Comparison of Phenolic and Flavonoid Content and Antioxidant and Chelating Activities of Rhizophora mangle in Different Anthropogenically-Polluted Coastal Lagoons

Concentrations of organochlorine pesticides (OCPs) in human blood plasma from Hong Kong: Markers of exposure and sources from fish

The concentrations of typical organochlorine pesticides (OCPs) (DDTs, HCHs, PCP-Na, and HCB) were measured to understand distribution and source of OCPs in surface and columnar sediments of Poyang Lake in 2006. And OCPS concentrations in surface sediment in 2017 were made a comparison with those in 2006 at several same sampling sites. OCPs showed higher concentrations in main stream than in river mouths (entrance of river flow into lake) of the lake. The average concentrations of HCHs and DDTs were 4.63 ± 3.86 and 20.15 ± 26.86 ng/g in surface sediments in 2006, respectively. Concentrations of OCPs in 2017 were lower than in 2006, such as HCHs average 1.98 ± 2.04 ng/g and DDTs average 4.87 ± 1.48 ng/g in 2017, indicating historical residual and degradation. The primary isomers of HCHs and DDTs in the lake were α-HCH, γ-HCH and p,p′-DDD, respectively. HCHs were from historical residual and lindane application. DDTs were from historical residual. PCP-Na total concentrations in surface sediment were 77.36 ng/g in 2006 and 44.04 ng/g in 2017. The concentration of HCB residues in surface sediment was 0.92 ± 0.90 ng/g in 2006 and 0.42 ± 0.38 ng/g in 2017. The concentrations of OCPs in columnar sediments showed annual variations, and the peak concentrations occurred in 1953, 1961, 1974, 1982, and 1995, showing close relations with onset of production OCPs pesticide in 1950s and its later prohibition in 1980s and a large number agricultural cultivated land decrease in 1990s in China. The concentrations of HCB in columnar sediments were average 2.33 ± 1.26 ng/g. OCPs of columnar sediments were from historical residues and lindane input. The main contamination of OCPs was PCP-Na and p,p′-DDD in Poyang Lake. On the whole, the combination of surface samples (0–5 cm in depth) and columnar samples (0–38 cm in depth) in a single study would give insight into OCPs pollution levels in different years (temporal resolution) and in different regions (spatial resolution) in Poyang Lake.

Residual levels of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) in karst groundwater in Nanshan Laolongdong were measured using a gas chromatograph equipped with a micro-63Ni electron capture detector to determine the residual characteristics including concentration, distribution, and source of OCPs and PCBs. Results revealed that the total concentration range of OCPs was 34.8-623.2 ng·L-1, and the mean value was 215.6 ng·L-1, among which the total concentration ranges of HCHs, DDTs, and other OCPs were 8.2-23.6, 4.5-363.7, and 22.2-235.9 ng·L-1, respectively, and the mean values were 15.9, 104.5, and 95.3 ng·L-1; the total concentration range of PCBs was 6.0-40.7 ng·L-1, and the mean value was 16.8 ng·L-1. Overall, the pollution of OCPs and PCBs was above average; the results of multiple comparisons revealed that statistically significant differences occurred in the concentration of some OCPs and PCBs. The pollution levels in the water of each sampling point in the study area were quite different; however, the seasonal distribution of OCPs and PCBs was relatively uniform. Source analyses revealed that HCHs' source was the input of lindane in the surrounding environment, DDTs recently originated from illegal use of industrial DDT, other OCPs originated from atmospheric deposition and agricultural input, and PCBs' sources included both historical remains and enterprise production processes. The results of Pearson correlation analyses revealed that some organo-halogen pollutants were homologous or had similar sources and decomposition mechanisms. According to health risk assessment model, drinking water in the study area would not cause obvious harm to human health, but children were more sensitive to pollutants than adults.

