica Griseb

Sideritis scardica Griseb. is a critically endangered Balkan endemic species, known for its antioxidant, neuroprotective and anti-inflammatory properties. The aim of the present study was to detail an efficient protocol for the micropropagation of S. scardica. In vitro cultures were initiated from the shoot tips of 40 days-old in vivo seedlings and the effects of different plant growth regulator treatments were examined. A Murashige and Skoog nutrient medium (MS) containing 1 mg/L zeatin and 0.1 mg/L indole-3-acetic acid (IAA) proved to be the most efficient for shoot multiplication as it produced quality, vigorous shoots with a mean number of six shoots per explant. For the first time, the antioxidant and antitumor activities of extracts from in vitro-obtained plants were evaluated. In vitro cultivated plants grown in the field revealed a higher total polyphenol content (3929.1 ± 112.2 mg GAE/100 g vs. 3563.5 ± 52.8 mg GAE/100 g) and higher ORAC antioxidant activity (1211.6 ± 27.3 µmol TE/g vs. 939.9 ± 52.4 µmol TE/g) than in situ cultivated plants. A comparison of the antitumor activities of extracts from in vitro propagated shoots, field-grown in vitro-obtained plants and in situ plants on HeLa (cervical adenocarcinoma), HT-29 (colorectal adenocarcinoma) and MCF-7 (breast cancer) human cancer cell lines showed that in vitro propagated shoots had a significant concentration-dependent cytotoxic effect on the cervical adenocarcinoma cell line HeLa, while the field-grown in vitro-obtained and in situ-collected samples induced the highest reduction in the viability of the mammary carcinoma cell line MCF-7. In both cases, the cells of the control non-tumor cell line, BALB/3T3, were significantly less affected. The results showed that the in vitro multiplication protocol ensured the obtainment of numerous plants with antioxidant and antitumor potential.