Comparative Study of Phytochemical Profiles and Antioxidant Potential of Leaf and Root Essential Oils from Clausena anisata (Willd.) Hook Growing in South-Western Nigeria

Abstract

The use of synthetic antioxidants to curtail the menace of oxidative stress caused by excessive free radicals in living cells has become worrisome. This is because of the associated drawbacks from their usage and their high costs. It is therefore imperative to provide better antioxidants from natural sources free from side effects. Plant extracts possess biochemicals with proven antioxidant properties. This research therefore explored the comparison of the phytochemicals and antioxidant properties of essential oils from leaves and roots of Clausena anisata. This was achieved by subjecting pulverized leaves and roots (500 g each) of the plant to hydrodistillation individually for 4 hours and gave 0.70±0.03 % and 0.43±0.01 % of essential oils respectively. Characterization of the oils was done using GC-MS and the analysis revealed abundance of oxygenated monoterpenoids (46.6% and 23.1%) and oxygenated sesquiterpenoids (20.6% and 36.8%) in the oils. Terpinen-4-ol (24.3% and 6.8%), α-terpineol (13.4% and 11.9%), estragole (9.2% and 5.7%), anethole (6.3% and 6.1%) and α-cadinol (6.1 % and 29.9%) were the major isoprenoids in the oils. The antioxidant activity was investigated by evaluating the oils’ abilities to scavenge DPPH radicals in comparison with ascorbic acid. The oils demonstrated moderate DPPH radical scavenging activity with the leaf oil showing a higher activity (IC₅₀ = 13.31 µg/mL) than the root oil (IC₅₀ = 19.85 µg/mL). Ascorbic acid that was used as a reference showed activity with IC₅₀ value of 9.24 µg/mL. These results showed that both oils scavenged DPPH radicals and their activities could be linked to the predominant of oxygenated compounds in the oils. The oils could therefore be used as natural antioxidants to prevent oxidative stress and its health complications after clinical trial.