Determination of Volatile Constituents of the Essential Oil and Absolute of Nyctanthes arbortristis L. Flowers Grown in Sri Lanka

The volatile constituents of the essential oil and absolute of Nyctanthes arbortristis L. flowers grown in Sri Lanka were investigated. Hydro-distillation and solvent extraction were used to obtain the essential oil and the absolute respectively. The volatile samples were analyzed by capillary GC-FID and GC-MS techniques. This study led to the identification of 48 chemical constituents of the essential oil and 4 in the absolute. The essential oil composition was dominated by phytol (32.2 %) and methyl palmitate (14.7 %). Other well-known volatile constituents such as linalool (0.8 %), eucarvone (0.9 %), phytone (1.4 %), nonadecane (2.3 %), methyl myristate (1.1 %), cis-9-tricosene (3.6 %), n-pentacosane (1.6 %) and geranylgeraniol (2.7 %) were also identified in the essential oil. The absolute was dominated by butyl acetate (80.8 %) followed by phenethyl acetate (1.7 %), linalool oxide (1.4 %) and 2-butoxyethyl acetate (1.4 %)

<it>Piper betle</it> shows antioxidant activities, inhibits MCF-7 cell proliferation and increases activities of catalase and superoxide dismutase

<p>Abstract</p> <p>Background</p> <p>Breast cancer is the most common form of cancer and the focus on finding chemotherapeutic agents have recently shifted to natural products. <it>Piper betle</it> is a medicinal plant with various biological activities. However, not much data is available on the anti-cancer effects of <it>P. betle</it> on breast cancer. Due to the current interest in the potential effects of antioxidants from natural products in breast cancer treatment, we investigated the antioxidant activities of the leaves of <it>P. betle</it> and its inhibitory effect on the proliferation of the breast cancer cell line, MCF-7.</p> <p>Methods</p> <p>The leaves of <it>P. betle</it> were extracted with solvents of varying polarities (water, methanol, ethyl acetate and hexane) and their phenolic and flavonoid content were determined using colorimetric assays. Phenolic composition was characterized using HPLC. Antioxidant activities were measured using FRAP, DPPH, superoxide anion, nitric oxide and hyroxyl radical scavenging assays. Biological activities of the extracts were analysed using MTT assay and antioxidant enzyme (catalase, superoxide dismutase, glutathione peroxidase) assays in MCF-7 cells.</p> <p>Results</p> <p>Overall, the ethyl acetate extract showed the highest ferric reducing activity and radical scavenging activities against DPPH, superoxide anion and nitric oxide radicals. This extract also contained the highest phenolic content implying the potential contribution of phenolics towards the antioxidant activities. HPLC analyses revealed the presence of catechin, morin and quercetin in the leaves. The ethyl acetate extract also showed the highest inhibitory effect against the proliferation of MCF-7 cells (IC₅₀=65 μg/ml). Treatment of MCF-7 cells with the plant extract increased activities of catalase and superoxide dismutase.</p> <p>Conclusions</p> <p>Ethyl acetate is the optimal solvent for the extraction of compounds with antioxidant and anti-proliferative activities. The increased activities of catalase and superoxide dismutase in the treated cells could alter the antioxidant defense system, potentially contributing towards the anti-proliferative effect. There is great potential for the ethyl acetate extract of <it>P. betle</it> leaf as a source of natural antioxidants and to be developed as therapeutics in cancer treatment.</p