Effects on photosynthetic and antioxidant systems of harmful cyanobacteria by nanocrystalline Zn-MOF-FA.

Metal-organic frameworks (MOFs) constitute new class of materials recently used by researchers in the field of controlling cyanobacteria. However, the use of MOFs in combination with allelochemicals for cyanobacteria inhibition had not been investigated before. The present study is aimed towards the investigation of the effect and mechanism of cyanobacteria inhibition by combining MOF with allelochemical (ferulic acid, FA) for the first time. In this study, the results showed that the synergistic effect of Zn2+ and FA from Zn-MOF-FA could inhibit cyanobacteria to a greater extent than the corresponding dosage of Zn2+ and FA. The inhibition ratio of Microcystis aeruginosa has been found to be more than 50% when the Zn-MOF-FA concentration exceeds 2 mg·L-1 after four days exposure. Zn-MOF-FA at 1 mg·L-1 did not completely inhibit M. aeruginosa, and the inhibition effect has been of only temporary type. The inhibitory effect of Zn-MOF-FA on algae has mainly been attributed to the hindrance of electron transfer and energy capture in the photosynthetic system and the oxidative damage caused by reactive oxygen species (ROS).

Effects of Dracontomelon duperreanum Leaf Litter on the Growth and Photosynthesis of Microcystis aeruginosa.

This study investigated the use of Dracontomelon duperreanum leaf litter extract (DDLLE) in inhibiting the growth and photosynthesis of the algae Microcystis aeruginosa. The goal of the study was to evaluate a potential solution for cyanobacterial bloom prevention. M. aeruginosa was exposed to extract concentrations from 0.4 to 2.0 g L-1. Chlorophyll-a (Chl-a) content and photosynthesis levels were assessed using pulse amplitude modulated fluorimetry phytoplankton analyzer. Results suggested that the extract could efficiently suppress M. aeruginosa growth. The content of Chl-a was only 19.0 µg L-1 and achieved 96.0% inhibition rate when exposed to 2.0 g L-1 on day 15. Growth rate in response to different extract concentrations were consistent with changes in the photosynthesis efficiency (alpha), maximal relative electron transport rate and maximal photochemical efficiency of photosystem II (F v /F m ). Furthermore, several kinds of volatile chemicals and their concentrations in DDLLE had been identified by GC-MS, which of them play major role to suppress the growth of M. aeruginosa should be further studied.

DNA protective effect of ginseng and the antagonistic effect of Chinese turnip: A supplementation study.

AIM: The aim of this clinical study is to provide scientific evidence for supporting traditional Chinese application and usage to the patients. For this purpose, we tested the ability if Panax ginseng extract to lower oxidative damage to nuclear DNA in human lymphocytes by comparing the effect of cooked Chinese turnip on this effect. MATERIALS AND METHODS: Seven healthy subjects (4 males and 3 females from 37 to 60 years) participated two occasions which were at least 2 weeks apart. About 2 mL of fasting blood sample for baseline measurement was taken on arrival. They were requested to ingest the content of 5 ginseng capsules in 200 mL water. The subject remained fasting for 2 h until the second blood sample taken. In the other occasion, the experiment was repeated except a piece of cooked turnip (10 g) was taken with the ginseng extract. The two occasions could be interchanged. Comet assay was performed on two specimens on the same day for the evaluation of lymphocytic DNA damage with or without oxidative stress. RESULTS: For the group with ginseng supplementation, there was a significant decrease in comet score for hydrogen peroxide (H2O2) treatment over the 2-h period while no change in DNA damage for unstressed sample. For the group with ginseng together with turnip supplementation, there was no significant difference in comet score for both H2O2 treatment and phosphate-buffered saline treatment. Ginseng extract could reduce DNA damage mediated by H2O2 effectively, but this protection effect was antagonized by the ingestion of cooked turnip at the same time. CONCLUSION: In the current study, commercial ginseng extract was used for supplementing volunteers. Ginseng extract could protect DNA from oxidative stress in vivo while turnip diminished the protection.

Effects of Dracontomelon duperreanum defoliation extract on Microcystis aeruginosa: physiological and morphological aspects.

