Determination of anthocyanins, organic acids, and phenolic acids in hibiscus market products using LC/UV/MS.

Hibiscus sabdariffa has gained increasing attention from consumers as a natural, healthy food ingredient, leading to a myriad of available products, yet there is a lack of understanding of the quality and chemical diversity among commercially available hibiscus products. Here, we conducted a survey on the chemistry of 29 hibiscus products (calyces, beverages, and extracts). UHPLC-DAD and UHPLC-QQQ/MS methods with high sensitivity and selectivity were developed to evaluate the chemical profiles pertaining to the sensory attributes (color and taste). Two major anthocyanins (delphinidin-3-sambubioside and cyanindin-3-sambubioside), eight organic acids, and 23 phenolic acids were identified and quantified in hibiscus market products. The results showed that hibiscus samples contained < 0.001-2.372% of total anthocyanins, 0.073-78.002% of total organic acids, and 0.001-1.041% of total phenolic acids, and demonstrated significant variations in market products. This is the first time that an in-depth organic acid profiling was conducted on hibiscus products using UHPLC-QQQ/MS. This method can also be extended to chemical profiling, sensory analysis, quality control, authentication, and standardization of other natural products.

Protective Effects of Polyphenol-Rich Extracts against Neurotoxicity Elicited by Paraquat or Rotenone in Cellular Models of Parkinson's Disease.

Parkinson's disease (PD) is a neurodegenerative disorder involving motor symptoms caused by a loss of dopaminergic neurons in the substantia nigra region of the brain. Epidemiological evidence suggests that anthocyanin (ANC) intake is associated with a low risk of PD. Previously, we reported that extracts enriched with ANC and proanthocyanidins (PAC) suppressed dopaminergic neuron death elicited by the PD-related toxin rotenone in a primary midbrain culture model. Here, we characterized botanical extracts enriched with a mixed profile of polyphenols, as well as a set of purified polyphenolic standards, in terms of their ability to mitigate dopaminergic cell death in midbrain cultures exposed to another PD-related toxicant, paraquat (PQ), and we examined underlying neuroprotective mechanisms. Extracts prepared from blueberries, black currants, grape seeds, grape skin, mulberries, and plums, as well as several ANC, were found to rescue dopaminergic neuron loss in PQ-treated cultures. Comparison of a subset of ANC-rich extracts for the ability to mitigate neurotoxicity elicited by PQ versus rotenone revealed that a hibiscus or plum extract was only neuroprotective in cultures exposed to rotenone or PQ, respectively. Several extracts or compounds with the ability to protect against PQ neurotoxicity increased the activity of the antioxidant transcription factor Nrf2 in cultured astrocytes, and PQ-induced dopaminergic cell death was attenuated in Nrf2-expressing midbrain cultures. In other studies, we found that extracts prepared from hibiscus, grape skin, or purple basil (but not plums) rescued defects in O2 consumption in neuronal cells treated with rotenone. Collectively, these findings suggest that extracts enriched with certain combinations of ANC, PAC, stilbenes, and other polyphenols could potentially slow neurodegeneration in the brains of individuals exposed to PQ or rotenone by activating cellular antioxidant mechanisms and/or alleviating mitochondrial dysfunction.

Protective effects of polyphenol-rich extracts against neurotoxicity elicited by paraquat or rotenone in cellular models of Parkinson's disease.

