**Conflict of interest**

None.

**2.9. Inflammation**

138 Potential of Essential Oils

a high-fructose diet [4].

**2.10. Angiogenesis**

rotic activity [50].

**3. Conclusions**

The levels of expression of intercellular adhesion molecule (ICAM)-1 and vascular cell adhesion molecule (VCAM)-1 in endothelial cells increase during inflammation [60], with the expression of these adhesion molecules being regulated by inflammatory cytokines such as interleukin (IL)-1 and TNF-α [61]. Several essential oils have been shown effective in inhibiting this process. For example, the treatment of HUVECs exposed to high glucose with *Fructus Alpiniae zerumbet* essential oil was shown to reduce the secretion of IL-8, TNF-α, ICAM-1, and VCAM-1 by inhibiting nuclear factor kappa B (NF-κB) signaling, suggesting that this essential oil has endothelial protective effects [29]. Similarly, the treatment of human aortic SMCs with *Schisandra chinensis* essential oil decreased TNF-α-induced matrix metalloproteinase-9 (MMP-9) activation, inducible NO synthase and cyclooxygenase-2 (COX-2) expression by inhibiting NF-κB signaling [50]. In an animal study, oral administration of *Curcuma longa* L. essential oil to rats exposed to myocardial ischemia/reperfusion injury reduced endothelial cell-induced inflammation by decreasing the expression of E-selectin and ICAM-1 [25]. Similarly, *Syzygium aromaticum* essential oil reduced plasma TNF-α concentration in rats fed

The proliferation and migration of vascular SMCs play essential roles in the pathophysiological changes of cardiovascular systems. *Radix angelica* essential oil was found to dosedependently inhibit HUVEC proliferation and migration, and, at concentrations above 20 μg/ ml, to reduce endothelial tube formation, indicating that *R. angelica* essential oil has antiangiogenic effects [48]. Similarly, *Schisandra chinensis* essential oil effectively decreased the TNF-αinduced migration of human aortic SMCs. These findings, together with the antiinflammatory and antioxidant effects of this oil, suggested that *Schisandra chinensis* oil has antiatheroscle-

Animal studies have also assessed the effects of essential oils on angiogenesis. For example, supplementation of a hyperlipidemic diet with *Oenothera biennis* essential oil for 6 weeks reduced endothelial lesions of the aorta and neointimal proliferation of the arterial wall in rabbits [43]. *Citrus bergamia Risso* essential oil reduced the neointima/media ratio and the cross-sectional area of the carotid artery in rats that underwent balloon-induced vascular injury, with these effects

Essential oils are natural substances extracted from aromatic plants with biological properties, including antioxidant and antiinflammatory activities. This chapter reviewed the effects of essential oils on CVD-related factors. Evidence has shown that essential oils have multiple effects, improving lipid balance, liver function, and endothelial function; reducing blood pressure, diabetes induction, and oxidative stress; enhancing vascular relaxation; and inhibiting thrombosis, inflammation, and angiogenesis. Essential oils and their active components may therefore be promising therapeutic agents for CVDs. Studies are needed to clarify the effects

accompanied by decreased expression of lectin-like receptor for oxidized LDL [23].

of these oils on patients and to elucidate their specific mechanisms of action.
