Simple and sensitive determination of Cr (III), Cu (II) and Pb (II) in tea infusions using AgNPs-modified resin combined with laser-induced breakdown spectroscopy.

The detection of heavy metals in tea infusions is important because of the potential health risks associated with their consumption. Existing highly sensitive detection methods pose challenges because they are complicated and time-consuming. In this study, we developed an innovative and simple method using Ag nanoparticles-modified resin (AgNPs-MR) for pre-enrichment prior to laser-induced breakdown spectroscopy for the simultaneous analysis of Cr (III), Cu (II), and Pb (II) in tea infusions. Signal enhancement using AgNPs-MR resulted in amplification with limits of detection of 0.22 µg L-1 for Cr (III), 0.33 µg L-1 for Cu (II), and 1.25 µg L-1 for Pb (II). Quantitative analyses of these ions in infusions of black tea from various brands yielded recoveries ranging from 83.3% to 114.5%. This method is effective as a direct and highly sensitive technique for precisely quantifying trace concentrations of heavy metals in tea infusions.

Effects of instant controlled pressure drop treatment combined with refractance window drying on infusion quality of made green tea.

BACKGROUND: The study aimed to determine the effects of instant controlled decompression of steam pressure, termed as ICPD (instant controlled pressure drop) on fresh tea leaves, when combined with refractance window drying (RWD) of rolled green teas during green tea manufacturing. The ICPD steam treatment pressure (TP; 0.1-0.3 MPa), treatment time (TT; 10-20 s) and refractance window drying temperature (RWDT; 70-90 °C) were used as the processing parameters for manufacturing of green tea. RESULT: Response surface methodology was employed to enumerate the effects of ICPD process conditions and temperature of RWD on total phenolic content (TPC), total flavonoid content (TFC) and DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity of the green tea infusion. An optimum condition for green tea processing was found at TP 0.2 MPa, TT 20 s with RWDT at 70 °C. In comparison to made green tea manufactured without ICPD treatment, the ICPD treated green tea showed enhanced TPC, TFC and DPPH radical scavenging activity along with better colour and sensory attributes. The microstructural study of ICPD treated green tea samples showed more deformed cell surface integrity, larger stomatal pore size and cracks at the leaf surface in comparison with non-treated green tea sample. CONCLUSION: Present study reveals that an ICPD treatment at 0.2 MPa for 20 s can be used as an alternative to the traditional enzyme inactivation step of hot water treatment, for green tea leaves to improve the infusion quality in terms of increased levels of TPC and TFC and DPPH radical scavenging activity. © 2024 Society of Chemical Industry.

Reducing microplastics in tea infusions released from filter bags by pre-washing method: Quantitative evidences based on Raman imaging and Py-GC/MS.

Microplastics released from plastic-based filter bags during tea brewing have attracted widespread attention. Laser confocal micro-Raman and direct classical least squares were used to identify and estimate micron-sized microplastics. Characteristic peaks from pyrolysis-gas chromatography/mass spectrometry of polyethylene terephthalate, polypropylene, and nylon 6 were selected to construct curves for quantification submicron-sized microplastics. The results showed that microplastics released from tea bags in the tea infusions ranged from 80 to 1288 pieces (micron-sized) and 0 to 63.755 µg (submicron-sized) per filter bag. Nylon 6 woven tea bags released far fewer microplastics than nonwoven filter bags. In particular, a simple strategy of three pre-washes with room temperature water significantly reduced microplastic residues with removal rates of 76 %-94 % (micron-sized) and 80 %-87 % (submicron-sized), respectively. The developed assay can be used for the quantitative evaluation of microplastics in tea infusions, and the pre-washing reduced the risk of human exposure to microplastics during tea consumption.

Correlations of kratom (Mitragyna speciosa Korth.) tea bag preparations and reported pharmacological effects.