Aims: Plants need an appropriate amount of nutrients such as copper for growth and development. However, excess of copper may interrupt plant development and cause stress that led to biochemical compounds being synthesized. The influence of a high copper sulfate concentration on phenolic and flavonoid content in Phyllanthus tenellus plants was investigated.
 Place and Duration of Study: The experiment was conducted in a government compound at MARDI Serdang, Selangor, Malaysia (2° 59' 31.7292'' N 101° 41' 56.706'' E), from April 2021 to Jun 2021.
 Methodology: The experiment was conducted using a vertical column planting system under a side-netted rain shelter. The plants were subjected to 0.5 M copper sulfate sprayed after 60 days of planting and harvested 0.5, 1.5, 3, 6, 12 and 24 h after sprayed for further analysis. Total phenolic content was calculated as mg gallic acid equivalent and total flavonoid content was measured as quercetin equivalent.
 Results: Highest total phenolic and flavonoid content was detected after 0.5 hours of copper sulfate application and started to decrease towards 24 hours after sprayed. Treated samples showed a 1.18-fold increase in total phenolic content and 1.4-fold increase in total flavonoid content compared to control untreated samples after 0.5 hours of sprayed. Control samples showed stability in both total phenolic and flavonoid content throughout the harvesting periods. Phenolic is the major secondary metabolites in Phyllanthus tenellus plants.
 Conclusion: Data revealed that the application of 0.5 M copper sulfate is able to enhance total phenolic and flavonoid content in Phyllanthus tenellus plants. The study suggested that the optimum harvesting time is 0.5 hours after copper sulfate application.

The focus of the present study was to determine the association of the anti-oxidant activity of Costus speciosus (Koen Ex. Retz.) Sm. with the total phe-nolic content and the total flavonoid content. The antioxidant activity of the extracts was quantified by diphenylpicrylhydrazyl (DPPH) assay. The total phenolic content was determined by the Folin-Ciocalteau method and the total flavonoid content was determined by the aluminium chloride method. Among the four extracts of the plant, the ethanol extract exhibited the high-est antioxidant activity and also the highest total phenolic and flavonoid con-tents. A strong correlation was observed between the antioxidant activity and the total phenolic and flavonoid contents. A statistical model was de-rived to explain this dependence and a non-linear association was observed between the antioxidant activity and the total flavonoid content.

Karst wetland plays an important role in the ecological environment; however, due to the existence of karst pipeline, pollutants can threaten the underground environment through the highly developed karst pipeline. Therefore, understanding the pollution characteristics of the karst surface environment is the premise of pollution ecological risk assessment and prevention. In this study, 24 organochlorine pesticides (OCPs) were analyzed to study the concentration, composition, source, and risk of OCPs in water and surface sediments in the Huixian Wetland of Guilin. The results showed that:the concentration of OCPs in water ranged from 3.17 ng·L-1 to 92.50 ng·L-1, and the concentration of OCPs in sediment ranged from 1.16 ng·g-1 to 219.52 ng·g-1, showing the main pollution characteristics of HCHs and DDTs. The concentration of OCPs in water was higher in the wet season than that in the dry season. The concentration of OCPs in sediments was higher in the dry season than that in the wet season. The isomer ratios revealed that OCPs in the study area were mainly derived from long-term degradation residues, and some sites had new input of lindane. Based on Monte Carlo simulation, the human health risk assessment of the study area showed that the 95% quantile carcinogenic risk of OCPs in water was greater than 1×10-6, with potential but acceptable health risk. The non-carcinogenic risk was lower than 1, which indicated that the level of OCPs residues in the water in the study area was not enough to cause non-carcinogenic risk to the human body.

Polyphenols are recognized as significant phytochemicals responsible for the health-promoting properties of honey. Their levels and chemical diversity in honey are mainly dependent on the floral and geographical origin of the honey. In this study, we investigated the influence of altitudinal variation on the total phenolic content (TPC) and total flavonoid content (TFC) of Acacia and Ziziphus honey collected from the Asir region of Saudi Arabia. Samples were collected at four altitudes (113, 317, 511, and 576 meters above sea level). The monofloral origin of the honey was confirmed and characterized by melisopalynological analysis. The Folin–Ciocalteu and aluminum chloride methods were applied for the determination of TPC and TFC, respectively. Results showed that the TPC and TFC values were significantly different between Acacia and Ziziphus honey collected at the same altitudes, and both types exhibited high levels of phenolic compounds. There was a significant positive correlation between altitude and both TPC and TFC in Acacia honey. In contrast, a significant negative correlation was found between altitude and both TPC and TFC in Ziziphus honey. We concluded that altitude significantly influenced the TPC and TFC of honey and that the effects may differ based on floral origin. Further investigation is required to develop a deeper understanding of the relationship between altitude and the content of polyphenols in honey.

