Synergistic Effects of Potentilla fruticosa L. Leaves Combined with Green Tea Polyphenols in a Variety of Oxidation Systems

Response of laying hens fed diet supplemented with a mixture of olive, laurel, and rosemary leaf powders: Metabolic profile, oxidative status, intestinal histomorphology, and egg quality

This study aimed to evaluate the effects of a mixture of olive, laurel, and rosemary leaf powders, on the oxidative state, biochemical, immune, intestinal morphophysiological parameters, and egg quality of laying hens. One hundred Lohmann Brown hens (28 weeks old) were equally assigned to two groups (n. 50) corresponding to a basal control diet (CON) or the diet supplemented with 6 g/kg feed of leaf powder mixture (LPM) containing olive, laurel, and rosemary leaves (1:1:1), for 60 days. Oxidative status, biochemical indices, immune response, cecal short chain fatty acids (SCFAs), intestinal morphological characteristics, and some egg traits were evaluated at the end of the experiment. The results indicated that LPM improved (P < 0.05) the oxidative status (TOS, ROMs), the immune system (IL-6, IL-1β, and TNF-α), the total protein and HDL cholesterol content, whereas it decreased (P < 0.05) total cholesterol and LDL cholesterol. Aspartate aminotransferase (AST), alkaline phosphatase (ALP), and alanine aminotransferase were significantly (P < 0.05) lower in the LPM than in the CON group. A significant increase (P < 0.05) in SCFA content in the caecum, as well as in villi height and crypt depth in both duodenum and ileum of LPM-treated hens, was observed. Egg quality parameters were not influenced (P > 0.05) by LPM. These findings indicate that LPM can be considered a candidate as an antioxidant ingredient for functional food in laying hens.

Antidiabetic Potential of Tea and Its Active Compounds: From Molecular Mechanism to Clinical Evidence

Diabetes mellitus (DM) is a chronic endocrine disorder that poses a long-term risk to human health accompanied by serious complications. Common antidiabetic drugs are usually accompanied by side effects such as hepatotoxicity and nephrotoxicity. There is an urgent need for natural dietary alternatives for diabetic treatment. Tea (Camellia sinensis) consumption has been widely investigated to lower the risk of diabetes and its complications through restoring glucose metabolism homeostasis, safeguarding pancreatic β-cells, ameliorating insulin resistance, ameliorating oxidative stresses, inhibiting inflammatory response, and regulating intestinal microbiota. It is indispensable to develop effective strategies to improve the absorption of tea active compounds and exert combinational effects with other natural compounds to broaden its hypoglycemic potential. The advances in clinical trials and population-based investigations are also discussed. This review primarily delves into the antidiabetic potential and underlying mechanisms of tea active compounds, providing a theoretical basis for the practical application of tea and its active compounds against diabetes.

Drinking brick tea containing high fluoride increases the prevalence of osteoarthritis in Tibetan, China

The prevalence of osteoarthritis (OA) in Tibetans is higher than that in Han, while Tibetans have a habit of drinking brick tea with high fluoride. A cross-sectional study was conducted to explore the association between fluoride exposure in drinking brick tea and OA. All subjects were divided into four groups by the quartiles (Q) of tea fluoride (TF) and urine fluoride (UF). ROC was plotted and OR were obtained using logistic regression model. The prevalence of OA in the Q3 and Q4 group of TF were 2.2 and 2.7 times higher than in the Q1 group, and the prevalence of OA in the Q2, Q3 and Q4 group of UF were 3.2, 3.5, and 4.1 times higher than in the Q1 group. ROC analysis showed the cutoff values were 4.523 mg/day (TF) and 1.666 mg/L (UF). In conclusion, excessive fluoride in drinking brick tea could be a risk factor for developing OA.

Leaf Stoichiometry of Potentilla fruticosa Across Elevations in China's Qilian Mountains

