Protective Effect of Alkaloid-rich Extract of Brimstone Tree (Morinda lucida) on Neurotoxicity in the Fruit-fly (Drosophila melanogaster) Model

Abstract

Brimstone plant is one of the medicinal plants found in Nigeria used in fore-lore medicine with little scientific information on its 
alkaloid constituents. This study was aimed at investigating the effect of alkaloid-rich compounds from the plant in manganeseinduced (MgCl2) neurotoxicity in the fruit fly. In addition, alkaloid compounds will be characterized using gas chromatograph 
coupled with flame ionization detector (GC-FID). Alkaloid-rich extract was prepared by solvent extraction method, fruit flies 
were pre-treated with the extract (0.5 – 1.0mg/ml) in a fortified diet before induction with MgCl2. The survival rate and negative 
geotaxis were observed. Thereafter, the activity of acetylcholinesterase (AChE) enzyme, antioxidantive potentials in in-vivo 
reactive oxygen species (ROS) thiobarbituric acid reactive species (TBARS), total thiol content, nitric oxide (NO*), hydroxyl 
oxide (OH*) scavenging ability, ferric reducing antioxidant property (FRAP) and 2, 2’-azino-bis (3-ethylbenzthiazoline-6-
sulphonic acid) (ABTs*) radical scavenging ability were carried out on the flies’ homogenate. Results obtained revealed that the 
alkaloid-rich extract regulated the neuro-protective activity of AchE, reduced the reactive oxygen species level in the induced 
flies with an increased in antioxidantive potential, higher survival rate and increases in the life span of the flies with 50% reduction 
in the mortality rate. The GC-MS showed a total of (1.55/100mg) of different plant-derived alkaloids such as dicentrine, atropine, 
aporphine. These alkaloids-rich compounds were found to have anti-oxidative, anti-nociceptive, anti-inflammatory and anticholinergic activities. In conclusion, this study suggests that alkaloids from brimstone plant could be the reason for the observed 
biological activities for the prevention of neuronal related complications.