Yu Tang Tung

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.

Protective effect of Acacia confusa bark extract and its active compound gallic acid against carbon tetrachloride-induced chronic liver injury in rats

Acacia confusa Merr. (Leguminosae), a species native to Taiwan, is widely distributed on the hills and lowlands of Taiwan, and has been traditionally used as a medicine. The hepatoprotective effects of A. confusa bark extract (ACBE) and its active constituent gallic acid were evaluated against carbon tetrachloride (CCl(4))-induced hepatotoxicity in rats. CCl(4)-induced hepatic pathological damage and significantly increased the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and malondialdehyde (MDA) in plasma, and cytochrome P4502E1 (CYP2E1) protein expression in hepatic samples, and decreased the activities of superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT) in erythrocytes. Treatment with ACBE, gallic acid or silymarin could decrease significantly the AST, ALT, and MDA levels in plasma, and CYP2E1 expression in liver tissues, and increase the activities of SOD and GPX in erythrocyte when compared with CCl(4)-treated group. Liver histopathology also showed that ACBE, gallic acid or silymarin could significantly reduce the incidence of liver lesions induced by CCl(4). These results suggested that the ACBE and gallic acid exhibit potent hepatoprotection against CCl(4)-induced liver damages in rats, and the hepatoprotective effects of ACBE and gallic acid may be due to the modulation of antioxidant enzymes activities and inhibition of lipid peroxidation and CYP2E1 activation.

Antioxidant activities and phytochemical characteristics of extracts from Acacia confusa bark

The present study was carried out to evaluate the antioxidant activities of bark extract of Acacia confusa and some of the isolated constituents from its ethyl acetate (EtOAc) fraction in various in vitro systems to gain mechanistic insights. Results from antioxidant assays together with authentic antioxidant standards revealed that EtOAc fraction showed strong superoxide radical scavenging activity, reducing power, and ferrous ion-chelating ability. Following an in vitro antioxidant activity-guided fractionation procedure, 16 constituents including 12 benzoic acids, three cinnamic acids and one lignans were isolated and identified from the EtOAc fraction. We also evaluated the structure-activity relationships of benzoic and cinnamic acid derivatives. Results obtained indicated that the bark extracts and the derived phytochemicals from A. confusa have a great potential to prevent disease caused by the overproduction of radicals and also it might be used as a potential source of natural antioxidant agent.

Bovine lactoferrin inhibits lung cancer growth through suppression of both inflammation and expression of vascular endothelial growth factor.

Lung cancers are among the most common cancers in the world, and the search for effective and safe drugs for the chemoprevention and therapy of pulmonary cancer has become important. In this study, bovine lactoferrin (bLF) was used in both in vitro and in vivo approaches to investigate its activity against lung cancer. A human lung cancer cell line, A549, which expresses a high level of vascular endothelial growth factor (VEGF) under hypoxia, was used as an in vitro system for bLF treatment. A strain of transgenic mice carrying the human VEGF-A165 (hVEGF-A165) gene, which induces pulmonary tumors, was used as an in vivo lung cancer therapy model. We found that bLF significantly decreased proliferation of A549 cells by decreasing the expression of VEGF protein in a dose-dependent manner. Furthermore, oral administration of bLF at 300 mg/kg of body weight 3 times a week for 1.5 mo to the transgenic mice overexpressing hVEGF-A165 significantly eliminated expression of hVEGF-A165 and suppressed the formation of tumors. Additionally, treatment with bLF significantly decreased the levels of proinflammatory cytokines, such as tumor necrosis factor-α, and antiinflammatory cytokines, such as IL-4 and IL-10. Levels of IL-6, which is both a proinflammatory and an antiinflammatory cytokine, were also reduced. Treatment with bLF decreased levels of tumor necrosis factor-α, IL-4, IL-6, and IL-10 cytokines, resulting in limited inflammation, which then restricted growth of the lung cancer. Our results revealed that bLF is an inhibitor of angiogenesis and blocks lung cell inflammation; as such, it has considerable potential for therapeutic use in the treatment of lung cancer.

