Chestnut Peel Research Articles

Evaluation of sustainability of fabrication process and characterization studies of activated carbon nanocatalyst from waste chestnut peels

This study uses waste chestnut peels to synthesize low-cost activated carbon-based catalysts through pyrolysis and calcination, investing distinct structural and compositional variations for sustianble application in manufacturing innovation and allied industries. The X-ray diffraction (XRD) analysis indicated sharp crystalline peaks in the calcinated product, contrasting with the amorphous nature of carbon material with some partially crystalline and distorted graphitic phases of the pyrolyzed product. Fourier-transform Infrared spectroscopy (FT-IR) analysis shows the presence of various functional groups such as O–H, C–O, C–H, CO, and CC. The analysis made through the scanning electron microscope (SEM) and transmission electron microscope (TEM) depicted a packed and agglomerated structure with different irregular particle shapes in the calcined carbon, while the sample prepared through pyrolysis exhibited a network-like structure with some interconnected voids. Energy dispersive X-ray (EDX) analysis showed varying carbon content which is found to be 47.41 % in the case of the calcinated sample and 99.7 % in the product prepared through pyrolysis. The calcined carbon exhibited a band gap of 4 eV, while the pyrolyzed carbon showed a higher band gap of 4.8 eV. In addition, the catalyst prepared through the calcination process exhibited significantly higher luminance intensity than that produced through pyrolysis, while both samples showed an excitation-dependent emission property. This work presents two simple methods for synthesizing nanocarbon-based catalysts using waste lignocellulosic biomass. In addition, the optical properties of the resulting nanocarbons suggest that they can be further explored for their applications as catalysts or biosensing agents.

The Application of MgO-Modified Biochars for the Immobilization of Ni, Cu, Pb, and Cr in Stone Crushing and Mining-Polluted Soil

The objective of the present study was to investigate the impact of MgO 0.5 g/kg loaded in different organic waste materials on the properties of the modified biochars obtained. The waste materials included tea waste, wood waste, water chestnut peel, and pomegranate peel, which were used to create tea waste MgO-modified biochar (TWMgO-MBC), wood waste MgO-modified biochar (WSMgO-MBC), water chestnut peel MgO-modified biochar (WCMgO-MBC), and pomegranate peel MgO-modified biochar (PPMgO-MBC). All the MgO-modified biochars were prepared at 600 °C for 2 h and applied at 0.5 and 1% doses for the immobilization of Ni, Cu, Pb, and Cr in stone crushing and mining-polluted soil and the reduction in their uptake by pearl millet (Pennisetum glaucum) plant. The greatest fresh and dry biomasses were observed at 45.04% and 31.29%, respectively, with the application of TWMgO-MBC 1% in stone-crushing-polluted soil. The highest degree of immobilization of Ni (76.67%) was observed for the WSMgO-MBC 1% treatment, Cu (73.45%) for WCMgO-MBC 1%, Pb (76.78%) for WSMgO-MBC 1%, and Cr (70.55%) for WCMgO-MBC 1%, in comparison with the control. The maximum uptake of Ni, Cu, Pb, and Cr in the shoot of pearl millet was reduced by 78.43% with WSMgO-MBC 1%, 75.06% with WSMgO-MBC 1%, 90.81% with WCMgO-MBC 1%, and 85.71% with WSMgO-MBC 1% as compared with the control. The greatest reduction in Ni, Cu, Pb, and Cr in the root of pearl millet was observed at 77.81% with WSMgO-MBC 1%, 68.09% with WCMgO-MBC 1%, 84.03% with WCMgO-MBC 1%, and 88.73% with WCMgO-MBC 1%, in comparison with the control. The present study demonstrated that the TWMgO-MBC 1% treatment was highly effective for improving plant growth, while the WSMgO-MBC 1%, and WCMgO-MBC 1% treatments were found to be highly effective for immobilizing heavy metals in polluted soils, thus facilitating safe crop cultivation. Future studies should concentrate on the long-term application of MgO-modified biochars for the remediation of multimetal-polluted soils.