Parkinson's disease (PD) is a neurodegenerative disorder involving motor symptoms caused by a loss of dopaminergic neurons in the substantia nigra region of the brain. Epidemiological evidence suggests that anthocyanin (ANC) intake is associated with a low risk of PD. Previously, we reported that extracts enriched with ANC and proanthocyanidins (PAC) suppressed dopaminergic neuron death elicited by the PD-related toxin rotenone in a primary midbrain culture model. Here, we characterized botanical extracts enriched with a mixed profile of polyphenols, as well as a set of purified polyphenolic standards, in terms of their ability to mitigate dopaminergic cell death in midbrain cultures exposed to another PD-related toxicant, paraquat (PQ), and we examined underlying neuroprotective mechanisms. Extracts prepared from blueberries, black currants, grape seeds, grape skin, mulberries, and plums, as well as several ANC, were found to rescue dopaminergic neuron loss in PQ-treated cultures. Comparison of a subset of ANC-rich extracts for the ability to mitigate neurotoxicity elicited by PQ versus rotenone revealed that a hibiscus or plum extract was only neuroprotective in cultures exposed to rotenone or PQ, respectively. Several extracts or compounds with the ability to protect against PQ neurotoxicity increased the activity of the antioxidant transcription factor Nrf2 in cultured astrocytes, and PQ-induced dopaminergic cell death was attenuated in Nrf2-expressing midbrain cultures. In other studies, we found that extracts prepared from hibiscus, grape skin, or purple basil (but not plums) rescued defects in O 2 consumption in neuronal cells treated with rotenone. Collectively, these findings suggest that extracts enriched with certain combinations of ANC, PAC, stilbenes, and other polyphenols could potentially slow neurodegeneration in the brains of individuals exposed to PQ or rotenone by activating cellular antioxidant mechanisms and/or alleviating mitochondrial dysfunction.

Acrolein: formation, health hazards and its controlling by dietary polyphenols.

Acrolein, a highly reactive toxic aldehyde, is a common dietary and environmental contaminant which can also be generated endogenously. Exposure to acrolein has been positively associated with some pathological conditions, such as atherosclerosis, diabetes mellitus, stroke, and Alzheimer's disease. At the cellular level, acrolein induces various harmful effects, particularly protein adduction and oxidative damages. Polyphenols are a group of secondary plant metabolites ubiquitously presented in fruits, vegetables, and herbs. Recent evidence has gradually solidified the protective role of polyphenols by working as acrolein scavengers and regulator of acrolein toxicities. This was largely attributed to the ability of polyphenols as antioxidants and sacrificial nucleophiles in trapping acrolein. This review discussed the exposure and toxicity of acrolein, summarized the known and anticipated contribution of polyphenols in ameliorating acrolein contamination and its health hazards.

Volatile metabolites from new cultivars of catnip and oregano as potential antibacterial and insect repellent agents.

Plant based natural products have been widely used as antibacterial and insect repellent agents globally. Because of growing resistance in bacterial plant pathogens and urban pests to current methods of control, combined with the long- and short-term negative impact of certain chemical controls in humans, non-target organisms, and the environment, finding alternative methods is necessary to prevent and/or mitigate losses caused by these pathogens and pests. The antibacterial and insect repellent activities of essential oils of novel cultivars of catnip (Nepeta cataria L. cv. CR9) and oregano (Origanum vulgare L. cv. Pierre) rich in the terpenes nepetalactone and carvacrol, respectively, were evaluated using the agar well diffusion assay and petri dish repellency assay. The essential oils exhibit moderate to high antibacterial activity against three plant pathogens, Pseudomonas cichorii, Pseudomonas syringae and Xanthomonas perforans of economic interest and the individual essential oils, their mixtures and carvacrol possess strong insect repellent activity against the common bed bug (Cimex lectularius L.), an urban pest of major significance to public health. In this study, the essential oils of catnip and oregano were determined to be promising candidates for further evaluation and development as antibacterial agents and plant-based insect repellents with applications in agriculture and urban pest management.

Successive harvests affect the aromatic and polyphenol profiles of novel catnip (Nepeta cataria L.) cultivars in a genotype-dependent manner.