ETHNOPHARMACOLOGICAL RELEVANCE: The use of herbal tea infusions is widespread in ethnomedicine throughout the world. One such ethnobotanical is kratom (Mitragyna speciosa Korth., Rubiaceae) which has gained considerable interest as an herbal supplement in recent years in the West beyond its native Southeast Asia. Traditional, kratom leaves are either chewed fresh or made into a tea infusion to treat fatigue, pain, or diarrhea. However, dried kratom leaf powder and hydroalcoholic extracts are more commonly used in Western countries, raising the question of exposure to kratom alkaloids and related effects. AIM OF THE STUDY: A specific kratom tea bag product was analyzed for mitragynine content using tea infusion preparation and methanolic extraction. Consumers of both the tea bag product and other kratom products completed an online anonymous survey to determine demographics, kratom use patterns, and self-reported beneficial and detrimental effects. MATERIALS AND METHODS: Kratom tea bag samples were extracted using pH-adjusted water or methanol and analyzed using an established LC-QTOF method. A modified kratom survey was distributed to consumers of the kratom tea bag products and other kratom products over a 14-month period. RESULTS: Tea infusion extraction of tea bag samples resulted in lower mitragynine levels (0.062-0.131% (w/w)) compared to methanolic extraction (0.485-0.616% (w/w)). Kratom tea bag consumers did report similar, although often milder beneficial effects compared to consumers using other kratom products. Overall self-reported health was better among kratom tea bag consumers whereas improvement of a diagnosed medical condition was less in tea bag consumers compared to those using other kratom products. CONCLUSIONS: Traditional tea infusions of Mitragyna speciosa dried leaves provide benefits to consumers despite substantially lower mitragynine content. These effects may be less pronounced but indicate that tea infusions provide a potentially safer formulation compared to more concentrated products.

Degradation of imidacloprid and acetamiprid in tea (Camellia sinensis) infusion by ultraviolet light irradiation.

The degradation of imidacloprid and acetamiprid in tea infusion by ultraviolet (UV) light irradiation was investigated in this study. Results showed that the influence of UV light irradiation on the quality of tea infusion was controllable and UV light irradiation was effective on the degradation of both pesticides. The maximum removal rates were 75.2% for imidacloprid and 17.6% for acetamiprid after irradiation (650 µW/cm,2 120 min). The degradation of both pesticides followed the first-order kinetics model. Three degradation products were identified for imidacloprid and one for acetamiprid based on liquid chromatography-tandem mass spectrometry analysis. The degradation pathway of imidacloprid involved in the cleavage of C-C bond with the loss of nitro group followed by the hydrogenation, oxidation and hydrolysis, while the degradation of acetamiprid involved in the oxidation at the chlorine atom with the bonding of C atoms at positions 1 and 4 on the pyridine ring. Simultaneously, the toxicity of both pesticides was mitigated by UV light irradiation according to LO2 cell toxicity evaluation. The study provided a low-cost and effective way to reduce imidacloprid and acetamiprid from tea infusion, and it has the potential to be applied to the ready-to drink tea beverage production in industrial scale.

Phenolic-based non-ionic deep eutectic solvent for rapid determination of water soluble neonicotinoid insecticides in tea infusion.

Challenges were raised to established analytical method for monitoring water soluble neonicotinoid insecticide (NEOs) residues in tea infusion. Phenolic-based non-ionic deep eutectic solvent (NIDES) composed by a mixture of DL-menthol and thymol (molar ratio of 1:3) was applied to achieve the determination of selected NEOs. Factors influenced extraction efficiency have been evaluated and molecular dynamics approach was conducted aming to provide a new insight to explain its extraction mechanism. It is found that Boltzmann averaged solvation energy of NEOs was negatively correlated with extraction efficiency. The method validation results indicated good linearities (R2 ≥ 0.99), sensitive LOQs (0.05 µg L-1), high precisions (RSD < 11%) and satisfactory recoveries (57.7%∼98%) at 0.05 µg L-1 âˆ¼ 100 µg L-1. The intake risk of NEOs in tea infusion samples were acceptable which residues in range of 0.1 µg L-1 âˆ¼ 3.5 µg L-1 for thiamethoxam imidacloprid and thiacloprid. This method showed advantages of rapid, green, and easy operation.