Synergistic co-catalytic nanozyme system for highly efficient one-pot colorimetric sensing at neutral pH: Combining molybdenum trioxide and Fe(III)-Modified covalent triazine framework

This study investigates the co-catalytic capabilities of MoO3 nanosheets in enhancing the enzyme-like catalytic activity of a two-dimensional ultrathin Fe(III)-modified covalent triazine framework (Fe-CTF) under neutral pH conditions. The unique physicochemical surface properties and two-dimensional structures of Fe-CTF enable the direct immobilization of native enzymes (glucose oxidase (GOD) and xanthine oxidase (XOD)) through adsorption, eliminating the need for chemical processes. Efficient immobilization of the native enzymes within the Fe-CTF/GOD(XOD) hybrid is achieved through multipoint attachment involving various interactions. The Fe-CTF/MoO3 co-catalytic system exhibits enzyme-mimicking activity at neutral pH and, when combined with the high catalytic activity of the immobilized native enzymes, enables the development of a colorimetric method for glucose detection. This method demonstrates excellent facilitation, rapidity, sensitivity, and selectivity, with a linear detection range of 50–1000 μM and a limit of detection of 8.8 μM for glucose. Furthermore, a straightforward one-pot colorimetric method is established for screening XOD inhibitors. The inhibitory potential of a crude extract derived from Chinese water chestnut peel on XOD activity is evaluated using this method. The findings of this study pave the way for the utilization of nanozyme/native enzyme hybrids in pH-neutral conditions for one-pot colorimetric sensing. This work contributes to the advancement of enzyme-based sensing technologies and holds promise for various applications in biosensing and biomedical research.

Pyrolysis of low-value waste Trapa natans peels: An exploration of thermal decomposition characteristics, kinetic behaviour, and pyrolytic liquid product

The current work seeks to maximise the bio-oil yield by optimizing the experimental conditions and process parameters for the pyrolysis of water chestnut peels (WCP). The pyrolysis process was carried out in a stainless steel reactor to produce the pyrolysis product. The kinetic analysis was carried out using the model-free techniques such as Ozawa-Flynn-Wall (OFW), Vyazovkin (VZK), and Kissinger-Akahira-Sunose (KAS), while the thermal degradation profile was measured using a thermogravimetric analyzer (TGA) at dynamic heating rates (10, 15, and 20 °C min−1). Additionally, Gas Chromatography (GC) was used to study the non-condensable gases, whereas biochar was characterized according to its physicochemical properties. The results of the kinetic analysis exhibited that utilising the KAS, OFW, and VZK, the average apparent activation energies of WCP were obtained to be 344.37, 337.10, and 325.10 kJ mol−1, respectively. The thermal pyrolysis results revealed that the highest bio-oil yield (42.20 wt%) was achieved at 600 °C temperature, 25 °C min−1 heating rate, and 6 cm bed height. According to GC results, the hydrocarbon levels increased as the temperature increased. Biochar's suitability for usage in various industrial applications was validated by the findings of its characterization.

THE IMPACT OF CHESTNUT VARIETY ON RECOVERY OF POLYPHENOLS FROM PEELS PRETREATED BY OHMIC HEATING OPTIMIZED BY RESPONSE SURFACE METHODOLOGY

The purpose of this study was to optimize ohmic heating (OH) conditions using response surface methodology (RSM) for maximum recovery of polyphenols from industrial chestnut peel waste. Box-Behnken design (BBD) was applied to investigate the effects of three independent variables, namely electric field (V/cm), heating time (sec) and salt concentration (%). From RSM, optimum pretreatment conditions were obtained as 20 V/cm, 100 sec and salt concentration of 0.32%. Three chestnut peels were pretreated by these optimal conditions and their polyphenols were extracted using different solvents. Polyphenol contents and antioxidant capacities of peel extracts were dependent on the variety and extraction solvents used. HPLC analyses showed that ellagic acid was the most abundant phenolic compound in all varieties. OH pretreatment had a positive effect on extraction. Additionally, alcoholic extraction had a better recovery effect compared to water. The peel waste of Kiraz variety was found to be a good source for polyphenols.

Bioactive Antioxidant Compounds from Chestnut Peels through Semi-Industrial Subcritical Water Extraction.

