Chemistry and Medicinal Potentials of the Seed Essential Oil of Eucalyptus toreliana F. Muell Grown in Nigeria

Abstract

E. toreliana is a distinct aromatic plant with several medicinal applications to cure many ailments. Chemistry and medicinal potentials of the seed essential oil of Eucalyptus toreliana F. Muell grown in Nigeria were examined in this study. The phytochemical composition of the seed essential oil was evaluated using multidimensional GCxGC-MS, MS and FT-IR. The seed oil was also investigated for its total phenolic content, antioxidant and acute toxicity, anti-inflammatory and antinociceptive potentials. Analyses of the seed essential oil extract resulted in the identification of 70 compounds representing 98.53 % of the oil. α-Pinene (16.0%), Copaene (10.0%), 1R-α-Pinene (8.0%), DL-Pinene (8.0%), β-trans- Ocimene (5.0%), α-Bisabolol oxide B (5.0%), Oleamide (5.0%) and Globulol (4.0%) were detected as the major components accounted for 65% of the oil. The total phenolics content of the seed oil of E. toreliana was estimated as 191.68±0.0006 μgmg-1 GAE. The results of DPPH and FRAP antioxidant showed that the oil possessed strong free radical scavenging and reducing potentials with IC50 9.0 μgml-1 each in both methods. No sign of toxicity was noticed in the rats which indicate that the seed oil was relatively non-toxic and safe. The oil at 1000 μgkg-1 (p.o.) gave 99.61% significant inhibition of paw edema. In the antinociceptive assay the oil inhibited the licking time by 88.69% and 75.90% in first phase (neurogenic pain) and second phase (inflammatory pain) respectively. These results showed that the seed essential oil of E. toreliana possesses antioxidant, anti-inflammatory and antinociceptive potentials, which provided an initial scientific validation of the seed essential oil as a phytotherapeutic agent against reactive oxidative, nociceptive and inflammatory processes.