Background Cuminum cyminum L., commonly known as cumin, has been traditionally used in Thai traditional medicine and traditional food flavoring. The present study investigated the chemical composition, antimicrobial activity against all tested major food-borne pathogenic bacteria, and bioactive components of essential oil extracted from C. cyminum L. collected in Thailand. Methods The main components of the essential oil were investigated by gas chromatography–mass spectrometry (GC-MS) technique. Antibacterial activities against Bacillus cereus, Staphylococcus aureus, Escherichia coli, and Salmonella Typhi were investigated by disk diffusion and microdilution method. The presence of the biologically active antibacterial components was also confirmed by the thin-layer chromatography (TLC)-bioautography. Results The main components of the essential oil investigated by GC-MS were cuminaldehyde (27.10%), beta-pinene (25.04%) and gamma-terpinene (15.68%). The essential oil exhibited antibacterial activity against B. cereus, S. aureus, E. coli and S. Typhi. The essential oil showed the strongest antimicrobial activity against B. cereus with a comparable inhibition zone to tetracycline. TLC confirmed the presence of biologically active antibacterial component in the essential oil against all tested food-borne bacteria. It is further demonstrated that cuminaldehyde was the most active compound in TLC-bioautography which inhibited all of tested bacteria. Conclusions Essential oil extracted from C. cyminum L. exhibited antibacterial activity against all tested major food-borne pathogenic bacteria. Cuminaldehyde is a major bioactive component. Our results suggest that the essential oil extracted from C. cyminum L. could be applied as an alternative natural preservative to control food-borne disease and have the potential for further development of new antibacterial agents.

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Background: Zanthoxylum rhetsa (Roxb.) DC and Zanthoxylum limonella Alston are spices for flavouring in indigenous Thai food. They are traditionally used as an aromatic, astringent, antimicrobial, antiseptic and antidiabetic agent. The purpose of this study is to examine their chemical compositions and evaluate antibacterial, antioxidant and anticancer properties of the essential oils. Materials and Methods: The essential oils of Z. rhetsa and Z. limonella were analysed for phytochemical constituents by Gas chromatography–mass spectrometry (GC-MS). The antibacterial activity was determined against several bacteria using the microdilution method. Antioxidant capacity was determined by free radical scavenger 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2-azinobis-3-ethyl-benzothiazoline-6-sulfonic acid (ABTS) methods. The anticancer activity was determined with two breast cancer cell lines (MCF-7 and MDA-MB-231) and the normal African green monkey kidney epithelial (Vero) cell line and using MTT assay. Results: Sabinene (22.51%) and terpinene-4-ol (32.33%) were found to be major components of Z. rhetsa essential oil while limonene (57.94%) and alpha-phelladrene (15.54%) were the major components of Z. limonella essential oil. Essential oil from Z. limonella exhibited broad spectrum antibacterial activity. Z. rhetsa and Z. limonella essential oils exhibited moderate antioxidant activity. The essential oil from Z. rhetsa possessed the ability to inhibit breast cancer cell (MCF-7 and MDA-MB-231) proliferation and cell viability. Conclusion: This study suggest that the essential oils from Z. limonella and Z. rhetsa could be applied as safe antibacterial and antioxidant agents for food and have the potential for further development of new anticancer agents.

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In the wild-type allele, DNA methylation levels of 10 consecutive CpG sites adjacent to the upstream 5′-breakpoint of α-thalassemia Southeast Asian (SEA) deletion are not different between placenta and leukocytes. However, no previous study has reported the map of DNA methylation in the SEA allele. This report aims to show that the SEA mutation is associated with DNA methylation changes, resulting in differential methylation between placenta and leukocytes. Methylation-sensitive high-resolution analysis was used to compare DNA methylation among placenta, leukocytes, and unmethylated control DNA. The result indicates that the DNA methylation between placenta and leukocyte DNA is different and shows that the CpG status of both is not fully unmethylated. Mapping of individual CpG sites was performed by targeted bisulfite sequencing. The DNA methylation level of the 10 consecutive CpG sites was different between placenta and leukocyte DNA. When the 10th CpG of the mutation allele was considered as a hallmark for comparing DNA methylation level, it was totally different from the unmethylated 10th CpG of the wild-type allele. Finally, the distinct DNA methylation patterns between both DNA were extracted. In total, 24 patterns were found in leukocyte samples and 9 patterns were found in placenta samples. This report shows that the large deletion is associated with DNA methylation change. In further studies for clinical application, the distinct DNA methylation pattern might be a potential marker for detecting cell-free fetal DNA.