Chestnut peels are a poorly characterized, underexploited by-product of the agri-food industry. This raw material is rich in bioactive compounds, primarily polyphenols and tannins, that can be extracted using different green technologies. Scaling up the process for industrial production is a fundamental step for the valorization of the extract. In this study, subcritical water extraction was investigated to maximize the extraction yield and polyphenol content. Lab-scale procedures have been scaled up to the semi-industrial level as well as the downstream processes, namely, concentration and spray drying. The extract antioxidant capacity was tested using in vitro and cellular assays as well as a preliminary evaluation of its antiadipogenic activity. The temperature, extraction time, and water/solid ratio were optimized, and the extract obtained under these conditions displayed a strong antioxidant capacity both in in vitro and cellular tests. Encouraging data on the adipocyte model showed the influence of chestnut extracts on adipocyte maturation and the consequent potential antiadipogenic activity. Chestnut peel extracts characterized by strong antioxidant power and potential antiadipogenic activity were efficiently obtained by removing organic solvents. These results prompted further studies on fraction enrichment by ultra- and nanofiltration. The semi-industrial eco-friendly extraction process and downstream benefits reported here may open the door to production and commercialization.

OPTIMIZATION OF EXTRACTION OF POLYPHENOLS FROM CHESTNUT WASTE PRETREATED BY OHMIC HEATING USING BOX-BEHNKEN DESIGN

Chestnut processing produces a large amount of waste peels, which contain considerable polyphenols. The aim of this research was to optimize the extraction method for phenolic compounds from industrial chestnut peel pretreated by ohmic heating (OH) by using response surface methodology (RSM). Box-Behnken design (BBD) was used to investigate the effects of three independent variables; namely, extraction time, solid to solvent (S/S) ratio, and temperature, on total phenolic content (TPC) and antioxidant capacity (AC). All independent variables influenced the TPC and AC of the peel extracts. The optimum extraction conditions found were 22.02 min, 1/39.70 (w/v), and 60 °C for extraction time, S/S ratio, and extraction temperature, respectively, resulting in the highest TPC of 34.83 mg GAE/g dry matter (DM) and AC of 35621.38 mmol ascorbic acid equivalent (AEAC)/100 g DM by DPPH. This study showed that water was highly successful for the extraction of polyphenols from the pretreated chestnut peel.

Valorisation of agricultural by-product: Optimisation of alcohol-based extraction of polyphenols from chestnut peel using Box-Behnken Design

In the present work, solvent concentration, extraction time, and solid to solvent (S/S) ratio were evaluated in order to recover the majority of polyphenols from chestnut peel waste using ethanol and methanol. Extraction method for polyphenols from peel pre-treated by ohmic heating (OH) was optimised using response surface methodology (RSM). The effect of these independent variables on total phenolic content (TPC) and antioxidant capacity (AC) was studied using Box-Behnken Design (BBD). A second-order polynomial model provided a satisfactory fit to the experimental data with a high coefficient of determination (R2) value. Results showed that S/S ratio and solvent concentration were generally significant variables during extraction in terms of TPC and AC. The optimum extraction conditions were obtained as 1/10 of S/S ratio and 60% of solvent concentration for both solvents. As the optimum extraction time, 82.41 min for ethanolic extraction and 116.97 min for methanolic extraction were selected. Under these optimal conditions, TPC values of the ethanolic and methanolic extracts were found to be 39.02 and 38.79 mg gallic acid equivalents per gram of dry matter (mg GAE/g DM), respectively, thus indicating highly close agreement to the predicted values. Consequently, the effectiveness of the solvents used was found to be very similar to each other. The OH pre-treatment appeared to be a promising technique for polyphenolic extraction from industrial wastes.

Chestnut peels and wheat bran at different water level influence the physical properties of pan bread

