Ex-vivo Uterine Contractile activities of Leaf Extract and Fractions of Manniophyton fulvum Mull. Arg. (Euphorbiaceae) and Identification of Associated Secondary Metabolites

Abstract

Manniophyton fulvum is a herb with claimed anti-dysmenorrhea properties ascribed to the leaves in ethnomedicine. This study 
aimed to determine the effects of the methanol leaf extract and fractions on isolated mouse uterine contraction. Methanol extract 
of the leaf was obtained by Soxhlet extraction and partitioned into chloroform and water. The isolated and mounted mouse uterine 
tissues was treated with the extract, chloroform and aqueous fractions at a concentration range of 0.0007 – 7.777 µg/ml. The 
chloroform and aqueous fractions were equally tested on oxytocin and potassium chloride pre- contracted uterine tissue at 
concentration range of 0.34 – 34.3 µg/mL. LC-HRFTMS analysis of methanol extract and aqueous fraction was also carried out. 
The extract and aqueous fraction were observed to significantly (p< 0.05) increase the frequency and amplitude of spontaneous
contractions in a concentration dependent manner, while the chloroform fraction concentration-dependently inhibited similar 
contractions. The aqueous fraction potentiated oxytocin and potassium chloride augmented contractions in a similar manner, 
while the chloroform fraction significantly inhibited augmented contractions. Spectroscopic analysis identified eight and nine 
compounds in the methanol extract and aqueous fraction respectively, belonging to coumarin, terpenoid, and flavonoid classes 
of natural compounds. Evidence from this study suggests that constituents responsible for uterine contraction are present in the 
polar (aqueous) fraction of the extract, while the non-polar fraction (chloroform) contains compounds with uterine relaxing 
effects.