Effect of Dietary Purified Xanthohumol from Hop (Humulus lupulus L.) Pomace on Adipose Tissue Mass, Fasting Blood Glucose Level, and Lipid Metabolism in KK-Ay Mice

Reducing gut microbiome-driven adipose tissue inflammation alleviates metabolic syndrome

BACKGROUND

The gut microbiota contributes to macrophage-mediated inflammation in adipose tissue with consumption of an obesogenic diet, thus driving the development of metabolic syndrome. There is a need to identify and develop interventions that abrogate this condition. The hops-derived prenylated flavonoid xanthohumol (XN) and its semi-synthetic derivative tetrahydroxanthohumol (TXN) attenuate high-fat diet-induced obesity, hepatosteatosis, and metabolic syndrome in C57Bl/6J mice. This coincides with a decrease in pro-inflammatory gene expression in the gut and adipose tissue, together with alterations in the gut microbiota and bile acid composition.

RESULTS

In this study, we integrated and interrogated multi-omics data from different organs with fecal 16S rRNA sequences and systemic metabolic phenotypic data using a Transkingdom Network Analysis. By incorporating cell type information from single-cell RNA-seq data, we discovered TXN attenuates macrophage inflammatory processes in adipose tissue. TXN treatment also reduced levels of inflammation-inducing microbes, such as Oscillibacter valericigenes, that lead to adverse metabolic phenotypes. Furthermore, in vitro validation in macrophage cell lines and in vivo mouse supplementation showed addition of O. valericigenes supernatant induced the expression of metabolic macrophage signature genes that are downregulated by TXN in vivo.

CONCLUSIONS

Our findings establish an important mechanism by which TXN mitigates adverse phenotypic outcomes of diet-induced obesity and metabolic syndrome. TXN primarily reduces the abundance of pro-inflammatory gut microbes that can otherwise promote macrophage-associated inflammation in white adipose tissue. Video Abstract.

Application of Nanomicelles in Enhancing Bioavailability and Biological Efficacy of Bioactive Nutrients

Nutraceuticals provide many biological benefits besides their basic nutritional value. However, their biological efficacies are often limited by poor absorption and low bioavailability. Nanomaterials have received much attention as potential delivery systems of nutrients and phytonutrients for multiple applications. Nanomicelles are nanosized colloidal structures with a hydrophobic core and hydrophilic shell. Due to their unique characteristics, they have shown great perspectives in food and nutraceutical science. In this review, we discussed the unique properties of nanomicelles. We also emphasized the latest advances on the design of different nanomicelles for efficient delivery and improved bioavailability of various nutrients. The role of nanomicelles in the efficacy improvement of bioactive components from nutraceutical and health foods has been included. Importantly, the safety concerns on nano-processed food products were highlighted.

Antioxidants in Hops: Bioavailability, Health Effects and Perspectives for New Products

Hop plant (Humulus lupulus L.) has been used by humans for ages, presumably first as a herbal remedy, then in the manufacturing of different products, from which beer is the most largely consumed. Female hops cones have different useful chemical compounds, an important class being antioxidants, mainly polyphenols. This narrative review describes the main antioxidants in hops, their bioavailability and biological effects, and the results obtained by now in the primary and secondary prevention of several non-communicable diseases, such as the metabolic syndrome related diseases and oncology. This article presents in vitro and in vivo data in order to better understand what was accomplished in terms of knowledge and practice, and what needs to be clarified by additional studies, mainly regarding xantohumol and its derivates, as well as regarding the bitter acids of hops. The multiple protective effects found by different studies are hindered up to now by the low bioavailability of some of the main antioxidants in hops. However, there are new promising products with important health effects and perspectives of use as food supplements, in a market where consumers increasingly search for products originating directly from plants.