In breadmaking, dietary fibres are used to improve the nutritional quality of the final products; on the other hand, they may affect the physical and sensory properties. This work aimed to the evaluate, on pan breads, the effect of substituting 3 g of wheat flour with an equivalent amount of fibre rich ingredients: chestnut peels (CP) or wheat bran (WB), in comparison to a traditional wheat bread formulation (C). The effect of four levels of added water (54, 60, 66, 71 g/100 of flour) was also tested. The fibre content of CP (33%) and WB (42%) affected their water binding capacity and, consequently, the quality of the final loaves, according to the different water addition levels. In bread crumb, water content and water activity increased proportionally to the water addition levels, being instead in the crust also affected by the presence of fibres: lower water retention capacity was observed for CP, in comparison to WB and C. The loaf volume resulted higher for C in comparison to WB and CP, in relation to the larger dimensions of the crumb pores, probably due to the interfering effect of fibres during the development of the gluten network. Crumb hardness resulted higher for C at low water addition levels, being instead higher for CP at high water addition levels. CP showed a darker and redder colour, than both WB and C bread, for the presence of the brown pigments carried by chestnut peels. PCA analysis confirmed that more water is required for both the fibre-enriched breads to show characteristics similar to the control loaves.

Evaluation of the Potential of Agro-Industrial Waste-Based Composts to Control Botrytis Gray Mold and Soilborne Fungal Diseases in Lettuce

Composts are widely used in horticulture as organic amendments to improve the properties of soils. Composts have also been reported to enhance the disease suppressive potential of soils and, therefore, could be used as a strategy for managing plant diseases. The aim of this study was to test the ability of soils amended with four different agro-industrial waste-based composts (chestnut peels and shells, spent coffee grounds, grape marc, and olive leaves) to inhibit the growth and activity of Botrytis cinerea and several soilborne pathogens. First, the capacity of aqueous compost extracts to inhibit the growth of Botrytis cinerea and five soilborne fungi was evaluated in vitro using a broth macrodilution method. Second, lettuce plants were grown on soils amended with composts and inoculated either with B. cinerea or the soilborne fungus Fusarium oxysporum Schlechtendahl isolated from lamb’s lettuce. The determination of minimal inhibitory concentrations indicated that none of the composts inhibited the mycelium growth of the selected fungal pathogens. However, the pathogens did not cause any damage on plants grown on the chestnut- and olive-based composts. Lettuce yields were also highest for plants grown with composts made from chestnut and olive, irrespective of the amount of compost incorporated into soils (5% or 10%, weight basis). The grape-based compost also exhibited a fertilization effect, although the effect was associated with increased Fusarium wilt severity. Both N immobilization and symbiosis with the compost’s microflora were used to explain the pathogenicity of F. oxysporum Schlechtendahl in response to amendment with composts made from grape and coffee wastes. The beneficial effects of the chestnut- and olive-based composts reported in this study could be exploited in strategies aimed at reducing reliance on synthetic pesticides for the control of fungi in lettuce cultivation.

Water Chestnut Peel Facilitated Biogenic Synthesis of Zinc Oxide Nanoparticles and their Catalytic Efficacy in the Ring Opening Reaction of Styrene Oxide

AbstractSustainable initiatives using various biologically active plant materials have been receiving huge amount of attention in the immediate past. Herein, we present the plant mediated synthetic methodology for preparing zinc oxide (ZnO) nanoparticles (NPs) via a greener protocol using water chestnut peel (WCP), an agricultural bio‐waste whose versatility is well known both behaving as a stabilizing and reducing agent. This method of synthesis of ZnO NPs ensures a cost competitive, non‐toxic, economically viable and environmentally benign pathway while using WCP as efficient scaffolds. The crystalline nature and morphology of as synthesized NPs were confirmed using Powder X‐ray Diffraction (PXRD) and Scanning Electron Microscopy (SEM). Biogenically synthesized NPs have average crystalline size 20.49 nm and irregular spikes morphology. Furthermore, the biogenically synthesized ZnO NPs were utilized for catalysing the ring opening reaction of styrene oxide from aniline and aniline derivatives enabling the reaction reach up to 99 % yields. Motivated by the excellent conversion of ring opening reaction the biogenically synthesized catalyst has also been explored to earmark their versatility and efficiency for facilitating numerous organic transformations which simultaneously emphasise their role in safeguarding the environment.

