Cytoprotective Properties of Citronella Oil (Cymbopogon nardus (L.) Rendl.) and Lemongrass Oil (Cymbopogon citratus (DC.) Stapf) through Attenuation of Senescent-Induced Chemotherapeutic Agent Doxorubicin on Vero and NIH-3T3 Cells.

OBJECTIVE: This study aimed to determine the cytoprotective potentials of citronella (Cymbopogon nardus (L.) Rendl.) essential oil (CO) and lemongrass (Cymbopogon citratus (DC.) Stapf) essential oil (LO). METHODS: The essential oils from citronella and lemongrass were obtained by steam-water distillation, then analyzed using Gas Chromatography-Mass Spectrophotometry (GC-MS) to determine the chemical constituents. The antioxidant activity of CO and LO was compared using a total antioxidant capacity kit. The viability of normal kidney epithelial cells Vero and fibroblast NIH-3T3 as the cell models were tested using a trypan blue exclusion assay. The effect of cellular senescence inhibition on both cell models was measured using senescence-associated ß-galactosidase (SA-ß-gal) staining. The mechanism of action of CO and LO in the protection of cellular damage against doxorubicin was also confirmed through 2',7'-dichlorofluorescin diacetate (DCFDA) staining to discover the ability to decrease reactive oxygen species (ROS) levels and a gelatin zymography assay to observe the activity of matrix metalloproteinases (MMPs). RESULTS: The major marker components of CO and LO were citronellal and citral, respectively. Both oils showed low cytotoxic activity against Vero and NIH-3T3 cells, with IC50 values of over 40 µg/mL. LO exhibited higher antioxidant capacity than CO, but there was no effect on the intracellular ROS level of both oils on Vero and NIH-3T3 cells. However, CO and LO decreased cellular senescence induced by doxorubicin exposure on both cells, as well as suppressed MMP-2 expression.  Conclusion: Both CO and LO decrease the cellular senescence and MMP-2 expression with less cytotoxic effects on normal cells independently from their antioxidant capacities. The results were expected to support the use of CO and LO as tissue protective and anti-aging agents in maintaining the body's cellular health against chemotherapeutics or cellular damaging agents.

In vitro synergistic effect of hesperidin and doxorubicin downregulates epithelial-mesenchymal transition in highly metastatic breast cancer cells.

BACKGROUND: We previously reported that in highly metastatic breast cancer cells, doxorubicin (DOX) at non-toxic concentrations promoted cell migration and invasion. Hesperidin (30, 5, 9-dihydroxy-40-methoxy-7-orutinosyl flavanone) is a flavonoid glycoside isolated from citrus/lemon plant that possesses a cytotoxic effect in several cancer cells. In this study, we investigate whether DOX efficacy is enhanced by hesperidin (Hsd) and the molecular pathway involved in highly metastatic breast cancer, 4T1. METHODS: Combined cytotoxicity of Hsd and DOX was evaluated with MTT assay and was analyzed using Chou-Talalay's method. To better understand the underlying mechanism, several factors, including apoptosis and cell cycle arrest were analyzed by flow cytometry. In addition, antimigration activity was evaluated by scratch wound healing assay, MMP-9 expression by ELISA and gelatin zymography, and Rac-1 protein level using western blot. The data on survival rate and expression level of MMP-9 and Rac-1 were obtained from Gene Expression OMNIBUS (GEO). RESULTS: Under MTT assay, Hsd showed a cytotoxic effect in a concentration-dependent manner with an IC50 value of 284 µM on 4T1 cells. Hsd synergistically enhanced the cytotoxic effect of DOX which seemed to correlate with an increase in apoptotic cell death, G2/M cell cycle arrest and blocked the migration of 4T1 cells. At 10 nM, doxorubicin induced lamellipodia formation, and increased the level of Rac-1 and metalloproteinase-9 (MMP-9) expression. Interestingly, combined treatment of DOX and Hsd dramatically downregulated the expression of MMP-9 and Rac-1. These results indicated that Hsd block the cell migration induced by DOX under in vitro studies. CONCLUSION: These findings strongly suggest that Hsd possesses a potential synergistic effect that can be developed to enhance the anticancer efficacy of DOX and reduce the risks of chemotherapy use in highly metastatic breast cancer.

