Alpha-pinene

Effect of alpha-pinene on nuclear translocation of NF-kappa B in THP-1 cells.[Pubmed:15066217]

Acta Pharmacol Sin. 2004 Apr;25(4):480-4.

AIM: To study the effects of Alpha-pinene on nuclear translocation of nuclear factor-kappa B (NF-kappa B) and the expression of the inhibitor of NF-kappa B (I kappa B alpha) in human monocyte THP-1 cell line. METHODS: THP-1 cells were incubated with Alpha-pinene (1, 10, and 100 mg/L, for 30 min) before being stimulated with lipopolysaccharide (LPS, 1 mg/L, 30 min). The location of NF-kappa B p65 subunit (NF-kappa B/p65) in THP-1 cells was detected by immunofluorescence and laser scanning confocal microscope (LSCM). The expression of NF-kappa B/p65 in nuclei and that of I kappa B alpha in cytoplasm were measured by Western-blot analysis. RESULTS: The majority of FITC-labelled NF-kappa B/p65 was located in the nuclei being stimulated with LPS. Whereas, no such fluorescence was seen in the nuclei of the groups pretreated with Alpha-pinene or control cells. Alpha-pinene pretreatment decreased the NF-kappa B/p65 nuclear translocation in LPS-stimulated THP-1 cells, and this effect was dose-dependent, but there was no reaction in LPS-unstimulated THP-1 cells. Alpha-pinene pretreatment increased I kappa B alpha protein level in cytoplasm, compared with that in LPS-stimulated THP-1 cells. CONCLUSION: In a dose-related fashion, Alpha-pinene inhibits the nuclear translocation of NF-kappa B induced by LPS in THP-1 cells, and this effect is partly due to the upregulation of I kappa B alpha expression.

alpha-Pinene inhibits growth and induces oxidative stress in roots.[Pubmed:17028297]

Ann Bot. 2006 Dec;98(6):1261-9.

BACKGROUND AND AIMS: Determining the mode of action of allelochemicals is one of the challenging aspects in allelopathic studies. Recently, allelochemicals have been proposed to cause oxidative stress in target tissue and induce an antioxidant mechanism. Alpha-pinene, one of the common monoterpenoids emitted from several aromatic plants including forest trees, is known for its growth-inhibitory activity. However, its mechanism of action remains unexplored. The aim of the present study was to determine the inhibitory effect of Alpha-pinene on root growth and generation of reactive oxygen species, as indicators of oxidative stress and changes in activities of antioxidant enzymes. METHODS: Effects of Alpha-pinene on early root growth were studied in five test species, Cassia occidentalis, Amaranthus viridis, Triticum aestivum, Pisum sativum and Cicer arietinum. Electrolyte leakage, lipid peroxidation, hydrogen peroxide generation, proline accumulation, and activities of the enzymes superoxide dismutase (SOD), ascorbate peroxidase (APX), guaiacol peroxidase (GPX), catalase (CAT) and glutathione reductase (GR) were studied in roots of C. occidentalis. KEY RESULTS: Alpha-pinene inhibited the radicle growth of all the test species. Exposure of C. occidentalis roots to Alpha-pinene enhanced solute leakage, and increased levels of malondialdehyde, proline and hydrogen peroxide, indicating lipid peroxidation and induction of oxidative stress. Activities of the antioxidant enzymes SOD, CAT, GPX, APX and GR were significantly elevated, thereby indicating the enhanced generation of reactive oxygen species (ROS) upon Alpha-pinene exposure. Increased levels of scavenging enzymes indicates their induction as a secondary defence mechanism in response to Alpha-pinene. CONCLUSIONS: It is concluded that Alpha-pinene inhibits early root growth and causes oxidative damage in root tissue through enhanced generation of ROS, as indicated by increased lipid peroxidation, disruption of membrane integrity and elevated antioxidant enzyme levels.