Medicinal Plants In Taiwan Research Articles

Antioxidant activities of ethanolic extract and lyoniresinol from bark of Zelkova serrata

Reactive oxygen species- (ROS) induced oxidation stress is a key cause of human health problems. Studies have shown that many diseases, such as Alzheimer’s disease, Parkinson’s disease, diabetes, carcinogenesis and inflammatory diseases, are associated with ROS. Plant polyphenols have the ability to remove these ROS in the human body, indicating their potential to improve human health. Zelkova serrata is a traditional medicinal plant in Taiwan and all of its plant parts have various health applications and even antioxidant activities. This study aimed to understand the antioxidant activities of bark polyphenols from Z. serrata and their active components. Results showed that the ethanolic extract of bark had free-radical scavenging abilities and reducing power. Although the extract barely had any flavonoids or condensed tannins, it comprised polar polyphenols with antioxidant activities. Furthermore, antioxidant activities in the extract originated mainly from lyoniresinol via hydrogen atom and electron transfer. These findings suggest that the bark extract of Z. serrata is also a potential resource for health improvement.

First records of powdery mildew fungi (Erysiphales) on medicinal plants in Taiwan

BackgroundProduction of medicinal plants in Taiwan is not only hampered by international market competition, but also lack of knowledge of their pathogens, such as powdery mildew fungi (Erysiphales, Ascomycota). Records of these fungi in Taiwan originate from few researchers for the last one hundred years and are still incomplete. Since powdery mildews in tropical/subtropical environments rarely develop the sexual stages with morphologically diagnostic characteristics, internal transcribed spacer sequences (ITS) of the ribosomal RNA genes obtained from the asexual stages have become important modern tools for species identification.ResultsPowdery mildews on medicinal plants from educational and ornamental plantations in Taiwan were identified based on the anamorph morphology and ITS sequences. Four powdery mildews on medicinal plants are new records for Taiwan, Arthrocladiella mougeotii on Lycium chinense, Erysiphe glycines on Pueraria lobata, Erysiphe lespedezae on Bauhinia sp., Desmodium caudatum, and Uraria crinita, and E. lonicerae on Lonicera japonica. Eryngium foetidum is a new host for Erysiphe heraclei hitherto known on other host plants in Taiwan. Eryngium foetidum and Uraria crinita are new host plants for powdery mildews worldwide. Only specific field collection of the pathogens yielded the new records, not checking plant specimens in a phanerogam herbarium. The pathogens did not cause death of the host plants, but appeared to enhance stress by infection of mature leaves.ConclusionsTaxonomic study of powdery mildews in Taiwan results into new host records of economically important medicinal plants in Taiwan with potential consequences for plant production and quarantine and also shows that host records are quite incomplete worldwide. Although ITS sequences were useful for species identification, the lack of data for several species on the same host genus on the one hand and the low variation between closely related species on the other indicate the need for further study.

Flavonoids and bis-coumarin from the tubers of Apios taiwanianus

Apios taiwanianus is a medicinal plant in Taiwan. The tuber of A. taiwanianus is used as a folk medicine to treat hyperthyroidism, herpes, and tumors. We carried out the phytochemical study of A. taiwanianus. One new isoflavone, apioisoflavone (2) along with nineteen known compounds were isolated from the tubers of A. taiwanianus. The structures of these compounds were determined by spectral analyses and comparison with those in the literature. Compounds lupinalbin A (6) and dephnoretin (11) were shown to enhance the alkaline phosphatase (ALP) activity in MC3T3-E1 osteoblasts.

Antioxidant, Anti-inflammatory, and Antiproliferative Activities of Taxillus sutchuenensis