Hydrophobic-action-driven removal of six organophosphorus pesticides from tea infusion by modified carbonized bacterial cellulose.

The abuse of organophosphorus pesticides (OPPs) in tea planting makes it easy to transfer from tea into its infusion, bringing potential health risks to consumers. Thus, it is essential to adopt reliable techniques to remove OPPs from tea infusion. In this study, three treatment methods were used to modify carbonized bacterial cellulose (CBC) to improve its adsorption performance. Among them, CBC treated by hydrazine hydrate (N-CBC) had the best adsorption effect, whose removal rate for dicrotophos is 13 times that of CBC. The in-depth study of adsorption mechanism proved that hydrophobic interaction dominated the adsorption of OPPs onto N-CBC. The pseudo-second-order kinetic model and Langmuir isotherm model were more suitable to describe the process. Additionally, there were no significant changes in tea infusion quality after N-CBC treatment. This work clarifies that N-CBC benefitted from simple preparation method, excellent adsorption performance and unique adsorption mechanism has potential applications in tea infusion.

Determination of four aflatoxins on dark tea infusions and aflatoxin transfers evaluation during tea brewing.

In daily tea drinking, little is known on aflatoxin transfers from tea-leaf to infusion during brewing and the actual intake. A verified aflatoxins analytical method on tea infusion is significant to the exposure assessment. Here, an optimal method 3 (M3) was screened and validated on four aflatoxins (B1, B2, G1 and G2) simultaneous determination. Recoveries of AFG1 and AFB1 were 87.37 %±1.99 %-102.03 %±8.62 %, and AFG2 and AFB2 were 83.99 %±8.65 %-100.14 %±1.69 %. The correlation coefficient on the fortified samples determination was > 0.99 for each aflatoxin. In accuracy and precision validation, aflatoxins recoveries in high and low fortified samples were 85.94 %-103.83 %, and RSDs were 2.20 %-9.15 %. Method applicability test showed that the M3 was qualified for six different dark tea types. Extraction rate of 30-days stored AFB1 fortified tea-leaf by acetonitrile-water (84:16, v/v) was < 50 %; meanwhile, only 2.94 % spiked AFB1 was released by ten times tea brewing which indicated that Puerh tea have strong adsorbability to aflatoxin.

Antidiabetic and Toxicological Effects of the Tea Infusion of Summer Collection from Annona cherimola Miller Leaves.

Annona cherimola Miller (Ac) is a plant used in Mexican traditional medicine for the treatment of diabetes. In this work, the tea infusion extracts obtained from 1.5 g of leaf powder from Ac collected in May (AcMa), June (AcJun), July (AcJul), and August (AcAu) were evaluated on streptozocin-induced diabetic (STID) mice and for subchronic toxicity in STID and non-diabetic (ND) mice. In addition, extracts were subjected to high-performance liquid chromatography with diode array detection (HPLC-DAD). Results showed that the tea infusion extract of the sample collected in August (AcAu) exhibited the most significant antihyperglycemic activity during all acute assays. The analysis of the extracts (AcMa, AcJu, AcJul, and AcAu) by HPLC-DAD revealed that flavonoid glycosides, rutin, narcissin, and nicotiflorin were the major components. In addition, the sample AcAu contained the best concentration of flavonoids. In the case of subchronic oral toxicity, the AcAu sample did not cause mortality in STID mice, and histopathological analysis revealed significant improvement in the changes associated with diabetes in the liver and kidneys. These findings suggest that the Ac leaves collected in August may be a source of flavonoids such as rutin, with antidiabetic potential. In addition, these findings support the use of Ac to treat diabetes in traditional medicine.

Antidiabetic Activity of Hot Tea Infusion of Leaves of Moringa stenopetala in Streptozotocin-Induced Diabetic Rats.