Introduction: Catnip (Nepeta cataria L.) produces volatile iridoid terpenes, mainly nepetalactones, with strong repellent activity against species of arthropods with commercial and medical importance. Recently, new catnip cultivars CR3 and CR9 have been developed, both characterized by producing copious amounts of nepetalactones. Due to its perennial nature, multiple harvests can be obtained from this specialty crop and the effects of such practice on the phytochemical profile of the plants are not extensively studied. Methods: In this study we assessed the productivity of biomass, chemical composition of the essential oil and polyphenol accumulation of new catnip cultivars CR3 and CR9 and their hybrid, CR9×CR3, across four successive harvests. The essential oil was obtained by hydrodistillation and the chemical composition was obtained via gas chromatography-mass spectrometry (GC-MS). Individual polyphenols were quantified by Ultra-High-Performance Liquid Chromatography- diode-array detection (UHPLC-DAD). Results: Although the effects on biomass accumulation were independent of genotypes, the aromatic profile and the accumulation of polyphenols had a genotype-dependent response to successive harvests. While cultivar CR3 had its essential oil dominated by E,Z-nepetalactone in all four harvests, cultivar CR9 showed Z,E-nepetalactone as the main component of its aromatic profile during the 1st, 3rd and 4th harvests. At the second harvest, the essential oil of CR9 was mainly composed of caryophyllene oxide and (E)-ß-caryophyllene. The same sesquiterpenes represented the majority of the essential oil of the hybrid CR9×CR3 at the 1st and 2nd successive harvests, while Z,E-nepetalactone was the main component at the 3rd and 4th harvests. For CR9 and CR9×CR3, rosmarinic acid and luteolin diglucuronide were at the highest contents at the 1st and 2nd harvest, while for CR3 the peak occurred at the 3rd successive harvest. Discussion: The results emphasize that agronomic practices can significantly affect the accumulation of specialized metabolites in N. cataria and the genotype-specific interactions may indicate differential ecological adaptations of each cultivar. This is the first report on the effects of successive harvest on these novel catnip genotypes and highlights their potential for the supply of natural products for the pest control and other industries.

Kinkéliba (Combretum micranthum) Leaf Extract Alleviates Skin Inflammation: In Vitro and In Vivo Study.

Kinkéliba (Combretum micranthum, Seh-Haw in Wolof) is a popular bush tea in West African countries. Although the kinkéliba plant's leaves have been widely consumed for its nutritional and medicinal properties, its benefits on skin health potential have been practically untouched. In human epidermal primary keratinocytes, vitexin and isovitexin-rich kinkéliba extract treatment significantly (p < 0.001) enhanced up to 39.6% of the cell survival rate decreased by UV radiation irritation. The treatment of kinkéliba leaf extracts also reduced the production of UV-induced pro-inflammatory cytokines IL-6 and IL-8 by 57.6% and 42.5%, respectively (p < 0.001), which cause skin redness and skin barrier dysfunction, as well as wrinkles and collagen degradation. The anti-inflammation efficacy of kinkéliba leaf extracts might involve significant inhibition on the levels of cellular reactive oxygen species (ROS) (-70.8%, p < 0.001) and nitrotyrosine (-56.9%, p < 0.05). Further topical applications of kinkéliba leaf extract gel were found to reduce sodium lauryl sulfate (SLS)-induced skin inflammation: at D7, the skin trans-epidermal water loss (TEWL) and skin redness (a* value) were both reduced by 59.81% (p < 0.001) and 22.4% (p < 0.001), compared with D0. In vitro and in vivo data support a new topical application of the kinkéliba leaf as an effective active ingredient for the treatment of skin inflammation, as well as subsequent barrier dysfunction and inflammaging.

Temperature prediction of solar greenhouse based on NARX regression neural network.

Temperature has an important influence on plant growth and development. In protected agriculture production, accurate prediction of temperature environment is of great significance. However, due to the time series, nonlinear and multi coupling characteristics of temperature, it is difficult to achieve accurate prediction. We proposed a method for building a solar greenhouse temperature prediction model based on a timeseries analysis, that considers the time series characteristics and dynamic temperature changes in the greenhouse system. The method would predict the temperature of greenhouse, and provide reference for the temperature change law in protected agriculture. A parameter analysis was performed on the nonlinear autoregressive exogenous (NARX) neural network, and a solar greenhouse temperature time series prediction model was established using the NARX regression neural network. The results showed that the proposed model depicted a maximum absolute error of 0.67 °C, and model correlation coefficient of 0.9996. Compared with the wavelet and BP neural networks, the NARX regression neural network accurately predicted and significantly outperformed in the solar greenhouse temperature prediction model. Moreover, the prediction model can accurately predict temperature trends within the solar greenhouse and is pivotal to obtaining precise control of solar greenhouse temperature.

