Lime (Citrus aurantifolia (Christm.) Swingle) Essential Oils: Volatile Compounds, Antioxidant Capacity, and Hypolipidemic Effect

Abstract

Lime peels are mainly obtained from the byproducts of the juice manufacturing industry, which we obtained and used to extract essential oil (2.3%) in order to examine the antioxidant and hypolipidaemic effects. We identified 60 volatile compounds of lime essential oil (LEO) with GC/MS, of which the predominant constituents were limonene, γ-terpinene, and β-pinene. Lime essential oil was measured according to the DPPH assay and ABTS assay, with IC₅₀ values of 2.36 mg/mL and 0.26 mg/mL, respectively. This study also explored the protective effects of LEO against lipid-induced hyperlipidemia in a rat model. Two groups of rats received oral LEO in doses of 0.74 g/100 g and 2.23 g/100 g with their diets. Eight weeks later, we found that the administration of LEO improved the serum total cholesterol, triglyceride, low-density lipoprotein cholesterol, alanine aminotransferase, and aspartate transaminase levels in the hyperlipidemic rats (p < 0.05). Simultaneously, the LEO improved the health of the rats in terms of obesity, atherogenic index, and fatty liver.

Keywords: antioxidant capacity; hypolipidemic effect; lime essential oil (LEO).

Figure 1

Comparison of EC₅₀ values toward 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay (A) and 3-ethylbenzothiazolin-6-sulfonic acid (ABTS) (B) radical scavenging rates of lime essential oils.

Figure 2

Histopathological changes of lime on liver in Wistar rats induced by high-fat diets. (A: Control, B: HF, C: LEO-N, D: LEO-H) H&E stain, 400×. Control (C): normal diet, HF: high-fat diet, lime essential oil normal dose (LEO-N): high-fat diet containing 0.744% lime essential oils, lime essential oil normal high dose (LEO-H): high-fat diet containing 2.232% lime essential oils.