Structural characterization of polysaccharides with potential antioxidant and immunomodulatory activities from Chinese water chestnut peels

Chinese water chestnut peels are a kind of vegetable processing waste containing many active components such as polysaccharides, the structure of which remains unknown. To elucidate the structure of polysaccharides from Chinese water chestnut peels, two polysaccharides named WVP-1 and WVP-2 were isolated. WVP-1 (3.16 kDa) consisted of mannose (1.75 %), glucose (84.69 %), galactose (6.32 %), and arabinose (7.24 %), while WVP-2 (56.97 kDa) was composed of mannose (3.18 %), rhamnose (1.52 %), glucuronic acid (1.42 %), galacturonic acid (4.83 %), glucose (11.51 %), galactose (36.02 %), and arabinose (41.53 %). Linkage and NMR data indicated that WVP-1 was composed mainly of →4)-α-d-Glcp(1→ and a certain proportion of →3)-β-d-Glcp-(1→, including linear and branched polysaccharides simultaneously. WVP-2 was a pectin-like polysaccharide with →4)-α-d-GalpA6Me-(1→ units and the branch points of →3,4)-α-l-Arap-(1→, →3,6)-β-d-Galp-(1→. WVP-2 exhibited stronger potential antioxidant and immunomodulatory activities than WVP-1 in vitro. These results provide a foundation for the further study of polysaccharides from Chinese water chestnut peels.

Adsorption of Cr(VI) Ions using Activated Carbon Produced from Indian Water Chestnut (Trapa natans) Peel Powder

The indiscriminate discharge of heavy metals into water and soil from anthropogenic practices is becoming prominent threat to the environment. Heavy metals like chromium, cadmium, lead, arsenic, nickel etc. are heavily toxic and carcinogenic in nature. This study emphasizes the adequacy of activated water chest nut (Trapa natans) peel powder as a new adsorbent material for removal of chromium(VI) metal ions. Adsorption experiments were performed in batch process. Various process parameters like contact time, temperature, solution pH, dose of adsorbent, metal ion concentration etc. were optimized. The physico-chemical properties of adsorbent material were characterized by FTIR and XRD. The morphology, topology of adsorbent surface was characterized by scanning electron microscopy (SEM) and Brunauer, Emmett and Teller (BET) which revealed a highly porous structure and available specific surface area. The adsorption capacity (maximum) was counted as 59.17 mg/g and specific surface area was found 23.467 m2/g at a pH 7. The adsorption process for Cr(VI) ions was in a good agreement with Langmuir isotherm. The process also followed pseudo second order kinetics. The obtained result shows that activated water chest nut (Trapa natans) peel powder (AWCPP) can be a hopeful low-cost and eco-friendly bio-adsorbent for removal of Cr(VI) metal ions and also better adsorbent than other various reported adsorbents.

Chestnut peels: from a food waste to a valuable and functional ingredient for cereal-based products.

In the last decade, research dealing with the use of chestnut has received considerable interest due to chestnut’s promising potential to produce high quality and healthy products with high nutritional value. It can be consumed as fresh, boiled, or roasted. Besides, chestnut is also ground into flour which can be used in the production of diverse high quality products such as bread, cookie, cake, breakfast cereals and also pasta. A new perspective may be the use of the chestnut pericarp, now considered a waste and that represents from 6 to 10 % of the fresh fruit weight, in formulations for cereal-based products. The use of this by-product, naturally rich in antioxidants and fibers, may represent a way to enhance the chestnut supply chain, making it more sustainable, as well as giving an improved nutritional contribution to the chestnut products. In the present research work, feasibility of the addition of chestnuts’ pericarp in several cereal-based products was studied, particularly bread, biscuits and pasta. Studied products were prepared both with wheat flour and in a gluten free version. Chestnut peels showed a great water absorption capacity with great effects on dough rheological properties regardless the product. Similarly, chestnut peels deeply influenced the appearance of the enriched products with a darker colour and the presence of brown particulates. Moreover, chestnut peels enhanced also total antioxidant content of all tested products. In general, chestnut peels showed many challenges in gluten-free formulations as it competed with other thickening agents for water and hindered the formation of a network responsible of the final product structure. Finally, considering all the tested products, the optimal chestnut peels addition varied from 3 g/100g to 7 g/100g of the recipe.

