Anti-inflammatory effects of Myrtol standardized and other essential oils on alveolar macrophages from patients with chronic obstructive pulmonary disease.
BACKGROUND
Myrtol standardized is established in the treatment of acute and chronic bronchitis and sinusitis. It increases mucociliar clearance and has muco-secretolytic effects. Additional anti-inflammatory and antioxidative properties have been confirmed for Myrtol standardized, eucalyptus oil, and orange oil in several in vitro studies.


OBJECTIVE
The aim of this study was to prove the ability of essential oils to reduce cytokines release and reactive oxygen species (ROS) production derived from ex vivo cultured alveolar macrophages.


METHODS
Alveolar macrophages from patients with chronic obstructive pulmonary disease (COPD, n=26, GOLD III-IV) were pre-cultured with essential oils (10(3)-10(-8)%) for 1 h and then stimulated with LPS (1 microg/ml). After 4 h and 20 h respectively a) cellular reactive oxygen species (ROS) using 2',7'-dichlorofluorescein (DCF), and b) TNF-alpha, IL-8, and GM-CSF secretion were quantified.


RESULTS
In comparison with negative controls, pre-cultured Myrtol, eucalyptus oil and orange oil (10-4%) reduced in the LPS-activated alveolar macrophages ROS release significantly after 1+20 h as follows: Myrtol -17.7% (P=0.05), eucalyptus oil -21.8% (P<0.01) and orange oil -23.6% (P<0.01). Anti-oxidative efficacy was comparable to NAC (1 mmol/l). Essential oils also induced a TNF-alpha reduction: Myrtol (-37.3%, P<0.001), eucalyptus oil (-26.8%, P<0.01) and orange oil (-26.6%, P<0.01). TNF-a reduction at 1+4 h and 1+20 h did not vary (Myrtol: -31.9% and -37.3% respectively, P= 0.372) indicating that this effect occurs early and cannot be further stimulated. Myrtol reduced the release of GM-CSF by -35.7% and that of IL-8 only inconsiderably.


CONCLUSIONS
All essential oils tested have effective antioxidative properties in ex vivo cultured and LPS-stimulated alveolar macrophages. Additionally, Myrtol inhibited TNF-a and GM-CSF release best indicating additional potent anti-inflammatory activity.
St. George Medical Center, Robert-Koch-Hospital, Leipzig, Germany.
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Rantzsch
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Vacca
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Dück
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Gillissen
D000328:Adult; D000368:Aged; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D004338:Drug Combinations; D005260:Female; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000037:antagonists & inhibitors; D006801:Humans; D016209:Interleukin-8 / Q000037:antagonists & inhibitors; D016676:Macrophages, Alveolar / Q000187:drug effects* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D039821:Monoterpenes / Q000494:pharmacology*; D009822:Oils, Volatile / Q000494:pharmacology*; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy*; D017382:Reactive Oxygen Species / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors
D000893:Anti-Inflammatory Agents; D004338:Drug Combinations; D016209:Interleukin-8; D039821:Monoterpenes; D009822:Oils, Volatile; D017382:Reactive Oxygen Species; D014409:Tumor Necrosis Factor-alpha; C055632:myrtol; D016178:Granulocyte-Macrophage Colony-Stimulating Factor