Background: Moringa stenopetala is a traditionally used medicinal plant that has been used for the management of different disorders including diabetes in Ethiopia. This study was aimed to assess the antidiabetic activity of hot tea infusion of leaves of Moringa stenopetala in streptozotocin-induced diabetic rats. Methods: Experimental animals were Wistar male rats aged 4-6 weeks weighing 200-250 gram. The animals were maintained in equal light/dark series of laboratory conditions, and the average ambient temperature was 23±2 °C. The hot tea infusion of Moringa stenopetala leaves of different concentrations (as fine and coarse powder decoction), distilled water (10 mL/kg), and 150 mg/kg body weight of metformin were administered to diabetic rats as test, negative control, and positive standard drugs, respectively. Sucrose oral challenge test was also carried out to assess the effect of Moringa stenopetala hot tea infusion on postprandial glucose level. Blood glucose level was measured at 0, 30, 60, 90, and 180 minutes. Statistical analysis was conducted by SPSS package version 23, and the p-value less than 0.05 was declared as level of statistical significance. Results: The phytoconstituents that tested positive in hot tea infusion of Moringa stenopetala leaves were alkaloids, tannins, flavonoids, saponins, and terpenoids. Different experimental groups treated with the hot tea infusion of Moringa stenopetala leaves showed significant reduction of blood glucose level after 30 minutes of hot tea infusion administration. In addition, the hot tea infusion at a different concentration for both fine and coarse powders reduced significantly raised blood glucose level. The present findings revealed that the hot tea infusion has blood glucose-lowering and antioxidant effects with wide safety margin. Conclusion: The findings indicated that the hot tea infusion of the leaves of Moringa stenopetala shows a credible reduction in blood glucose level in rats.

Chemical fingerprinting, comparative in vitro antioxidant properties, and biochemical effects of ginger and bitterleaf infusion.

Botanicals with remarkable pharmacological properties include Zingiber officinale Roscoe [Zingiberaceae] (ginger) and Gymnanthemum amygdalinum (Delie) Sch. Bip [Asteraceae] (bitterleaf). The plants are frequently used as teas and decoctions, and have been studied in the treatment of various illnesses. Thus, this study investigated the in vitro antioxidant activities and chemical fingerprints of ginger and bitter leaf infusions separately and as a combination. In addition, we assessed the effects of the tea infusions on rat liver and kidney indices. The findings from this study showed that the bitterleaf infusion had the highest phenolic content (21.77 ± 3.140 µg gallic acid equivalent/mg) in comparison with that of ginger (15.17 ± 1.50 µg gallic acid equivalent/mg) and their combination (8.81 ± 0.48 µg gallic acid equivalent/mg). The ginger infusion had the highest flavonoid content (547.15 ± 1.17 µg quercetin equivalent/mg), which was preceded by bitterleaf (473.02 ± 10.48 µg quercetin equivalent/mg) and the ginger and bitterleaf infusion (415.08 ± 4.15 µg quercetin equivalent/mg). Furthermore, our results showed that the tea infusions had no significant effect on the liver function indices (ALT and AST) compared to the control. In contrast, the rat plasma urea significantly increased in the groups given bitterleaf and a combination of ginger and bitterleaf infusions, while creatinine significantly decreased in the group that received the combined form of the infusion. The GC-MS analysis of ginger and bitterleaf infusions revealed that n-hexadecanoic acid, oleic acid, and ergosterol were most abundant in the bitterleaf infusion. At the same time, gingerol, 2-butanone, and 4-(4-hydroxy-3-methoxyphenyl) were the most abundant in the ginger infusion. Together, the findings are not only evidence in support of the medicinal value of these plants but also reinforce their prospects as nutriceuticals.

Accumulation of potentially toxic elements in Chinese tea (Camellia sinensis): Towards source apportionment and health risk assessment.

