Biological Activities and Volatile Constituents of Aegle marmelos (L.) Corrêa from Nepal

Abstract

Aegle marmelos, a deciduous fruit tree that grows in Nepal, has numerous uses in traditional medicine, being used as an anti-inflammatory, antidiarrheal, heart disease treatment, and in birth control. In this study, leaves were collected to obtain, analyze, and examine the bioactivity of the essential oil of A. marmelos, which is often referred to as bael tree in Nepal. The essential oil from leaves was obtained by hydrodistillation. The chemical composition, determined by GC-MS, revealed 82 compounds, with 81 components being identified. The major component was limonene (64.1%), with the other two abundant components being (E)-β-ocimene (9.7%) and germacrene B (4.7%). Bioassay screening of the essential oil indicated marginal toxicity against MCF-7 human breast adenocarcinoma cells (LC50 = 98.2 μg mL), but good larvicidal activity against mosquitoes (Culex pipiens) (LC50 = 2.15 μg mL), nematocidal activity against Caenorhabditis elegans, (LC50 = 113 μg mL) and insecticidal activity against termites (Reticulitermes virginicus), fruit flies (Drosophila melanogaster), and fire ants (Solenopsis invica × richteri). The essential oil of A. marmelos showed remarkable brine shrimp lethality. Antimicrobial and antifungal activity of the leaf oil was negligible. Most of the observed biological activity was apparently due to the relatively high level of limonene (64.1%) in the essential of the leaf essential oil from A. marmelos. INTRODUCTION Aegle marmelos (L.) Corr. Serr. (Rutaceae) is one of only three species in genus Aegle (Sharma et al., 2011), is a subtropical fruit-bearing, deciduous tree that grows throughout hills and plains of the sub-Himalayan countries of Nepal, India, Sri Lanka, and Bangladesh (Sekar et al., 2011). The species, which is normally characterized by a thick trunk with spiny branches and a soft, flaky bark (Sekar et al., 2011), grows to a height of 7 to 8 m and has pale-green leaves with 3-5 leaflets that release an aroma when bruised. The plant has greenish-white flowers that bloom in late spring and produce an oval-shaped, sweet-tasting, soft fruit covered in a woody shell that turns yelow when the fruit ripens (Dhankhar et al., 2011; Sekar et al., 2011). A. marmelos has several common names, and in Nepal, is referred to as the bael tree. The plant is often seen growing in temple gardens of Nepal where the leaves are used in prayers to Lord Shiva and an important fertility ritual, Bel biha (Sekar et al., 2011). Considered one of the most important medicinal plants in southern and southeastern Asia, the entire plant is traditionally used to treat an array of ailments. Various tissues of A. marmelos have demonstrated positive effects on heart diseases (root bark) (Kakiuchi et al., 1991), dysentery and inflammation (leaves) (Arul et al., 2005), diabetes (leaf extract) (Kumar et al., 2009), and ulcers (Udupa et al., 1994). Satyal et al.: Biological Activities and Volatile Constituents of Aegle marmelos