Impact of Cold versus Hot Brewing on the Phenolic Profile and Antioxidant Capacity of Rooibos (Aspalathus linearis) Herbal Tea

Functional potential of a new plant-based fermented beverage: Benefits through non-conventional probiotic yeasts and antioxidant properties

Functional foods represent one of the fastest-growing, newer food category, and plant sources with functional properties are increasingly used as analogues of fermented milk-based derivatives. In this study, blended wort-rooibos beverages fermented with probiotic yeasts are proposed for the first time. Benefits of functional, non-conventional Lachancea thermotolerans (Lt101), Kazachstania unispora (Kum3-B3), Meyerozyma guilliermondii (Mg112), Meyerozyma caribbica (Mc58) and Debaryomyces hansenii (Dh36) yeast strains and the content of bioactive metabolites were evaluated. Viability tests on the probiotic yeasts confirmed previous results obtained in other matrices. The functional footprint of probiotic yeasts Lt101, Mg112 and Dh36 was confirmed by a balanced nutritional profile of the final drinks, also supported by aromatic and sensory analyses. In vitro estimated glycaemic index ranged between 77 % and 87 % without any influence on glycaemic response. Strains Dh36, Mc58, Kum3-B3 and Mg112 showed high antioxidant capacity and high total phenolic content, supporting the health promoting effect of the beverages.

Total Polyphenol Contents and Mineral Profiles in Commercial Wellness Herbal Infusions: Evaluation of the Differences between Two Preparation Methods

The popularity of the consumption of wellness herbal teas is due to the many health-promoting properties they seem to possess. Modern preparation methods using coffee machines are also popular today. Therefore, the purpose of this research was to evaluate differences in infusions obtained by the traditional method using filters and by espresso coffee machines using pods. In this regard, different herbal materials were selected and purchased in two different types of herbal containers, and the corresponding infusions were analyzed for the contents of total polyphenols and mineral elements. Results showed that filter infusions had higher polyphenol and mineral contents than pod infusions, excluding Cd and Pb. For each of the plant materials used, differences due to the method of infusion preparation are highlighted. From a qualitative point of view, both methods of infusion preparation are valid, but the filter infusion method allows a higher transfer of minerals and polyphenols into the infusion, improving quality. The analyzed infusions can be safely consumed with respect to As, Cd, Pb, and Hg contents. Good amounts of polyphenols and Mn can be obtained by drinking a cup of any of the infusions analyzed, especially the mate infusion obtained by the filter technique, with amounts of 429 mg for polyphenols and 69.27% of the RDA for manganese.

Polyphenols in edible plant leaves: an overview of their occurrence and health properties

Edible plant leaves (EPLs) constitute a major renewable functional plant biomass available all year round, providing an essential source of polyphenols in the global diet. Polyphenols form a large family of antioxidant molecules. They protect against the harmful effects of free radicals, strengthen immunity and stimulate the body's natural defenses thanks to their antibacterial and antiviral functions. This study refers to phenolic compounds from 50 edible plant leaves divided into four categories: green leafy vegetables, underutilized leafy vegetables, leafy spices and leafy drinks. It provides data on the identification, occurrence and pharmacological functions of polyphenols contained in EPLs, and provides a better understanding of trends and gaps in their consumption and study. Certain EPLs, such as moringa (Moringa oleifera Lam.), tea (Camellia sinensis L.) and several leafy spices of the Lamiaceae family, reveal important characteristics and therapeutic potential. The polyphenol composition of EPLs makes them functional plants that offer relevant solutions in the fight against obesity, the management of food insecurity and the prevention of chronic diseases.