Tea (Camellia sinensis) is a popular beverage that is consumed globally. However, a better understanding of potentially toxic elements (PTEs) content in tea leaves and infusion is necessary to minimize risk on human health. Therefore, 249 tea samples (grown in different areas) covering six types of tea were collected in China to investigate the PTEs contents, identify their potential source and assess the health risk associated with drinking tea. PTE contents in tea leaves across six tea types were ND-0.900 (Cd), 0.005-2.133 (As), ND-5.679 (Pb), ND-13.86 (Cr), 1.601-22.93 (Ni), ND-2.048 (Se), 0.109-622.4 (F), 13.02-269.9 (Rb), 1.845-50.88 (Sr), and 2.796-53.23 (Ba) mg/kg. The result of tea infusion showed that 14.3 %-44.1 % (green tea), 14.5 %-46.7 % (black tea), 10.5 %-25.3 % (dark tea), 13.6 %-34.2 % (oolong tea), 16.9 %-40.7 % (yellow tea), and 19.9 %-35.1 % (white tea) of F were released. All tea types, except green tea, exhibited comparatively low leachability of Cd, As, Pb and Cr in tea infusion. The source apportionment revealed that PTEs in tea leaves mainly originated from soil parental materials, while industrial activities, fertilizer application, and manufacturing processes may contribute to exogenous Se, Cd, As, and Cr accumulation. Health risk assessment indicated that F in tea infusion dominated the health risk. Humans may be exposed to a higher health risk by drinking green tea compared to that of other tea types. Nevertheless, the long-term tea consumption is less likely to contribute to pronounced non-carcinogenic and carcinogenic risks. This study confirmed that tea consumption is an important and direct pathway of PTEs uptake in humans. The health risk associated with drinking tea should be of concern.

Rapid and easy ICP OES determination of selected major, minor and trace elements in Pu-erh tea infusions using the response surface methodology along with the joint desirability function approach.

A new analytical method was proposed for multielement (Al, Ba, Ca, Cu, Fe, K, Mg, Mn, Na, Sr and Zn) analysis of Pu-erh teas infusions by inductively coupled plasma optical emission spectrometry. The Box-Behnken response surface design together with individual desirability functions and the joint desirability function approach was applied to develop experimental conditions of this new procedure, being alternative to high-temperature wet digestion. The procedure involved the samples to be just 5-fold diluted with 1.7 mol L-1 HNO3. The proposed method was precise (relative standard deviations within 2-8%), true (relative errors from -8 to +6%) and guaranteed very good detectability (detection limits within 1-6 ng g-1, except for Ca and Fe). It was used for analysis of infusions of Pu-erh teas as well as to verify the effect of their preparation conditions (steeping water temperature, steeping time).

Optimization of reaction conditions for the design of cereal-based dietary fibers with high antioxidant capacity.

BACKGROUND: Bound antioxidants are distinguished by their strong potential to defend the body against oxidative stress. Cereal bran fractions contain antioxidant compounds bound to dietary fiber, but this only occurs to a limited extent. Increasing the quantity of bound antioxidant compounds using soluble phenolic compounds is thought to be a possible method for designing cereal-based dietary fibers with high antioxidant potential. Certain cereal bran samples (wheat, oat, rye, and rice) were reacted with different concentrations of beverages (green tea infusion, black tea infusion, espresso, and red wine), rich in various soluble phenolic compounds. The interactive effects of parameters (time, temperature, and pH) and the optimum conditions for the reaction were determined using response surface methodology. RESULTS: Green tea infusion (30 g·L-1 ) was found to be the most effective beverage. The pH rather than the time and temperature had significant (O p < 0.0001) effects on the reaction. Neutral or slightly alkaline conditions (pH 7.0-7.9) and mild temperatures (at about 50 °C) were found to be optimum to increase the antioxidant capacity of cereal bran samples. The total antioxidant capacity of oat bran treated with green tea infusion under optimum conditions (53.3 °C, pH 7.4, 60.0 min) reached 226.42 ± 0.88 mmol Trolox equivalent·kg-1 . The free amino groups in cereal bran were also found to decrease (32-95%) after treatment. CONCLUSION: It is possible to design functional cereal-based dietary fibers, rich in bound antioxidant compounds through treatment with green tea infusion under optimum conditions. © 2022 Society of Chemical Industry.

Concentrations, leachability, and health risks of mercury in green tea from major production areas in China.