Anti-inflammatory activities of essential oils and their constituents from different provenances of indigenous cinnamon (Cinnamomum osmophloeum) leaves

Context: Cinnamomum osmophloeum Kaneh. (Lauraceae) is one of the indigenous tree species in Taiwan. This tree species has been of interest to researchers because the chemical constituents of its essential oil are similar to those of Cinnamomum cassia Presl. bark oil, known as cinnamon oil, which is commonly used in foods and beverages. Objective: The anti-inflammatory activities of the leaf essential oils and their major compounds from seven provenances of C. osmophloeum are investigated here for the first time. Materials and methods: Chemical compositions of hydrodistilled essential oils obtained from C. osmophloeum leaves were analyzed by gas chromatography-mass spectrometry (GC-MS), and the effects of essential oils on nitric oxide (NO) production in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages were investigated. Results: The leaf essential oils of cinnamaldehyde type and mixed type strongly inhibited NO production, with IC50 values ranging from 9.7-15.5 μg/mL. Furthermore, trans-cinnamaldehyde is responsible for the inhibitory activity of cinnamaldehyde type, and T-cadinol and α-cadinol are responsible for the inhibitory activity of mixed type. Discussion and conclusion: These findings demonstrate that the leaf essential oils and their constituents of C. osmophloeum have excellent anti-inflammatory activities and thus have great potential as a source for natural health products.

Curcumin reduces pulmonary tumorigenesis in vascular endothelial growth factor (VEGF)‐overexpressing transgenic mice

SCOPE We investigated the inhibition of pulmonary tumor formation through treatment with curcumin in transgenic mice. METHODS AND RESULTS In this study, a strain of transgenic mice carrying human vascular endothelial growth factor A₁₆₅ (hVEGF-A₁₆₅) gene to induce pulmonary tumor was used as an in vivo cancer therapy model. We found that curcumin significantly reduced hVEGF-A₁₆₅ overexpression to normal, specifically in Clara cells of the lungs of transgenic mice, and suppressed the formation of tumors. In addition, we demonstrated a relationship between curcumin treatment and the expression of VEGF, EGFR, ERK2, and Cyclin A at the transcriptional and translational levels. We also noticed a reduction of Cyclin A and Cyclin B after curcumin treatment that had an effect on the cell cycle. Curcumin-induced inhibition of Cyclin A and Cyclin B likely results in decreased progression through S and G2/M phases. These results demonstrated that the expression of proteins involved in the S to M phase transition in transgenic mice is suppressed by curcumin. CONCLUSION A Data suggest that a blockade of the cell cycle may be a critical mechanism for the observed effects on vasculogenesis and angiogenesis following treatment with curcumin.

A Chinese herbal medicine, Gexia-Zhuyu Tang (GZT), prevents dimethylnitrosamine-induced liver fibrosis through inhibition of hepatic stellate cells proliferation

ETHNOPHARMACOLOGICAL EVIDENCE Gexia-Zhuyu Tang (GZT), also called Gexiazhuyu decoction (GXZYD), is a traditional Chinese herbal medicine for chronic liver diseases such as cirrhosis and liver fibrosis. AIM OF THE STUDY In this study, we have investigated the affects of GZT on a rat model of dimethylnitrosamine (DMN)-induced liver fibrosis. MATERIALS AND METHODS In this study, the protective effects of GZT on DMN-induced liver fibrosis were measured using a rat model. Following 5 weeks of DMN-treatment (8 mg/kg, i.p., given 3 consecutive days each week), oral administration of GZT at 1.8 g/kg daily via oral gavage for 2weeks beginning at week 13. RESULTS Both body and liver weights were significantly decreased. The reductions in body and liver weights corresponded with increasing liver damage severity. Furthermore, GZT-treatment remarkably decreased the levels of serum GOT (glutamate oxaloacetate transaminase) and GPT (glutamic pyruvic transaminase), and the mRNA expression levels of collagen alpha-1(I) and alpha-smooth muscle actin (alpha-SMA) in DMN-induced hepatic fibrosis. In addition, hepatic stellate cells (HSCs) play a major role in various types of liver fibrosis through initial myofibroblast transformation. The proliferation of HSCs was inhibited by GZT. Treatment with GZT also induced HSC apoptosis in a dose- and time-dependent manner. GZT treatment induced HSC apoptosis by facilitating Ca(2+) release from the mitochondria within 6h. Subsequently, caspases 3 and 12 were elevated by 72 h after treatment. CONCLUSIONS Our studies indicate that GZT exhibited both hepatoprotective and antifibrogenic effects in DMN-induced hepatic injury. These findings suggest that GZT may be useful in preventing the development of hepatic fibrosis.