Effects of tea addition on antioxidant capacity, volatiles, and sensory quality of beer

Green tea has great potential to enhance the quality of beer. In this study, green tea was added at different stages of beer brewing, and evaluated the antioxidant capacity, volatile components, as well as sensory quality. The results showed that the addition of green tea during the start of boiling has great potential for application, and the green tea beer (GTB) had remarkable antioxidant properties (ABTS radical scavenging ability, 8.67 mmol TE/L; DPPH radical scavenging ability, 3.97 mmol TE/L; reducing power, 3.28 mmol TE/L), and an excellent sensory quality (acceptance, 6.09/9). HPLC analysis indicated that the principal phenolics in GTB were catechin and caffeic acid, in addition, the relative amounts of ferulic acid, gallic acid can be used to differentiate between GTB and beer. HS-SPME-GC-MS analyses showed that ethyl caprylate, ethyl nonanoate, ethyl caprate, linalool, and phenethyl alcohol were potentially significant for the aroma profile of GTB.

Impact of Fermentation on the Phytochemical Content and Biological Properties of Moringa oleifera Lam. Shoot Teas

This work examined the variation in chemical and biological properties of Moringa oleifera Lam. shoot (MOS) teas prepared under different degrees of fermentation, viz: non-fermented, semi-fermented and fermented. The chemical composition was ascertained via FTIR, GC-MS, total phenolic and total flavonoid content. Also determined were the biological properties, including antioxidant, antimicrobial and alpha-amylase inhibitory activities. The data confirmed that MOS teas were rich in phenolic and flavonoid compounds, with fermented MOS tea displaying the highest phenolic and flavonoid contents. With respect to antioxidant property, all tea extracts exhibited good radical scavenging activities against DPPH⋅, ABTS⋅+ and NO⋅, and the radical scavenging capacity was in the order of non-fermented>semi-fermented>fermented MOS teas. The same trend was also observed for the antimicrobial activities against Staphylococcus aureus and Staphylococcus epidermidis. In contrast, the fermented MOS tea exhibited better α-amylase inhibitory activity compared to the non-fermented and semi-fermented MOS teas.

Comparative Analysis of Hot and Cold Brews from Single-Estate Teas (Camellia sinensis) Grown across Europe: An Emerging Specialty Product

Tea is grown around the world under extremely diverse geographic and climatic conditions, namely, in China, India, the Far East and Africa. However, recently, growing tea also appears to be feasible in many regions of Europe, from where high-quality, chemical-free, organic, single-estate teas have been obtained. Hence, the aim of this study was to characterize the health-promoting properties in terms of the antioxidant capacity of traditional hot brews as well as cold brews of black, green and white teas produced across the European territory using a panel of antioxidant assays. Total polyphenol/flavonoid contents and metal chelating activity were also determined. For differentiating the characteristics of the different tea brews, ultraviolet-visible (UV-Vis) spectroscopy and ultra-high performance liquid chromatography coupled with high-resolution mass spectrometry were employed. Overall, our findings demonstrate for the first time that teas grown in Europe are good quality teas that are endowed with levels of health-promoting polyphenols and flavonoids and that have an antioxidant capacity similar to those grown in other parts of the world. This research is a vital contribution to the characterization of European teas, providing essential and important information for both European tea growers and consumers, and could be of guidance and support for the selection of teas grown in the old continent, along with having the best brewing conditions for maximizing the health benefits of tea.

Pharmacological activity of Aspalathus linearis extracts: pre-clinical research in view of prospective neuroprotection

OBJECTIVES

Rooibos tea, a very popular everyday beverage made of Aspalathus linearis plant material and containing multiple polyphenolic compounds, reveals an expectation to positively affect various processes observed in the pathogenesis of neurodegenerative diseases as in the case of consumption of other polyphenol-abundant food products.

METHODS

This review is based on available data from pre-clinical in vitro and in vivo studies and presents a broad report on the pharmacological activity of the A. linearis extracts relevant for neurodegenerative diseases.

RESULTS

Flavonoids present in herbal infusions are absorbed from gastro-intestinal tract and may affect the central nervous system. The experimental investigations yield the results indicating to supporting role of A. linearis in the prevention of neurodegeneration, primarily owing to anti-oxidative and anti-inflammatory properties, anti-hyperglycaemic and anti-hyperlipidaemic effects as well as favourable impact on neurotransmission with following cognitive and behavioural after-math.

