ABSTRACT
Background: Zearalenone (ZEA), which is one of the most prevalent wheat and corn seeds mycotoxins causes acute and chronic toxicities in ruminants, poultry, and aquatic animals. Among commercial toxin binders, only a few active charcoals have the significant ability to adsorb ZEA contamination; nevertheless, active charcoal is not considered a sound additive by the feed industry. Aims: This study aimed to screen and identify the ZEA-degradation compounds of the Zataria multiflora (Shirazi thyme) in the cattle rumen fluid. Methods: In this investigation, essential oil and different extracts (n-hexane, ethyl acetate, and methanol) of the aerial part of Shirazi thyme (at three concentrations of 0.5, 1, and 2 mg/ml) were screened to reduce ZEA contamination conditions (2 µg/ml) in rumen fluid. ZEA-content was analyzed by high-performance liquid chromatography (HPLC) with a fluorescence detector. In addition, Shirazi thyme phytochemical compounds responsible for eliminating ZEA were localized by HPLC-based activity profiling and then identified by mass spectrometry (LC-MS). Results: Both n-hexane and methanol extracts of Z. multiflora, considerably remediated ZEA (63-78%) from rumen fluid. According to HPLC-based activity profiling of Z. multiflora extract and LC-MS analysis, two triterpene compounds, including ursolic and oleanolic acids were introduced as ZEA degradation agents. Conclusion: Z. multiflora could be recommended as a new botanical source, and ursolic and oleanolic acids could be introduced as new phytochemical compounds that degrade ZEA.
ABSTRACT
Thymus species are well known as medicinal plants because of their biological and pharmacological properties. Thymus caramanicus is an endemic species grown in Iran. Variation in the quantity and quality of the essential oil of wild population of T. caramanicus at different phenological stages including vegetative, floral budding, flowering and seed set are reported. The oils of air-dried samples were obtained by hydrodistillation. The yields of oils (w/w%) at different stages were in the order of: flowering (2.5%), floral budding (2.1%), seed set (2.0%) and vegetative (1.9%). The oils were analyzed by GC and GC-MS. In total 37, 37, 29 and 35 components were identified and quantified in vegetative, floral budding, full flowering and seed set, representing 99.3, 98.6, 99.2 and 97.8% of the oil, respectively. Carvacrol was the major compound in all samples. The ranges of major constituents were as follow: carvacrol (58.9-68.9%), p-cymene (3.0-8.9%), γ-terpinene (4.3-8.0%), thymol (2.4-6.0%) and borneol (2.3-4.0%). Antibacterial activity of the oils and their main compounds were tested against seven Gram-positive and Gram-negative bacteria by disc diffusion method and determining their minimum inhibitory concentration (MIC) values. The inhibition zones (IZ) and MIC values for bacterial strains, which were sensitive to the essential oil of T. caramanicus, were in the range of 15-36mm and 0.5-15.0mg/ml, respectively. The oils of various phenological stages showed high activity against all tested bacteria, of which Bacillus subtilis and Pseudomonas aeruginosa were the most sensitive and resistant strains, respectively. Thus, they represent an inexpensive source of natural antibacterial substances that exhibited potential for use in pathogenic systems.