Bioavailability and Cardiometabolic Effects of Xanthohumol: Evidence from Animal and Human Studies

Xanthohumol is the main prenylflavonoid in hops and has been associated with a wide range of health benefits, due to its anti-inflammatory, anti-oxidative, and cancer-preventive properties. Increasing evidence suggests that xanthohumol positively affects biomarkers associated with metabolic syndrome and cardiovascular diseases (CVDs). This review summarizes the effects of xanthohumol supplementation on body weight, lipid and glucose metabolism, systemic inflammation, and redox status. In addition, it provides insights into the pharmacokinetics of xanthohumol intake. Animal studies show that xanthohumol exerts beneficial effects on body weight, lipid profile, glucose metabolism, and other biochemical parameters associated with metabolic syndrome and CVDs. Although in vitro studies are increasingly elucidating the responsible mechanisms, the overall in vivo results are currently inconsistent and quantitatively insufficient. Pharmacokinetic and safety studies confirm that intake of xanthohumol is safe and well tolerated in both animals and humans. However, little is known about the metabolism of xanthohumol in the human body, and even less about its effects on body weight and CVD risk factors. There is an urgent need for studies investigating whether the effects of xanthohumol on body weight and cardiometabolic parameters observed in animal studies are reproducible in humans, and what dosage, formulation, and intervention period are required. This article is protected by copyright. All rights reserved.

Xanthohumol alleviates T2DM-induced liver steatosis and fibrosis by mediating the NRF2/RAGE/NF-κB signaling pathway

Hyperglycemia-associated advanced glycation end products (AGEs) and the receptor for AGE (RAGE) contribute to nonalcoholic fatty liver disease (NAFLD). Xanthohumol (XH) exhibits protective activities against liver diseases. Aim: To investigate the effects of XH on Type II diabetes mellitus (T2DM)-induced liver steatosis and fibrosis. Methods: NAFLD rat models were duplicated. Biomolecular markers were detected. Quantitative real-time PCR (RT-PCR) and western blot were used to detect mRNA and protein expression. Immunofluorescence assays were employed to identify the subcellular locations. Results: XH significantly ameliorated hyperglycemia and hyperlipidemia in rats. XH attenuated the expression of RAGE and NF-κB signaling. XH significantly alleviated inflammation and oxidation by upregulating NRF2 expression. Knockdown of NRF2 blocked XH protection in hepatocytes. Conclusion: XH protected against T2DM-induced liver steatosis and fibrosis by mediating NRF2/AGE/RAGE/NF-κB signaling.

Tetrahydroxanthohumol, a xanthohumol derivative, attenuates high-fat diet-induced hepatic steatosis by antagonizing PPARγ

We previously reported xanthohumol (XN), and its synthetic derivative tetrahydro-XN (TXN), attenuates high-fat diet (HFD)-induced obesity and metabolic syndrome in C57Bl/6J mice. The objective of the current study was to determine the effect of XN and TXN on lipid accumulation in the liver. Non-supplemented mice were unable to adapt their caloric intake to 60% HFD, resulting in obesity and hepatic steatosis; however, TXN reduced weight gain and decreased hepatic steatosis. Liver transcriptomics indicated that TXN might antagonize lipogenic PPARγ actions in vivo. XN and TXN inhibited rosiglitazone-induced 3T3-L1 cell differentiation concomitant with decreased expression of lipogenesis-related genes. A peroxisome proliferator activated receptor gamma (PPARγ) competitive binding assay showed that XN and TXN bind to PPARγ with an IC50 similar to pioglitazone and 8-10 times stronger than oleate. Molecular docking simulations demonstrated that XN and TXN bind in the PPARγ ligand-binding domain pocket. Our findings are consistent with XN and TXN acting as antagonists of PPARγ.