Investigation of Volatile Iridoid Terpenes in Nepeta cataria L. (Catnip) Genotypes.

Catnip (Nepeta cataria L.) is of scientific interest largely due to the production of nepetalactones, volatile iridoid terpenes with strong arthropod repellent activity. However, the plant can also produce other bioactive volatile iridoids, such as nepetalic acid (NA), nepetalactam (NT) and dihydronepetalactone (DHNL) that have not been studied extensively. Germplasm studies on plants that can produce such compounds are scarce. The present study evaluated the chemical diversity of catnip genotypes with a focus on NA, NT and DHNL. A total of 34 genotypes were harvested at different times over two years. The ethanolic extract of the plants was screened for iridoids by ultra-high-performance liquid chromatography/triple quadrupole mass spectrometry. CR9 × CR3 genotype had the highest value for biomass yield, while cultivar CR9 had the highest value for accumulated NA. Genotype UK.2 had the highest value for accumulated NT yield and CR5 had the highest value for accumulated DHNL. Overall, patented cultivars and elite selections performed better than other less studied genotypes. Harvest time influenced the accumulation of secondary metabolites differentially for the genotypes. This is the first germplasm study with a focus on these iridoid compounds, yet more studies are necessary as genotype characterization is essential for breeding and standardization of products for industry.

Repellency of novel catnip (Nepeta cataria) cultivar extracts against Ixodes scapularis and Haemaphysalis longicornis (Acari: Ixodida: Ixodidae).

Tick bites are a major public health concern due to the vector role that many tick species have in transmitting human pathogens. Synthetic repellents such as N­diethyl-meta-toluamide (DEET) remain the standard for repellency. Still, there is a need for natural commercial alternatives with similar or better properties than DEET. We evaluated the repellency of two extracts, CR3 and CR9, derived for newly developed catnip cultivars on two tick species, Ixodes scapularis and Haemaphysalis longicornis. Dose-response in vitro assays showed that CR3 and CR9 extracts have similar repellency properties to DEET. At a 20% concentration, both CR3 and CR9 extracts exhibited a repellency of 100%. Catnip extracts maintained their repellency properties for at least 8 h. In a two-choice assay, I. scapularis, but not H. longicornis, was more sensitive to CR3 than DEET. In addition, CR3 reduces the life span of I. scapularis, suggesting that it has an acaricidal effect on ticks. In summary, CR3 and CR9 catnip extracts are promising tick repellents that should be further developed, alone or in combination with other tick repellents, and tested for their use as tick repellents for humans.

Role of Polyphenol-Derived Phenolic Acid in Mitigation of Inflammasome-Mediated Anxiety and Depression.

Overexposure to mental stress throughout life is a significant risk factor for the development of neuropsychiatric disorders, including depression and anxiety. The immune system can initiate a physiological response, releasing stress hormones and pro-inflammatory cytokines, in response to stressors. These effects can overcome allostatic physiological mechanisms and generate a pro-inflammatory environment with deleterious effects if occurring chronically. Previous studies in our lab have identified key anti-inflammatory properties of a bioavailable polyphenolic preparation BDPP and its ability to mitigate stress responses via the attenuation of NLRP3 inflammasome-dependent responses. Inflammasome activation is part of the first line of defense against stimuli of different natures, provides a rapid response, and, therefore, is of capital importance within the innate immunity response. malvidin-3-O-glucoside (MG), a natural anthocyanin present in high proportions in grapes, has been reported to exhibit anti-inflammatory effects, but its mechanisms remain poorly understood. This study aims to elucidate the therapeutic potential of MG on inflammasome-induced inflammation in vitro and in a mouse model of chronic unpredictable stress (CUS). Here, it is shown that MG is an anti-pyroptotic phenolic metabolite that targets NLRP3, NLRC4, and AIM2 inflammasomes, subsequently reducing caspase-1 and IL-1ß protein levels in murine primary cortical microglia and the brain, as its beneficial effect to counteract anxiety and depression is also demonstrated. The present study supports the role of MG to mitigate bacterial-mediated inflammation (lipopolysaccharide or LPS) in vitro and CUS-induced behavior impairment in vivo to address stress-induced inflammasome-mediated innate response.

