Ethyl acetate extract of Chinese medicinal herb Sarcandra glabra induces growth inhibition on human leukemic HL-60 cells, associated with cell cycle arrest and up-regulation of pro-apoptotic Bax/Bcl-2 ratio.

Sarcandra glabra (Thunb.) Nakai, colloquially known as Caoshanhu, is a Chinese medicinal herb with reported anti-tumor, anti-inflammatory, anti-viral and non-specific immunoenhancing properties. Although the plant has been clinically used for treating a variety of diseases, its bioactive ingredients are largely unknown and its mode of action has never been investigated. In this study, the anti-tumor property of ethyl acetate (EA) extract of S. glabra was investigated by determining its in vitro growth-inhibitory effects on a panel of human cancer cell lines of different histotypes. Growth inhibition of the EA extract on the cancer cells seemed to be selective, and the leukemic HL-60 was found to be the most responsive after 48 h of treatment (IC50=58 microg/ml). Flow cytometric studies further illustrated that the extract might interfere with DNA replication and thus arrested the cell cycle at S phase in the leukemic cells, followed by DNA fragmentation and loss of phospholipid asymmetry in the plasma membrane after 72 h of treatment. Concurrently, the pro-apoptotic Bax/Bcl-2 ratio was also up-regulated by more than 178% of the control level. All these findings suggested that the extract had initiated apoptosis to kill the leukemic cells. Results from this pioneer study help to establish a scientific foundation for future research and development of the bioactive ingredients in EA extract of S. glabra as efficacious anti-cancer agents.

A case study on fuel oil contamination in a mangrove swamp in Hong Kong.

Mangroves commonly found along tropical and subtropical coastlines are susceptible to oil pollution. In December 2000, around 500 1 m tall Kandelia candel saplings at the age of 3-5 years old located at the foreshore region of Sheung Pak Nai swamp, Hong Kong SAR, were found to be damaged by oil pollution. More than 80% of the saplings were either dead or washed away and leaving less than 5% healthy saplings with dense green leaves. Elevated concentrations of light n-alkanes (ranging from n-C14 to n-C20), pristane and phytane were recorded in surface sediments collected in December 2000. The ratio between light and total n-alkanes was 0.4. The total petroleum hydrocarbons (60-80 microg g(-1) TPH) and unresolved complex mixtures (60-70 microg g(-1) UCM) were higher than the background values of other mangrove sediments in Hong Kong, which were 40 and 20 microg g(-1), respectively. In certain root zone sediments, TPH concentrations were above 1000 microg g(-1). These results suggest that surface sediments in Sheung Pak Nai were contaminated by petroleum oil, most likely by illegal discharge of fuel oil which occurred between 1998 and 2002. One year later, in December 2001, unhealthy saplings had recovered and re-grown. The concentrations of TPH and UCM in sediments declined to around 40 microg g(-1), pristane and phytane dropped by 80%, and the ratio of light to total n-alkanes was 0.15, suggesting that residual oil in sediments was weathered leading to a remarkable recovery of the unhealthy saplings.

Attitudes of Hong Kong Chinese to traditional Chinese medicine and Western medicine: survey and cluster analysis.

OBJECTIVES: To determine whether within a cohort of Hong Kong out-patients definable subtypes exist based on their attitudes to traditional Chinese medicine and Western medicine. DESIGN: Data were collected using a structured questionnaire. SETTING: The sample of 503 subjects was recruited at two local outpatient clinics in Hong Kong. MAIN OUTCOME MEASURES: The study employs demographic variables, illness status, the Chinese-Western Medical Belief Scale, trust of physicians and subjects' preferences on consultation fees, attitude of health care professional, efficacy of service and waiting time during consultation. RESULTS: A cluster analysis yielded three clusters based on their attitudes towards traditional Chinese and Western medicine. One cluster, 24% of the sample, is noted for being older, poorer, more likely to be female and to have chronic conditions; they are sceptical of western physicians. The second cluster (63% of the sample) is younger and have considerably more belief in Western than traditional Chinese medicine. The third group (14%) is intermediate in age and is noted for a marked faith in both forms of medicine. CONCLUSIONS: A clear profile of these attitudes of Hong Kong Chinese may benefit health care professionals in making appropriate patient-doctor relationships and planning patient care.

