Crude and Partition Extracts of Newbouldia laevis Leaves Attenuate Excitotoxin-induced Stereotypy in Mice

Abstract

Aims: This study was designed to investigate the effects of crude ethanol and partition extracts of Newbouldia laevis leaves on excitotoxin-induced stereotypy in mice.
 Place and Duration of Study: The study was carried out in the Laboratory of the Department of Pharmacology and Therapeutics, College of Health Sciences, Ladoke Akintola University of Technology, Ogbomoso, Nigeria, between July and October, 2020.
 Methodology: Following pretreatment of mice with graded doses (150 - 600 mg/kg b.w) of crude extract (NLE) and partition fractions [n-butanol partition fraction (BPE), n-hexane partition fraction (HPE) and ethylacetate partition fraction (EAPE)] of Newbouldia laevis leaves, stereotypy was induced by the administration of methamphetamine (35 mg/kg b.w) and apomorphine (5mg/kg b.w.), and stereotypy scores were recorded thereafter. The effects of BPE and NLE on catalepsy were also determined. Statistical significance was taken at P<0.05
 Results: In both apomorphine and methamphetamine models, stereotyped behavior was significantly decreased (P<0.05) in the treated mice compared to the control. The degree of protection offered by Newbouldia laevis extracts against excitotoxin-induced stereotypy was in the order: BPE>NLE>EAPE>HPE. In the catalepsy test, BPE (600 mg/kg b.w) significantly potentiated haloperidol-induced catalepsy compared to control (P<0.05). Likewise, NLE significantly increased catalepsy compared to control (P<0.05).
 Conclusion: Findings from this study indicate that crude and partition extracts of Newbouldia laevis leaves attenuated stereotypy in methamphetamine and apomorphine models, and thus could be effective remedy for schizophrenia-like psychosis.

Studies on the Toxicological Properties of Ethanol Stem-Bark Extract of Newbouldia laevis (P. Beauv) Seem in Rats

“…The oral median lethal doses (LD50) of N. laevis stem-bark extract were estimated to be greater than 5000 mg/kg suggesting that the extract was relatively safe and non-toxic. 19 This result is consistent with the report of [27][28] who reported that no mortality was recorded up to 5000 mg/kg in the root and ethanol leaf extracts of N. laevis and the estimated LD50 was greater than 5000 mg/kg. For the 28 days treatment, an obvious increase in weight was seen as from week 2 at which the group that received the highest dose (1,000 mg/kg) showed significant (p ≤ 0.05) increase in weight compared to all other groups, but subsequently in weeks 3 and 4, significant (p ≤ 0.05) and dose dependent weight increase was observed at all doses administered (Figure 1).…”

“…The increase in creatinine and urea in this study agrees with the previous study by. 28 The kidney histology in this study also showed tubular necrosis and glomerular necrosis with lymphocyte hyperplasia that might have caused this increase in creatinine and urea and increase in systemic lymphocyte seen in this study. Sodium (Na + ) and Clions are usually the predominant cation and anion of the extracellular fluid (ECF).…”