Antiviral activity of aframomum melegueta against severe acute respiratory syndrome coronaviruses type 1 and 2.

Plant-based compounds with antiviral properties against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been identified in Aframomum melegueta through computational models. The seed extract have been traditionally used to treat different illnesses. In this study, ethanolic extracts were prepared for six commercial samples of A. melegueta seeds. Antiviral activity was tested using the XTT cytotoxicity assay and cell-based SARS-CoV-1 and 2 pseudoviral models. The presence of gingerols and other non-volatile components in the seed extracts was determined using an Agilent 1290 UPLC/DAD in tandem with an Agilent 6546 QTOF-MS. Our results showed selective antiviral activity with TI values as high as 13.1. Fifteen gingerols were identified by chromatographic analysis, with 6-gingerol being the dominant component in each seed extract. A combination of 6-gingerol with techtochrysin, previously identified in computational models as a potential active ingredient against SARS-CoV-2, demonstrated additive antiviral activity with CI values between 0.8715 and 0.9426. We confirmed the antiviral activity of A. melegueta predicted through computational models and identified a different compound, 6-gingerol, as a potential active ingredient.

Method development and validation for analysis of phenolic compounds in fatty complex matrices using enhanced matrix removal (EMR) lipid cleanup and UHPLC-QqQ-MS/MS.

Reliable analysis of phenolic compounds in fatty matrices is a challenging task. In this work, a robust analytical method was developed and validated for 55 phenolic compounds employing QuEChERS (quick, efficient, cheap, easy, rugged and safe) and Enhanced Matrix Removal (EMR)-lipid cleanup in 96-well plates for sample preparation, coupled with ultra-high performance liquid chromatography with triple quadrupole mass spectrometry (UHPLC-QqQ-MS/MS). Seven high-fat matrices of pork brain, belly and liver; horse serum, beef, salmon and avocado were explored for method validation and led to promising stepwise recoveries of extraction, clean-up, drying-reconstitution of most analytes ranging from 75% to 113%, and with an accuracy of 78%∼117%, except for six catechin-analogues. The matrix removal efficiency of EMR was determined using UHPLC-quadruple time of flight (QTOF)-MS, and results indicated that 56%∼77% of co-extractives were removed. This method would be readily extended to wide range of applications demanding high-throughput and sensitive analysis of phenolic compounds in fatty samples.

Assessment of lemon juice adulteration by targeted screening using LC-UV-MS and untargeted screening using UHPLC-QTOF/MS with machine learning.

The aim of this work was to develop an approach combining LC-MS-based metabolomics and machine learning to distinguish between and predict authentic and adulterated lemon juices. A targeted screening of six major flavonoids was first conducted using ultraviolet ion trap MS. To improve the prediction accuracy, an untargeted methodology was carried out using UHPLC-QTOF/MS. Based on the acquired metabolic profiles, both PCA and PLS-DA were conducted. Results exhibited a cluster pattern and a separation potential between authentic and adulterated samples. Five machine learning models were then developed to further analyze the data. The model of support vector machine achieved the highest prediction power, with accuracy up to 96.7 ± 7.5% for the cross-validation set and 100% for the testing set. In addition, 79 characteristic m/z were tentatively identified. This work demonstrated that untargeted screening coupled with machine learning models can be a powerful tool to facilitate detection of lemon juice adulteration.

Prevalence, Distribution and IgG Antibody Levels Associated with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Among Health-System and Community-Based Employees and Patients.

