Case Study of Bacterial Decontamination of an Aromatic and Medicinal Plant: Decontamination of Thymus Satureioides by Gamma Radiation at Low Doses and Impact on Hygienic and Physicochemical Quality

The purpose of our study is to verify the usefulness of gamma irradiation treatment at low doses (0.25, 0.5 and 1 kGy) combined to vacuum packaging on commercial teas of Thymus satureioides deliberately contaminated with Escherichia coli. The efficiency and the influence of the process on contamination level and the shelf life of the product were studied. The phenolic composition and concentration were identified in the unirradiated and irradiated thyme. The total phenolic content (TPC) was assayed by the Folin-Ciocalteu method, the individual phenolic compounds were determined by high liquid chromatography (HPLC) and the essential oil was characterized by gas chromatography coupled to mass spectroscopy (GC-MS). The plant was observed by scanning electrons microscopy and the radioactivity effect was analyzed. The results show a complete decontamination of thyme depending to the dose and the storage time. Privileged hygienic quality was found in the irradiated thyme with the highest concentrations of polyphenols. The process showed the conservation of thyme quality without any alteration of its characteristics or radioactivity effect.

Antimicrobial activity and chemical constitution of essential oil from Moroccan thyme (Thymus satureioides C.) on five microbial contaminants

Antimicrobial preservatives are widely added to health products to prevent microbial contamination. However, because of the risks attributed to several synthetic agents, manufacturers are searching for new natural agents. Therefore, this work investigated the different physicochemical characteristics of one of those natural ingredients, the essential oil (EO) of Moroccan thyme (Thymus satureioides C.) and its antimicrobial potential against five microbial strains. The physicochemical parameters (density, refractive index, optical rotation, miscibility, acid value, ester value, and flash point) were measured and the chemical composition was determined by GC/MS. The antimicrobial activity was assessed using disc diffusion method and a macrodilution broth method. The EO yield was 1.01% compared to the dry matter. Fifty-two compounds were identified. The major compounds were thymol (28.66%), borneol (21.16%) and α- terpineol (12.33%). The disc diffusion method revealed that all the strains tested showed sensitivity to the EO at concentration of 1636 μg per disc. For the minimum inhibitory concentration (MIC) and the minimum microbicidal concentrations (MMC), similar results were obtained for Staphylococcus aureus and Escherichia coli (640 μg/mL), for Pseudomonas aeruginosa (960 μg/mL) and for Candida albicans (800 μg/mL) baring Aspergillus brasiliensis, which had 480 μg/mL and 640 μg/mL for the MIC and MMC, respectively.

Ethnopharmacology, Phytochemistry, and Pharmacological Properties of Thymus satureioides Coss.

Thymus satureioides Coss. (Lamiaceae) is a Moroccan medicinal plant locally known as “Azkouni” or “Zaitra.” It is widely used in traditional medicine to treat various ailments, including hypertension, diabetes, cold, fever, dermatological and circulatory disorders, immune problems, bronchitis, nociception, cooling, pharyngitis, cough, and influenza. The current review aims to critically summarize the literature on ethnopharmacological uses, chemical profile, and pharmacological investigations of T. satureioides in order to provide data support and scientific evidences for further investigations. Electronic databases such as Scopus, PubMed, Web of Science, SciFinder, ScienceDirect, Google Scholar, and Medline were used to gather data on T. satureioides. Chemical characterization of T. satureioides essential oils (EOs) and extracts allowed to identify a total of 139 bioactive compounds, mainly belonging to the terpenoids, phenolic acids, and flavonoids classes. T. satureioides especially its essential oils exhibited numerous biological activities such as antibacterial, antifungal, anti-inflammatory, antioxidant, antidiabetic, anticancer, antiparasitic, and hypolipedemic activities. In light of these findings, further studies to transmute the traditional application of T. satureioides into scientific-based information are strongly required. Additional in vivo pharmacological studies are recommended to validate the results of the in vitro studies. Moreover, comprehensive preclinical and clinical trials on the pharmacological mechanisms of action of this plant and its bioactive compounds on molecular targets should be performed. Finally, more efforts must be focused on toxicological assessments and pharmacokinetic studies, in order to ensure the safety and the efficiency of T. satureioides.

Antioxidant, anti-inflammatory and anticoagulant activities of three Thymus species grown in southeastern Morocco

Background Thyme has been used for centuries in southeastern Morocco to treat a wide range of diseases such as inflammation disorders. The aim of the current study is to examine and to compare in vitro the anti-inflammatory, antioxidant, and anticoagulant activities of three thyme species grown in southeastern Morocco. Results Data showed that all studied species possess an important antioxidant activity: Thymus atlanticus (IC50 = 16.59 μg/mL), Thymus zygis (IC50 = 15.43 μg/mL), and Thymus satureioides (IC50 = 14.65 μg/mL). Concerning the anti-inflammatory activity, the highest effect was depicted in Thymus atlanticus followed by Thymus zygis and Thymus satureioides. With regard to the anticoagulant activity, the aqueous extract of these species prolongs activated partial thromboplastin time, prothrombin time, and thrombin time significantly (p < 0.05) in a dose-dependent manner. Conclusion Our results provide evidence that thymus extract exhibits marked antioxidant, anticoagulant, and anti-inflammatory effects, thus justifying the popular uses of these plants to treat some inflammatory and cardiovascular illnesses.