A novel bioactivity of andrographolide from Andrographis paniculata on cerebral ischemia/reperfusion-induced brain injury through induction of cerebral endothelial cell apoptosis.
BACKGROUND
Andrographolide, extracted from the leaves of Andrographis paniculata (Burm. f.) Nees (Acanthaceae), is a labdane diterpene lactone. It is widely reported to possess anti-inflammatory and antitumorigenic activities. Cerebral endothelial cells (CECs) play a crucial role in supporting the integrity and the function of the blood-brain barrier (BBB). However, no data are available concerning the effects of andrographolide in CECs. The aim of this study was to examine the detailed mechanisms of andrographolide on CECs.


OBJECTIVE
This study investigated a novel bioactivity of andrographolide on cerebral ischemia/reperfusion-induced brain injury.


METHODS
CECs were treated with andrographolide (20-100 µΜ) for the indicated times (0-24 h). After the reactions, cell survival rate and cytotoxicity were tested by the MTT assay and the lactate dehydrogenase (LDH) test, respectively. Western blotting was used to detect caspase-3 expression. In addition, analysis of cell cycle and apoptosis using PI staining and annexin V-FITC/PI labeling, respectively, was performed by flow cytometry. We also investigated the effect of andrographolide on middle cerebral artery occlusion (MCAO)/reperfusion-induced brain injury in a rat model.


RESULTS
In the present study, we found that andrographolide (50-100 µΜ) markedly inhibited CEC growth according to an MTT assay and caused CEC damage according to a LDH test. Our data also revealed that andrographolide (50 µM) induced CEC apoptosis and caspase-3 activation as respectively detected by PI/annexin-V double staining and western blotting. Moreover, andrographolide arrested the CEC cell cycle at the G0/G1 phase by PI staining. In addition, andrographolide (5 mg/kg) caused deterioration of MCAO/reperfusion-induced brain injury in a rat model.


CONCLUSIONS
These data suggest that andrographolide may disrupt BBB integrity, thereby deteriorating MCAO/reperfusion-induced brain injury, which are, in part, associated with its capacity to arrest cell-cycle and induce CEC apoptosis.
Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan.
Ting-Lin
TL
Yen
Wen-Hsien
WH
Hsu
Steven Kuan-Hua
SK
Huang
Wan-Jung
WJ
Lu
Chao-Chien
CC
Chang
Li-Ming
LM
Lien
George
G
Hsiao
Joen-Rong
JR
Sheu
Kuan-Hung
KH
Lin
D035685:Andrographis / Q000737:chemistry; D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000009:adverse effects*; D017209:Apoptosis / Q000187:drug effects*; D001812:Blood-Brain Barrier / Q000187:drug effects / Q000201:enzymology; D053148:Caspase 3 / Q000737:chemistry / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D002552:Cerebral Ventricles / Q000098:blood supply / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D004224:Diterpenes / Q000009:adverse effects*; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D004789:Enzyme Activation / Q000187:drug effects; D020244:Infarction, Middle Cerebral Artery / Q000503:physiopathology*; D008297:Male; D051379:Mice; D018515:Plant Leaves / Q000737:chemistry; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000139:chemically induced* / Q000201:enzymology / Q000209:etiology; D016192:Resting Phase, Cell Cycle / Q000187:drug effects
D000894:Anti-Inflammatory Agents, Non-Steroidal; D004224:Diterpenes; C030419:andrographolide; D053148:Caspase 3