BACKGROUND: Following the high morbidity and mortality due to Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infections in New Orleans, Louisiana, we sought to assess progress toward herd immunity. METHODS: Ochsner Health employees and patients who volunteered for Abbott SARS-CoV-2 immunoglobulin G (IgG) antibody test between March 1 and May 1, 2020 were included. We estimated IgG prevalence and used logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI) for variables associated with IgG test status. RESULTS: Of the 13,343 participants with IgG test results, 78.6% were women, 70.6% were non-Hispanic White, 21.1% non-Hispanic Black, 2.9% Hispanic Americans and 5.4% belonged to other races. Overall, 7.99% (95% CI: 7.53-8.45%) of the participants tested IgG positive. In age-, sex- and body mass index (BMI)-adjusted analyses, non-Hispanic Blacks were 2.7-times more likely to test positive than non-Hispanic Whites (OR=2.72; 95% CI: 2.33-3.19). Corresponding ORs (95% CIs) were 1.29 (0.84-1.99) for Hispanic Americans and 1.22 (0.85-1.75) for Other race/ethnicities. Compared to participants in administrative occupations, physician assistants (OR=7.14; 95% CI: 1.72-29.6) and therapists (OR=4.74; 95% CI: 1.49-15.03) were significantly more likely to have IgG antibodies while the association among nurses was not significant (OR=2.35; 95% CI: 0.96-5.77). Relative to 1.40, the test threshold for positivity, our measurements indicate a strong immune response (5.38±1.69), especially among those with a higher BMI. CONCLUSIONS: SARS-COV-2 IgG antibodies were prevalent only in 8% of the participants. IgG prevalence was highest among non-Hispanic Blacks and participants with higher BMI but was lower among older participants.

Changes in polyphenol serum levels and cognitive performance after dietary supplementation with Concord grape juice in veterans with Gulf War Illness.

AIMS: We investigated whether the consumption of Concord grape juice (CGJ) was associated with increased bioavailability of serum metabolites and their potential impact on cognitive performance in Veterans with Gulf War Illness (GWI). MAIN METHODS: Twenty-six veterans were selected from a cohort of 36 enrolled in a 24-week randomized, double-blind, Phase I/IIA clinical trial exploring whether the consumption of Concord grape juice (CGJ) was tolerable and safe in Veterans with GWI and improved cognitive function and fatigue. These 26 veterans were selected based on their completion of the entire 24-week protocol and documented adherence to the study beverage ≥80%. Differences in serum metabolite levels between CGJ and placebo at midpoint and endpoint were evaluated using two-way repeated measures ANOVA with post hoc Sidak's multiple comparison test. Bivariate correlations to assess for possible relationships between change in serum metabolite levels and change in cognitive function as measured by the Halstead Category Test-Russell Revised Version (RCAT) were also conducted. KEY FINDINGS: Seventy-six metabolites were identified and quantified in this study, with three (cyanidin-glucuronide, me-cyanidin-glucuronide, and me-malvidin-glucuronide) found to be significantly higher (p < 0.05) in the CGJ group compared to placebo at 24 weeks. Significant associations between changes in cognitive function and changes in serum levels of epicatechin-sulphate (r = 0.48, p = 0.01) and petunidin-glucuronide (r = 0.53, p < 0.01) from baseline to 24 weeks were also observed. SIGNIFICANCE: Our data suggest that dietary supplementation with CGJ is associated with increased bioavailability of specific phenolic metabolites, some of which may be correlated with cognitive performance.

Dissolution Study on Grape Polyphenol Hard Gelatin Capsule Dietary Supplements.