Fate of polycyclic aromatic hydrocarbon (PAH) contamination in a mangrove swamp in Hong Kong following an oil spill.

The fate of polycyclic aromatic hydrocarbon (PAH) contamination in a mangrove swamp (Yi O) in Hong Kong after an oil spill accident was investigated. The concentrations and profiles of PAHs in surface sediments collected from five quadrats (each of 10 m x 10 m) covering different degrees of oil contamination and the most contaminated mangrove leaves were examined in December 2000 (30 days after the accident) and March 2001 (126 days later). The concentrations of total PAHs in surface sediments ranged from 138 to 2,135 ng g(-1), and PAHs concentrations decreased with time. In the most contaminated sediments, total PAHs dropped from 2,135 (30 days) to 1,196 ng g(-1) (120 days), and the decrease was smaller in less contaminated sediments. The percentage reduction in sediment PAHs over three months (44%) was less significant than that in contaminated leaves (85%), indicating PAH in or on leaves disappeared more rapidly. The PAH profiles were very similar in sediments collected from quadrats Q1 and Q2 with benzo[a]anthracene and pyrene being the most abundant PAH compounds, but were different in the other three quadrats. The proportion of the light molecular weight PAHs to total PAHs increased after three months, especially phenanthrene. Results suggest that physical and photo-chemical weathering (tidal washing and photo-oxidation) of crude oil in surface sediments and on plant leaves were important processes in the first few months after the oil spill. The PAH contamination in Yi O swamp came from both petrogenic and pyrolytic sources. The petrogenic characteristic in the most contaminated sediment was confirmed with high values of phenanthrene to anthracene ratio (>10) and low values of fluoranthene to pyrene ratio (0.3-0.4).

Livestock wastewater treatment by a mangrove pot-cultivation system and the effect of salinity on the nutrient removal efficiency.

The present investigation compared the capacity of greenhouse pot-cultivation systems under two salinity conditions (freshwater and saline water) with two mangrove species (Bruguiera gymnorrhiza and Kandelia candel) to remove nutrients from livestock wastewater. During the whole treatment period there were relatively stable leachate TOC concentrations for wastewater-treated pots. Leachate NH4(+)-N concentration of B. gymnorrhiza pots was generally lower than that of K. candel pots. Leachate PO4(3-)-P concentration of pots receiving wastewater under freshwater condition was higher than that under saline water condition. Soil inorganic N content was more than two times higher for the wastewater treatments than that for the controls under low salinity condition and slower rate of increase under saline water condition. Soil P nutrients of both total and extractable inorganic forms significantly increased for both systems due to the discharges of livestock wastewater under both salinity conditions. The rate of increase in P contents for plants receiving livestock wastewater was 1-4 times that of the controls, much more than that in N contents (0.04-1.30 times). N nutrient removal efficiencies were 84.3% (65.6% by soil and 18.7% by plant) and 95.5% (32.2% by soil and 63.4% by plant), respectively by Kandelia candel and B. gymnorrhiza pot-cultivation systems under freshwater condition. Under saline water condition, N nutrient removal efficiencies by K. candel and B. gymnorrhiza pot-cultivation systems were 92.7% (80.7% by soil and 12.0% by plant) and 98.0% (67.6% by soil and 30.3% by plant), respectively. P nutrient removal efficiencies by K. candel and B. gymnorrhiza systems under freshwater condition were 79.2% (76.6% by soil and 2.6% by plant) and 91.8% (88.2% by soil and 3.6% by plant), respectively. The corresponding values were 88.0% (84.2% by soil and 3.8% by plant) and 97.8% (95.9% by soil and 1.9% by plant) under saline water condition.

