Anti-neuroinflammatory effects of the extract of Achillea fragrantissima.
BACKGROUND
The neuroinflammatory process plays a central role in the initiation and progression of neurodegenerative diseases such as Parkinson's and Alzheimer's diseases, and involves the activation of brain microglial cells. During the neuroinflammatory process, microglial cells release proinflammatory mediators such as cytokines, matrix metalloproteinases (MMP), Reactive oxygen species (ROS) and nitric oxide (NO). In the present study, extracts from 66 different desert plants were tested for their effect on lipopolysaccharide (LPS) - induced production of NO by primary microglial cells. The extract of Achillea fragrantissima (Af), which is a desert plant that has been used for many years in traditional medicine for the treatment of various diseases, was the most efficient extract, and was further studied for additional anti-neuroinflammatory effects in these cells.


METHODS
In the present study, the ethanolic extract prepared from Af was tested for its anti-inflammatory effects on lipopolysaccharide (LPS)-activated primary cultures of brain microglial cells. The levels of the proinflammatory cytokines interleukin1β (IL-1β) and tumor necrosis factor-α (TNFα) secreted by the cells were determined by reverse transcriptase-PCR and Enzyme-linked immunosorbent assay (ELISA), respectively. NO levels secreted by the activate cells were measured using Griess reagent, ROS levels were measured by 2'7'-dichlorofluorescein diacetate (DCF-DA), MMP-9 activity was measured using gel zymography, and the protein levels of the proinflammatory enzymes cyclooxygenase-2 (COX-2) and induced nitric oxide synthase (iNOS) were measured by Western blot analysis. Cell viability was assessed using Lactate dehydrogenase (LDH) activity in the media conditioned by the cells or by the crystal violet cell staining.


RESULTS
We have found that out of the 66 desert plants tested, the extract of Af was the most efficient extract and inhibited ~70% of the NO produced by the LPS-activated microglial cells, without affecting cell viability. In addition, this extract inhibited the LPS - elicited expression of the proinflammatory mediators IL-1β, TNFα, MMP-9, COX-2 and iNOS in these cells.


CONCLUSIONS
Thus, phytochemicals present in the Af extract could be beneficial in preventing/treating neurodegenerative diseases in which neuroinflammation is part of the pathophysiology.
Department of Food Quality and Safety, Volcani Center, Agricultural Research Organization, Bet Dagan 50250, Israel. aelmann@volcani.agri.gov.il
Anat
A
Elmann
Sharon
S
Mordechay
Hilla
H
Erlank
Alona
A
Telerman
Miriam
M
Rindner
Rivka
R
Ofir
D031162:Achillea / Q000737:chemistry*; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D002478:Cells, Cultured; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000276:immunology; D006801:Humans; D053583:Interleukin-1beta / Q000235:genetics / Q000276:immunology; D008297:Male; D017628:Microglia / Q000187:drug effects* / Q000201:enzymology / Q000276:immunology*; D019636:Neurodegenerative Diseases / Q000188:drug therapy / Q000201:enzymology / Q000235:genetics / Q000276:immunology*; D009569:Nitric Oxide / Q000276:immunology; D052247:Nitric Oxide Synthase Type II / Q000235:genetics / Q000276:immunology; D010936:Plant Extracts / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
D000893:Anti-Inflammatory Agents; D053583:Interleukin-1beta; D010936:Plant Extracts; D009569:Nitric Oxide; D052247:Nitric Oxide Synthase Type II; D051546:Cyclooxygenase 2