Methods for a dissolution study by ultra-high performance liquid chromatography/triple quadrupole mass spectrometry (UHPLC-QqQ/MS) analysis of grape polyphenol dietary supplements, namely, grape seed extract (GSE) and resveratrol (RSV) capsules, were developed following the guidance of United States Pharmacopeia (USP) <2040>. Two dissolution media, 0.1 N hydrochloric acid (pH 1.2) and 0.05 M acetate buffer (pH 4.6), were evaluated with dissolution apparatus (USP 1), 100 rpm rotation speed, and 900 ml dissolution medium volume. Dissolution profiling was performed over 120 min. Major phenolic compounds of gallic acid, catechin, epicatechin, and procyanidin B2 were quantitated to obtain the dissolution profile of GSE capsules, and trans-RSV was used for RSV capsules. Results indicated that the released trans-RSV for RSV capsules in both of the dissolution media meets the USP standards, and that for the GSE capsules, all the four marker compounds passed the dissolution test in the HCl medium but did not reach a 75% release within 60 min in the acetate buffer. These promising results suggest that the general USP dissolution protocols are adequate for the successful release of RSV capsules in HCl medium and acetate buffer and GSE capsules (in HCl medium), but may be inadequate for GSE capsules in acetate buffer. These results showed that under a low pH of 1.2 (simulated stomach environment), bioactive compounds were released on time from the GSE capsules and met the USP guidelines; however, under a higher pH of 4.6 (simulated duodenum environment), the same biomarkers failed, suggesting the need to further improve the dissolution of GSE over a wider range of pH environments to enhance bioavailability and efficacy.

Neuroprotective mechanisms of red clover and soy isoflavones in Parkinson's disease models.

Parkinson's disease (PD) is a neurodegenerative disorder characterized by nigrostriatal degeneration and the spreading of aggregated forms of the presynaptic protein α-synuclein (aSyn) throughout the brain. PD patients are currently only treated with symptomatic therapies, and strategies to slow or stop the progressive neurodegeneration underlying the disease's motor and cognitive symptoms are greatly needed. The time between the first neurobiochemical alterations and the initial presentation of symptoms is thought to span several years, and early neuroprotective dietary interventions could delay the disease onset or slow PD progression. In this study, we characterized the neuroprotective effects of isoflavones, a class of dietary polyphenols found in soy products and in the medicinal plant red clover (Trifolium pratense). We found that isoflavone-rich extracts and individual isoflavones rescued the loss of dopaminergic neurons and the shortening of neurites in primary mesencephalic cultures exposed to two PD-related insults, the environmental toxin rotenone and an adenovirus encoding the A53T aSyn mutant. The extracts and individual isoflavones also activated the Nrf2-mediated antioxidant response in astrocytes via a mechanism involving inhibition of the ubiquitin-proteasome system, and they alleviated deficits in mitochondrial respiration. Furthermore, an isoflavone-enriched soy extract reduced motor dysfunction exhibited by rats lesioned with the PD-related neurotoxin 6-OHDA. These findings suggest that plant-derived isoflavones could serve as dietary supplements to delay PD onset in at-risk individuals and mitigate neurodegeneration in the brains of patients.

Development and validation of a micro-QuEChERS method with high-throughput enhanced matrix removal followed with UHPLC-QqQ-MS/MS for analysis of raspberry ketone-related phenolic compounds in adipose tissues.

Raspberry ketone (RK) is a major flavor compound in red raspberries, and it has been marketed as a popular weight-loss dietary supplement with high potential in accumulating in fatty tissues. However, challenges in extracting and characterizing RK and its associated phenolic compounds in fatty tissues persist due to the complex matrix effect. In this work, we reported a high-throughput sample preparation method for RK and 25 related phenolic compounds in white adipose tissues using an improved micro-scale QuEChERS (quick, efficient, cheap, easy, rugged and safe) approach with enhanced matrix removal (EMR)-lipid cleanup in 96-well plates, followed by UHPLC-QqQ-MS/MS analysis. The absolute recovery was 73-105% at the extraction step, and achieved 71-96% at the EMR cleanup step. The EMR cleanup removed around 66% of total lipids in the acetonitrile extract as profiled by UHPLC-QTOF-MS/MS. The innovative introduction of a reversed-phase C18 sorbent into the extract significantly improved the analytes' recovery during SpeedVac drying. The final accuracy achieved 80-120% for most analytes. Overall, this newly developed and validated method could serve as a powerful tool for analyzing RK and related phenolic compounds in fatty tissues.