Aims: This study aimed to investigate the total phenolic and flavonoid content and DPPH free-radical scavenging activity of Vernonia amygdalina planted in Mekong Delta. The optimized conditions for maceration of pandan leaves included drying method, ratio of pandan leaf powder-to-solvent, and extraction time.
 Methodology: The fresh pandan leaves were divided into two equal portions, subjected to different drying methods: shade and oven drying. The dried leaf powder was macerated in ethanol at room temperature. The maceration was conducted with 3 different ratios of pandan leaf powder-to-solvent (w/v) (1:10, 1:15 and 1:20), and the extraction time was 1, 2 and 3 days. The total flavonoid content was determined using aluminum chloride method whereas the total phenolic content was assessed using Folin-Ciocalteu assay. Meanwhile, the antioxidant activity of the plant extracts was quantitatively evaluated using DPPH test.
 Results: The results indicated that the best conditions for maceration of pandan leaves were 1:10 shade-dried leaf powder-to-solvent ratio in 1-day extraction time. Accordingly, the total flavonoid and phenolic content was found to be the highest value of 130.02 ± 2.24 mg QE/g of dried extract and 100.67 ± 1.76 mg GAE/g of dried extract (p < 0.05), respectively. The lowest IC50 of DPPH free-radical scavenging activity of pandan leaf extract was found to be 0.90 ± 0.02 mg/mL (p < 0.05). In addition, the Pearson’s correlation coefficient between IC50 of DPPH free-radical scavenge activity and total flavonoid content was R2 = 0.74 compared to that of phenolic content with the value of R2 = 0.69, indicating that the IC50 of DPPH free-radical scavenge capacity of pandan leaves was influenced chiefly by flavonoid compounds.
 Conclusion: There was a significant difference in phenolic and flavonoid content and DPPH free-radical scavenging activity between shade-dried and oven-dried pandan leaf extracts.

Blue mussels (Mytilus edulis) collected from 34 locations along the south and east coast of Korea were analyzed for polychlorinated biphenyls (PCBs) and organochlorine (OC) pesticides. Maximum concentrations of PCBs and total OC pesticides were 98.5 and 20.5 ng/g, wet weight, respectively. Extracts were fractionated by Florisil chromatography and each fraction was screened for dioxin-like activity in vitro, using recombinant rat hepatoma cells (H4IIE-luc). Fraction 2 (F-2), which contained hexachlorocyclohexanes, chlordanes, p,p'-DDD, and p,p'-DDT, generally elicited significant dioxin-like activity compared to control, whereas Fraction 1 (F-1), which contained PCBs, p,p'-DDE, and hexachlorobenzene, did not. The greatest magnitude of dioxin-like response observed was 44% of the maximum response elicited by a 2,000 pM 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) standard. The relatively low magnitudes of dioxin-like response observed for F-1 samples were consistent with the relatively low PCB concentrations. At concentrations equal to the maximum observed in the mussel samples, neither individual OC pesticides nor a mixture of OC pesticides yielded a significant dioxin-like response in the H4IIE-luc assay. Thus, the concentrations of OC pesticides in F-2 did not appear to have accounted for the dioxin-like activity observed. This suggests the presence of unidentified and/or unknown, acid-stable, dioxin-like compounds in F-2. This study suggests that in vitro bioassays are useful in assessing the contamination of mussels collected from coastal marine locations.

The total phenolic and flavonoid content were assessed in Ficus deltoidea that growing in the greenhouse under four different water field capacity (FC) condition, namely: A40 (40% FC), A60 (60% FC), A80 (80% FC), and A100 (100% FC-control) and in the field, investigated for 6, 9, and 12 months after planting (MAP). This finding showed that the drought stress treatment increased the total phenolic content (TPC) and total flavonoid content (TFC) of F. deltoidea that grown in the greenhouse. The highest TPC of stems extract were obtained on A40 at 12 MAP, whereas the highest TFC of stems extracts found at 6 months MAP. Leaves extract has the higher TPC and TFC on 12 MAP as compared to 6, and 9 MAP. The result showed that the older the plant age of F. deltoidea the higher the TPC and TFC of leaves. At the 12 MAP, the leaves extract has the higher TFC as compared to the stems extract.

Phenolic and flavonoid contents in plants play a great role in scavenging free radicals in the body and act as antioxidants; thus making their determination very vital. Total phenolic and flavonoid contents of the methanol extract of Voacanga africana root bark and its fractions (n-hexane, ethyl acetate and n-butanol) were carried out in this study. The total phenolic content was determined by using Folin-Ciocalteau assay while the the total flavonoid content was determined by the aluminium chloride colorimetric assay method. The result obtained showed that n-hexane fraction of the plant exhibited the highest (116.607±95.13 mgGAE/g) total phenolic content (TPC) at all concentrations followed by ethyl acetate fraction of the plants. The highest total flavonoid content across concentrations (300, 250, 200, 100, 50 and 25 μg/ml) was exhibited by n-hexane fraction (467.143±44.22 mg QE/g). From the results, it was concluded that n-hexane fraction of V. Africana root bark exhibited the highest total phenolic and total flavonoid contents at all concentrations (ppm), followed by ethyl acetate. It could be deduced that V. africana root bark possesses phenolic and flavonoid contents depending on the type of extract or fraction; thus justifying its folkloric use in the treatment of diseases.Keywords: Phytochemicals, Phenols, Flavonoids, Voacanga africana, Root bark, Fraction