Harmful cyanobacteria bloom contributes to economic loss as well as the threat to human health. Agricultural waste products, particularly straw, have been used to control bloom while arbor plant is the potential candidate for limiting antialgal activity. This study investigated the use of Dracontomelon duperreanum defoliation extract (DDDE) to inhibit the activity of Microcystis aeruginosa. The primary goal of the research was to explore the solution to control cyanobacterial bloom. The photosynthetic activity, cell morphology, membrane integrity, and esterase activity of M. aeruginosa were determined using phytoplankton analyzer pulse amplitude modulation (Phyto-PAM) and flow cytometry before and after exposure to DDDE. The inhibitory rate of M. aeruginosa was about 99.6 % on day 15 when exposed to 2.0 g L(-1). A reduction of chlorophyll a (Chl-a) activity and changes in cell membrane suggested the algistatic property of DDDE. Inhibition of photosynthetic activity was reflected by changing mean Chl-a fluorescence intensity (MFI) which was about 52.5 % on day 15 when exposed to 2.0 g L(-1) DDDE as well as relative electron transport rates (rETRs) of algal cell. These changes might contribute to the suppression of M. aeruginosa. Algal cell exposed to DDDE may lead to cell volume reduction or slow growth. This resulted in a decreased proportion of normal or swollen granular cells after DDDE treatment.

American ginseng tea protects cellular DNA within 2 h from consumption: results of a pilot study in healthy human volunteers.

The acute genoprotective effect of Panax quinquefolius (American ginseng) has been investigated. The experiment was carried out to explore the DNA protective effect after a single dose of American ginseng tea bag infusion. Fourteen subjects (6 males and 8 females) were recruited in this study. Seven of them (3 males and 4 females) were asked to drink a cup of freshly prepared American ginseng infusions. Water was taken by the remaining subjects as the control group. Blood samples of both groups were taken before and 2 h post-ingestion. The blood samples were challenged with ultraviolet B irradiation followed by using comet assay. Completed slides were stained with Giemsa stain and DNA damage was assessed. Results showed a significant decrease in comet score after American ginseng supplementation and no change in the control group. The current study demonstrated a cup of American ginseng infusion could protect cellular DNA from oxidative stress at least within 2 h.

Rapid but mild genoprotective effect on lymphocytic DNA with Panax notoginseng extract supplementation.

BACKGROUND: Panax notoginseng (PN) is a well-known Chinese medicinal herb traditionally used as a hemostatic agent that strengthens and builds blood. The free radicals scavenging and antioxidant property of PN have been demonstrated in various studies either in vitro or in animal models, however, the genoprotective effect at human cellular level remains to be elucidated. AIM: The current supplementation study aimed to investigate the genoprotective effect of PN. The study explored the DNA protection effect after a single dose of 2500 mg commercial notoginseng extract in water. MATERIALS AND METHODS: Six subjects, (3 males, 3 females) were recruited and each attended two trials. In the first trial, pre-ingestion and 2 hour-post-ingestion blood samples were collected and they were challenged with 50 µM H2O2. In the second trial, water was taken instead as control. Lymphocytes with or without challenge were then subjected to comet assay. DNA damage was assessed under fluorescent microscope. RESULTS: Results showed a significant (P < 0.05) but mild decrease (3%) in the comet score after PN supplementation, indicating that PN supplementation reduces the H2O2-induced DNA damage in the lymphocytes and enhanced their resistance to oxidative damage giving a mild acute genoprotective effect against oxidant challenge. No change of comet score was observed in control trial.

Genoprotective effect of the Chinese herbal decoction xiao jian zhong tang.

The Chinese herbal decoction formula Xiao Jian Zhong Tang (XJZT) is one of the classic formulas from the classic traditional Chinese medicine (TCM). Previous studies on XJZT found that it is effective for treating peptic ulcer, irritable bowel syndrome, functional gastroenteritis and similar psychosomatic disorders of the digestive organs. It has also been shown that all the herbs used in XJZT contain antioxidants. In this study, we investigated the in vitro DNA protection effect of the individual herb extracts and the whole formula. Water extract of the herbs and XJZT were used to pre-treat human lymphocytes. The lymphocytes were then exposed to hydrogen peroxide. The in vitro DNA protection effect of the herbs was investigated by comet assay. No DNA protective effect (P < 0.05) was found for individual herb extracts, but XJZT showed protection of human lymphocytic DNA upon oxidative stress (P < 0.05). The in vitro DNA protection effect of XJZT was conferred by the synergistic effect of the herbs, while the individual herbs had no such effect.

Direct human DNA protection by Coriolus versicolor (Yunzhi) extract.

