The Bioavailability, Extraction, Biosynthesis and Distribution of Natural Dihydrochalcone: Phloridzin.

Phloridzin is an important phytochemical which was first isolated from the bark of apple trees. It is a member of the dihydrochalcones and mainly distributed in the plants of the Malus genus, therefore, the extraction method of phloridzin was similar to those of other phenolic substances. High-speed countercurrent chromatography (HSCCC), resin adsorption technology and preparative high-performance liquid chromatography (HPLC) were used to separate and purify phloridzin. Many studies showed that phloridzin had multiple pharmacological effects, such as antidiabetic, anti-inflammatory, antihyperglycaemic, anticancer and antibacterial activities. Besides, the physiological activities of phloridzin are cardioprotective, neuroprotective, hepatoprotective, immunomodulatory, antiobesity, antioxidant and so on. The present review summarizes the biosynthesis, distribution, extraction and bioavailability of the natural compound phloridzin and discusses its applications in food and medicine.

Simultaneous extraction and separation of bioactive compounds from apple pomace using pressurized liquids coupled on-line with solid-phase extraction.

The objective of this work was the development of an on-line extraction/fractionation method based on the coupling of pressurized liquid extraction and solid-phase extraction for the separation of phenolic compounds from apple pomace. Several variables of the process were evaluated, including the amount of water of the first stage (0-120 mL), temperature (60-80 °C), solid-phase extraction adsorbent (Sepra, Isolute, Strata X and Oasis) and activation/elution solvent (methanol and ethanol). The best results were observed with the adsorbent Sepra. The temperature had a small effect on recovery, but significant differences were observed for phlorizin and a quercetin derivative. Results indicate that ethanol can be used to replace methanol as an activation, extraction/elution solvent. While using mostly green solvents (water, ethanol, and a small amount of methanol that could be reused), the developed method produced higher or similar yields of acids (2.85 ± 0.19 mg/g) and flavonoids (0.97 ± 0.11 mg/g) than conventional methods.

Purified Phlorizin from DocynIa Indica (Wall.) Decne by HSCCC, Compared with Whole Extract, Phlorizin and Non-Phlorizin Fragment Ameliorate Obesity, Insulin Resistance, and Improves Intestinal Barrier Function in High-Fat-Diet-Fed Mice.

Natural products generally contain complex and multiple bioactive compounds that are responsible for the effects on health through complicated synergistic and/or suppressive actions. As an important raw material of local ethnic minority tea, ethnomedicines and food supplements in southwestern areas of China, Docynia indica (Wall.) Decne (DID) mainly consists of phlorizin (PHZ), which is the main active component. In this study, the holistic activities and the interactions of components of PHZ, non-phlorizin (NP) in the DID extract (DIDE) were evaluated. A rapid and effective high-speed counter-current chromatography (HSCCC) was performed to knock out PHZ from DIDE and the purity of PHZ was 96.01% determined by HPLC, with a recovery rate of 96.76%. After 13 weeks of treatment course in a high-fat diet (HFD)-induced obese mice model, the results revealed that the DIDE and PHZ significantly decreased weight gain, blood lipid levels, hyperplasia of adipocytes and alleviated inflammation (p < 0.05). Both DIDE and PHZ improves insulin resistance (p < 0.001). Meanwhile, the intestinal barrier function was improved compared to HFD group, through the determination of serum lipopolysaccharides (LPS), glucagon-likepeptide-2 (GLP-2) and hematoxylin-eosin staining of jejunum. Interestingly, after NP treatment, the metabolic syndrome of the HFD-induced obesity appeared to have a similar improvement. All the experiments showed that there is a synergistic weakening phenomenon when PHZ and NP interact with each other in the mixed state. In conclusion, for the PHZ and NP showing a good effect on anti-obesity, anti-inflammation, and intestinal barrier function, DIDE could be a good source of functional food to prevent obesity.

Optimization of the ultrasound-assisted extraction of antioxidant phloridzin from Lithocarpus polystachyus Rehd. using response surface methodology.

