Phytochemistry and Therapeutic Potentials of the Seed Essential Oil of Eucalyptus maculata Hook from Nigeria

Ololade ZS, Olawore NO and

Abstract

The aim of this research was to study the phytochemicals, therapeutic potentials of the seed essential oil of E. maculata Hook grown in Nigeria. Composition of the seed essential oil was investigated by GC, GC-MS, MS and FT-IR. Analyses of the volatile oil resulted in the identification of fifty-eight phytocompounds representing 98.95% of the oil. Cyclofenchene (7.0%), α-pinene (8.0%), 1R-α-pinene (6.0%), 1S-α-pinene (7.0%), DL-pinene (6.0%) and β-trans-Ocimene (8.0%) were detected as the principal components accounted for 42% of the seed essential oil. None of these main compounds has ever been detected in the leaves extracts of E. maculata that had been investigated before except α-Pinene. The total phenolics content of the seed oil of E. maculata was estimated as 195.84 ± 0.002 μg/mg GAE. The results of free radical scavenging capacity using DPPH and FRAP methods showed that the oil possessed strong antioxidant activity with IC50 8.0 and 10.0 µgml-1 respectively. The acute toxicity test showed that the seed oil extract is safe to be used in vivo. The seed oil at 1000 µgkg-1 (p.o.) gave 87.50% significant inhibition of paw edema. In the antinociceptive assay the oil inhibited the licking time by 86.46% in first phase (neurogenic pain) and 60.10% in the second phase (inflammatory pain). These results showed that the seed oil of E. maculata could be an active source of substances with antioxidant, anti-inflammatory and analgesic activities. The pharmacological potentials of the investigated seed oil could be explained by their antioxidant properties, due to their high phenolic and terpenoids contents.

Relevant Publications in Organic Chemistry: Current Research