The Effect of Modified Curcumin Compounds on the Numbers and Morphology of Microglia

Abstract

Chronic neuroinflammation is a promising therapeutic target in many neurodegenerative and age‐related brain disorders. In this study, we investigated two highly bioavailable curcumin preparations, Longvida (LC) and Meriva (MC) for their anti‐inflammatory properties, using the GFAP‐IL6 mouse model. We hypothesized that the highly bioavailable curcumin, as a potent cytokine‐suppressive anti‐inflammatory drug, will decrease microglial and astroglial activation measured by cell number and morphology, and consequently improve motor and cognitive functions.MethodsGFAP‐IL6 and wild type mice were fed with LC and MC for 1 and 5 months, respectively. LC fed mice were tested on the elevated walking beam, Rotarod, Barnes maze and Novel object recognition tests before all the mice were sacrificed. Immunohistological staining for microglia and astrocytes were carried out and unbiased stereological analysis was completed for all groups on microglia(labelled by Iba‐1 and TSPO) and astrocytes numbers (GFAP) as well as the morphology of the cells were analyzed using the MBF Biosciences system (StereoInvestigator and Neurolucida 360).ResultsShort term MC oral administration lead to a dose‐dependent reduction in neuroinflammatory markers. Moreover, MC decreased the number of activated microglia and astroglia, as well as changed the microglial morphology from activated to resting state. Long term LC treatment led to a significant decrease in the number of microglia in the hippocampus and cerebellum and in turn, led to significant improvement of both motor and cognitive function. Both short‐ and long‐term consumption of modified curcumin preparations significantly downregulated microglial activation GFAP‐IL6 mice. Spatial memory and recognition memory improvements were also found in mice fed with LC in comparison to control counterparts. Our results promise potential therapeutic applications of both Longvida and Meriva curcumin against brain inflammation and associated cognitive and motor decline.Support or Funding InformationThe present study was supported by a project grant (#P00023016) by Indena S.P.A, Italy to GM and EG. F.U has been supported by a postgraduate scholarship by Western Sydney University.