CONTEXT AND OBJECTIVE: Scientific evidence has shown Coriolus versicolor (L. ex Fr.) Quel (also known as Yunzhi) has the role of immunomodulator in therapeutic effect. The aim of this in vitro study was to investigate the antioxidative effect of Yunzhi and to explore the mechanisms behind its DNA protection. MATERIALS AND METHODS: Commercial Yunzhi extract was dissolved in water and diluted in five concentrations (10(1)-10(5) µg/L) with appropriate buffers. Lymphocytes harvested from three healthy subjects were incubated with Yunzhi extract for 30 min. Cells were then subjected to 5 min oxidant challenge by 45 µM hydrogen peroxide. The standard alkaline comet (SAC) assay and lysed cell comet (LCC) assay were performed in parallel. DNA damage of each treatment was scored under a fluorescence microscope and compared with the cells without Yunzhi pretreatment. RESULTS: U-shaped dose-response was seen in both versions of the comet assay. Yunzhi at 10(4) µg/L demonstrated a genoprotective effect against oxidative damage in the SAC assay (25% decrease in comet score). In the LCC assay, a trend of protection in lymphocytes was observed but it did not reach statistical significance. CONCLUSION: A direct antioxidant effect of Yunzhi against oxidant challenge on the DNA of lymphocytes was evidenced. The active component in Yunzhi was likely to be membrane permeable.

A study of DNA protective effect of orange juice supplementation.

The potential acute genoprotective effect of orange juice supplementation was investigated. Six healthy subjects (aged 33 to 60 years; 3 women and 3 men) were asked to drink 400 mL of commercial orange juice, which contained 100 mg vitamin C and 40.8 g sugar. Venous blood (2 mL) was taken before and 2 h after ingestion (test trial). A week later, the subjects were asked to repeat the trial by drinking 400 mL water with 100 mg vitamin C and 40.8 g glucose (control trial). Lymphocytes isolated from blood samples underwent comet assay on the day of collection. Pre- and postingestion DNA damage scores were measured in both the test and control trials. Results showed that there was a significant decrease in DNA damage induced by hydrogen peroxide after 2 h of supplementation with orange juice, and no change in baseline DNA damage. There was no significant decrease in the DNA damage in lymphocytes in the control trial.

Protective effect of grape seed extracts on human lymphocytes: a preliminary study.

Grape seed extracts (GSEs) possess a broad spectrum of antioxidative properties that protects various cells from free radicals and oxidative stress. In this study, the genoprotective effect of GSE on human lymphocytic DNA was studied using standard and lysed cell comet assays. Lymphocytes from 5 healthy subjects were pretreated with GSE in different concentrations. The standard and lysed cell comet assays were performed on treated, untreated, challenged, and unchallenged cells in parallel. Cells were then subjected to an oxidant challenge induced with 5-min exposures to hydrogen peroxide. In the standard comet assay, GSE significantly diminished hydrogen-peroxide-induced DNA damage in a dose-dependent manner. In the lysed cell assay, however, the antioxidant effect was diminished at a higher GSE concentration. Data indicate that the cell membrane might play a role in limiting cellular access to antioxidants, which directly affects the genoprotective or potential pro-oxidant effect of antioxidants on human DNA. Using both standard and lysed cell comet assays in parallel could be a useful way to elucidate the mechanism of protection or damage by antioxidants.

In vitro antioxidation activity and genoprotective effect of selected Chinese medicinal herbs.

Some traditional Chinese medicinal seeds and fruits are well known for their antioxidant properties. This research aims to investigate whether Fructus Lycii, Fructus Schisandrae Chinensis, Fructus Ligustri Lucidi and Semen Cuscutae protect DNA from oxidant challenge by hydrogen peroxide (H(2)O(2)). The standard comet assay was used to assess the genoprotective effect of these medicinal herbs. Blood was taken from three healthy adults, aged from 36 to 42. Lymphocytes were isolated and treated with different concentrations of aqueous herbal extracts, while controls were treated with phosphate buffered saline. The lymphocytes were stressed with 50 µM H(2)O(2). Treated cells were embedded in agarose and layered on slides. These sandwiched lymphocytes were lysed and afterwards subjected to an electric field in an alkaline environment. Damaged DNA was pulled out from the nucleus towards the positive electrode as a comet tail; its density was related to the degree of DNA damage. Finally, the slides were stained with fluorescence dye and tails were visually scored for 100 cells. The experiment was repeated three times and DNA damage in treated cells was compared to the controls. There was no statistical difference in DNA damage among the herb treated cells and untreated cells in the comet assay. Our data demonstrated that the selected medicinal herbs did not show in vitro DNA protection in the comet assay against oxidant challenge.