Xanthohumol prolongs lifespan and decreases stress-induced mortality in Drosophila melanogaster

Aging is a significant risk factor that links to the genesis of human diseases. The capacity to scavenge free radicals and adapt to various stresses is essential for expanding living organisms' lifespan. The evidences on the promotion of longevity by dietary supplementation are growing. Drosophila or fruit fly is one of the most effective models for the evaluation of anti-aging compounds. Xanthohumol (XN) is a potential bioactive substance for the prevention and treatment of many diseases. The previous studies have reported its potent activities as antioxidant, anticancer, anti-inflammatory, antiviral, antibacterial antiplasmodial, and antiobesity. In this study, the effect of XN supplementation on the lifespan extension was investigated in Drosophila melanogaster. The effects of XN on the improvement of the recovery from cold and heat shock, the resistance to starvation stress, and free radical-induced oxidative stress in XN-treated flies were also evaluated. Results showed that supplementation with XN at 0.5 mg/mL diet extended the mean lifespan by 14.89%. This was consistent with a significant improvement of locomotor activity of the Drosophila fed with an XN-mixed diet compared with those fed with a control diet. XN supplementation significantly increased the antioxidant enzyme activities at both 25 and 40 days. Drosophila treated with XN exhibited increased survival after exposure to hydrogen peroxide and paraquat. Finally, XN supplementation improved the recovery from cold and heat shock, the resistance to starvation stress, and acetic acid-induced stress. The present study shows that dietary supplementation with XN revealed the longevity effect and ameliorated stress-induced mortality in Drosophila.

Metabolic Impact of Flavonoids Consumption in Obesity: From Central to Peripheral

The prevention and treatment of obesity is primary based on the follow-up of a healthy lifestyle, which includes a healthy diet with an important presence of bioactive compounds such as polyphenols. For many years, the health benefits of polyphenols have been attributed to their anti-oxidant capacity as free radical scavengers. More recently it has been described that polyphenols activate other cell-signaling pathways that are not related to ROS production but rather involved in metabolic regulation. In this review, we have summarized the current knowledge in this field by focusing on the metabolic effects of flavonoids. Flavonoids are widely distributed in the plant kingdom where they are used for growing and defensing. They are structurally characterized by two benzene rings and a heterocyclic pyrone ring and based on the oxidation and saturation status of the heterocyclic ring flavonoids are grouped in seven different subclasses. The present work is focused on describing the molecular mechanisms underlying the metabolic impact of flavonoids in obesity and obesity-related diseases. We described the effects of each group of flavonoids in liver, white and brown adipose tissue and central nervous system and the metabolic and signaling pathways involved on them.

The Effect of Hops (Humulus lupulus L.) Extract Supplementation on Weight Gain, Adiposity and Intestinal Function in Ovariectomized Mice

Estrogen decline during menopause is associated with altered metabolism, weight gain and increased risk of cardiometabolic diseases. The gut microbiota also plays a role in the development of cardiometabolic dysfunction and is also subject to changes associated with age-related hormone changes. Phytoestrogens are plant-based estrogen mimics that have gained popularity as dietary supplements for the treatment or prevention of menopause-related symptoms. These compounds have the potential to both modulate and be metabolized by the gut microbiota. Hops (Humulus lupulus L.) contain potent phytoestrogen precursors, which rely on microbial biotransformation in the gut to estrogenic forms. We supplemented ovariectomized (OVX) or sham-operated (SHAM) C57BL/6 mice, with oral estradiol (E2), a flavonoid-rich extract from hops, or a placebo carrier oil, to observe effects on adiposity, inflammation, and gut bacteria composition. Hops extract (HE) and E2 protected against increased visceral adiposity and liver triglyceride accumulation in OVX animals. Surprisingly, we found no evidence of OVX having a significant impact on the overall gut bacterial community structure. We did find differences in the abundance of Akkermansia muciniphila, which was lower with HE treatment in the SHAM group relative to OVX E2 treatment and to placebo in the SHAM group.