Gas-liquid chromatographic determination of 4-chlorophenoxyacetic acid residues in mung bean sprouts.

A gas-liquid chromatographic (GLC) method is described for determining 4-chlorophenoxyacetic acid (CPA) residues in mung bean sprouts. The residues were extracted from samples by using ethyl acetate followed by liquid-liquid partition into 5% NaHCO3 solution. After acidification and reextraction with ethyl acetate, CPA was reacted with pentafluorobenzyl bromide (PFB-Br) to form the PFB derivative. The reaction mixture was separated on a silica gel column to remove excess reagent, and the derivative was eluted with a solution of 75% toluene in hexane. GLC separations were performed on a 3% OV-1 column at 230 degrees C. As low as 10 pg CPA could be quantitated, which is equivalent to about 0.05 ppm at residue level, using an electron capture detector. Recoveries of CPA from fortified mung bean sprouts (0.05, 0.20, and 0.50 ppm) ranged from 71 to 107%. The PFB derivative was further identified by gas chromatography-mass spectrometry.

1,3-beta-D-glucanases from Pisum sativum seedlings. I. Isolation and purification.

Two buffer-soluble endo-1,3-beta-D-glucanases (EC 3.2.1.6) have been purified to within 1% of electrophoretic homogeneity from etiolated Pisum sativum stem tissues. Purified glucanase I and II differ in physical properties, such as electrophoretic mobility in sodium dodecyl sulfate polyacrylamide gels (Mr values were 22 000 and 37 000, respectively) and isoelectric focusing, (pI values were 5.4 and 6.8, respectively). Although the enzymes have similar pH optima (5.5--6.0), Km values for various substrates (0.6--7.4 mg/ml) and thermal inactivation profiles, they are localized in different tissues and they differ markedly in the rates with which they attack the internal linkages of long- vs. short-chain substrates. Glucanase I is concentrated in apical regions of the stem and is most effectively assayed reductometrically (as laminarinase), while glucanase II is localized in mature regions and is relatively more active in viscometric assays (as carboxymethyl-pachymanase).

1,3-beta-D-glucanases from Pisum sativum seedlings. II. Substrate specificities and enzymic action patterns.

Two purified pea 1,3-beta-D-glucanases (EC 3.2.1.6) hydrolyse laminarin (degree of polymerization 20), laminaridextrins (degree of polymerization 3--7), and their reduced 3H-derivatives, 1,3-beta-D-glucans which are partially substituted (carboxymethyl-pachyman) or crystalline (curdlan), and mixed-linkage beta-glucans. Enzyme kinetics and product-formation indicate endo-hydrolase activity with weak transglycosylase capacity. The enzymes do not hydrolyse beta-glucosides, the 1,3 linkage adjacent to the reducing end of chains, or cellulose and its derivatives. They degrade mixed-linkage beta-glucans, in a manner similar to Rhizopus arrhizus endo-1,3-beta-D-glucanase, to form the products expected from hydrolysis of linkages adjacent to 1,3-beta linkages. With respect to action patterns, glucanase I (from apical growing tissue) differs from glucanase II (from basal maturing tissue) in several respects: (a) on a molar basis, I generates reducing groups from all substances more rapidly than II; (b) lower laminaridextrins are hydrolysed by I at the non-reducing terminal linkage, while II preferentially hydrolyses internal linkages; (c) laminarin is hydrolysed to lower laminaridextrins by I more rapidly than II, but I takes longer than II to completely degrade laminarin chains; (d) the enzymes are differentially sensitive to different classes of non-competitive inhibitors. It is concluded that these beta-glucanases differ in such a way that I preferentially continues to degrade fragments produced by endo-hydrolytic attack on long chains ('multiple attack' action pattern), while II hydrolyses internal linkages of the longest chains available ('multi-chain attack').