DISCUSSION

The multiple pharmacological activities and safety of Aspalathus linearis extracts are commented in the manuscript. The continuous rooibos tea consumption seems to be safe (despite anecdotal liver irritation); however, there is a risk of herbal-drug interactions.

Harvest Stage and Brewing Conditions Impact Mineral Content, Phenolic Compounds, and Antioxidant Capacity of Lemon Balm (Melissa officinalis L.) Herbal Tea

Lemon balm (Melissa officinalis L.) is commonly consumed as an herbal tea for its antioxidant health benefits. Young seedlings known as microgreens are popular for their distinct flavors and can contain higher mineral content on a dry weight basis compared to their adult counterparts. However, the use of microgreens for herbal teas has not been previously investigated. In this study, lemon balm was grown to adult and microgreen harvest stages and prepared as herbal teas by brewing with boiled (100 °C) water for 5 minutes and room temperature water (22 °C) for 2 hours. The effects of harvest time and brewing method on the mineral content, phenolic compounds, and antioxidant capacity of lemon balm herbal teas were assessed. Results showed that adult lemon balm tea contained higher total phenolics, total flavonoids, rosmarinic acid, and antioxidant capacity than microgreen teas, with hot preparations containing the highest amounts (p ≤ 0.05). In contrast, microgreen lemon balm teas contained higher amounts of minerals (p ≤ 0.05), including calcium, potassium, magnesium, sodium, phosphorus, copper, and zinc. In general, brewing conditions did not impact the content of most minerals. Overall, the results support the potential of using dried microgreens as herbal teas. Microgreen lemon balm teas prepared hot and cold offer antioxidant compounds and are richer sources of minerals than adult teas. The ease of growth for microgreens offers consumers the opportunity for home preparation of a novel herbal tea beverage.

Inhibition of Browning in Apples Using Betacyclodextrin-Assisted Extracts of Green Rooibos (Aspalathus linearis)

Green rooibos' bioactive compounds contribute greatly towards its antioxidant activity. The anti-browning activity of aqueous (GRE) and beta-cyclodextrin (β-GRE)-assisted extracts of green rooibos was investigated in canned apples. Freeze-dried extracts (GRE and β-GRE) obtained at 40 °C for 60 min were added in canned apples at 0.25 and 0.5% prior to heat processing and stored at 23 and 37 °C for 24 weeks. Lightness (L*), colour difference (DE*), furfural and hydroxymethyl furfural (HMF) were determined to establish the effect of extracts against non-enzymatic browning (NEB) development. The L* value decreased, whereas DE*, HMF and furfural increased with increased storage time and temperature. A higher inhibition was observed for samples stored at 23 °C, and storage at 37 °C reduced (p < 0.05) the inhibitory capacity of extracts. Greater inhibition against NEB development was reported for β-GRE 0.25 and 0.5 via the L* value (40.93-46.67%), β-GRE 0.25 for DE* (46.67%) and β-GRE 0.25 and 0.5 for HMF (59.55-67.33%). No differences (p > 0.05) were observed in furfural inhibition between all extracts, although inhibition was reported at 62.69-72.29%. Browning inhibition correlated with the reaction rate constant (k₀) and activation energy (Ea), exhibiting a correlation coefficient of 0.925, 0.964, 0.932 and 0.754 for L*, DE*, HMF and furfural, respectively.