Health risk assessment of organochlorine pesticides in soil and water samples from food waste dumpsites

Cross-regional scale studies of organochlorine pesticides in air in China: Pollution characteristic, seasonal variation, and gas/particle partitioning

Moringa stenopetala is a socioeconomic valued tree that is widely available and cultivated in Southern part of Ethiopia. The leaves have been traditionally used as a food source with high nutritional and medicinal values. The present work was carried out to evaluate the effect of thermal treatment on the total phenolic content, total flavonoid content, antioxidant activities and α-amylase inhibition of aqueous leaf extracts obtained from M. stenopetala during maceration and different decoction time interval (5, 10 and 15 min). The total phenolic and flavonoid contents were determined by the Folin-ciocalteu and aluminum chloride methods, respectively whereas antioxidant activities were determined by 2,2-diphenyl-1-picryl-hydrazyl(DPPH) radical scavenging, reducing power, phosphomolybdenum and ferrous ion chelating assays and α-amylase inhibition potential was determined using 3,5-dinitrosalicylic acid method. Total phenolic and total flavonoid contents ranged from 34.35 ± 1.06 to 39.47 ± 1.33 mgGAE/g and 10.44 ± 0.61 to 20.36 ± 0.93 mgQRE/g, respectively. Decoction for 10 min extract showed ferrous ion chelating (92.52 ± 0.17 %), DPPH radical scavenging (91.52± 0.59 %), α-amylase inhibition (69.06 ± 0.14%), ferric reducing power (0.765 ± 0.14) and total antioxidant activity (0.329 ± 0.32), respectively. DPPH, reducing power, total antioxidant and α-amylase inhibition activities showed positive linear correlation (R2=0.853, R2= 0.857 , R2= 0.864 and R2=0.930), respectively with total phenolic content but ferrous ion chelating activity were found to be weakly correlated (R2=0.481). Based on present investigation, it could be concluded that major lose of total phenolic content, antioxidant and α-amylase inhibition activities of the crude leaf extracts of M. stenopetala leaves were observed at decoction time for 15 min. Therefore, to maintain the total phenolic content, antioxidant and α-amylase inhibition activities of leaves, cooking practice should be at the optimum decoction time (5-10 min). Key words: Moringa stenopetala, antioxidant, total phenolic content, α-amylase inhibition.

Surface soil samples were collected in two karst Tiankengs, Dashiwei and Datuo, situated within the Dashiwei Tiankeng group, located in Leye County of Guangxi province, South China. The soil samples were analyzed for 23 kinds of organochlorine pesticides (OCPs) using a gas chromatography electron capture detector device. The results showed that the concentrations of OCPs in soils of Dashiwei Tiankeng ranged from 0.03 to 5.13 ng/g for total OCPs, not detectable (ND) to 0.22 ng/g for Hexachlorocyclohexane (HCHs), and 0.01 to 3.61 ng/g for Dichlorodiphenyltrichloroethane and metabolites (DDTs). Concentration of the total OCPs in soils of Datuo Tiankeng ranged from 0.13 to 14.36 ng/g, ND to 0.39 ng/g for HCHs, and 0.01 to 3.28 ng/g for DDTs. These concentrations indicated that there could be new inputs of HCHs and DDTs from recent application of lindane and dicofol in this area. Further analysis also revealed that the concentration of OCPs at the bottom of both Tiankengs was higher than the top. The variability in concentrations between the top and the bottom was attributed to the “cold trapping effect” for persistent organic pollutants (POPs) in karst Tiankeng topography. The difference in temperature between the top and bottom of Tiankeng is a predominating factor which can cause a POPs “cold trapping effect.” Other environmental factors are proposed to explain the difference in concentration such as humidity, topography (or slope), wind speed, wind direction, solar radiation, vegetation cover, and soil organic matter. The environmental condition of Dashiwei Tiankeng appears to favor the accumulation of OCPs than that of Datuo Tiankeng because Dashiwei Tiankeng is a matured Tiankeng but Datuo Tiankeng is a degraded one. Thus, there is the need for further studies on the environmental factors influencing distribution of OCPs in karst Tiankeng.