Rezumat

The present study evaluated three green extraction methods, accelerated solvent extraction (ASE), ultrasound-assisted extraction (UAE), and laser irradiation extraction (LE), for the polyphenolic compounds and vitamin C extraction of Cornus mas L. and Crataegus monogyna fruit extracts. The polyphenols and vitamin C of extracts were quantified using HPLC-DAD, and the total phenolic content, flavonoid content, antioxidant activity (DPPH and reducing power), and antidiabetic activity were also studied. The antidiabetic activity was examined by the inhibition of alpha-amylase and alpha-glucosidase, and in vitro on a beta TC cell line (beta-TC-6). The results showed significant differentiation in the extraction yield between the methods used, with the ASE and LE presenting the highest values. The C. mas fruit extract obtained by ASE exhibited the best antioxidant activity, reaching an IC50 value of 31.82 +/- 0.10 mu g/mL in the DPPH assay and 33.95 +/- 0.20 mu g/mL in the reducing power assay. The C. mas fruit extracts obtained by ASE and LE also have the highest inhibitory activity on enzymes associated with metabolic disorders: alpha-amylase (IC50 = 0.44 +/- 0.02 mu g/mL for the extract obtained by ASE, and 0.11 +/- 0.01 mu g/mL for the extract obtained by LE at combined wavelengths of 1270 + 1550 nm) and alpha-glucosidase (IC50 of 77.1 +/- 3.1 mu g/mL for the extract obtained by ASE, and 98.2 +/- 4.7 mu g/mL for the extract obtained by LE at combined wavelengths of 1270 + 1550 nm). The evaluation of in vitro antidiabetic activity demonstrated that the treatment with C. mas and C. monogyna fruit extracts obtained using ASE stimulated the insulin secretion of beta-TC-6 cells, both under normal conditions and hyperglycemic conditions, as well. All results suggest that C. mas and C. monogyna fruit extracts are good sources of bioactive molecules with antioxidant and antidiabetic activity.

Rezumat

The present study evaluated the antioxidant and antidiabetic properties of Medicago sativa and Solidago virgaurea extracts enriched in polyphenolic compounds. The extracts were obtained by accelerated solvent extraction (ASE) and laser irradiation. Then, microfiltration was used for purification, followed by nanofiltration used to concentrate the two extracts. The obtained extracts were analyzed to determine their antioxidant activity using DPPH radical scavenging and reducing power methods. The antidiabetic properties have been investigated in vitro on a murine insulinoma cell line (beta-TC-6) by the inhibition of alpha-amylase and alpha-glucosidase. M. sativa obtained by laser irradiation and concentrated by nanofiltration showed the highest DPPH center dot scavenging (EC50 = 105.2 +/- 1.1 mu g/mL) and reducing power activities (EC50 = 40.98 +/- 0.2 mu g/mL). M. sativa extracts had higher inhibition on alpha-amylase (IC50 = 23.9 +/- 1.2 mu g/mL for concentrated extract obtained after ASE, and 26.8 +/- 1.1), while S. virgaurea had the highest alpha-glucosidase inhibition (9.3 +/- 0.9 mu g/mL for concentrated extract obtained after ASE, and 8.6 +/- 0.7 mu g/mL for concentrated extract obtained after laser extraction). The obtained results after evaluating in vitro the antidiabetic activity showed that the treatment with M. sativa and S. virgaurea polyphenolic-rich extracts stimulated the insulin secretion of beta-TC-6 cells, both under normal conditions and under hyperglycemic conditions as well. This paper argues that M. sativa and S. virgaurea polyphenolic-rich extracts could be excellent natural sources with promising antidiabetic potential.