The purpose of this study was to optimize the extraction process of phloridzin from Lithocarpus polystachyus Rehd. leaves using response surface methodology and to determine the antioxidant capacity of the extract. A Box-Behnken design was used to analyze the effects of ethanol concentration, liquid-solid ratio, soak time and extraction time on the extraction yield of phloridzin. The content of phloridzin was determined by high-performance liquid chromatography. To assess the antioxidant capacity of the extract, three in vitro test systems were used (1,1-,diphenyl-2-picrylhydrazyl, hydroxyl radical scavenging test and reduction force). The optimal parameters obtained by response surface methodology were a volume fraction of ethanol of 64%, a liquid-solid ratio of 37:1, a soaking time of 35 h and a sonication time of 38 min. The proportion of the extraction of phloridzin from L. polystachyus under these industrial process conditions was 3.83%. According to the obtained results, response surface methodology could be suggested as an adequate model for optimizing the extraction process of phloridzin from L. polystachyus. Ultrasound extraction significantly increased the extraction rate of phloridzin, which could be used as an antioxidant in pharmaceutical and food products.

Analysis of Polyphenolic Compounds in Extracts from Leaves of Some Malus domestica Cultivars: Antiradical and Antimicrobial Analysis of These Extracts.

In this study, methanol, ethyl acetate, water extracts, and precipitate were obtained from leaves of Malus domestica cultivars: Golden delicious, Jonagold, Elstar, Ligol, and Mutsu. Antiradical activity of these extracts was measured using the ABTS+∙ radical, and antimicrobial activity was measured with the disk-diffusion method. Phenolic compounds were measured with the colorimetric method and identified with high performance liquid chromatography (HPLC). The highest antiradical activity was observed for the Jonagold variety, and in particular strong activity was noted for ethyl acetate extracts. Antimicrobial activity was observed against strains of Staphylococcus aureus, Enterococcus faecalis, and the fungus Candida glabrata. Particularly susceptible to the extracts activity appeared to be Staphylococcus aureus, but the growth of Candida glabrata was inhibited in the presence of ethyl acetate extracts. With the HPLC method we identified a high amount of phloridzin (above 500 mg per g of ethyl acetate extracts), lower amounts of hyperoside, isoquercitrin, and quercitrin, and traces of p-hydroxybenzoic and chlorogenic acids. The contribution of phloridzin to antiradical activity of methanol and ethyl acetate extracts was very high (above 90%). In water extract the contribution of phloridzin was between 38.9 and 55.2%, chlorogenic acid 22.7 and 36.1%, and hyperoside 12.2 and 13.3%.

Phloridzin derivatives inhibiting pro-inflammatory cytokine expression in human cystic fibrosis IB3-1 cells.

Cystic Fibrosis (CF) is the most diffuse autosomal recessive genetic disease affecting Caucasians. A persistent recruitment of neutrophils in the bronchi of CF patients contributes to exacerbate the airway tissue damage, suggesting that modulation of chemokine expression may be an important target for the patient's well being thus the identification of innovative anti-inflammatory drugs is considered a longterm goal to prevent progressive tissue deterioration. Phloridzin, isolated from Malus domestica by a selective molecular imprinting extraction, and its structural analogues, Phloridzin heptapropionate (F1) and Phloridzin tetrapropionate (F2), were initially investigated because of their ability to reduce IL-6 and IL-8 expression in human CF bronchial epithelial cells (IB3-1) stimulated with TNF-α. Release of these cytokines by CF cells was shown to be controlled by the Transcription Factor (TF) NF-kB. The results of the present investigation show that of all the derivatives tested, Phloridzin tetrapropionate (F2) is the most interesting and has greatest potential as it demonstrates inhibitory effects on the expression and production of different cytokines involved in CF inflammation processes, including RANTES, VEGF, GM-CSF, IL-12, G-CSF, MIP-1b, IL-17, IL-10 and IP-10, without any correlated anti-proliferative and pro-apoptotic effects.

[Chemical constituents of Fortunella margarita fruits].