Green tea has many health benefits and is the most consumed type in China. However, the heavy metals and contaminants in tea can also pose a great risk to human health. In this study, mercury (Hg) concentration in green tea collected from 11 provinces in China was examined. The leaching characteristics of Hg during brewing and the associated exposure to drinkers were also evaluated. Results indicated a low potential of Hg accumulation in green tea. The Hg content of green tea from Wanshan District, Guizhou Province-which has the largest Hg mine in China and is severely contaminated by Hg-could be limited by controlling the harvest time of tea leaves. The average Hg content of green tea from 43 tea production sites in China was only 6.3 ± 6.4 µg/kg dry weight. The brewing experiments of green tea showed that the leaching ratio of Hg was 22.61 ± 7.58% for 40 min of a single brew, and increased to 32.83 ± 12.37% after four rounds (3 min/ round) of brewing. The leaching of Hg from tea leaves was significantly affected by leaching time, temperature, and solid-liquid ratio but not by water hardness. The risk of Hg exposure from green tea intake was found to be very low, with an average hazard quotient (HQ) value of only 1.82 ± 1.85% for a single brew in 40 min and 2.64 ± 2.68% after four rounds of brewing. However, in some highly contaminated areas, with HQ values as high as 43.12 ± 2.41%, green tea intake may still pose a high risk of Hg exposure, and this risk should not be ignored.

Exposure Assessment of Fluoride Intake Through Commercially Available Black Tea (Camellia sinensis L.) from Areas with High Incidences of Chronic Kidney Disease with Undetermined Origin (CKDu) in Sri Lanka.

Fluoride is a beneficial trace element for human health as its deficiency and excess levels can cause detrimental health effects. In Sri Lanka, dry zone regions can have excessive levels of fluoride in drinking water and can cause dental and skeletal fluorosis. In addition to drinking water, traditional habits of tea consumption can cause an additional intake of fluoride in the population. A total number of 39 locally blended black tea samples were collected from a village where chronic kidney disease with undetermined origin (CKDu) is prevalent. In addition, unblended tea samples were obtained from tea-producing factories. The fluoride contents in infusions of 2% weight per volume (w/v) were measured using calibrated ion-selective fluoride electrodes. The mean fluoride content was 2.68±1.03 mg/L in loose tea, 1.87±0.57mg/L in packed tea samples, and 1.14±0.55 mg/L in unblended tea. Repeated brewing of the same tea leaves showed that over 50% of fluoride leached into the solution in the first infusion. An estimate of the daily total average fluoride intake via tea consumption per person is 2.68 mg per day. With groundwater in many dry zone regions in Sri Lanka showing high fluoride levels that exceed 0.5 mg/L, the additional daily intake can rapidly exceed recommended thresholds of 2 mg/day. This can add to adverse health impacts that might also relate to CKDu.

The performance of water-soluble fluoride transformation in soil-tea-tea infusion chain system and the potential health risk assessment.

BACKGROUND: Water-soluble fluoride (WS-F) can be absorbed directly by tea plants from soil and comprises a major source of dietary F in tea consumers. To reveal the WS-F accumulation in tea leaves and assess WS-F health risks, 70 sets of samples including tea leaves at three maturity stages and corresponding topsoil were collected from Xinyang, China. The WS-F contents in tea samples and pH values in soil samples were determined. RESULTS: The contents of WS-F in tea leaves exhibited a positive correlation with leaf maturity. The contents of WS-F in tea leaves showed a positive correlation with WS-F contents in the soil as the soil pH value exceeds 5. All the bud with two leaves samples, 84.29% of the third to sixth leaves samples, and 78.57% mature leaves samples in 5-min infusion tend to be no health threat. The leaching characteristics of WS-F from tea leaves were influenced by the leaf maturity and soaking time. CONCLUSION: Taking measures to control pH and WS-F concentration of plantations soil, as well as drinking tea infusion made from young leaves or reducing soaking time could decrease the WS-F health risk. © 2021 Society of Chemical Industry.

Effect of Ferrous Ion on Heat-Induced Aroma Deterioration of Green Tea Infusion.