DNA protective effect of ginseng and the antagonistic effect of Chinese turnip: a preliminary study.

The genoprotective effect of American and Asian ginseng on human lymphocytic DNA was studied. Using the comet assay, aqueous extracts of both types of ginseng were shown to diminish hydrogen peroxide-induced DNA damage. In contrast, and in accordance with traditional Chinese medicine beliefs, addition of the juice from Chinese turnip counteracted the beneficial effect of ginseng. Results showed that incubating ginseng along with turnip juice abolished the DNA protective effect of both American and Asian ginseng. Although the exact mechanism has not been elucidated, the counteracting effect of turnip on ginseng seems unlikely to be mediated by enzymatic action as the effect was seen with boiled as well as unboiled turnip extract.

Caffeine as a photoprotective agent for diminishing phototoxicity.

Skin whitening with Chinese herbal medicine has been used in ancient Asia. However, phototoxicity of the active ingredient limits the application. The modified comet assay was used in the current study to detect DNA crosslinking induced by phototoxicity. Result showed that caffeine at 5 µmol/L was able to reduce 5-methoxypsoralen-induced phototoxicity with ultraviolet C (UVC) exposure.

A panel study to evaluate quality of life assessments in patients suffering from allergic rhinitis after treatment with a Chinese herbal nasal drop.

Allergic rhinitis impairs quality of life (QOL). To assess the changes in QOL of patients with perennial allergic rhinitis (PAR) after treatment with Allergic Rhinitis Nose Drops (ARND), 35 patients were divided into 2 groups in a randomized, double-blinded and placebo-controlled study, with a cross-over arrangement over 7 weeks, applying ARND or placebo. Group A (n = 20) started with ARND first for 2 weeks followed by a 3-week washout before placebo for the last 2 weeks, while Group B (n = 15) started with placebo first and finished with ARND after washout. The changes in Clinical Symptoms Score (CSS) and QOL were observed. A decrease in CSS was observed in patients of both groups after treatment with ARND, but no change was observed with the placebo. Group A patients also showed significant improvements in complexion and sleep (P < 0.05 for both) after treatment with ARND, but no change with the placebo. Group B patients showed significant improvements in appetite and digestion (P < 0.01) as well as joy (P < 0.05) after cross-over treatment with ARND, but no change with the placebo. ARND may have a therapeutic effect by relieving clinical symptoms and improving the QOL in patients with PAR.

An in vitro study of the antioxidant activities and effect on human DNA of the Chinese herbal decoction 'Liu Wei Di Huang'.

A Chinese medicinal formulation, 'Liu Wei Di Huang', and its individual components have been tested for the genoprotective effect on human DNA by the comet assay. Results showed no DNA protection contributed by this prescription. However, the aqueous extracts of individual herbs, namely Cortex Moutan and Rhizoma Dioscoreae, were able to decrease by 10-15% the DNA stand break from hydrogen peroxide-mediated oxidative stress. This provides insight to further evaluate the interaction among herbs and the search for the active ingredient responsible for the DNA protective effect.

Effects of incense smoke on human lymphocyte DNA.

Incense burning is common in Southeast Asia, where it is a traditional and ceremonial practice in deity worship and paying respect to ancestors. However, incense emissions are an important source of indoor air pollution in Asia, and may induce health problems to those exposed. In this in vitro study the effects of incense emissions on human DNA were investigated using the comet assay. Particulates in smoke from six kinds of incense were trapped in saline or ethanol and human lymphocytes were exposed under controlled conditions. Results showed that DNA damage, including strand breaks, was induced by both aqueous and ethanolic extracts of two samples. The ethanolic extract of one sample induced DNA damage, while no significant DNA damage was found in the remaining three samples. The mechanisms underlying DNA damage induced by incense emissions were also investigated. Catalase (CAT), sodium azide, and superoxide dismutase (SOD) were co-incubated with extract, which exerted significant DNA damaging effects. Results showed that CAT with or without SOD diminished DNA damage, whereas sodium azide did not seem able to reduce DNA damage. Data indicate there are potential adverse health effects of such exposure, particularly for temple workers.

Antioxidant protection of edible oils.

