Phycocyanobilin reduces brain injury after endothelin‐1‐ induced focal cerebral ischaemia

Abstract

Pharmacological therapies for interrupting biochemical events of the ischaemic cascade and protecting against stroke in humans are as yet unavailable. Up to now, the neuroprotective activity in cerebral ischaemia of phycocyanobilin (PCB), a tetrapyrrolic natural antioxidant, has not been fully examined. Here, we evaluated if PCB protects PC12 neuronal cells against oxygen and glucose deprivation plus reperfusion, and its protective effects in a rat model of endothelin‐1‐induced focal brain ischaemia. PCB was purified from the cyanobacteria Spirulina platensis and characterized by spectrophotometric, liquid and gas chromatography and mass spectrometry techniques. In Wistar rats, PCB at 50, 100 and 200 μg/kg or phosphate‐buffered saline (vehicle) was administered intraperitoneally at equal subdoses in a therapeutic schedule (30 minutes, 1, 3 and 6 hours after the surgery). Brain expression of myelin basic protein (MBP) and the enzyme CNPase was determined by immunoelectron microscopy. PCB was obtained with high purity (>95%) and the absence of solvent contaminants and was able to ameliorate PC12 cell ischaemic injury. PCB treatment significantly decreased brain infarct volume, limited the exploratory behaviour impairment and preserved viable cortical neurons in ischaemic rats in a dose‐dependent manner, compared to the vehicle group. Furthermore, PCB at high doses restored the MBP and CNPase expression levels in ischaemic rats. An improved PCB purification method from its natural source is reported, obtaining PCB that is suitable for pharmacological trials showing neuroprotective effects against experimental ischaemic stroke. Therefore, PCB could be a therapeutic pharmacological alternative for ischaemic stroke patients.

Phycobiliproteins: Structural aspects, functional characteristics, and biotechnological perspectives

“… PCB as a therapeutic pharmacological alternative for ischaemic stroke patients. [126] Spirulina sp. / Prevents streptozotocin-induced increase activity of hippocampal cholinesterases, BAX, and the levels of BCL-2 and ChAT.…”

Beneficial Effects of Spirulina Consumption on Brain Health

“…PCB treatment significantly reduced brain infarct volume, limited exploratory behavior impairment, and preserved viable cortical neurons in ischemic rats in a dose-dependent manner with respect to the vehicle group. Furthermore, PCB at high doses restored the expression levels of myelin basic protein and the enzyme CNPase in ischemic rats [ 65 ].…”

A Fundamental Role for Oxidants and Intracellular Calcium Signals in Alzheimer’s Pathogenesis—And How a Comprehensive Antioxidant Strategy May Aid Prevention of This Disorder

“…Indeed, the bewildering range of disease models in which phycocyanin or spirulina has been found beneficial may reflect the fact that, in a wide range of pathologies, NADPH oxidase becomes activated in the affected tissues and either exacerbates or even mediates the syndrome [27]. Although the utility of PCB or of whole spirulina appears so far to have received little study in rodent AD models, its protective activity is well documented in rodent models of Parkinson's disease and ischemic stroke-which demonstrates that it has access to the brain and can provide important antioxidant protection there [35][36][37][38][39][40][41][42].…”