Evaluation of the Anti-Diabetic Activity of Some Common Herbs and Spices: Providing New Insights with Inverse Virtual Screening

Culinary herbs and spices are widely used as a traditional medicine in the treatment of diabetes and its complications, and there are several scientific studies in the literature supporting the use of these medicinal plants. However, there is often a lack of knowledge on the bioactive compounds of these herbs and spices and their mechanisms of action. The aim of this study was to use inverse virtual screening to provide insights into the bioactive compounds of common herbs and spices, and their potential molecular mechanisms of action in the treatment of diabetes. In this study, a library of over 2300 compounds derived from 30 common herbs and spices were screened in silico with the DIA-DB web server against 18 known diabetes drug targets. Over 900 compounds from the herbs and spices library were observed to have potential anti-diabetic activity and liquorice, hops, fennel, rosemary, and fenugreek were observed to be particularly enriched with potential anti-diabetic compounds. A large percentage of the compounds were observed to be potential polypharmacological agents regulating three or more anti-diabetic drug targets and included compounds such as achillin B from yarrow, asparasaponin I from fenugreek, bisdemethoxycurcumin from turmeric, carlinoside from lemongrass, cinnamtannin B1 from cinnamon, crocin from saffron and glabridin from liquorice. The major targets identified for the herbs and spices compounds were dipeptidyl peptidase-4 (DPP4), intestinal maltase-glucoamylase (MGAM), liver receptor homolog-1 (NR5A2), pancreatic alpha-amylase (AM2A), peroxisome proliferator-activated receptor alpha (PPARA), protein tyrosine phosphatase non-receptor type 9 (PTPN9), and retinol binding protein-4 (RBP4) with over 250 compounds observed to be potential inhibitors of these particular protein targets. Only bay leaves, liquorice and thyme were found to contain compounds that could potentially regulate all 18 protein targets followed by black pepper, cumin, dill, hops and marjoram with 17 protein targets. In most cases more than one compound within a given plant could potentially regulate a particular protein target. It was observed that through this multi-compound-multi target regulation of these specific protein targets that the major anti-diabetic effects of reduced hyperglycemia and hyperlipidemia of the herbs and spices could be explained. The results of this study, taken together with the known scientific literature, indicated that the anti-diabetic potential of common culinary herbs and spices was the result of the collective action of more than one bioactive compound regulating and restoring several dysregulated and interconnected diabetic biological processes.

Xanthohumol Suppresses NPC1L1 Gene Expression through Downregulation of HNF-4α and Inhibits Cholesterol Uptake in Caco-2 Cells

Xanthohumol (Xan) is a prenylated chalcone mainly found in hops; it has been demonstrated to function against hypercholesterolemia, hyperlipidemia, and atherosclerosis. In this study, we focused on the hypocholesterolemic effect of Xan on cholesterol uptake and the underlying molecular mechanisms of Xan in human intestinal Caco-2 cells. The microarray data showed that Niemann-Pick C1-like 1 (NPC1L1), an essential transporter for dietary cholesterol absorption, was significantly downregulated in Xan-treated Caco-2 cells. We demonstrated that Xan (10 and 20 μM) suppressed the mRNA and protein expression of NPC1L1 by 0.65 ± 0.12-fold and 0.54 ± 0.15-fold and 0.72 ± 0.04-fold and 0.44 ± 0.12-fold, respectively, compared to that of the vehicle-treated Caco-2 cells. Moreover, Xan (10 and 20 μM) significantly inhibited cholesterol uptake by approximately 12 and 32% in Caco-2 cells. NPC1L1 promoter activity was significantly suppressed by Xan, and a DNA element within the NPC1L1 promoter involved in Xan-mediated NPC1L1 reduction located between the -120 and -20 positions was identified. Moreover, Xan markedly decreased the mRNA and protein levels of hepatocyte nuclear factor 4α (HNF-4α), a critical activator of NPC1L1 transcription, and subsequently attenuated HNF-4α/NPC1L1 promoter complex formation, resulting in the suppression of NPC1L1 gene expression. Finally, we demonstrated that Xan markedly abolished lovastatin-induced NPC1L1 overexpression in Caco-2 cells. These findings reveal that Xan suppresses NPC1L1 expression via downregulation of HNF-4α and exerts inhibitory effects on cholesterol uptake in the intestinal Caco-2 cells. Our findings suggest Xan could serve as a potential cholesterol-lowering agent and supplement for statin therapy.