The Cytotoxic and Anti-Migratory Properties of Caesalpinia sappan and Ficus septica, in Combination with Doxorubicin on 4T1 TNBC Cells with Nephroprotective Potential.

OBJECTIVE: To evaluate the anti-cancer properties of Caesalpinia sappan and Ficus septica in combination with doxorubicin on 4T1 cells, confirm their nephroprotective activities, and predict the molecular targets of the underlying mechanisms. METHODS: The cytotoxic activities of all extracts and doxorubicin were determined by MTT assay followed by cell cycle and apoptosis analysis using flow cytometry. Immunoblotting was used to determine the protein expressions. The proteins involved in the cell proliferation and migration were analyzed through bioinformatics approaches, whereas, the interaction between compounds and protein targets was observed through molecular docking. Furthermore, the effect of the extracts on cell migration was analyzed by scratch wound healing assay. The intracellular ROS after treatment with extracts was observed using DCFDA staining flow cytometry. RESULTS: Both ECS and EFS performed cytotoxic properties and significantly enhanced doxorubicin's cytotoxic effects against 4T1 cells. However, these cytotoxic activities did not correlate with the cell cycle progression. On the contrary, the combination treatment caused apoptosis that may correlate with the decreasing of IκBα phosphorylation, indicating that all agents targeted the inhibition of NF-κB activation. The combination treatments also inhibited cell migration and decreased MMP-9 expression. TNBC proliferation and metastasis needed at least 54 proteins to be activated, some of them are related to NF-κB activation. The inhibitory effect of ECS correlated with the interaction of brazilin and brazilein to IKK, a kinase protein that plays a role in IκBα phosphorylation. In addition, ECS and EFS reduced ROS expression in Vero cells caused by doxorubicin. CONCLUSION: In conclusion, ECS and EFS effectively enhanced the cytotoxic effect of doxorubicin and inhibit cell migration on 4T1 cells and these activities may correlate to the inhibitory effect of NF-κB activation. ECS and EFS also exhibit ROS suppressing effect on Vero cells that may be beneficent to reduce nephrotoxicity of chemotherapeutic treatment.

Different Cytotoxic Effects of Vetiver Oil on Three Types of Cancer Cells, Mainly Targeting CNR2 on TNBC.

OBJECTIVE: To investigate vetiver oil (VO) selectivity effects on several cancer cell types and identify the ß-caryophyllene role and mechanisms to prevent cancer development. METHODS: Cytotoxic effects of VO on three types of cancer cells (WiDr, 4T1, T47D) were determined using MTT assay. VO's effects on the cell cycle and apoptosis were analyzed using flow cytometry. Intracellular Reactive Oxygen Species (ROS) of cells after treatment with VO was observed with DCFDA staining. Bioinformatics study and molecular docking were used to determine the molecular targets of VO. RESULTS: VO contained various essential oils in which ß-caryophyllene was the most abundant. 4T1 cells performed the lowest IC50 value. WiDr and 4T1 cells showed an arrest in the G2/M phase, while T47D showed an increase of sub G1 population after VO treatment. On the other hand, apoptosis was only observed in WiDr and T47D cells. ROS levels were increased significantly in WiDr and T47D cells but not in 4T1 cells. Cannabinoids CB2 receptor (CNR2) was highly expressed in 4T1 cells and commonly exhibited a low survival rate on Triple Negative Breast Cancer (TNBC) patients. CNR2 was the notable target of ß-caryophyllene and performed agonistic interaction, which might have contributed to its cytotoxic activity against 4T1 cells. CONCLUSION: The molecular interaction of VO cannabinoid agonists and the CNR2 receptor was the underlying cause of VO cytotoxicity, which is a VO distinction on TNBC. Therefore, VO is better suited for use as an anti-cancer agent in TNBC cells.