Juniperus Communis Extract Exerts Antitumor Effects in Human Glioblastomas Through Blood-Brain Barrier

Abstract

Background/Aims: Herbal materials derived from Juniperus communis (JCo) possess anticancer activity. In this study, we evaluated the efficacy of a JCo berry extract in suppressing glioblastoma growth. Methods: The effects of JCo extract on the viability of normal and glioma cell lines was analyzed using a modified 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The synergistic therapeutic effect of JCo extract and temozolomide (TMZ) on glioma cells was examined by MTT analysis. Flow cytometry analysis, the terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) test, and western blotting were performed to identify the apoptotic pathway. To determine the in vivo efficacy of the JCo extract, rats were injected with 5 × 10⁴ rat glioma RG2 cells in the back skin and brain hemisphere and then received a subcutaneous injection in the back skin that contained either JCo extract or vehicle. Finally, blood and histologic examinations were performed to evaluate JCo toxicity. Results: The IC₅₀ values of JCo extract were 57–69 µg/mL and 49–67 µg/mL in the glioblastoma cell lines after 24 and 48 h, respectively. However, in non-tumor cell lines, the respective IC₅₀ values of JCo extract were 76–105 µg/mL and 77–108 µg/mL. The JCo extract had a stronger cytotoxicity and a larger range of IC₅₀ values in glioma than in normal cells as compared to those effects caused by temozolomide (TMZ). In addition, the results of flow cytometry analysis, TUNEL test, and western blotting revealed that the JCo extract induced glioma cell cycle arrest through intrinsic and extrinsic apoptotic pathways. In the in vivo studies, a significant reduction of tumor size in JCo-treated rats, as measured by animal MRI, demonstrated that the JCo extract effectively inhibited glioma cell growth and successfully penetrated the blood-brain barrier. The immunohistochemical (IHC) staining detected positive signals of PCNA, VEGFR-1, and VEGFR -2 in 44.49%, 5.88%, and 5.85% of JCo-treated glioma cells, respectively. However, positive signals of PCNA, VEGFR-1, and VEGFR-2 were detected in 73.08%, 9.67%, and 11.70% of vehicle-treated glioma cells, respectively. The IHC examination of PCNA and VEGFR-1 and -2 indicated that JCo extract significantly decreased the degree of neovascularization. However, no significant differences in serum levels of blood cell count and hepatic enzymes, renal function index, and the histologic appearance of vital organs were detected between the JCo and vehicle-treated rats. Conclusion: The JCo extract penetrated the blood-brain barrier and significantly induced glioma cell apoptosis by reducing neovascularization via suppression of the PI3K/AKT/mTOR pathway. Furthermore, JCo extract was less cytotoxic to non-neoplastic vital organs than TMZ.

Zimbro (Juniperus communis L.) as a Promising Source of Bioactive Compounds and Biomedical Activities: A Review on Recent Trends

“…On the other hand, the administration of J. communis essential oils (200 mg/kg) in BALB/c nude mice injected with HepG2 cancer cells showed the capacity to reduce tumor growth and extend the lifespan with no or low systemic and pathological toxicity [ 132 ]. Similar information was reported by Lai and colleagues [ 133 ] and Tsai and collaborators [ 135 ] regarding the antitumor effects of this plant against human colorectal adenocarcinoma and glioblastoma.…”

“…On the other hand, essential oil and distilled extracts from J. communis berries revealed the potential to suppress A549 human lung adenocarcinoma epithelial-cell growth and development, revealing IC 50 values of 69.4 and 1270 µg/mL, respectively, after 24 h of treatment [ 71 ]. Additionally, they also showed the ability to suppress the development of SH-SY5Y human neuroblastoma cells after 24 h of exposure (IC 50 score of 53.7 µg/mL), which is evidence that this plant can penetrate the blood–brain barrier [ 134 , 135 , 142 ]. The capacity of J. communis plant material (twigs, leaves and berries) to suppress NCI-H460 lung carcinoma, MCF-7, AGS gastric carcinoma, and Caco-2 cell growth was also evaluated, revealing IC 50 values varying depending on the origin [ 75 ].…”

Biodiversity of wild spice plants of the Central Kazakhstan region and their medicinal potential

“…The hydroalcoholic extract obtained from J. communis has genoprotective, antioxidant, antifungal and antiinflammatory properties (Fierascu et al 2018). The research results showed that J. сommunis extract successfully penetrates the blood-brain barrier and effectively inhibits the growth of glioma cells (Tsai et al 2018).…”

Nutraceutical Aspects of Selected Wild Edible Plants of the Italian Central Apennines

“…Methanolic extracts of J. communis leaves have been found to block the growth and development of C6 rat-brain tumor and HeLa human-cervix carcinoma cells, PC3 humanprostate cancer cells, HCT 116 human-colon cancer cells, and MCF7 breast cancer cells. Essential oil and extracts from J. communis berries have also been found to suppress A549 human lung adenocarcinoma epithelial cells' growth and development, as well as suppress the development of SH-SY5Y human neuroblastoma cells [330,331].…”