Effectiveness of Local Waste Materials as Organic-Based Coagulant in Treating Water

The adequacy of chemicals as coagulants such as alum is all around perceived. Nevertheless, there are numerous drawbacks related with the use including high operational costs, impeding impacts on human wellbeing and generation of huge sludge volumes. In this manner, it is crucial to supplant these chemical coagulants with organic-based coagulants to minimize the downsides. Therefore, the aim of this study is to identify the suitability of selected local wastes in becoming organic-based coagulant as to treat raw water. Regarding choice of organic-based coagulants, this study focused on the local waste materials, which are chestnut peels, bagasse and maize cobs. These waste materials were prepared by washing, drying, grinding lastly sieving in obtaining powder of coagulants ready to be used. A jar test was then performed to decide the effect of individual characteristic coagulants on the effectiveness of turbidity removal under different working variables of pH and coagulant dosage. Based on the findings, bagasse contributed to the highest yield of 79.5% followed by chestnut and maize cob. From the jar test experiments, the optimum dosage of 90 mg/L and pH 7.5 was obtained. At these optimizations, highest turbidity removal of 97.3% was recorded by bagasse compared to the other tested natural coagulants. This showing that bagasse as one of the representatives of organic wastes has the potential to physically treat the water. Keywords: Organic-based coagulant; Organic wastes; Coagulant dosage; Turbidity removal.

Composition of phenolic and antioxidant activity of water chestnut peel during digestion in vitro as affected by blanching time

ABSTRACT Water chestnut peels have good antioxidant activity. The effects of simulated gastric fluid (SGF) and intestinal fluid (SIF) fluid digestion in vitro on the active substance and antioxidant activity of water chestnut peels that were pre-treated using different boiling times (P10 and P30) were investigated. The results showed that the SGF obviously increased both the total phenolic content and total flavonoid content of water chestnut peels. The SGF digestion significantly enhanced both the FRAP and ABTS antioxidant capacity of water chestnut peels only blanched with P10. However, the SIF digestion significantly increased the FRAP and ABTS antioxidant capacity of all water chestnut peels regardless of whether these were pre-treated or not. The HPLC results showed that the simulated digestion in vitro enhanced the flavonoids content of the peels. Water chestnut peels could be used as an inexpensive source of natural functional food ingredients.

Removal of RY42 anionic dye pollutant from aqueous solution using novel reusable adsorbent prepared from water chestnut peel and fruit

Herein a novel low-cost reusable adsorbent namely water chestnut (WCN) peels and fruit were used for the dye polluted wastewater treatment. Moreover, to enhance the adsorption efficiency of WCN peel and fruit it surface was modified with sodium dodecyl sulphate, whereas surface area of sample was changed via immobilizing the sample in to beads using polyvinyl alcohol- Sodium alginate. Surface modification and change in surface area reduced the adsorption potential of WCN peel and fruit for reactive yellow 42 dye as compared to unmodified sample of WCN. A distinct change in surface morphology after surface modification was observed by scanning electron microscopy. At optimized concentration of dye (50 mgL-1) equilibrium was attained within 120 minutes, kinetic data obtained was well interpreted by pseudo-second order kinetic model. Langmuir and Freundlich isothermal models were applied to explain isothermal data. Statistical analysis was done using regression line. A 0.01 M NaOH solution successfully eluted the dye from adsorbent, confirming it as reusable adsorbent

Enzyme-assisted ultrasonic-microwave synergistic extraction and UPLC-QTOF-MS analysis of flavonoids from Chinese water chestnut peels

Chinese water chestnut [Eleocharis dulcis (Burm. f.) Trin. ex Hensch] peels (CWCPs) were a kind of vegetable waste and the present work was focusing on its comprehensive exploitation and utilization. Enzyme-assisted ultrasonic-microwave synergistic extraction (EAUMSE) of flavonoids from CWCPs was investigated, along with their qualitative and quantitative analysis using a combination of ultra-performance liquid chromatography-photodiode array (UPLC-PDA) and quadrupole-time-of-flight mass spectrometry (QTOF-MS). An optimal yield of 1.48% (w/w) was achieved with a 2:1 ratio (w/w) of cellulase and pectinase, 1.5% enzyme concentration, 5.0 pH, 50 °C hydrolysis temperature, 2 h hydrolysis time, with ethanol and 0.1 mol/L NaH2PO4 buffer (2:1, v/v) mixture as solvent, ultrasound and microwave power was 50 and 200 W, respectively, and 60 s extraction time. The flavonoid yield by EAUMSE was 26.50%, 22.31% and 12.98% higher than that by solvent extraction (SE), ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE), respectively. Sixteen flavonoids were characterised, including four new ones, with the major flavonoids being luteolin (249 mg/100 g DW), eriodictyol (97 mg/100 g DW), 6-methylluteolin (74 mg/100 g DW) and fisetin (46 mg/100 g DW). The EAUMSE was an effective and green method for flavonoid extraction in the functional food and pharmaceutical industries.