Combinatorial Epigenetics Impact of Polyphenols and Phytochemicals in Cancer Prevention and Therapy

Polyphenols are potent micronutrients that can be found in large quantities in various food sources and spices. These compounds, also known as phenolics due to their phenolic structure, play a vital nutrient-based role in the prevention of various diseases such as diabetes, cardiovascular diseases, neurodegenerative diseases, liver disease, and cancers. However, the function of polyphenols in disease prevention and therapy depends on their dietary consumption and biological properties. According to American Cancer Society statistics, there will be an expected rise of 23.6 million new cancer cases by 2030. Due to the severity of the increased risk, it is important to evaluate various preventive measures associated with cancer. Relatively recently, numerous studies have indicated that various dietary polyphenols and phytochemicals possess properties of modifying epigenetic mechanisms that modulate gene expression resulting in regulation of cancer. These polyphenols and phytochemicals, when administrated in a dose-dependent and combinatorial-based manner, can have an enhanced effect on epigenetic changes, which play a crucial role in cancer prevention and therapy. Hence, this review will focus on the mechanisms of combined polyphenols and phytochemicals that can impact various epigenetic modifications such as DNA methylation and histone modifications as well as regulation of non-coding miRNAs expression for treatment and prevention of various types of cancer.

Role of Characteristic Components of Humulus lupulus in Promoting Human Health

Over the next 50 years, the prevention and control of chronic diseases, such as obesity, cardiovascular disease, Alzheimer's disease, and many cancers, will be one of the most critical challenges in human health. Plant biochemistry and phytonutrient supplements are a promising complementary therapy for the management of chronic disease. Among them, Humulus lupulus has attracted special attention throughout the world because it contains numerous dietary phytochemicals that not only contribute to the aroma and flavor of beer but may also be used for medicinal purposes, as its properties include antiseptic, (an)aphrodisiac, anticancer, antiplatelet, antibacterial, antidiuretic, anti-inflammatory, sedative, hypnotic, and stomachic properties. This review sought to identify and understand the risk factors for chronic disease with a focus on two types of phytochemicals, bitter acids and xanthohumol. The goal was to understand how their metabolites promote human health and reduce the risk of chronic disease.

Influence of Alcohol Consumption on Body Mass Gain and Liver Antioxidant Defense in Adolescent Growing Male Rats

The World Health Organization (WHO) reported that alcohol consumption is a serious problem in adolescents. The aim of the study was to assess the influence of the time of exposure of various alcoholic beverages on body mass as well as on select parameters of liver antioxidant defense in adolescent Wistar rats. Thirty-day-old animals were divided into 12 groups (six animals in each): control and groups receiving various beverages containing 10% of alcohol (ethanol, red wine, beer), observed for two, four, and six weeks. The body weight gain and energy supply were analyzed for body mass assessment. The catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase, transferase (GST), reductase activities, total antioxidant status, and glutathione level (GSH) were analyzed, for a liver antioxidant defense assessment. Group receiving red wine was characterized by the highest alcohol intake, lowest dietary intake, and highest total energy supply (p < 0.05). However, this did not influence body weight gain (p > 0.05). Reduced diet intake in groups receiving alcohol was counterbalanced by its energy value. Therefore, the energy supply was not lower than for the control (p > 0.05). Alcohol consumption and the experiment duration influenced CAT, SOD, and GST activities and GSH level. Alcohol consumption may influence hepatic antioxidant defense in adolescent male rats, but without influence on body weight gain.