Rezumat

Ag nanoparticles (AgNPs) were biosynthesized using sage (Salvia officinalis L.) extract. The obtained nanoparticles were supported on SBA-15 mesoporous silica (S), before and after immobilization of 10% TiO2 (Degussa-P25, STp; commercial rutile, STr; and silica synthesized from Ti butoxide, STb). The formation of AgNPs was confirmed by X-ray diffraction. The plasmon resonance effect, evidenced by UV-Vis spectra, was preserved after immobilization only for the sample supported on STb. The immobilization and dispersion properties of AgNPs on supports were evidenced by TEM microscopy, energy-dispersive X-rays, dynamic light scattering, photoluminescence and FT-IR spectroscopy. The antioxidant activity of the supported samples significantly exceeded that of the sage extract or AgNPs. Antimicrobial tests were carried out, in conditions of darkness and white light, on Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli and Candida albicans. Higher antimicrobial activity was evident for SAg and STbAg samples. White light increased antibacterial activity in the case of Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa). In the first case, antibacterial activity increased for both supported and unsupported AgNPs, while in the second one, the activity increased only for SAg and STbAg samples. The proposed antibacterial mechanism shows the effect of AgNPs and Ag+ ions on bacteria in dark and light conditions.

Rezumat

In recent years, increased attention has been paid to the recovery of bioactive compounds from waste and by-products resulting from the agro-industrial sector and their valorization into new products, which can be used in the health, food, or agricultural industry, as innovative and sustainable approaches to waste management. In this work, two of these by-products resulting from the fruit-processing industry were used for the recovery of bioactive compounds (polyphenols), namely lingonberry pomace (Vaccinium vitis-idaea) and grape pomace (Vitis vinifera). Two green extraction techniques were employed to obtain hydroalcoholic extracts (solvent: 50% EtOH, 10% mass): ultrasound-assisted extraction (UAE) and accelerated solvent extraction (ASE). The extracts were subjected to micro- and ultrafiltration processes, and further analyzed to determine the bioactive compound content through spectrophotometric (UV-Vis) and chromatographic (HPLC-PDA) methods. Additionally, the extracts exhibited significant enzyme inhibition, particularly against alpha-amylase and beta-glucosidase, suggesting potential anti-diabetic properties. The extracts characteristics, polyphenolic content, antioxidant capacity and enzyme inhibitory ability, were statistically compared, and significant differences were found between the two extraction methods. The grape pomace concentrated extracts showed a pronounced inhibitory activity on both analyzed enzymes compared to the lingonberry pomace concentrated extracts, closer to the standard used; e.g., IC50 alpha-amylase = 0.30 +/- 0.01 mu g/mL (IC50 acarbose = 0.3 +/- 0.01 mu g/mL), IC50 alpha-glucosidase = 0.60 +/- 0.01 mu g/mL (IC50 acarbose = 0.57 +/- 0.02 mu g/mL). These findings highlight the potential of agro-industrial residues as bioactive compound resources, with their valorization through application in food, nutraceutical, or pharmaceutical industries therefore contributing to the sustainable development and promotion of circular economy principles with the recovery of valuable inputs from plant by-products.

Rezumat

Lately, there has been increased interest in the development of phytochemical alternatives for the prevention and treatment of type 2 diabetes, the alternatives that are able to reduce or prevent glucose absorption by inhibiting digestive enzymes. In this context, this study aims to analyze the inhibitory alpha-amylase and alpha-glucosidase activities of Artemisia abrotanum and Symphytum officinale polyphenolic compound-rich extracts obtained by membrane technologies (micro- and ultrafiltration). Polyphenols and flavones content, HPLC-MS polyphenolic compounds profiling, antioxidant activity, and cytotoxic potential of these herbs were determined. Major phenolic acid compounds were chlorogenic acid, ellagic acid, caffeic acid, and rosmarinic acid. The flavone content was higher in the case of A. abrotanum extracts, and the major compounds were rutin and umbelliferone. The polyphenolic-rich extract of A. abrotanum had the highest quantities of polyphenols, 977.75 mu g/mL, and flavones, 552.85 mu g/mL, as well as a pronounced alpha-amylase inhibitory activity (IC50 1881.21 +/- 1.8 mg/mL), a value close to acarbose inhibitory activity (IC50 1110.25 +/- 8.82 mg/mL) that was used as the control for both enzymes. The alpha-glucosidase inhibitory activity was higher for both herb extracts, more pronounced for S. officinale polyphenolic-rich extract (IC50 291.56 +/- 2.1 mg/mL), a value higher than that of acarbose (IC50 372.35 +/- 3.2 mg/mL). These plants show potential as a complementary therapy for type 2 diabetes management.