Aroma deterioration is one of the biggest problems in processing tea beverages. The aroma of tea infusion deteriorates fast during heat sterilization and the presence of ferrous ion (Fe2+) aggravates it. The underlying mechanism remains unveiled. In this study, Fe2+ was verified to deteriorate the aroma quality of green tea infusion with heat treatment. Catechins were necessary for Fe2+-mediated aroma deterioration. By enhancing the degradation of catechins, Fe2+ dramatically increased the production of hydrogen peroxide (H2O2). Fe2+ and H2O2 together exacerbated the aroma of green tea infusion with heat treatment. GC-MS analysis revealed that the presence of Fe2+ enhanced the loss of green/grassy volatiles and promoted the formation of new volatiles with diversified aroma characteristics, resulting in a dull scent of green tea infusion. Our results revealed how Fe2+ induced aroma deterioration of green tea infusion with heat treatment and could help guide tea producers in attenuating the aroma deterioration of tea infusion during processing.

The pro-apoptotic properties of a phytonutrient rich infusion of A. cherimola leaf extract on AML cells.

Annonaceae family has broad uses in herbal medicine for treatment of several diseases, whether through seeds' or leaves' extracts. The present study investigates the antiproliferative and antitumor activity of Annona cherimola aqueous leaf (AAL) extract/infusion in acute myeloid leukemia (AML) cell lines in vitro. High-resolution LC-MS was first used to analyze the composition of the aqueous extract. Cell proliferation assay, Annexin V staining, cell cycle analysis, dual Annexin V/PI staining, cell death quantification by ELISA, ROS level detection and Western Blotting were then performed to elucidate the therapeutic effects of AAL extract. The results obtained revealed a potent antioxidant activity of AAL extract. Moreover, the extract exhibited dose- and time-dependent antiproliferative effects on AML cell lines by decreasing cell viability with an IC50 of 5.03% (v/v) at 24 h of treatment of KG-1 cells. This decrease in viability was accompanied with a significant increase in apoptotic cell death with cell cycle arrest and flipping of the phosphatidylserine from the inner to the outer leaflet of the cell membrane. The respective overexpression and downregulation of proapoptotic proteins like cleaved caspase-8, cleaved PARP-1 and Bax and antiapoptotic proteins like Bcl-2 further validated the apoptotic pathway induced by AAL on AML cells. Finally, LC-MS revealed the presence of several compounds like fatty acids, terpenes, phenolics, cinnamic acids and flavonoids that could contribute to the antioxidant and anti-cancer effects of this herbal infusion. In addition to the generally known nutritional effects of the Annona cherimola fruit and leaves, the presented data validates the antioxidant and anti-cancerous effects of the leaf infusion on AML cell lines, proposing its potential therapeutic use against acute myeloid leukemia with future in vivo and clinical trials.

Development of a syringe membrane-based microextraction method based on metal-organic framework mixed-matrix membranes for preconcentration/extraction of polycyclic aromatic hydrocarbons in tea infusion.

Inevitably, the residues of polycyclic aromatic hydrocarbons (PAHs) in tea leaves will be transferred to hot tea infusion, constituting a certain drinking risk; consequently, it is imperative to develop rapid, sensitive, and robust approaches for their trace-level detection. Herein, we developed a syringe membrane-based microextraction (SMME) method for preconcentration/extraction of PAHs in tea infusions. This method utilized metal-organic framework-mixed matrix membranes (MOF-MMMs) as adsorbents, which anchored the nanoparticles of MOFs onto the surface of PVDF membrane. The UiO-66 (Zr)-based MMM possessed high Brunauer-Emmett-Teller (BET) surface area (320.5 m2 g-1) and pore volume (0.18 cm3 g-1), thus enhancing extraction/adsorption efficiency. Under optimized conditions, the limits of detection for PAHs reached as low as 0.02-0.08 µg L-1 with extraction recoveries of 85.5-102.1%, and the inter-day and intra-day precision was lower than 8.4% in tea infusions. Consequently, the SMME/HPLC-DAD method shows a great potential in conventional monitoring of PAHs in tea samples.