Therapeutic Application of Micellar Solubilized Xanthohumol in a Western-Type Diet-Induced Mouse Model of Obesity, Diabetes and Non-Alcoholic Fatty Liver Disease

Xanthohumol (XN), a prenylated chalcone from hops, has been reported to exhibit a variety of health-beneficial effects. However, poor bioavailability may limit its application in the prevention and therapy of diseases. The objective of this study was to determine whether a micellar solubilization of xanthohumol could enhance the bioavailability and biological efficacy of xanthohumol in a Western-type diet (WTD) induced model of obesity, diabetes and non-alcoholic fatty liver disease (NAFLD). After 3 weeks feeding with WTD, XN was additionally applied per oral gavage as micellar solubilizate (s-XN) or native extract (n-XN) at a daily dose of 2.5 mg/kg body weight for a further 8 weeks. Control mice received vehicle only in addition to the WTD. WTD-induced body weight-gain and glucose intolerance were significantly inhibited by s-XN application. Furthermore, WTD-induced hepatic steatosis, pro-inflammatory gene expression (MCP-1 and CXCL1) and immune cell infiltration as well as activation of hepatic stellate cells (HSC) and expression of collagen alpha I were significantly reduced in the livers of s-XN-treated mice compared to WTD controls. In contrast, application of n-XN had no or only slight effects on the WTD-induced pathological effects. In line with this, plasma XN concentration ranged between 100–330 nmol/L in the s-XN group while XN was not detectable in the serum samples of n-XN-treated mice. In conclusion, micellar solubilization enhanced the bioavailability and beneficial effects of xanthohumol on different components of the metabolic syndrome including all pathological steps of NAFLD. Notably, this was achieved in a dose more than 10-fold lower than effective beneficial doses of native xanthohumol reported in previous in vivo studies.

Humulus lupulus L. Extract Prevents Ovariectomy-Induced Osteoporosis in Mice and Regulates Activities of Osteoblasts and Osteoclasts

OBJECTIVE

To systematically evaluate the protective effects of Humulus lupulus L. extract (HLE) on osteoporosis mice.

METHODS

In vivo experiment, a total of 35 12-week-old female ICR mice were equally divided into 5 groups: the sham control group (sham); the ovariectomy with vehicle group (OVX); the OVX with estradiol valerate [EV, 0.2 mg/(kg•d)] the OVX with low- or high-dose HLE groups [HLE, 1 g/(kg•d) and 3 g/(kg•d)], 7 in each group. Treatment began 1 week after the ovariectomized surgery and lasted for 12 weeks. Bone mass and trabecular bone mircoarchitecture were evaluated by micro computed tomography, and bone turnover markers in serum were evaluated using enzyme-linked immunosorbent assay (ELISA) kits. In vitro experiment, osteoblasts and osteoclasts were treated with HLE at doses of 0, 4, 20 and 100 µg/mL. Biomarkers for bone formation in osteoblasts and bone resorption in osteoclasts were analyzed.

RESULTS

Compared with the OVX group, HLE exerted bone protective effects by the increase of estradiol (P<0.05), the improvement of cancellous bone structure, bone mineral density (P<0.01) and the reduction of serum alkaline phosphatase (ALP), tartrate resistant acid phosphatase (TRAP), bone gla-protein, c-terminal telopeptides of type I collagen (CTX-I) and deoxypyridinoline levels (P<0.01 for all). In vitro experiment, compared with the control group, HLE at 20 µg/mL promoted the cell proliferation (P<0.01), and increased the expression of bone morphogenetic protein-2 and osteopontin levels in osteoblasts (both P<0.05). HLE at 100 µg/mL increased the osteoblastic ALP activities, and HLE at all dose enhanced the extracellular matrix mineralization (both P<0.01). Furthermore, compared with the control group, HLE at 20 µg/mL and 100 µg/mL inhibited osteoclastic TRAP activity (P<0.01), and reduced the expression of matrix metalloproteinase-9 and cathepsin K (both P<0.05).

CONCLUSION

HLE may protect against bone loss, and have potentials in the treatment of osteoporosis.