The effects of a green Rooibos (Aspalathus linearis) extract on metabolic parameters and adipose tissue biology in rats fed different obesogenic diets

Current pharmaceutical treatments addressing obesity are plagued by high costs, low efficacy and adverse side effects. Natural extracts are popular alternatives, but evidence for their anti-obesity properties is scant. We assessed the efficacy of a green (minimally-oxidized) Rooibos (Aspalathus linearis) extract (GRT) to ameliorate the effects of obesogenic feeding in rats, by examining body weight, metabolic measures, adipose tissue cellularity and tissue-resident adipose stem cells (ASCs). Furthermore, we performed statistical correlations to explore the relationships and interactions between metabolic and adipose tissue measures. Using an in vivo/ex vivo study design, male Wistar rats were maintained for 17 weeks on one of 3 diets: CON (laboratory chow), OB1 (high-sugar, medium fat) or OB2 (high-fat, high-cholesterol) (n = 24 each). From weeks 11-17, half of the animals in each group received oral GRT supplementation (60 mg per kg body weight daily). Blood and tissue samples were collected, and ASCs from each animal were cultured. Diets OB1 and OB2 induced divergent metabolic profiles compared to CON, but metabolic measures within dietary groups were mostly unaffected by GRT supplementation. Notably, diets OB1 and OB2 uncoupled the positive association between visceral adiposity and insulin resistance, while GRT uncoupled the positive association between elevated serum cholesterol and liver damage. Obesogenic feeding and GRT supplementation induced adipocyte enlargement in vivo, but lipid accumulation in cultured ASCs did not differ between dietary groups. Larger adipocyte size in subcutaneous fat was associated with favourable glucose metabolism measures in all GRT groups. In conclusion, GRT affected the associations between systemic, adipose tissue-level and cellular measures against the background of obesogenic diet-induced metabolic dysregulation.

Mediterranean Food Industry By-Products as a Novel Source of Phytochemicals with a Promising Role in Cancer Prevention

The Mediterranean diet is recognized as a sustainable dietary approach with beneficial health effects. This is highly relevant, although the production of typical Mediterranean food, i.e., olive oil or wine, processed tomatoes and pomegranate products, generates significant amounts of waste. Ideally, this waste should be disposed in an appropriate, eco-friendly way. A number of scientific papers were published recently showing that these by-products can be exploited as a valuable source of biologically active components with health benefits, including anticancer effects. In this review, accordingly, we elaborate on such phytochemicals recovered from the food waste generated during the processing of vegetables and fruits, typical of the Mediterranean diet, with a focus on substances with anticancer activity. The molecular mechanisms of these phytochemicals, which might be included in supporting treatment and prevention of various types of cancer, are presented. The use of bioactive components from food waste may improve the economic feasibility and sustainability of the food processing industry in the Mediterranean region and can provide a new strategy to approach prevention of cancer.

Aspalathus linearis (Rooibos) and Agmatine May Act Synergistically to Beneficially Modulate Intestinal Tight Junction Integrity and Inflammatory Profile

In order to promote gastrointestinal health, significant increases in the prevalence of gastrointestinal disorders should be paralleled by similar surges in therapeutics research. Nutraceutical interventions may play a significant role in patient management. The current study aimed to determine the potential of Aspalathus linearis (rooibos) to prevent gastrointestinal dysregulation resulting from high-dose trace-amine (TA) exposure. Considering the substantial female bias in functional gastrointestinal disorders, and the suggested phytoestrogenicity of rooibos, the study design allowed for a comparison between the effects of an ethanol extract of green rooibos and 17β-estradiol (E2). High levels of ρ-tyramine (TYR) and agmatine (AGM), but not β-phenethylamine (PEA) or tryptamine (TRP), resulted in prostaglandin E2 (PGE2) hypersecretion, increased tight-junction protein (TJP; occludin and ZO-1) secretion and (dissimilarly) disrupted the TJP cellular distribution profile. Modulating benefits of rooibos and E2 were TA-specific. Rooibos pre-treatment generally reduced IL-8 secretion across all TA conditions and prevented PGE2 hypersecretion after exposure to both TYR and AGM, but was only able to normalise TJP levels and the distribution profile in AGM-exposed cells. In contrast, E2 pre-treatment prevented only TYR-associated PGE2 hypersecretion and TJP dysregulation. Together, the data suggest that the antioxidant and anti-inflammatory effects of rooibos, rather than phytoestrogenicity, affect benefits illustrated for rooibos.

