Acute Toxicity Studies, Physicochemical and GC/MS Analyses of Monodora myristica (Gaertn.) Dunal Oil

Abstract

Background: The seeds of Monodora myristica, a tropical plant belonging to the family Annonaceae, are widely used as condiments in the preparation of a number of African delicacies, to impart or enhance flavour. Their use is largely due to the volatile and fixed oils contained in the nuts.

Objective: To screen for the acute toxicity (LD₅₀) profile, determine the physicochemical properties, as well as carry out GC-MS analysis of the seed oil of Monodora myristica.

Method: The acute toxicity screening was done using Lorke’s method. Physicochemical profile of the oil was determined using standard methods. GC-MS analysis of the oil sample was also carried out, using Shimadzu GCMS-QP2010SE.

Results: The acute toxicity study showed that the oil sample had an LD₅₀ of 316 mg/kg. The acid value was determined to be 9.27 mg KOH/g oil, while saponification value was 194.95 mg KOH/g oil. GC-MS analysis of the oil revealed that it contained fatty acids such as n-hexadecanoic acid, cis-vaccenic acid and 9,12-octadecadienoic acid; as well as terpinoids such as alpha-terpineol and alpha-cadinol.

Conclusion:  Results of the toxicological screening indicates that Monodora myristica oil is moderately toxic as the LD₅₀ was within 50 – 500 mg/kg range. The oil has a relatively high tendency to go rancid due to the high acid value of 9.27 mg KOH/g oil.