OBJECTIVE: To study the chemical constituents of the fruits of Fortunella margarita. METHODS: The constituents were isolated and purified on silica gel column and other column chromatography, and their structures were determined by means of spectral techniques and physicochemical data. RESULTS: 11 compounds were isolated and identified as fortunellin (1), naringenin (2), phloridzin (3), nicotinflorin (4), rhoifolin (5), 4'-methoxy vitexin-2"-O-alpha-L-rhamnopyranoside (6), 4'-methoxy isovitexin-2"-O-alpha-L-rhamnopyranoside (7), rutin (8), phloretin-3', 5'-di-C-beta-glucopyranoside (9), 5-hydroxymethyl-furaldehyde (10) and beta-sitosterol (11). CONCLUSION: Compound 2 - 4,7 and 10 are isolated from the plant for the first time.

Phloridzin isolated from Acanthopanax senticosus promotes proliferation of α6 integrin (CD 49f) and ß1 integrin (CD29) enriched for a primary keratinocyte population through the ERK-mediated mTOR pathway.

We investigated the proliferative effect of a Acanthopanax senticosus extract (ASE) on human CD49f(+)/CD29(+) keratinocytes and isolated phloridzin from A. senticosus as an active compound. In addition, the possible mechanisms of action were examined. We found that the ASE and phloridzin-promoted proliferation of CD49f(+)/CD29(+) cells using MTT and Click-iT™ EdU flow cytometry assays. In addition, phosphorylation of the p44/42 MAPK (ERK), mTOR, p70 S6 kinase (p70S6K), S6 ribosomal protein (S6RP), eukaryotic initiation factor 4B (eIF4B), and eIF4E was stepwise induced in CD49f(+)/CD29(+) cells. Furthermore, the ASE and phloridzin significantly induced the production of vascular endothelial growth factor and interleukin-6 in CD49f(+)/CD29(+) cells. Similarly, ASE and phloridzin-induced phosphorylation of the mTOR/p70S6K/S6RP/eIF4B/eIF4E pathway was blocked in response to pretreatment with PD98059, a specific ERK inhibitor. Taken together, these results indicate that ASE and phloridzin-induced proliferation of CD49f(+)/CD29(+) cells under serum-free conditions was mediated by the ERK-dependent mTOR pathway.

[Sodium-glucose co-transporter-2 inhibitors: from the bark of apple trees and familial renal glycosuria to the treatment of type 2 diabetes mellitus]. / Inhibidores SGLT-2: de la corteza del manzano y la glucosuria familiar al tratamiento de la diabetes mellitus tipo 2.

The therapeutic armamentarium for the treatment of hyperglycemia in type 2 diabetes mellitus is still inadequate. We are currently witnessing the introduction of a new mode of hypoglycemic treatment through induction of glycosuria to decrease the availability of the metabolic substrate, i.e. glucose. Clinical trials have shown that sodium-glucose co-transporter-2 (SGLT2) inhibitors are as efficacious as other oral hypoglycemic drugs. This article discusses the basic features of this new treatment concept and the efficacy and safety of this new drug group.

Simultaneous separation and purification of total polyphenols, chlorogenic acid and phlorizin from thinned young apples.

An efficient preparative separation of polyphenols from thinned young apples (TYA) has been developed in the present study. X-5 resin was verified to offer the best adsorption capacity and desorption ratio for total polyphenols among the eight macroporous resins investigated. Influential factors, such as pH value and concentration of feeding solution, strippant, and adsorption isotherm to the separation of total polyphenols, were successively investigated on X-5 resin. After one run treatment, the phenolic content was increased 2.12-fold from 35.17% to 74.64%, with a recovery yield of 89.35%. Chlorogenic acid and phlorizin were selectively purified using X-5 and polyamide resins. The contents of chlorogenic acid and phlorizin were 15.20% and 97.52% with recovery yields of 89.16% and 64.95%, respectively. The method developed will provide a potential approach for its wide industrial and pharmaceutical use.

Isolation of Prunin from the fruit shell of Bixa orellana and the effect of ß-cyclodextrin on its binding with calf thymus DNA.

