Sclareol Exhibits Anti-inflammatory Activity in Both Lipopolysaccharide-Stimulated Macrophages and the λ-Carrageenan-Induced Paw Edema Model

Sclareol (<b>1</b>) is a natural fragrance compound used widely in the cosmetic and food industries. Lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages and the λ-carrageenan-induced edema mouse paw model were applied to examine the anti-inflammatory potential of <b>1</b> and its possible molecular mechanisms. The experimental results obtained demonstrated that this compound inhibited cell growth, nitric oxide (NO) production, and the expression of the inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins in LPS-stimulated macrophages. Compound <b>1</b> also reduced paw edema, the tissue content of NO, tumor necrosis factor-alpha (TNF-α), malondialdehyde (MDA), iNOS and COX-2 protein expression, and neutrophil infiltration within the tissues after λ-carrageenan stimulation. The present study suggests that the anti-inflammatory mechanisms of <b>1</b> might be related to a decrease of inflammatory cytokines and an increase of antioxidant enzyme activity

Inhibitory effect of DSW on balloon angioplasty-induced neointimal hyperplasia.

<p>Tissue sections from rat carotid arteries were further stained with hematoxylin-eosin to observe the thickness of neointimal layer of arterial wall (A–F). The expression levels of MMP-2 and PCNA proteins were detected with immunohistopathological analysis (H and I). The images were acquired by microscopy at 200-fold magnification. The manifestation of vessel restenosis was presented as the ratio of neointima- to-media area (N/M ratio). L, lumen; N, neointima layer; M, media layer. Red arrow is protein experssion.*<i>P</i><0.05, and **<i>P</i>< compared with BA + water group, respectively.</p

Effect of blood biochemical parameters of SD rats after 4-week treatment with sham + water, BA + water, BA + MgCl₂, and DSW.

<p>Concentration unit: U/L. BA, balloon angioplasty; RDA, recommended dietary allowances; ALT, alanine aminotransferase; AST, aspartate aminotransferase; ALP, alkaline phosphatase; GGT, γ-glutamyltransferase. Mg²⁺: serum Mg²⁺ concentration. Values are mean ± SEM, n = 6.</p><p>*<i>p</i><0.05 compared to sham + water.</p

DSW-induced regulation of VSMC viability.

<p>Cell viability was analyzed with the MTT proliferation assay. One-fold (1x) DSW was defined as water-diluted DSW containing a level of magnesium equal to that of the magnesium chloride used in the present experiment. The results are shown as % of the control. *<i>P</i><0.05, and **<i>P</i><0.01 compared with the 15% FBS-treated group, respectively.</p

Effects of DSW on VSMC migration. Cell migration was analyzed with transwell assays.

<p>The images were taken at 400-fold magnification. The 1x DSW was defined as water-diluted DSW containing the same level of magnesium as the magnesium chloride used in the present experiment. The results are shown as % of the control (15% FBS).*<i>P</i><0.05, and **<i>P</i><0.01 compared with the 15% FBS-treated group, respectively. #<i>P</i><0.05 compared with the MgCl₂-treated group.</p

Molecular regulation by DSW of cell growth and migration of VSMCs.

<p>Inhibitory mechanisms of DSW on cell growth- and migration-associated proteins were analyzed by using the methods of Western blot (WB) and gelatin zymography. Beta-actin was used as internal control in Western blot. The results are shown as % of the control (15% FBS). The MMP-2 activity was normalized to the values of the 15% FBS group. *<i>P</i><0.05, and **<i>P</i><0.01 compared with the 15% FBS-treated group, respectively.</p

Differences in magnesium content in the balloon-injured carotid artery.

<p>*<i>P</i><0.05 compared with BA + water group, respectively.</p