Optimising the Polyphenolic Content and Antioxidant Activity of Green Rooibos (Aspalathus linearis) Using Beta-Cyclodextrin Assisted Extraction

Antioxidant activity associated with green rooibos infusions is attributed to the activity of polyphenols, particularly aspalathin and nothofagin. This study aimed to optimise β-cyclodextrin (β-CD)-assisted extraction of crude green rooibos (CGRE) via total polyphenolic content (TPC) and antioxidant activity assays. Response surface methodology (RSM) permitted optimisation of β-CD concentration (0−15 mM), temperature (40−90 °C) and time (15−60 min). Optimal extraction conditions were: 15 mM β-CD: 40 °C: 60 min with a desirability of 0.985 yielding TPC of 398.25 mg GAE·g−1, metal chelation (MTC) of 93%, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging of 1689.7 µmol TE·g−1, ferric reducing antioxidant power (FRAP) of 2097.53 µmol AAE·g−1 and oxygen radical absorbance capacity (ORAC) of 11,162.82 TE·g−1. Aspalathin, hyperoside and orientin were the major flavonoids, with quercetin, luteolin and chrysoeriol detected in trace quantities. Differences (p < 0.05) between aqueous and β-CD assisted CGRE was only observed for aspalathin reporting the highest content of 172.25 mg·g−1 of dry matter for extracts produced at optimal extraction conditions. Positive, strong correlations between TPC and antioxidant assays were observed and exhibited regression coefficient (R2) between 0.929−0.978 at p < 0.001. These results demonstrated the capacity of β-CD in increasing polyphenol content of green rooibos.

New Insights into the Efficacy of Aspalathin and Other Related Phytochemicals in Type 2 Diabetes-A Review

In the pursuit of bioactive phytochemicals as a therapeutic strategy to manage metabolic risk factors for type 2 diabetes (T2D), aspalathin, C-glucosyl dihydrochalcone from rooibos (Aspalathus linearis), has received much attention, along with its C-glucosyl flavone derivatives and phlorizin, the apple O-glucosyl dihydrochalcone well-known for its antidiabetic properties. We provided context for dietary exposure by highlighting dietary sources, compound stability during processing, bioavailability and microbial biotransformation. The review covered the role of these compounds in attenuating insulin resistance and enhancing glucose metabolism, alleviating gut dysbiosis and associated oxidative stress and inflammation, and hyperuricemia associated with T2D, focusing largely on the literature of the past 5 years. A key focus of this review was on emerging targets in the management of T2D, as highlighted in the recent literature, including enhancing of the insulin receptor and insulin receptor substrate 1 signaling via protein tyrosine phosphatase inhibition, increasing glycolysis with suppression of gluconeogenesis by sirtuin modulation, and reducing renal glucose reabsorption via sodium-glucose co-transporter 2. We conclude that biotransformation in the gut is most likely responsible for enhancing therapeutic effects observed for the C-glycosyl parent compounds, including aspalathin, and that these compounds and their derivatives have the potential to regulate multiple factors associated with the development and progression of T2D.

Comparison of Phenolic Content and Antioxidant Activity for Fermented and Unfermented Rooibos Samples Extracted with Water and Methanol