The ability of different cooking oils to withstand oxidation was investigated in relation to their native antioxidant capacity [measured as the Ferric Reducing/Antioxidant Power (FRAP) value]. The antiperoxidation effect of the presence of the Chinese herbs, du-zhong (Cortex Eucommia ulmoides) and ginseng (Panax ginseng C.A. Mayer) in corn oil was also investigated over 26 days' storage at 55 degrees C. Results showed that sesame oil had the highest FRAP value (803 microM), followed by canola oil (400 microM), and sunflower, peanut, corn and olive oils (100-153 microM). Oils with higher intrinsic antioxidant content showed higher resistance to oxidation, although this was not statistically significant. Corn oil to which was added the herbs du-zhong, ginseng or both had increased resistance to oxidation (conjugated diene level and lipid peroxide formation) over 26 days. FRAP values of the oil/herb mixtures decreased during this time, implying utilisation of herbal antioxidants. Results have implications for increasing the shelf-life and usage time of cooking oils by addition of herbs which can increase resistance of the oil to oxidation. Results have implications also for health, as it is possible that ingestion of these herbs could increase resistance of polyunsaturated fatty acids of cell membranes and lipoproteins to oxidation within the body.

Antioxidants in fruits and vegetables: a study of cellular availability and direct effects on human DNA.

The effects of several types of whole fruits and vegetables on human lymphocytic DNA were investigated by using two versions of the comet assay. The total antioxidative capacity, as the FRAP value, and ascorbic acid (AA) content were also measured to explore the relationship between the effect and antioxidant content.

Is the yin-yang nature of Chinese herbal medicine equivalent to antioxidation-oxidation?

It has been suggested that yin-yang theory described in traditional Chinese medicine is somewhat equivalent to the modern theory of antioxidant-oxidant balance. Some yin-tonic Chinese herbal medicines possess antioxidant properties. In this context, the DNA protective effect of 12 yin-tonic and 13 yang-tonic herbs were tested using the single cell gel electrophoresis (comet) assay. Lymphocytes from three healthy subjects were pre-incubated with aqueous herb extract, and the comet assay was performed on treated, untreated, challenged and unchallenged cells in parallel, oxidant challenge being induced by 5 min exposure to hydrogen peroxide. Results using this ex vivo cellular assay showed protection by some herbs. Seven out of 12 yin-tonic Chinese herbs demonstrated decreased DNA damage after treatment while 10 out of 13 yang-tonic herbs showed protection. Among 25 herbs tested, rhizome of Ligusticum sinensis Oliv. and aerial part of Artemisia annua L. demonstrated greatest DNA protective effect. Results indicated that the yin nature of herbs may not be necessarily associated with superior antioxidative effect to yang-tonic herbs, at least in terms of DNA protection against oxidant challenge.

Fasting plasma zeaxanthin response to Fructus barbarum L. (wolfberry; Kei Tze) in a food-based human supplementation trial.

Age-related macular degeneration (AMD) is a common disorder that causes irreversible loss of central vision. Increased intake of foods containing zeaxanthin may be effective in preventing AMD because the macula accumulates zeaxanthin and lutein, oxygenated carotenoids with antioxidant and blue light-absorbing properties. Lycium barbarum L. is a small red berry known as Fructus lycii and wolfberry in the West, and Kei Tze and Gou Qi Zi in Asia. Wolfberry is rich in zeaxanthin dipalmitate, and is valued in Chinese culture for being good for vision. The aim of this study, which was a single-blinded, placebo-controlled, human intervention trial of parallel design, was to provide data on how fasting plasma zeaxanthin concentration changes as a result of dietary supplementation with whole wolfberries. Fasting blood was collected from healthy, consenting subjects; fourteen subjects took 15 g/d wolfberry (estimated to contain almost 3 mg zeaxanthin) for 28 d. Repeat fasting blood was collected on day 29. Age- and sex-matched controls (n 13) took no wolfberry. Responses in the two groups were compared using the Mann-Whitney test. After supplementation, plasma zeaxanthin increased 2.5-fold: mean values on day 1 and 29 were 0.038 (sem 0.003) and 0.096 (sem 0.009) micromol/l (P<0.01), respectively, for the supplementation group; and 0.038 (sem 0.003) and 0.043 (sem 0.003) micromol/l (P>0.05), respectively, for the control group. This human supplementation trial shows that zeaxanthin in whole wolfberries is bioavailable and that intake of a modest daily amount markedly increases fasting plasma zeaxanthin levels. These new data will support further study of dietary strategies to maintain macular pigment density.