Zerumbone-induced reactive oxygen species-mediated oxidative stress re-sensitizes breast cancer cells to paclitaxel

Chemotherapy is an effective approach for cancer therapy when plant-derived sensitizers are combined with chemotherapeutics. Zerumbone, a natural phytochemical, has been documented to have various pharmacological roles. Here, we evaluated the chemosensitization potential of zerumbone in a breast cancer cell line in vitro. Zerumbone-induced cytotoxicity in MCF-7 cells was assessed by 3-[4,5-dimethylthiazole-2-yl]-2,5-diphenyltetrazolium bromide (MTT)-based metabolic analysis. Reactive oxygen species (ROS)-mediated mitochondrial membrane alterations, DNA damage, and apoptotic morphological changes were measured by fluorescence microscopy methods. A biochemical assay was employed to analyze Thiobarbituric acid reactive substances (TBARS) and antioxidant levels. Apoptotic marker expression levels were investigated by immunoblotting. MTT assay revealed that zerumbone significantly enhanced paclitaxel (PTX)-induced cell death in breast cancer cells in a concentration-dependent manner. Furthermore, our study demonstrated that zerumbone (15 μM) significantly enhanced ROS when combined with PTX (1 μM) treatment. Additionally, we observed that zerumbone enhanced the impairment of mitochondrial membrane potential and oxidative DNA damage, thereby inducing apoptosis in combination with PTX. Western blot analysis indicated that zerumbone significantly upregulated BAX, caspase-7, and caspase-9 expression and decreased BCL-2 expression, thereby inducing proapoptotic protein-mediated cell death combined with PTX. The prooxidant properties of zerumbone potentially resensitize breast cancer cells to PTX by enhancing intracellular ROS-mediated oxidative stress.

Monitoring of Organochlorine Pesticide Residues in Human Breast Milk in the Northern Governorates of Jordan in 2019/2020 Compared with the Results of 2015 Study

One hundred and twenty samples of breast milk were collected from five northern governorates and districts in Jordan in 2019 and 2020 to monitor results for organochlorine pesticides as organic contaminants. The results showed that 36 samples (30%) of total 120 analyzed samples were contaminated as follows: 16 samples (13.3%) were contaminated with dieldrin, 4 samples (3.3%) with p,p'-DDE, 4 samples (3.3%) with p,p'-DDD, 8 samples (6.7%) with p,p'-DDT and 4 samples (3.3%) with o,p'-DDE. Comparing results of the current study with those of 2015 study, no residues for the HCHs in 2019/2020 study have been detected, an increase in the DDTs occurred and an increase in the cyclodiens in the 2019/2020 compared to the 2015 study.

Organochlorine Pesticides Residues in Human Breast Milk from the Middle Governorates in Jordan in 2013/2014

One hundred samples of mother breast milk were gathered from six middle governorates and districts in Jordan in 2013/2014 to monitor Organochlorine pesticides pollutants. The results showed clearly that banned organochlorine pesticides are still detected in the monitored samples in low concentration despite banning of these persistent pollutants in Jordan since 36 years ago. However, the results indicated that 1% of the contaminated samples contained β-HCH, 5% γ-HCH, 3% p,p'-DDD, 2% heptachlor, 45% p,p'-DDE and 3% p,p'-DDT. In addition, these monitored samples had no residues of aldrin, dieldrin, α-endosulfan, β-endosulfan, HCB, o,p'-DD, o,p'-DDT and o,p'-DDE. In conclusion, there was a decline in the residues of Organochlorine pesticides, particularly DDT group members.