Inflammation is related to several chronic diseases, including cancer and atherosclerosis. Taxillus sutchuenensis (Lecomte) Danser is a special folk medicinal plant in Taiwan. The aim of this study was to evaluate the antioxidant, anti-inflammatory, and antiproliferative activities of the aqueous-thanol extract from T. sutchuenensis (AETS) and its fractions. TEAC, DPPH radicals, total phenolic compounds, total flavonoid content, inhibition of NO production in LPS-induced RAW264.7 cells, and inhibition of cancer cell proliferation were tested. Among all fractions, the ethyl-acetate (EA) fraction showed the highest TEAC and DPPH radical scavenging activities. The EA fraction also had the highest polyphenol and flavonoid content. The EA fractions also decreased LPS-induced NO production and the expression of iNOS and COX-2 in RAW264.7 cells. The antiproliferative activities of the aqueous/ethanol extract and fractions were studied in vitro using A549 cells, and the results were consistent with their antioxidant capacities. EA fractions had the highest antiproliferative activity with an IC(50) of 454.38 ± 1.48 μg/ml. Quercetin also had antioxidant, anti-inflammatory, and antiproliferative activities. Quercetin might be an important bioactive compound in T. sutchuenensis. The experimental data indicated that T. sutchuenensis is a potent antioxidant medicinal plant, and such efficacy may be mainly attributed to its polyphenolic compounds.

Anti-tumor effect of Archidendron lucidum (Benth.) against esophageal cancer, colorectal cancer and hepatoma

Archidenron lucidum is an indigenous medicinal plant in Taiwan used for treatment of inflammatory diseases and cancer. This study was aimed to investigate its anti-cancer effect against gastrointestinal and hepatic malignancy. We found that the 50% effective concentrations of its methanol extract (MEAL) against human esophageal cancer CE81T/VGH, hepatoma HA22T/VGH and murine colorectal cancer CT26 cells were less than 5.0 µg/mL in vitro whereas those of water extract were greater than 30 µg/mL. Cell cycle arrest at G2/M phase was observed in all three cell lines treated with MEAL. Development of hypodiploidy cells suggests that apoptosis might be one of the cell death pathways of CE81T/VGH cells. Intraperitoneal injection with 1.25 mg/kg MEAL significantly inhibited syngeneic CT26 tumor growth in BALB/c mice without obvious toxicity in terms of changes in body weight, leukocyte count and plasma creatinine and alanine aminotransferase (ALT) levels. Higher dose (2.5 mg/kg) MEAL did not further increase the anti-tumor effect, but resulted in elevation of plasma ALT level. Our results indicate that optimal dose of MEAL might possess the anti-tumor effects against esophageal, hepatocellular and colorectal cancers with a relative safety profile. Accordingly, we are purifying effective and less toxic compounds from MEAL.

Anti-tumor effect of Archidendron lucidum (Benth.) against esophageal cancer, colorectal cancer and hepatoma

Archidenron lucidum is an indigenous medicinal plant in Taiwan used for treatment of inflammatory diseases and cancer. This study was aimed to investigate its anti-cancer effect against gastrointestinal and hepatic malignancy. We found that the 50% effective concentrations of its methanol extract (MEAL) against human esophageal cancer CE81T/VGH, hepatoma HA22T/VGH and murine colorectal cancer CT26 cells were less than 5.0 µg/mL in vitro whereas those of water extract were greater than 30 µg/mL. Cell cycle arrest at G2/M phase was observed in all three cell lines treated with MEAL. Development of hypodiploidy cells suggests that apoptosis might be one of the cell death pathways of CE81T/VGH cells. Intraperitoneal injection with 1.25 mg/kg MEAL significantly inhibited syngeneic CT26 tumor growth in BALB/c mice without obvious toxicity in terms of changes in body weight, leukocyte count and plasma creatinine and alanine aminotransferase (ALT) levels. Higher dose (2.5 mg/kg) MEAL did not further increase the anti-tumor effect, but resulted in elevation of plasma ALT level. Our results indicate that optimal dose of MEAL might possess the anti-tumor effects against esophageal, hepatocellular and colorectal cancers with a relative safety profile. Accordingly, we are purifying effective and less toxic compounds from MEAL.