As an individual plant species can develop its own leaf stoichiometry to adapt to environmental changes, this stoichiometry can provide critical information about a plant species' growth and its potential management in the ecosystem housing it. However, leaf stoichiometry is largely undocumented in regions with large environmental changes arising from differences in elevation. The leaf stoichiometry of Potentilla fruticosa L., a major alpine shrub playing an important role in supporting ecosystem functions and services in China's Qilian Mountains (Northeast Qinghai-Tibetan Plateau), was investigated at different elevations (2,400, 2,600, 2,800, 3,000, 3,200, 3,500, and 3,800 m). At each elevation, leaf elemental (C, N, and P) concentrations were measured in P. fruticosa leaves sampled from three plots (10 × 10 m), and edaphic properties were assessed in nine quadrats (1 × 1 m, three quadrats per plot). Temperature and precipitation were calculated using an empirical formula. Maximum and minimum leaf carbon (C) concentrations ([C] _leaf ) of 524 ± 5.88 and 403 ± 3.01 g kg^-1 were measured at 2,600 and 3,500 m, respectively. Leaf nitrogen (N) concentration ([N] _leaf ) showed a generally increasing trend with elevation and peaked at 3,500 m (27.33 ± 0.26 g kg^-1). Leaf phosphorus (P) concentration ([P] _leaf ) varied slightly from 2,400 to 3,200 m and then dropped to a minimum (0.60 ± 0.10 g kg^-1) at 3800 m. The [C] _leaf :[N] _leaf , [C] _leaf :[P] _leaf , and [N] _leaf :[P] _leaf varied little from 2,400 to 3,000 m but fluctuated somewhat at higher elevations. The main factors affecting P. fruticosa leaf stoichiometry were soil organic C, pH, and soil total P, and the main limiting element for the growth of P. fruticosa in the study area was P. In conclusion, changes in elevation affected leaf stoichiometry of P. fruticosa mainly due to altered soil properties, and addressing phosphorus limitation, especially at higher elevations mainly due to losses caused by high precipitation and sparse vegetation, is a key measure to promote P. fruticosa growth in this region.

The synergistic and antagonistic antioxidant interactions of dietary phytochemical combinations

The frequent intake of whole foods and dietary food variety is recommended due to their health benefits, such as prevention of multiple chronic diseases, including cancer, Alzheimer's disease, cardiovascular diseases, and type 2 diabetes mellitus. Often, consuming whole fruits or vegetables showed the enhanced effects than consuming the individual dietary supplement from natural products, which is widely explained by the interactive effects of co-existing phytochemicals in whole foods. Although research relevant to interactive effects among the bioactive compounds mounted up, the mechanism of interaction is still not clear. Especially, biological influence factors such as bioavailability are often neglected. The present review summarizes the progress on the synergistic and antagonistic effects of dietary phytochemicals, the evaluating models for antioxidant interactions, and the possible interaction mechanisms both in vitro and in vivo, and with an emphasis on biological-related molecular mechanisms of phytochemicals. The research on the interaction mechanism is of value for guiding how to take advantage of synergistic effects and avoid antagonistic effects in daily diets or phytochemical-based treatments for preventing chronic diseases.

Recent phytochemical and pharmacological advances in the genus Potentilla L. sensu lato - An update covering the period from 2009 to 2020

ETHNOPHARMACOLOGICAL RELEVANCE

Potentilla plants are still common herbal medicines used in folk medicine. This review provides an update of research undertaken on Potentilla from 2009 until 2020.

AIM OF THE STUDY

This comprehensive review considers biological updates, recent advances in phytochemical and pharmacological research, and toxicological reports on Potentilla sensu lato based on available data since 2009.

METHODS

A literature search was conducted using available databases including ScienceDirect, PubMed, Scopus, Web of Science, China National Knowledge Infrastructure and Google Scholar.

RESULTS

Until now, more than 210 new and known compounds, including flavonoids, tannins, triterpenes and phenolic compounds, have been confirmed and elucidated for numerous Potentilla species, i.e., in the underground and aerial parts of this genus. Modern pharmacology studies have revealed that those structures are responsible for a broad spectrum of pharmacological activities, such as anti-neoplastic, antihyperglycemic, anti-inflammatory, antioxidant, hepatoprotective, neuroprotective, antibacterial and anti-yeast effects.

CONCLUSIONS

However, in vitro studies must be re-considered due to the discovery of urolithins and their origins, including microbiota, which can lead to different results when applying Potentilla species and their extracts to in vivo conditions. Thus, future research should focus more on in vivo and particularly clinical studies to confirm the validity and safety of traditional uses. Particularly, the use of Potentilla alba extracts in the treatment of thyroid gland disorders should be further explored to confirm the underlying mechanism of their action, efficacy and safety. In addition, more clinical studies should focus on Potentilla erecta rhizome extracts for application as herbal remedies against dysentery, diarrhoea and inflammation of the skin.

