This Is AuburnElectronic Theses and Dissertations

Immune-Associated Chronic Inflammation: Biological Responses Between Endothelial Cells and T Cells Following Treatment with Thymus vulgaris and Eugenia caryophyllata Essential Oils




Clifton, Christie

Type of Degree

PhD Dissertation




Chronic inflammation is associated with autoimmune disorders and chronic diseases such as diabetes and cardiovascular disease. Prolonged interaction between circulating leukocytes (CD4+ T cells) and microvasculature endothelial cells (ECs) triggers excessive cytokine production, exposing adhesion and coagulation molecules. Consequences include altered T cell phenotype and EC physiology such as disrupted vascular integrity, immune cell transmigration, and platelet aggregation. Although excess inflammatory cytokines and coagulation factors can be detrimental, these otherwise protective molecules cannot be eradicated entirely. Medicinal plant extracts, including essential oils (EOs), have various constituents resulting in biological effects that are anti-inflammatory. Furthermore, phenolic EOs such as clove and thyme demonstrate immunomodulatory and anti-platelet activity. EOs naturally contain compounds with diverse physiological benefits, suggesting a multi-targeted therapeutic approach for prevention and treatment of immune-mediated inflammatory diseases. Thus, the present study was conducted to assess potential therapeutic effects of clove and thyme EOs towards markers of immune-associated vascular inflammation including E-selectin, intracellular adhesion molecule 1 (ICAM-1), and interleukin 6 (IL-6). Additionally, we investigated the effects of these oils towards the initiator of the coagulation cascade, tissue factor (TF). Tumor necrosis factor alpha (TNF-α) activated human umbilical vein endothelial cells (HUVECs) were incubated with clove (0.01%) and thyme EOs (0.01%) for 3 hr and 6 hr. These data show significant TF protein expression in all HUVEC conditions activated with TNF-α (p <0.001), yet no differences were observed with the addition of either EO as compared HUVECs treated with TNF-α alone. Other markers did not reveal significant differences statistically. As a secondary aim, activated and inactivated HUVECs were coincubated with CD4+ T cells prior to treatment with clove (0.01%) and thyme (0.01%) EO for 6 hr. These preliminary data suggest there may be a mild preventative and treatment effect with clove EO, while thyme EO increased protein expression of immune-associated vascular inflammation markers. We conclude that TF expression may contribute to TNF-α mediated inflammation, while ICAM-1, E-selectin, and IL-6 did not reveal significant modulation under TNF-α stimulation or treatment with EOs.