Xi Tao Yan

Coumarins and Lignans from Zanthoxylum schinifolium and Their Anticancer Activities

Zanthoxylum schinifolium is an aromatic shrub, and its pericarp and leaves are widely used in culinary applications in East Asian countries. It has also long been used in traditional Oriental medicine for treating the common cold, stomach ache, diarrhea, and jaundice. In this study, we identified two new compounds, zanthoxyloside (1) and schinifolisatin A (13), along with 23 known coumarins (2-12) and lignans (14-25), from a methanol extract of the stems of Z. schinifolium . The chemical structures of the compounds were determined by mass, 1D-, and 2D NMR spectroscopy. The anticancer effects of the isolated compounds were examined in three human cancer cell lines. Compounds 10-12 significantly reduced the proliferation of HL-60 human acute promyelocytic leukemia cells with IC50 values of 4.62-5.12 μM. Treatment of PC-3 prostate cancer cells and SNU-C5 colorectal cancer cells with compound 10 resulted in potent antiproliferative activity, with IC50 values of 4.39 and 6.26 μM, respectively. Also, compounds 10-12 induced the apoptosis of three cancer cells. Furthermore, the induction of apoptosis was accompanied by down-regulation of p-ERK1/2 MAPK, p-AKT, and c-myc levels, in a time-dependent manner. These data suggested that compounds 10-12 from Z. schinifolium have potential in cancer treatment.

Scopoletin and scopolin isolated from Artemisia iwayomogi suppress differentiation of osteoclastic macrophage RAW 264.7 cells by scavenging reactive oxygen species.

Artemisia iwayomogi has been used as a folk medicine for treating various diseases including inflammatory and immune-related diseases. Scopoletin (1) and scopolin (2) were isolated from this species. Scopoletin (1) showed more potent peroxyl radical-scavenging capacity, reducing capacity, and cellular antioxidant capacity compared to scopolin (2). The inhibitory effect of 1 on the receptor activator of nuclear factor κB ligand-induced osteoclastic differentiation of RAW 264.7 macrophage cells was also more potent than that of 2. The production of general reactive oxygen species (ROS) and superoxide anions during differentiation of preosteoclastic RAW 264.7 cells into osteoclasts was attenuated by compounds 1 and 2. These findings indicate that the suppressive effects of 1 and 2 on the differentiation of preosteoclastic RAW 264.7 cells is partially due to their intracellular antioxidant capacity, as they can scavenge ROS and play an important signaling role in the differentiation process.

Isolation of Nematicidal Triterpenoid Saponins from Pulsatilla koreana Root and Their Activities against Meloidogyne incognita

Pulsatilla koreana, a species endemic to Korea, is an important herb used in traditional medicine to treat amoebic dysentery and malaria. In the present study, 23 oleanane-type triterpenoid saponins 1–23 and eight lupane-type triterpenoid saponins 24–31 were isolated from the roots of P. koreana. Their structures were elucidated on the basis of spectroscopic data. The methanol extract and isolated compounds were next assessed for nematicidal activity against the root-knot nematode (Meloidogyne incognita). The methanol extract showed strong nematicidal activity after 48 h, with a LC50 value of 92.8 μg/mL. Compounds 2, 5, 9, 20, and 21 showed significant effects, with LC50 values ranging from 70.1 to 94.7 μg/mL after 48 h. These results suggest that triterpenoid saponins from P. koreana should be explored as potential natural nematicides for developing new agents to control root-knot nematode disease.