Plant Phenolics: Bioavailability as a Key Determinant of Their Potential Health-Promoting Applications

Phenolic compounds are secondary metabolites widely spread throughout the plant kingdom that can be categorized as flavonoids and non-flavonoids. Interest in phenolic compounds has dramatically increased during the last decade due to their biological effects and promising therapeutic applications. In this review, we discuss the importance of phenolic compounds' bioavailability to accomplish their physiological functions, and highlight main factors affecting such parameter throughout metabolism of phenolics, from absorption to excretion. Besides, we give an updated overview of the health benefits of phenolic compounds, which are mainly linked to both their direct (e.g., free-radical scavenging ability) and indirect (e.g., by stimulating activity of antioxidant enzymes) antioxidant properties. Such antioxidant actions reportedly help them to prevent chronic and oxidative stress-related disorders such as cancer, cardiovascular and neurodegenerative diseases, among others. Last, we comment on development of cutting-edge delivery systems intended to improve bioavailability and enhance stability of phenolic compounds in the human body.

High-Pressure Extraction of Antioxidant-Rich Fractions from Shrubby Cinquefoil (Dasiphora fruticosa L. Rydb.) Leaves: Process Optimization and Extract Characterization

Dasiphora fruticosa (basionym Potentilla fruticosa) is a shrub, known in traditional medicine for centuries. Due to the wide range of pharmacological effects, interest and applications of D. fruticosa extracts are continually increasing; however, reports on optimization of extraction conditions are scarce. Herein, a multi-step high-pressure extraction process with increasing polarity solvents was developed to isolate valuable fractions from D. fruticosa leaves. Supercritical CO₂ extraction recovered 2.46 g/100 g of lipophilic fraction, rich in polyunsaturated fatty acids. Further, pressurized liquid extractions (PLE) with acetone, ethanol, and water were applied to obtain antioxidant-rich higher polarity extracts. Under optimized PLE conditions, the cumulative polar fraction yield was 29.98 g/100 g. Ethanol fraction showed the highest yield (15.3 g/100 g), TPC values (148.4 mg GAE/g), ABTS^•+, and DPPH^• scavenging capacity (161.1 and 151.8 mg TE/g, respectively). PLE was more efficient than conventional solid–liquid extraction in terms of extraction time, extract yields, and in vitro antioxidant capacity. Phytochemical characterization of PLE extracts by UPLC-Q-TOF-MS revealed the presence of hyperoside, ellagic acid, among other health beneficial phenolic substances. Τhis study highlights the potential of high-pressure extraction techniques to isolate antioxidant-rich fractions from D. fruticosa leaves with multipurpose applications, including the prevention and treatment of chronic diseases.

Scrutinizing antioxidant interactions between green tea and some medicinal plants commonly used as herbal teas

Meta-analysis reports suggested that green tea (GT) consumption is associated with mild to moderate effects on major global killers. To enhance the health promoting potential of GT, one of the strategies is to combine it with traditionally used medicinal plants (Ocimum gratissimum, Cymbopogon citratus, Cymbopogon flexuosus, and Hibiscus rosa-sinensis). The aim of this investigation was to evaluate and compare the possible synergistic antioxidant interaction of binary combinations of GT with medicinal plants. Overall, GT and O. gratissimum combination showed the highest antioxidant potential and strongest synergistic interaction at EC₅₀ . A strong correlation was found between antioxidant capacity (DPPH, ABTS, NO, and hemolysis) and total phenolic content (TPC) (except lipid peroxidation) for individual infusions, but very weak correlation was observed for GT combinations. Whereas, for both individual and binary aqueous infusions, moderate to strong correlation was observed between antioxidant parameters and FTIR-selected peak (3250-3290 cm^-1 ) omitting lipid peroxidation for single infusions. PRACTICAL APPLICATIONS: The combination of GT with certain medicinal plants used as herbal teas can demonstrate synergistic interactions that may boost the health promoting potential of GT. This study provides basis for future designing and formulation of beverages containing GT combinations based on their antioxidant interactions that can potentially enhance the efficacy of GT as a chemopreventive agent. It may also promote the consumption of GT combinations that may help in realizing untapped potential of underutilized plants.

