Z-ligustilide attenuates lipopolysaccharide-induced proinflammatory response via inhibiting NF-kappaB pathway in primary rat microglia.
OBJECTIVE
To investigate the anti-inflammatory effect of Z-ligustilide (LIG) on lipopolysaccharide (LPS)-activated primary rat microglia.


METHODS
Microglia were pretreated with LIG 1 h prior to stimulation with LPS (1 microg/mL). After 24 h, cell viability was tested with MTT, nitric oxide (NO) production was assayed with Griess reagent, and the content of tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), and monocyte chemoattractant protein (MCP-1) was measured with ELISA. Protein expression of the nuclear factor-kappaB (NF-kappaB) p65 subunit, cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) was detected with immunocytochemistry 1 h or 24 h after LPS treatment.


RESULTS
LIG showed a concentration-dependent anti-inflammatory effect in LPS-activated microglia, without causing cytotoxicity. Pretreatment with LIG at 2.5, 5, 10, and 20 micromol/L decreased LPS-induced NO production to 75.9%, 54.4%, 43.1%, and 47.6% (P<0.05 or P< 0.01), TNF-alpha content to 86.2%, 68.3%, 40.1%, and 39.9% (P<0.01, with the exception of 86.2% for 2.5 micromol/L LIG), IL-1beta content to 31.5%, 27.7%, 0.6%, and 0% (P<0.01), and MCP-1 content to 84.4%, 50.3%, 45.1%, and 42.2% (P<0.05 or P<0.01), respectively, compared with LPS treatment alone. LIG (10 micromol/L) significantly inhibited LPS-stimulated immunoreactivity of activated NF-kappaB, COX-2, and iNOS (P<0.01 vs LPS group).


CONCLUSIONS
LIG exerted a potent anti-inflammatory effect on microglia through inhibition of NF-kappaB pathway. The data provide direct evidence of the neuroprotective effects of LIG and the potential application of LIG for the treatment of the neuroinflammatory diseases characterized by excessive microglial activation.
Wang
Jing
J
Department of Pharmacology and Biopharmaceutics, Sichuan University, Chengdu, China.
Du
Jun-rong
JR
Wang
Yu
Y
Kuang
Xi
X
Wang
Cheng-yuan
CY
D015107:4-Butyrolactone / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology / Q000633:toxicity; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000494:pharmacology* / Q000633:toxicity; D051546:Cyclooxygenase 2 / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D007249:Inflammation / Q000188:drug therapy* / Q000503:physiopathology; D008070:Lipopolysaccharides; D017628:Microglia / Q000187:drug effects / Q000378:metabolism; D016328:NF-kappa B / Q000187:drug effects* / Q000378:metabolism; D018696:Neuroprotective Agents / Q000008:administration & dosage / Q000494:pharmacology / Q000633:toxicity; D052247:Nitric Oxide Synthase Type II / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013237:Stereoisomerism
D000893:Anti-Inflammatory Agents; D008070:Lipopolysaccharides; D016328:NF-kappa B; D018696:Neuroprotective Agents; C027820:ligustilide; D052247:Nitric Oxide Synthase Type II; D051546:Cyclooxygenase 2; D015107:4-Butyrolactone