Rooibos is brewed from the medicinal plant Aspalathus linearis. It has a well-established wide spectrum of bio-activity properties, which in part may be attributed to the phenolic antioxidant power. The antioxidant capacity (AOC) of rooibos is related to its total phenolic content (TPC). The relation between TPC and AOC of randomly selected 51 fermented (FR) and 47 unfermented (UFR) rooibos samples was studied after extraction using water and methanol separately. The resulted extracts were assessed using two antioxidant assays, trolox equivalent antioxidant capacity (TEAC) and ferric reducing antioxidant power (FRAP). The results were analyzed using both simple statistical methods and machine learning. The analysis showed different trends of TPC and AOC correlations of FR and UFR samples, depending on the solvent used for extraction. The results of the water extracts showed similar TPC and higher AOC of FR than UFR samples, while the methanolic extracted samples showed higher TPC and AOC of UFR than FR. As a result, the methanolic extracts showed better agreement between TPC and AOC than water extracts. Possible explanations are given for these observed results. Although, the current literature demonstrates direct correlations of the TPC and AOC of rooibos water extracts. This study showed deviation and highlighted the importance of solvent selection and analysis methodology as an important factor in determining the TPC/AOC correlation and subsequently the expectation of the actual health benefits of rooibos herbal tea. In particular, unfermented and fermented samples can be accurately identified on the basis of a combination of assays (any two of TPC, FRAP and TEAC), especially if methanol is the solvent used. Machine learning analysis of assay data provides nearly identical results with classical statistical analytical methods. This is the first report on machine learning analysis and comparison of the TPC and AOC of rooibos herbal tea extracted with methanol and water, and highlights the importance of using methanol as a solvent to evaluate its AOC.

Boiling Technique-Based Food Processing Effects on the Bioactive and Antimicrobial Properties of Basil and Rosemary

Rosemary (Rosmarinus officinalis) and basil (Ocimum sanctum Linn) are mostly used as herbal teas, made by steeping whole or ground herbs in boiling water. Hence, it is important to know the effect of boiling time on the bioactivity of these herbs. The effect of different boiling times (5, 10, and 15 min) on the antioxidant and antimicrobial properties, and some selected phenolic compounds of these herbs was examined in this study. Experimental results revealed that basil displayed the highest total polyphenol content (TPC), total flavonoid content (TFC), and antioxidant activity when it was boiled for 5 min, and the lowest TPC was obtained when it was boiled for 15 min. On the other hand, rosemary had the highest TPC, TFC, and antioxidant potential after being boiled for 15 min, while it had the lowest after being boiled for 5 min. There was no growth inhibition of rosemary extracts against gram-negative bacteria, whereas higher growth inhibition was observed against gram-positive bacteria. The MIC and MBC of rosemary ethanolic extract against Listeria monocytogenes were 5 and 5 mg/mL and against B. subtilis were 10 and 10 mg/mL, respectively. While MIC and MBC of methanolic extract against L. monocytogenes were 5 and 5 mg/mL and against Bacillus subtilis were and 5 and 5 mg/mL, respectively. Salicylic acid was the most abundant (324.7 mg/100 g dry weight (dw)) phenolic compound in the rosemary sample boiled for 5 min, and acetyl salicylic acid was the most abundant (122.61 mg/10 g dw) phenolic compound in the basil sample boiled for 15 min.

Comparative In Vitro Antioxidant Capacity and Terpenoid Profiling of Pumpkin Fruit Pulps from a Serbian Cucurbita maxima and Cucurbita moschata Breeding Collection

Pumpkin is considered a healthy and functional food. The consumption of pumpkins and pumpkin-based foods has been shown to confer several beneficial effects on human health due to their antioxidant capacity and terpenoid content. Consequently, this study aimed to characterize the in vitro antioxidant capacity (using FRAP and ABTS assays), terpenoid profile (using an untargeted lipidomics approach via high-resolution UHPLC-Orbitrap mass spectrometry), and carotenoid content (by HPLC-DAD) in pumpkin fruit pulp from accessions differing for species (11 Cucurbita maxima and 9 Cucurbita moschata), cultivar, and origin, belonging to a Serbian breeding collection. These accessions are candidates for inclusion within programs intended to improve pumpkin fruit quality. The results obtained in this work allowed us to highlight the best marker compounds, discriminating both the region of accession collection or breeding (“origin”) and the plant species. Furthermore, our findings have helped to identify the most suitable antioxidant-rich varieties to select for national breeding programs for improving human health. These findings provide valuable information to the overall current understanding of the potential health benefits of pumpkins and the discriminant triterpenoids underlying the C. maxima and C. moschata accessions investigated here, which include those of Serbian and non-Serbian origin.