Naringenin-7-O-glucoside [Prunin (Pru)] was isolated from the fruit shell of Bixa orellana L. The binding of Pru with calf thymus DNA (ctDNA) and the influence of cyclomaltoheptaose (ß-cyclodextrin, ß-CD) on the binding were studied by absorption and fluorescence spectroscopic techniques. The comparison of the binding modes of Pru/ß-CD and ctDNA-Pru/ß-CD suggested that ß-CD extracted Pru from DNA for forming inclusion complex. Molecular modeling gave added support to the above results. Fluorescence microscopy was used to visualize the effect of ß-CD on the bindings.

Apple leaf extract as a potential candidate for suppressing postprandial elevation of the blood glucose level.

While the industrial value of fruits has long been recognized, only recently have the leaves of fruit trees been considered to have immense and mostly-untapped potential. In the present study, the physiological effects of apple leaf extract in mice were investigated. In addition, we sought to elucidate the active principle(s) and examined its potential for application. Apple leaf extract suppressed postprandial elevation of the blood glucose level and increased the residual amount of glucose in the small intestine in glucose-loaded mice compared with those in control mice. Bioassay-guided fractionation led to an active component that was identified as phloridzin, a known SGLT inhibitor, based on an analysis of its spectral data. With regard to an anti-hyperglycemic effect, extraction with ethanol from leaves of apple tree gave the best results. These effects decreased with heating during the extraction procedure. Since bolus ingestion of the extract did not affect blood glucose levels in normal mice with or without an overnight fast, the inhibitory effects on glucose absorption were not considered to be associated with unspecific gastrointestinal impairment and the extract did not cause hypoglycemia at a normally effective dose. Therefore, the leaf parts of apple tree may be a promising candidate as an industrial resource for maintaining good health in the future.

Preparative separation and identification of the flavonoid phlorhizin from the crude extract of Lithocarpus polystachyus Rehd.

The flavonoid phlorhizin is abundant in the leaves of Sweet Tea (ST, Lithocarpus Polystachyus Rehd). Phlorhizin was preparatively separated and purified from a crude ST extract containing 40% total flavonoids by static adsorption and dynamic desorption on ADS-7 macroporous resin and neutral alumina column chromatography. Only water and ethanol were used as solvents and eluants throughout the whole separation and purification process. Using a phlorhizin standard as the reference compound, the target compound separated from the crude ST extracts was analyzed by thin layer chromatography (TLC), high performance liquid chromatography (HPLC) and electrospray ionization mass spectrometry (EIS-MS) and identified as 99.87% pure (by HPLC-UV) phlorhizin. The results showed that 10 g of the target compound could be obtained from 40 g of the crude extracts in a single operation, indicating a 40% recovery. Therefore, this represents an efficient and environmentally-friendly technology for separating and purifying phlorhizin from ST leaves.

Inhibition of uropathogenic Escherichia coli by cranberry juice: a new antiadherence assay.

A combination of microplate technology and turbidity assessment for testing the adherence of P-fimbriated Escherichia coli to human uroepithelial cell line T24, validated with the addition of the known inhibitor 4-O-alpha-D-galactopyranosyl-alpha-D-galactopyranose (galabiose), resulted in a high-throughput, biologically relevant assessment of cranberry (Vaccinium macrocarpon). P-fimbriated ATCC E. coli strains 25922, 29194, and 49161 were inhibited by galabiose. ATCC 29194, a representative urine isolate containing the papGII allele (Class II fimbrial adhesin) and demonstrating the most significant inhibition in the presence of galabiose, was chosen for further testing. In this assay, a low-polarity fraction of cranberry juice cocktail demonstrated dose-dependent inhibition of E. coli adherence. Reported here, for the first time in V. macrocarpon, are 1-O-methylgalactose, prunin, and phlorizin, identified in an active fraction of cranberry juice concentrate. This in vitro assay will be useful for the standardization of cranberry dietary supplements and is currently being used for bioassay-guided fractionation of cranberry juice concentrate.