Antioxidant, Anti-inflammatory and Antiproliferative Activities of Kalanchoe gracilis (L.) DC Stem

Oxidative stress and inflammation are related to several chronic diseases including cancer and atherosclerosis. Kalanchoe gracilis (L.) DC is a special folk medicinal plant in Taiwan. The aim of this study was to evaluate the antioxidant, anti-inflammatory and antiproliferative activities of the methanolic extract and fractions of the stem of K. gracilis. TEAC, total phenolic compound content, total flavonoid content, DPPH radical scavenging activity, reducing power, inhibition of NO production in LPS-induced RAW264.7 cells, and inhibition of cancer cell proliferation were analyzed. Among all fractions, the chloroform fraction showed the highest TEAC and DPPH radical scavenging activities. The chloroform fraction also had the highest content of polyphenols and flavonoids. Chloroform fractions also decreased LPS-induced NO production and expressions of iNOS and COX-2 in RAW264.7 cells. The antiproliferative activities of the methanolic extract and fractions were studied in vitro using HepG2 cells, and the results were consistent with their antioxidant capacities. Chloroform fractions had the highest antiproliferative activity with an IC(50) of 136.85 ± 2.32 μg/ml. Eupafolin also had good pharmacological activity in the antioxidant, anti-inflammation and antiproliferative. Eupafolin might be an important bioactive compound in the stem of K. gracilis. The above experimental data indicated that the stem of K. gracilis is a potent antioxidant medicinal plant, and such efficacy may be mainly attributed to its polyphenolic compounds.

Inhibition of Xanthine Oxidase by Acacia confusa Extracts and Their Phytochemicals

Acacia confusa Merr. (Leguminosae) is traditionally used as a medicinal plant in Taiwan. In the present study, the XOD-inhibitory activity of ethanolic extracts from A. confusa was investigated for the first time. Results demonstrated that the ethanolic extract of A. confusa heartwood had a strong XOD-inhibitory activity. Among all fractions derived from heartwood extracts, the EtOAc fraction exhibited the best inhibitory activity. Following column chromatography and reverse-phase high-performance liquid chromatography, eight specific phytochemicals including melanoxetin, 7,8,3',4'-tetrahydroxyflavone, transilitin, okanin, 3,7,8,3'-tetrahydroxy-4'-methoxyflavone, 7,8,3'-trihydroxy-3,4'-dimethoxyflavone, 7,3',4'-trihydroxyflavone, and 7,3',4'-trihydroxy-3-methoxyflavone were isolated and identified from the EtOAc fraction. In addition, the IC(50) values indicated that okanin showed the strongest XOD-inhibitory effect (IC(50) value of 0.076 microM), followed by melanoxetin (0.274 microM) and allopurinol (4.784 microM). The present study revealed that okanin and melanoxetin showed excellent inhibition on XOD in noncompetitive and competitive mode, respectively, and their inhibitory activity is better than that of allopurinol. This is the first study that demonstrates the XOD-inhibitory performance of okanin and melanoxetin.

Preparative separation of oligostilbenes from Vitis thunbergii var. taiwaniana by centrifugal partition chromatography followed by Sephadex LH-20 column chromatography

Vitis thunbergii var. taiwaniana is a vitaceous native folk medicinal plant in Taiwan. The root of V. thunbergii var. taiwaniana is used to treat hepatitis and arthritis. Centrifugal partition chromatography (CPC) and Sephadex LH-20 gel filtration column chromatography were successively used to isolate and purify three oligostilbenes, (−)-vitisin B, (+)-vitisin A, and ampelopsin A, from the root of V. thunbergii var. taiwaniana. The two-phase solvent system of CPC composed of chloroform–methanol–water (6:7:4, v/v/v) was used for the preparative separation of the methanolic extract of V. thunbergii var. taiwaniana. Using CPC and Sephadex LH-20 column chromatography, about 1 g of the crude extract was separated, yielding 28.9 mg of (−)-vitisin B, 18.7 mg of (+)-vitisin A, and 18.2 mg of ampelopsin A at respective purities of 93%, 91%, and 90%.

Ecotypic variation of a medicinal plant Imperata cylindrica populations in Taiwan: mass spectrometry-based proteomic evidence

Cogon grass [Imperata cylindrica L. Beauv. var. major] is the only one species of Imperata, and one of the medicinal plants in Taiwan. The rhizome can be used for medicinal purposes. In the field alcohol dehydrogenase (ADH) activity, proline and sodium content in tissues of Imperata showed variation between wetland (Chuwei population) and the other two representative non-wetland ecotypes (Neihu and Sarlun populations). Chuwei ecotype is known tolerant to flood and salt shown in a flood and salt treatment experiment in previous study. A mass spectrometry (MS)-based proteomic analysis identified a fast moving 2-phospho-D-glycerate hydrolase (enolase) isoform only in the wetland ecotype on a native-polyacrylamide gel electrophoresis, whereas a slow moving enolase isoform was identified only in the non-wetland ecotypes. In addition, a mitochondrial malate dehydrogenase and a chloroplast ferredoxin-NADP(H) oxidoreductase were identified only in the wetland ecotype. These proteomic results provide additional evidence of the ecotypic variation among Imperata cylindrica ecotypes. The potential use of this novel approach to identify protein markers is discussed in the study.