Analysis of volatile compounds in rooibos tea (Aspalathus linearis) using different extraction methods and their relationship with human sensory perception

This study aimed to comparatively analyze the volatile flavor of rooibos tea (Aspalathus linearis) obtained by two commonly used flavor extraction methods, simultaneous distillation-extraction (SDE) and steam distillation under reduced pressure (DRP). The tea obtained by the two extraction methods, were analyzed by gas chromatography-mass spectrometry to identify volatile aroma-related compounds. Descriptive sensory analysis of the extracted rooibos tea flavor was carried out by a trained panel (n = 7). Fifty volatile compounds were identified, including 26 and 25 aroma-active compounds by SDE (45.9 µg/g) and DRP (37.5 µg/g), respectively. SDE recovered larger quantities of alcohols, acids, and esters, whereas DRP was useful for analyzing thermally unstable volatile compounds, including various alcohols, aldehydes, and hydrocarbons. Descriptive sensory analysis revealed that ketones and phenolic compounds may be responsible for the sensory attributes woody and grassy green, whereas the aldehydes and acidic compounds may contribute to floral and fruity.

Polyphenolic Profiling of Forestry Waste by UPLC-HDMSE

Polyphenols constitute a diverse array of naturally occurring secondary metabolites found in plants which, when consumed, have been shown to promote human health. Greater consumption may therefore aid in the fight against diseases such as obesity, diabetes, heart disease, cancer, etc. Tree bark is polyphenol-rich and has potential to be used in food supplements. However, it is important to gain insight into the polyphenol profile of different barks to select the material with greatest concentration and diversity. Ultra-performance liquid chromatography (UPLC) was coupled with an ion mobility time-of-flight high-definition/high-resolution mass spectrometer (UPLC-HDMSE) to profile ethanol extracts of three common tree barks (Pinus contorta, Pinus sylvestris, Quercus robur) alongside a commercial reference (Pycnogenol® extracted from Pinus pinaster). Through the use of Progenesis QI informatics software, 35 high scoring components with reported significance to health were tentatively identified across the three bark extracts following broadly the profile of Pycnogenol®. Scots Pine had generally higher compound abundances than in the other two extracts. Oak bark extract showed the lowest abundances but exhibited higher amounts of naringenin and 3-O-methylrosmarinic acid. We conclude that forestry bark waste provides a rich source of extractable polyphenols suitable for use in food supplements and so can valorise this forestry waste stream.

Phytochemical properties of black tea (Camellia sinensis) and rooibos tea (Aspalathus linearis); and their modulatory effects on key hyperglycaemic processes and oxidative stress

The comparative phytochemicals, antioxidative and antidiabetic activities of Camellia sinensis (black tea) and Aspalathus linearis (rooibos tea) were studied in vitro and ex vivo. Concentrated infusions of the teas showed significant free radical scavenging activities in vitro. They significantly increased the glutathione level, superoxide dismutase and catalase enzyme activities in oxidative hepatic injury, while concomitantly depleting malondialdehyde level. The teas significantly inhibited intestinal glucose absorption and α-amylase activities, and elevated muscle glucose uptake. LCMS phytochemical profiling revealed the presence of hydroxycaffeic acid, l-threonate, caffeine, vanillic acid, n-acetylvaline, and spinacetin 3-glucoside in C. sinensis. While quinolinic acid, coumestrol, phloroglucinol, 8-hydroxyquercetagetin, umbelliferone, and ajoene were identified in A. linearis. These results portray the antioxidant and antidiabetic potencies of both teas, with A. linearis showed better activity compared to C. sinensis. These teas may thus be used as functional foods in the management of diabetes and other oxidative stress related metabolic disorders.

