Effect of Treatment with Thyme Extract on Urinary Levels of Melatonin in an Experimental Autoimmune Encephalomyelitis Mouse Model.

BACKGROUND: Thymus vulgaris, or thyme belongs to the Lamiaceae family of aromatic plant species and has established antioxidant and anti-inflammatory properties. We examined the association between thyme extract treatment to recovered urinary levels of melatonin, a hormone with neuroprotective effects, in mice induced with EAE. METHODS: Eight B6 mice induced with EAE were randomized into two groups and exposed to either 50 mg/kg of thyme extract or PBS. After EAE induction, mice were injected i.p every other day from day 0 to 21. Four B6 mice without EAE were considered the healthy control group. Urine samples were collected consecutively for two 24 h periods on day 19 and 20. We examined whether thyme extract treatment modified urinary melatonin sulfate concentration (ng/mL) in EAE-induced mice using an ELISA. RESULTS: The clinical score and body weight in thyme-treated EAE group were significantly lower in comparison to the EAE control group at indicated time points. The urinary melatonin concentration was significantly lower in the EAE control group compared to the healthy mice. There was no significant difference between thyme-treated and EAE groups regarding the urine melatonin concentration. CONCLUSION: Our results show that exposing EAE mice to thyme extract improved their clinical symptoms, however, there was no significant effect on urinary melatonin concentration.

Beneficial effects of Thymus vulgaris extract in experimental autoimmune encephalomyelitis: Clinical, histological and cytokine alterations.

The imbalance between pro and anti-inflammatory cytokines plays an important role in the pathogenesis of multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). Thymus vulgaris (thyme) as a traditional medicinal plant has been reported to exert antimicrobial, antioxidant, and anti-inflammatory effects. Therefore, this study evaluated the modulatory effects of Thymus vulgaris on the clinical symptoms, histopathological scores, and the production of some anti-inflammatory (TGF-ß, IL-4, and IL-10) and pro-inflammatory (IFN-γ, IL-6 and IL-17) cytokines in EAE model. EAE was induced by MOG35-55 peptide and mice were treated intra-peritoneally (i.p) with phosphate buffered saline (PBS) in the control group or thyme extract (50 or 100 mg/kg of body weight, every other day) in thyme-treated EAE groups, from day 0 to +21 of post MOG immunization. Mice were sacrificed at day 22, and splenocytes were isolated and re-stimulated in vitro with MOG in order to measure the cytokine production and proliferation of re-stimulated cells by enzyme linked immunosorbent assay (ELISA) method and WST-1 reagent, respectively. The clinical symptoms and histopathological scores of the CNS were lower in thyme-treated than EAE control group. Furthermore, the production of IFN-γ and IL-6 by splenocytes was lower in thyme-treated EAE than in the control group. The production of IL-10 and TGF-ß increased in mice treated with thyme extract compared to the control group. In this study, we showed for the first time that the immunomodulatory effects of Thymus vulgaris in EAE model. Thus, the possible therapeutic potential of thyme for treatment of MS could be considered in future research.

Ferula gummosa gum induces apoptosis via ROS mechanism in human leukemic cells.

Ferula species known for its oleo-resins that are recognized valuable industrial crops and food products. In this study, we examined the level of cellular oxidants, cytotoxicity, apoptosis and differentiation induced by oleo resin gum from Ferula gummosa (30-250 µg/mL), as well as Arsenic trioxide (50 µM, as positive control), in leukemic (NB4 and HL-60 cells) and normal polymorph nuclear cells during 72 h. Resazurin assay was used to determine cell viability following treatment with F. gummosa (30-250 µg/mL). Intracellular reactive oxygen species was measured by fluorimetry using carboxy 2', 7'-dichlorofluorescein diacetate. Apoptotic cells were evaluated using PI staining of DNA fragmentation by flow cytometry (sub-G1 peak). Differentiation of cells evaluated by Giemsa staining and Nitro Blue Tetrazolium reduction. F. gummosa showed a concentration-dependent suppression in cell survival with IC50 values of 41.8 µg/mL for HL60 and 59.2 µg/mL for NB4 cells after 72 h treatment. ROS formation and apoptotic cells were concentration-dependently increased following treatment with F. gummosa, similar to As2O3. F. gummosa did not induce differentiation of leukemic cells towards granulocytic pattern. The resin did not have toxic effect on PMN cells (<800 µg/mL). In conclusion, the present study demonstrated that F. gummosa induced apoptosis through ROS mechanism on leukemic cells as a concentration and time dependent manner. The precise signaling pathway by which F. gummosa induce apoptosis needs further research.