In vitro antioxidant activity of phenolic-enriched extracts from Zhangping Narcissus tea cake and their inhibition on growth and metastatic capacity of 4T1 murine breast cancer cells

Phenolics, as the main bioactive compounds in tea, have been suggested to have potential in the prevention of various human diseases. However, little is known about phenolics and their bioactivity in Zhangping Narcissue tea cake which is considered the most special kind of oolong tea. To unveil its bioactivity, three phenolic-enriched extracts were obtained from Zhangping Narcissue tea cake using ethyl acetate, n-butanol, and water. Their main chemical compositions and in vitro bioactivity were analyzed by high-performance liquid chromatography (HPLC) and ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). The ethyl acetate fraction (ZEF) consisted of higher content of phenolics, flavonoids, procyanidins, and catechin monomers (including epigallocatechin gallate (EGCG), epicatechin gallate (ECG), and gallocatechin gallate (GCG)) than n-butanol fraction (ZBF) and water fraction (ZWF). ZEF exhibited the strongest antioxidant capacity in vitro due to its abundant bioactive compounds. This was validated by Pearson correlation and hierarchical clustering analyses. ZEF also showed a remarkable inhibition on the growth, migration, and invasion of 4T1 murine breast cancer cells.

Multi-approach metabolomics analysis and artificial simplified phytocomplexes reveal cultivar-dependent synergy between polyphenols and ascorbic acid in fruits of the sweet cherry (Prunus avium L.)

Fruits of the sweet cherry (Prunus avium L.) accumulate a range of antioxidants that can help to prevent cardiovascular disease, inflammation and cancer. We tested the in vitro antioxidant activity of 18 sweet cherry cultivars collected from 12 farms in the protected geographical indication region of Marostica (Vicenza, Italy) during two growing seasons. Multiple targeted and untargeted metabolomics approaches (NMR, LC-MS, HPLC-DAD, HPLC-UV) as well as artificial simplified phytocomplexes representing the cultivars Sandra Tardiva, Sandra and Grace Star were then used to determine whether the total antioxidant activity reflected the additive effects of each compound or resulted from synergistic interactions. We found that the composition of each cultivar depended more on genetic variability than environmental factors. Furthermore, phenolic compounds were the principal source of antioxidant activity and experiments with artificial simplified phytocomplexes indicated strong synergy between the anthocyanins and quercetins/ascorbic acid specifically in the cultivar Sandra Tardiva. Our data therefore indicate that the total antioxidant activity of sweet cherry fruits may originate from cultivar-dependent interactions among different classes of metabolite.

Cytotoxic and Enzyme Inhibitory Potential of Two Potentilla species (P. speciosa L. and P. reptans Willd.) and Their Chemical Composition

In this work, the biological and chemical fingerprints of three extracts (ethyl acetate, methanol, and water) from two Potentilla species (Potentilla reptans and P. speciosa) were investigated. Antioxidant, enzyme inhibitory, and cytotoxic activities were performed for the biological fingerprint. For the chemical characterization, total bioactive components, and individual phenolic components were determined using photometric and HPLC methods, respectively. The main identified phenolic compounds in these extracts were rutin and catechin. Methanol and water extracts contained the highest total phenolic and flavonoid content. The results of antioxidant assays showed that methanol and water extracts displayed higher antioxidant activity compared to the ethyl acetate extract. Generally, methanol and water extracts exhibited higher biological activities correlated with higher levels the bioactive components. For P. speciosa, the methanol extract exhibited the highest enzyme inhibitory activity (except BChE inhibitory activity). P. reptans exhibited also high antiproliferative activity against MCF-7 cells whilst P. speciosa had weak to moderate activity against both of A549 and MCF-7 cell lines. The results suggest that Potentilla species could be potential candidates for developing new phyto-pharmaceuticals and functional ingredients.

Simultaneous determination of eight catechins and four theaflavins in green, black and oolong tea using new HPLC-MS-MS method

A simple, rapid and accurate analytical method was developed for the analysis of eight tea catechins and four theaflavins simultaneously in three types of tea (green, black and oolong tea), using ultra high performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry (HPLC-MS-MS) in multiple-reaction monitoring (MRM) mode. This method using HPLC-MS-MS in positive mode was performed on a CAPCELL PAK C18 MGIII (2.0mm×100mm, 3μm) column (Shiseido) with the mobile phase consisting of 0.1% aqueous formic acid (A) and methanol (B) in gradient elution at a flow rate of 0.3mLmin^-1, and the column temperature set at 30°C. The optimized HPLC-MS-MS methodology is selective and specific, and was validated for eight catechins and four theaflavins widely reported in different teas. Satisfactory linearity was achieved in linear range (0.02-5μgmL^-1 for catechins and 0.02-20μgmL^-1 for theaflavins) and fine determination coefficient (r²>0.9935). The recoveries ranged from 65% to 115% with the RSD ranging from 2.4% to 6.7%. The methodology was used to evaluate the target polyphenols concentration in three types of tea samples.