Abstract:
Artemisinin-based Combination Therapy (ACT) is among the best chemotherapeutic
options for malaria. Artesunate (AS) + Amodiaquine (AQ) is a commonly used ACT in
Nigeria, having good efficacy but with side effects involving memory loss and impaired
motor coordination ranging from acute to chronic. Reports on acute effect of AS+AQ
on the cerebellum and hippocampus are controversial and there is dearth ofinformation
on its delayed effect on these brain areas. This study was designed to evaluate the effects
of AS+AQ administration on neurobehaviour and morphology of the hippocampus and
cerebellum in Wistar rat after three-day acute treatment.
Eighty adult male Wistar rats (120±5g) were divided into 4 groups (n=20): Group A:
Control (CT: Distilled water), Group B: AS (4mg/kg), Group C: AQ (10mg/kg) and
Group D: AS (4mg/kg) + AQ (10mg/kg). Drugs were administered orally, once daily
for 3 days and animals monitored for 14 days. Weights of the animals were recorded.
Spatial memory and motor function were evaluated using Morris water-maze and fore limb grip tests, respectively. Animals were sacrificed by cervical dislocation on the 4
th
and 15th day. Collected blood samples were analysed for full blood count. Excised
cerebelli and hippocampi were processed for lipid peroxidation, biochemical markers of
oxidative stress including nitric oxide (NO). Histological (Haematoxylin & Eosin) and
immunohistochemical techniques including Glial Fibrillary Acid Protein (GFAP) and
Cyclo-oxygenase II (COX-2) were also carried out. Data were analysed by ANOVA at
α0.05.
There was no significant variation in weight, neurobehavioural, haematological,
biochemical, morphological and immunohistochemical parameters between all groups
for the 3 days. At 14 days, AQ group had significant weight loss (30.40%) compared
with the CT group and significantly increased swimming time (22.86±2.70s) compared
with the CT group (4.14±0.74s). The AS (8.00±1.11s) and AQ (7.43±0.92s) had
significantly decreased grip time compared with CT (17.86±1.22s); AQ significantly
increased RBC (8.30±0.13/µL) and PCV (57.00±1.30%) compared with CT (RBC:
6.90±0.31/µL, PCV: 45.80±1.36%). Lipid peroxidation (per nmmol/g) increased
significantly in AS (233.07±2.26), AQ (257.14±2.06) and AS+AQ (223.32±1.99)
compared with CT (180.33±0.47). Ditto for NO (/µm/mg) (CT: 455.49±3.93, AS:
472.32±0.91, AQ: 525.74±10.11, AS+AQ: 480.95±2.917). The cerebellar Purkinje cell
population was significantly reduced in the AS (2.50±0.29) and AQ (1.25±0.25) groups
compared with CT (5.75±0.48), indicating pyknosis. Hippocampal Cornus Ammonis 1
cells were significantly depopulated in the AS (10.75 ±0.48) and AQ (7.25±0.48) groups
compared to the CT (13.25±0.25) group, also indicating pyknosis. The GFAP
expressions (per %area) significantly increased in the cerebelli of AS (55.95±1.85) and
AQ (57.79±1.85) groups compared with CT (23.60±3.02) and in AS (76.81±7.19) and
AQ (83.71±3.78) groups of hippocampus compared with CT (55.19±3.86), indicating
astrogliosis. Compared with CT (59.36±5.61), AS (83.99±5.18) and AQ (88.32±0.88)
had significantly increased hippocampal COX-2 expression per %area, indicating
inflammation.
Neurobehavioural and morphological changes due to Artesunate and Amodiaquine
administration in Wistar rats were significant only after 14 days.
