Anti-Tumor and Anti-Inflammatory Activity In Vivo of Apodanthera congestiflora Cogn. (Cucurbitaceae)

Xanthine Oxidase Inhibitory Activity and Chemical Composition of Pistacia chinensis Leaf Essential Oil

Gout is a common metabolic disease caused by abnormal purine metabolism that promotes the formation and deposition of monosodium urate crystals within joints that causes acute arthritis and can seriously affect the daily life of patients. Pistacia chinensis is one of the traditional medicinal plants of the Anacardiaceae family, and there have been many studies on its biological activity, including anti-inflammatory, antidepressant, antibacterial, antioxidant, and hypoglycemic activities. The aim of this study was to evaluate the antigout effect of P. chinensis leaf essential oil and its constituents through xanthine oxidase inhibition. Leaf essential oil showed good xanthine oxidase inhibitory activity for both substrates, hypoxanthine and xanthine. Six fractions were obtained from open column chromatography, and fraction E1 exhibited the best activity. The constituents of leaf essential oil and fraction E1 were analyzed by GC-MS. The main constituents of both leaf essential oil and fraction E1 were limonene and 3-carene; limonene showed a higher inhibitory effect on xanthine oxidase. Based on the enzyme kinetic investigation, limonene was the mixed-type inhibitor against xanthine oxidase. The results revealed that Pistacia chinensis leaf essential oil and limonene have the potential to act as natural remedies for the treatment of gout.

Antifungal Sesquiterpenoids from Michelia formosana Leaf Essential Oil against Wood-Rotting Fungi

Michelia formosana (Kanehira) Masamune is a broad-leaved species widespread in East Asia; the wood extract and its constituents possess antifungal activity against wood-decay fungi. Antifungal activities of leaf essential oil and its constituents from M. formosana were investigated in the present study. Bioassay-guided isolation was applied to isolate the phytochemicals from leaf essential oil. 1D and 2D NMR, FTIR, and MS spectroscopic analyses were applied to elucidate the chemical structures of isolated compounds. Leaf essential oil displayed antifungal activity against wood decay fungi and was further separated into 11 fractions by column chromatography. Four sesquiterpenoids were isolated and identified from the active fractions of leaf essential oil through bioassay-guided isolation. Among these sesquiterpenoids, guaiol, bulnesol, and β-elemol have higher antifungal activity against brown-rot fungus Laetiporus sulphureus and white-rot fungus Lenzites betulina. Leaf essential oil and active compounds showed better antifungal activity against L. sulphureus than against L. betulina. The molecular structure of active sesquiterpenoids all contain the hydroxyisopropyl group. Antifungal sesquiterpenoids from M. formosana leaf essential oil show potential as natural fungicides for decay control of lignocellulosic materials.

Cytotoxicity and Apoptosis Induction of 6,7-Dehydroroyleanone from Taiwania cryptomerioides Bark Essential Oil in Hepatocellular Carcinoma Cells

The objective of the present study is to evaluate the cytotoxicity of Taiwania cryptomerioides essential oil and its phytochemical on the Hep G2 cell line (human hepatocellular carcinoma). Bark essential oil has significant cytotoxicity to Hep G2 cells, and S3 fraction is the most active fraction in cytotoxicity to Hep G2 cells among the six fractions. The diterpenoid quinone, 6,7-dehydroroyleanone, was isolated from the active S3 fraction by bioassay-guided isolation. 6,7-Dehydroroyleanone exhibited significant cytotoxicity in Hep G2 cells, and the efficacy of 6,7-dehydroroyleanone was better than the positive control, etoposide. Apoptosis analysis of Hep G2 cells with different treatments was characterized via flow cytometry to confirm the cell death situation. Etoposide and 6,7-dehydroroyleanone could induce the apoptosis in Hep G2 cells using flow cytometric assay. Results revealed 6,7-dehydroroyleanone from T. cryptomerioides bark essential oil can be a potential phytochemical to develop the anticancer chemotherapeutic agent for the treatment of the human hepatocellular carcinoma.

Antimelanogenesis Effects of Leaf Extract and Phytochemicals from Ceylon Olive (Elaeocarpus serratus) in Zebrafish Model

The melanogenesis inhibition effect in zebrafish (Danio rerio) and antityrosinase activity of the ethanolic extract and its phytochemicals from Ceylon olive (Elaeocarpus serratus Linn.) leaves were investigated in this study. Among the leaf extract and four soluble fractions, the ethyl acetate soluble fraction exhibits the best antityrosinase and antimelanogenesis activities. One phenolic acid, gallic acid, and two flavonoids, myricetin and mearnsetin, are isolated from the active subfractions through the bioassay-guided isolation; their structures are elucidated based on the 1D and 2D NMR, FTIR, UV, and MS spectroscopic analyses. These compounds have significant antityrosinase activity whether using l-tyrosine or l-DOPA as the substrate; mearnsetin shows the optimal activity. In the enzyme kinetic investigation, both gallic acid and mearnsetin are the competitive-type inhibitors against mushroom tyrosinase, and myricetin acts as a mixed-type tyrosinase inhibitor. Leaf extract and an ethyl acetate soluble fraction show effective performance in the inhibition of melanin formation in zebrafish embryos. Mearnsetin also possesses a promising antimelanogenesis effect, which is superior to the positive control, arbutin. Results reveal that the Ceylon olive leaf extract and its phytochemicals, especially mearnsetin, have the potential to be used as antimelanogenesis and skin-whitening ingredients.