The Multiple Biological Targets of Hops and Bioactive Compounds

Botanical dietary supplements for women's health are increasingly popular. Older women tend to take botanical supplements such as hops as natural alternatives to traditional hormone therapy to relieve menopausal symptoms. Especially extracts from spent hops, the plant material remaining after beer brewing, are enriched in bioactive prenylated flavonoids that correlate with the health benefits of the plant. The chalcone xanthohumol (XH) is the major prenylated flavonoid in spent hops. Other less abundant but important bioactive prenylated flavonoids are isoxanthohumol (IX), 8-prenylnaringenin (8-PN), and 6-prenylnaringenin (6-PN). Pharmacokinetic studies revealed that these flavonoids are conjugated rapidly with glucuronic acid. XH also undergoes phase I metabolism in vivo to form IX, 8-PN, and 6-PN. Several hop constituents are responsible for distinct effects linked to multiple biological targets, including hormonal, metabolic, inflammatory, and epigenetic pathways. 8-PN is one of the most potent phytoestrogens and is responsible for hops' estrogenic activities. Hops also inhibit aromatase activity, which is linked to 8-PN. The weak electrophile, XH, can activate the Keap1-Nrf2 pathway and turn on the synthesis of detoxification enzymes such as NAD(P)H-quinone oxidoreductase 1 and glutathione S-transferase. XH also alkylates IKK and NF-κB, resulting in anti-inflammatory activity. Antiobesity activities have been described for XH and XH-rich hop extracts likely through activation of AMP-activated protein kinase signaling pathways. Hop extracts modulate the estrogen chemical carcinogenesis pathway by enhancing P450 1A1 detoxification. The mechanism appears to involve activation of the aryl hydrocarbon receptor (AhR) by the AhR agonist, 6-PN, leading to degradation of the estrogen receptor. Finally, prenylated phenols from hops are known inhibitors of P450 1A1/2; P450 1B1; and P450 2C8, 2C9, and 2C19. Understanding the biological targets of hop dietary supplements and their phytoconstituents will ultimately lead to standardized botanical products with higher efficacy, safety, and chemopreventive properties.

Effect of Solid Biological Waste Compost on the Metabolite Profile of Brassica rapa ssp. chinensis

Large quantities of biological waste are generated at various steps within the food production chain and a great utilization potential for this solid biological waste exists apart from the current main usage for the feedstuff sector. It remains unclear how the usage of biological waste as compost modulates plant metabolites. We investigated the effect of biological waste of the processing of coffee, aronia, and hop added to soil on the plant metabolite profile by means of liquid chromatography in pak choi sprouts. Here we demonstrate that the solid biological waste composts induced specific changes in the metabolite profiles and the changes are depending on the type of the organic residues and its concentration in soil. The targeted analysis of selected plant metabolites, associated with health beneficial properties of the Brassicaceae family, revealed increased concentrations of carotenoids (up to 3.2-fold) and decreased amounts of glucosinolates (up to 4.7-fold) as well as phenolic compounds (up to 1.5-fold).

Non-specific protein modifications may be novel mechanism underlying bioactive phytochemicals

In a variety of experimental models, dietary phytochemicals have been demonstrated to exhibit pronounced and versatile bioactivities. Importantly, the possibility of such phytochemicals for human application has been supported in part by epidemiological surveys, which have demonstrated that frequent ingestion of vegetables and fruits containing abundant phytochemicals lowers the risk of onset of various diseases. However, the action mechanisms underlying those dietary phytochemical activities remain to be fully elucidated. For example, even though the anti-oxidant effects of natural polyphenols have long received widespread attention from food scientists, their roles in and contribution to those bioactivities remain controversial because of their poor bioavailability, resulting in extremely low concentrations in the bloodstream. Meanwhile, another important question is why phytochemicals have beneficial effects for animals, including humans, since they are biosynthesized by plants as compounds necessary for adaptation to environmental stress. In regard to that fundamental question, we recently reported novel and unique mechanisms of action of zerumbone, a sesquiterpene with anti-inflammatory and chemopreventive properties. This agent was found to partially exhibit bioactivity through its non-specific interactions with cellular proteins. More strikingly, a non-specific protein binding action of zerumbone was revealed to partially contribute to its anti-inflammatory functions via activation of heat shock factor 1. The present review article highlights and introduces our recent findings regarding the proteo-stress-mediated mechanisms of this phytochemical, along with the concept of hormesis.