Antitumor, Antioxidant, and Nitrite Scavenging Effects of Chinese Water Chestnut (Eleocharis dulcis) Peel Flavonoids.

The preparation, quantification, and characterization of flavonoid compounds from Chinese water chestnut peel (CWCP) flavonoid extract and ethyl acetate fraction (EF), n-butanol fraction, and water fraction were studied. Among these, EF showed the maximum free radical levels (IC50 values of 0.36, 0.40, and 0.37 mg/mL for DPPH•, ABTS•+ , and •OH, respectively), nitrite scavenging effects (IC50 = 1.89 mg/mL), and A549 cell inhibitory activities (IC50 = 776.12 μg/mL) with the highest value of total flavonoid content (TFC, 421.32 mg/g). Moreover, the contents of 8 flavonoids in this fraction were quantified using high-performance liquid chromatography, and fisetin, diosmetin, luteolin, and tectorigenin were the 4 major flavonoids with levels of 31.66, 29.91, 13.69, and 12.41 mg/g, respectively. Luteolin produced a greater inhibition of human lung cancer A549 cells (IC50 = 59.60 μg/mL) than did fisetin, diosmetin, and tectorigenin. Flow cytometry revealed that the cellular mechanisms of luteolin inhibition of A549 cells were achieved via the induction of cell proliferation arrest at G1 phase and apoptosis/necrosis. Our findings suggest that flavonoids are closely associated with antitumor, antioxidant, and nitrite scavenging effects of CWCP.

Inhibition of lipopolysaccharide-induced neuroinflammatory events in Bv-2 microglia by chestnut peel extract

Purpose: To evaluate the protective effects of chestnut (Castenea cranata Siebold & Zucc., Fagaceae) peel extract on stimulated BV-2 microglial cells as well as its anti-oxidant properties.Methods: The ethyl acetate fraction of C. cranata peel (CCP) extract was used in the study to evaluate the anti-neuroinflammatory effects in BV-2 microglial cells. Cell viability was performed by 3-(4, 5- dimethylthiazol-2-yl)-2, 5- diphenyl-tetrazolium bromide (MTT) assay. Lipopolysaccharide (LPS) is used to activate BV-2 microglia. Nitric oxide (NO) levels were measured using Griess assay. Inducible NO synthase (iNOS) expressional levels were measured by Western blot analysis. Tumor necrosis factoralpha (TNF-α) production was evaluated by enzyme-linked immunosorbent assay (ELISA). Anti-oxidant properties were evaluated by 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging assay.Results: LPS-activated excessive release of NO in BV-2 cells was significantly inhibited (p < 0.001 at 100 μg/mL) by CCP extract. LPS-induced excessive production of inflammatory mediator such as iNOS was also significantly attenuated by CCP extract. Further, CCP extract significantly and dose dependently inhibited the TNF-α levels in LPS-induced BV-2 microglial cells (p < 0.05 at 20 μg/mL, p < 0.01 at 40 μg/mL and p < 0.001 at 80 and 100 μg/mL). CCP extract also scavenged DPPH radicals in a dose-dependent fashion (p < 0.05 at 0.01 mg/mL and p < 0.001 at 0.1 and 1 mg/mL) with an IC50 value of 0.08 μg/mL.Conclusion: Data from this study indicate that CCP extract attenuates neuroinflammatory responses in LPS-activated BV-2 microglia by inhibiting excessive production of pro-inflammatory mediators such as NO, iNOS and TNF-α. The strong anti-oxidant effect of CCP extract suggests that it possesses antineuroinflammatory properties.Keywords: Castenea cranata, Chestnut peel extract, DPPH radicals, Anti-oxidant, Neuroinflammation, BV-2 microglia