Effect of Phytocompounds from the Heartwood of Acacia confusa on Inflammatory Mediator Production

Acacia confusa Merr. (Leguminosae) is traditionally used as a medicinal plant in Taiwan. In the present study, anti-inflammatory activity of extracts from the heartwood of A. confusa were investigated for the first time. Results demonstrated that ethanolic extracts of A. confusa heartwood strongly suppressed NO production in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages. Among all fractions derived from ethanolic extracts, the EtOAc fraction exhibited the best inhibitory activity. Following column chromatography and reverse-phase high-performance liquid chromatography, 13 specific phytocompounds including 5 new flavonoids (i.e., 7,8,3',4'-tetrahydroxy-4-methoxyflavan-3-ol, 7,8,3',4'-tetrahydroxyflavone, 7,8,3'-trihydroxy-3,4'-dimethoxyflavone, 7,3',4'-trihydroxyflavone, and 7,3',4'-trihydroxy-3-methoxyflavone) were isolated and identified from the EtOAc fraction. In addition, melanoxetin (3,7,8,3',4'-pentahydroxyflavone), a major compound in the EtOAc fraction, markedly suppressed LPS-induced NO and prostaglandin E 2 (PGE 2) production. Moreover, melanoxetin completely suppressed gene expression of inducible NO synthase (iNOS) and cyclooxygenase-2 (COX-2) at 50 and 100 microM, respectively. This is the first report to identify the inhibitory bioactivities of melanoxetin on iNOS and COX-2.

Online RP-HPLC-DPPH Screening Method for Detection of Radical-Scavenging Phytochemicals from Flowers of Acacia confusa

Acacia confusa is traditionally used as a medicinal plant in Taiwan. In this study, phytochemicals and antioxidant activities of extracts from flowers of A. confusa were investigated for the first time. In addition, a rapid screening method, online RP-HPLC-DPPH system, for individual antioxidants in complex matrices was developed. Accordingly, six antioxidants including gallic acid ( 1), myricetin 3-rhamnoside ( 2), quercetin 3-rhamnoside ( 3), kaempferol 3-rhamnoside ( 4), europetin 3-rhamnoside ( 5), and rhamnetin 3-rhamnoside ( 6) were detected using the developed screening method. Of these, compounds 2, 3, and 5 were found to be major bioactive phytochemicals, and their contents were determined as 11.3, 6.7, and 8.7 mg/g of crude extract, respectively. By comparison with quercetin, a well-known antioxidant, these compounds had the order of compound 2 > compound 5 > quercetin > compound 3 for DPPH radical-scavenging activity. Their IC 50 values were 3.0, 3.2, 4.5, and 7.4 microM, respectively. Moreover, the same order was observed for superoxide radical-scavenging activity, and their IC50 values were 2.6, 2.7, 4.3, and 5.3 microM, respectively. However, for lipid peroxidation, quercetin, an aglycon, showed the best inhibitory activity. The IC50 values of quercetin, compound 2, compound 5, and compound 3 were 46.7, 88.5, 90.7, and 124.6 microM, respectively. These results indicated that a rhamnoside at the C3 position of flavonoids had a negative effect on radical-scavenging activity and antilipid peroxidation. In contrast, the number of hydroxyl groups on the B-ring exhibited a positive relationship with their inhibitory activities.