Isoorientin: A dietary flavone with the potential to ameliorate diverse metabolic complications

Isoorientin is a natural C-glucosyl flavone that is generating a lot of interest due to its multiple pharmacological activities. Increasing experimental data have shown that the robust antioxidant and anti-inflammatory properties of isoorientin remain important in ameliorating a number of metabolic complications. In fact, plants rich in isoorientin have demonstrated strong ameliorative properties against complications such as hyperglycemia, hyperlipidemia, and insulin resistance. However, while such evidence is accumulating, it has not been reviewed to better inform on the therapeutic potential of this flavone in improving human health. This review examines and extrapolates available literature on the potential beneficial or detrimental effects associated with the use of isoorientin in mitigating metabolic diseases, with a specific focus on diabetes, obesity, and insulin resistance, including associated complications. The discussion includes effective doses in various experimental settings and proposed molecular mechanisms by which isoorientin may exert its therapeutic effects. In addition, the protective effects of extracts of a number of isoorientin-rich plants against metabolic complications will be highlighted.

Effect of Jasonia glutinosa on immune and oxidative status of gilthead seabream (Sparus aurata L.)

Jasonia glutinosa (rock-tea, RT) has numerous biological activities. In the present work, the beneficial effects of dietary RT on gilthead seabream (Sparus aurata L.) were studied. Fish fed experimental diets containing 0 (control), 10 or 30% of RT for 15 and 30 days. Samples from skin mucus, blood, head kidney, liver and gut were obtained at 15 and 30 days. The antioxidant properties from RT were analysed such as the antioxidant capacity and phenolic content. The heat shock protein 70 level (HSP70) and the total oxidized proteins were evaluated on skin mucus as stress markers. Immune parameters, both humoral (peroxidase activity, immunoglobulin M levels and complement activity) and cellular (phagocytic, respiratory burst and peroxidase activities) were determined in skin mucus, serum or head-kidney leucocytes, respectively. Concomitantly, the expression of different genes related to inflammation and oxidative stress was studied both in liver and gut. Skin mucus peroxidase was significantly increased on fish fed 10% RT for 15 days with respect to the control group. In addition, Serum IgM levels were significantly increased while HSP70 levels and oxidized proteins were significantly decreased on skin mucus from fish fed 30% RT for 30 days, respectively. Besides, cellular immune parameters (phagocytosis, respiratory burst and peroxidase activity) were significantly higher in leucocytes from fish fed the RT diets for 15 days, but not for 30 days. Finally, the gene expression of antioxidant enzymes was up-regulated in liver at 15 and in liver and gut at 30 days. However, the expression of il1b and hsp70 was down-regulated in the liver of fish fed 30% RT for 30 days with respect to the values of control fish. The possible inclusion of RT in fish diets as an additive with antioxidant and/or immunostimulant activities is discussed.

Correlation of polyphenol content and antioxidant capacity of selected teas and tisanes from Brazilian market

Abstract In this work, it was evaluated the phenolic content, redox behavior and antioxidant capacity of several selected teas and tisanes from Brazilian market. The samples were classified as simple (single herb) or composed (blend of two or more herbs). In addition, complementary multivariate statistical approaches were used to identify the correlation and interdependence between the amount of major phytocomponents, such as phenols and flavonoids, as well as the antioxidant activity of the products. Results showed that the total polyphenol and total flavonoid concentrations are correlated to thermodynamic feasibility of reactive oxygen species reduction. The statistical modeling differentiated the results datasets in principal components, whose flavonoid content presented itself as the main parameter to segregate data between simple and composed products. On the other hand, the whole polyphenol content, in both teas and tisanes, was more relevant regarding their antioxidant capacity than the flavonoids content. Considering that the manufactures do not display the real amount of each herb in the labels of the composed products, it was not possible to confirm whether the blends of several species lead to a substantial enhancement on their antioxidant capacity. Furthermore, the redox profile and overall polyphenol content suggest that the consumption of green and black teas as well as traditional yerba mate may be worthwhile in preventing ailments associated with oxidative stress in Brazilian population. Notwithstanding, further clinical studies are required to validate this hypothesis.