Ultrasound‐assisted extraction of phenolic antioxidants from Acacia confusa flowers and buds

Acacia confusa Merr. (Leguminosae), a species native to Taiwan, is widely distributed on the hills and lowlands of Taiwan, and has been used in traditional medicines. In this study, the application of ultrasound-assisted extraction was used to extract the phenolic compounds from A. confusa flowers and buds for the first time. Among the extraction methods, it can significantly enhance the contents of phenolic compounds and antioxidant activities in A. confusa flower and bud extracts using ultrasound-assisted extraction (10  min×12 times). Considering both the solvent consumption and the time needed for extraction, ultrasound-assisted extraction was found to be the most practical approach for the rapid and efficient extraction of bioactive phenolic constituents. In addition, gallic acid, myricitrin-3-rhamnoside, quercitrin-3-rhamnoside, europetin-3-rhamnoside, kaempferol-3-rhamnoside, rhamnetin-3-glucoside, and rhamnetin-3-rhamnoside were also quantified in different extracts by RP-HPLC. It is clear that ultrasound-assisted extraction is an efficient method for extracting phenolic compounds from A. confusa flowers and buds.

Active Component of Danshen (Salvia miltiorrhiza Bunge), Tanshinone I, Attenuates Lung Tumorigenesis via Inhibitions of VEGF, Cyclin A, and Cyclin B Expressions

Tanshinone I (T1) and tanshinone II (T2) are the major diterpenes isolated from Danshen (Salvia miltiorrhiza Bunge). Three human lung adenocarcinoma cell lines, A549, CL1-0, and CL1-5, were treated with T1 and T2 for the in vitro antitumor test. Results showed that T1 was more effective than T2 in inhibiting the growth of lung cancer cells via suppressing the expression of VEGF, Cyclin A, and Cyclin B proteins in a dose-dependent manner. Moreover, a transgenic mice model of the human vascular endothelial growth factor-A165 (hVEGF-A 165) gene-induced pulmonary tumor was further treated with T1 for the in vivo lung cancer therapy test. T1 significantly attenuated hVEGF-A165 overexpression to normal levels of the transgenic mice (Tg) that were pretreated with human monocytic leukemia THP-1 cell-derived conditioned medium (CM). It also suppressed the formation of lung adenocarcinoma tumors (16.7%) compared with two placebo groups (50% for Tg/Placebo and 83.3% for Tg/CM/Placebo; P < 0.01). This antitumor effect is likely to slow the progression of cells through the S and G2/M phases of the cell cycle. Blocking of the tumor-activated cell cycle pathway may be a critical mechanism for the observed antitumorigenic effects of T1 treatment on vasculogenesis and angiogenesis.

Bioactive phytochemicals of leaf essential oils of Cinnamomum osmophloeum prevent lipopolysaccharide/ d -galactosamine (LPS/ d -GalN)-induced acute hepatitis in mice

The purpose of this study was to investigate the bioactive phytochemicals of leaf essential oils of Cinnamomum osmophloeum on lipopolysaccharide/D-galactosamine (LPS/D-GalN)-induced acute hepatitis. The results revealed that post-treatment with 100 μmol/kg trans-cinnamaldehyde, (-)-aromadendrene, T-cadinol, or α-cadinol significantly decreased the aspartate aminotransferase (AST), alanine aminotransferase (ALT), tumor necrosis factor-α (TNF-α), and interleukin 6 (IL-6) levels in serum. Moreover, both T-cadinol and α-cadinol treatments decreased the expressions of cleaved caspase-3 and cleaved poly-ADP ribose polymerase (PARP) in the liver tissues when compared with the LPS/D-GalN group. Liver histopathology also showed that silymarin, trans-cinnamaldehyde, (-)-aromadendrene, T-cadinol, or α-cadinol significantly reduced the incidence of liver lesions induced by LPS/D-GalN. These results suggest that the above phytochemicals exhibit potent hepatoprotection against LPS/D-GalN-induced liver damage in mice, and their hepatoprotective effects may be due to the modulation of anti-inflammatory activities.