In vitro Anti-leukemic and Antiviral Activities of Traditionally Used Medicinal Plants in Taiwan

Medicinal plants have been historically used as treatment for different kinds of human diseases. In this study, hot water (HW) extract of five Taiwanese traditionally used medicinal plants was evaluated for their in vitro anti-leukemic (including anti-K562, L1210, P3HR1, Raji and U937 leukemia cells) and antiviral (including HSV-1 and HSV-2) activities. Results showed that Blumea lacera exhibited broad anti-leukemic activity at magnitudes ranging from moderate to mild and Ixeris chinensis is effective at inhibiting the proliferation of K562 cells. B. lacera and Tithonia diversifolia suppressed the replication of HSV-1 and HSV-2, and had IC50 values below 100 microg/ml. The medicinal plants showed no cytotoxic effect at concentrations that inhibited HSV infection. It was, therefore, concluded that the HW extract of tested medicinal plants exhibited anti-leukemic and antiviral activities at different magnitudes of potency.

In vitro anti-herpes simplex viruses and anti-adenoviruses activity of twelve traditionally used medicinal plants in Taiwan.

As an effort to search for new antiviral agents from traditional medicine, the hot water (HW) extract of twelve traditionally used medicinal plants in Taiwan was evaluated for their in vitro anti-herpes simplex viruses (HSV; including HSV-1 and HSV-2) and anti-adenoviruses (ADV; including ADV-3, ADV-8 and ADV-11) activities with a XTT-based colorimetric assay. Results showed that the tested HW extracts exhibited anti-HSV and anti-ADV activities at different magnitudes of potency. Among the twelve medicinal plants, Boussingaultia gracilis var. pseudobaselloides (Basellaceae) and Serissa japonica (Rubiaceae) possessed broad spectrum of antiviral activity. Ardisia squamulosa (Myrsinaceae) and Artemisai princeps var. orientalis (Compositae) were more effective in inhibiting ADV-8 replication than the other four viruses. Cell cytotoxic assay demonstrated that all tested HW extracts had CC50 values higher than their EC50 values. It was concluded that the twelve traditionally used medicinal plants in Taiwan possessed antiviral activity, and some of them merit further investigation.

Antileukemic activity of selected natural products in Taiwan.

The aim of the present study was to evaluate the antileukemic activity of six chemical classes of pure compounds present in commonly used medicinal plants in Taiwan--such as the genus Plantago. Studies were conducted on a series of human leukemia and lymphoma cell lines. Results showed that water soluble compounds (aucubin, caffeic acid, chlorogenic acid, ferulic acid, p-coumaric acid and vanillic acid) exhibited a weak antileukemic activity (IC50: 26-56 microg/ml, SI: 2-11). On the other hand, water insoluble compounds such as triterpenoids (oleanolic acid and ursolic acid), monoterpene (linalool) and flavonoid (luteolin) possessed strong activity against human leukemia and lymphoma cell lines. Among them, linalool showed the strongest activity against histiocytic lymphoma cells U937 (IC50: 3.51 microg/ml, SI: 592.6) and Burkitt lymphoma cells P3HR1 (IC50: 4.21 microg/ml, SI: 494.1). Ursolic acid was effective against P3HR1 cells (IC50: 2.5 microg/ml, SI: 262.6) and chronic myelogenous leukemia cells K562 (IC50: 17.79 microg/ml, SI: 36.91), whereas oleanolic acid inhibited the growth of P3HR1 cells (IC50: 26.74 microg/ml, SI: 11.37). Luteolin exhibited effective activity against K562 cells (IC50 18.96 microg/ml, SI: 5.14) and P3HR1 cells (IC50: 18.99 microg/ml, SI: 5.13). We conclude that terpenes and flavonoid in commonly used medicinal plants possess strong activity against lymphoma and leukemia cells, especially human lymphoma cells, suggesting the potential use of these compounds for treatment of lymphoma.

Antiviral activity of eight commonly used medicinal plants in Taiwan.

In an effort to find new antiviral agents from natural products, hot water extracts of eight traditionally used medicinal plants in Taiwan were investigated in vitro for their activities against adenoviruses (ADV) and herpes simplex viruses (HSV). Results demonstrated that all extracts exhibited antiviral activity with different degrees of potency. Only two extracts were active in suppressing both HSV and ADV infections. Three extracts inhibited only ADV infection whereas one extract blocked only HSV infection. These results suggested that the aforementioned medicinal plants merit further investigation.