Isolation of xanthones from adventitious roots of St. John’s Wort (Hypericum perforatum L.) and their antioxidant and cytotoxic activities

In this phytochemical study, 5 xanthones, 1,3,5,6-tetrahydroxyxanthone [1], 1,5,6-trihydroxy-3-methoxyxanthone [2], ferrxanthone [3], brasilixanthone B [4], and neolancerin [5] were isolated from adventitious roots of St. John’s wort (Hypericum perforatum L.). Compound 1–5 were evaluated for antioxidant activities using the intracellular reactive oxygen species (ROS) radical scavenging 2′,7′-dichlorfluorescein-diacetate (DCFDA) assay and for cytotoxic activity against the HL-60 human promyelocytic leukemia cells. Among them, compound 1–4 exhibited scavenging activity with inhibition values of 27.4–33.2% at 10 μM; compound 1, 2, and 4 reduced the viability of HL-60 cells significantly, with IC50 values of 31.5, 28.9, and 27.7 μM, respectively.

Phenolic components from the stem of Acanthopanax koreanum and their inhibitory effects on NF-kappa B

Two novel phenolic glucosides (1–2), as well as seven known compounds (3–9), were isolated from the stem of Acanthopanax koreanum; their chemical structures were determined by chemical and spectroscopic methods and subsequently compared with previously reported data. Their inhibition of nuclear factor kappa B (NF-κB) was measured in human embryonic kidney (293T) cells by using an NF-κB luciferase assay.

Soluble epoxide hydrolase inhibitory activity of anthraquinone components from Aloe.

Aloe is a short-stemmed succulent herb widely used in traditional medicine to treat various diseases and as raw material in cosmetics and heath foods. In this study, we isolated and identified two new anthraquinone derivatives, aloinoside C (6) and aloinoside D (7), together with six known compounds from an aqueous dissolved Aloe exudate. Their structures were identified by spectroscopic analysis. The inhibitory effects of the isolated compounds on soluble epoxide hydrolase (sEH) were evaluated. Compounds 1-8 inhibited sEH activity potently, with IC50 values ranging from 4.1±0.6 to 41.1±4.2 μM. A kinetic analysis of compounds 1-8 revealed that the inhibitory actions of compounds 1, 6 and 8 were non-competitive, whereas those of compounds 2-5 and 7 were the mixed-type. Molecular docking increases our understanding of receptor-ligand binding of all compounds. These results demonstrate that compounds 1-8 from Aloe are potential sEH inhibitors.

Anti-Inflammatory and PPAR Transactivational Effects of Oleanane-Type Triterpenoid Saponins from the Roots of Pulsatilla koreana.

In this study, 23 oleanane-type triterpenoid saponins were isolated from a methanol extract of the roots of Pulsatilla koreana. The NF-κB inhibitory activity of the isolated compounds was measured in TNFα-treated HepG2 cells using a luciferase reporter system. Compounds 19–23 inhibited TNFα-stimulated NF-κB activation in a dose-dependent manner, with IC50 values ranging from 0.75–8.30 μM. Compounds 19 and 20 also inhibited the TNFα-induced expression of iNOS and ICAM-1 mRNA. Moreover, effect of the isolated compounds on PPARs transcriptional activity was assessed. Compounds 7–11 and 19–23 activated PPARs the transcriptional activity significantly in a dose-dependent manner, with EC50 values ranging from 0.9–10.8 μM. These results suggest the presence of potent anti-inflammatory components in P. koreana, and will facilitate the development of novel anti-inflammatory agents.

A new phenolic derivative with soluble epoxide hydrolase and nuclear factor-kappaB inhibitory activity from the aqueous extract of Acacia catechu

Abstract One novel phenolic compound, (4S,5R)-4-(3,4-dihydroxyphenyl)-5-(3-oxobutyl)dihydrofuran-2(3H)-one (1), as well as 12 known compounds (2–13) was obtained from the aqueous extract of Acacia catechu and their chemical structures were determined by spectroscopic analysis. Compounds 8 and 9 exhibited significant soluble epoxide hydrolase (sEH) inhibitory activities with IC50 values of 26.6 ± 0.5 and 24.4 ± 5.6 μM, respectively. Compounds 7–10 showed significant inhibitory effects on TNFα-induced nuclear factor kappa B (NF-κB) transcriptional activity in a dose-dependent manner, with IC50 values ranging from 11.15 to 19.45 μM. Graphical abstract