Rezumat

Rezumat

Recently, there has been increased interest in the discovery of new natural herbal remedies for treating diabetes and inflammatory diseases. In this context, this work analyzed the antidiabetic and anti-inflammatory potential of Artemisia absinthium, Artemisia vulgaris and Trigonella foenum-graecum herbs, which have been studied less from this point of view. Therefore, extracts were prepared and processed using membrane technologies, micro- and ultrafiltration, to concentrate the biologically active principles. The polyphenol and flavone contents in the extracts were analyzed. The qualitative analysis of the polyphenolic compounds was performed via HPLC, identifying chlorogenic acid, rosmarinic acid and rutin in A. absinthium; chlorogenic acid, luteolin and rutin in A. vulgaris; and genistin in T. foenum-graecum. The antidiabetic activity of the extracts was analyzed by testing their ability to inhibit alpha-amylase and alpha-glucosidase, and the anti-inflammatory activity was analyzed by testing their ability to inhibit hyaluronidase and lipoxygenase. Thus, the concentrated extracts of T. foenum-graecum showed high inhibitory activity on a-amylase-IC50 = 3.22 +/- 0.3 mu g/mL-(compared with acarbose-IC50 = 3.5 +/- 0.18 mu g/mL) and high inhibitory activity on LOX-IC50 = 19.69 +/- 0.52 mu g/mL (compared with all standards used). The concentrated extract of A. vulgaris showed increased alpha-amylase inhibition activity-IC50 = 8.57 +/- 2.31 mu g/mL-compared to acarbose IC50 = 3.5 +/- 0.18 mu g/mL. The concentrated extract of A. absinthium showed pronounced LOX inhibition activity-IC50 = 19.71 +/- 0.79 mu g/mL-compared to ibuprofen-IC50 = 20.19 +/- 1.25 mu g/mL.

Rezumat

Rezumat

This study presents the preparation of hybrid nanofiltration membranes based on poly(1,4-phenylene ether ether sulfone), polyacrylonitrile, poly(vinyl pyrrolidone), and SBA-15 mesoporous silica. Laser treatment of polymeric solutions to enhance the hydrophilicity and performance of membranes was investigated. The membranes' structure was characterized using scanning electron (SEM) and atomic force (AFM) microscopy and contact angle measurements. The addition of PAN in the casting solution produced significant changes in the membrane structure, from finger-like porous structures to sponge-like porous structures. Increased PAN concentration in the membrane composition enhanced the hydrophilicity of the membrane surface, which also accounted for the improvement in the antifouling capabilities. The permeation of apple pomace extract and the content of polyphenols and flavonoids were used to evaluate the efficacy of the hybrid membranes created. The results showed that the hybrid nanofiltration membranes based on PPEES/PAN/PVP/SBA-15: 15/5/1/1 and 17/3/1/1 exposed to laser for 5 min present a higher rejection coefficient to total polyphenols (78.6 +/- 0.7% and 97.8 +/- 0.9%, respectively) and flavonoids (28.7 +/- 0.2% and 50.3 +/- 0.4%, respectively) and are substantially better than a commercial membrane with MWCO 1000 Da or PPEES-PVP-based membrane.

Rezumat

Due to the increase of the incidence of type II diabetes nowadays there are attempts to find phytotherapeutic alternatives for the prophylaxis of this disease by inhibiting the enzymes involved in glucose uptake. Thus, in this study the α-amylase and α-glucosidase inhibitory activities of some hydroalcoholic Apium graveolens and Agropyrum repens extracts (50% EtOH, v/v, 10% weight) were analysed. Extracts were processed by membranare processes, microand ultrafiltration for obtaining rich-polyphenolic extracts. The polyphenols and flavones content and antioxidant activity of them were analysed. The extracts of both plants have shown inhibitory activities on the two digestive enzymes. © 2019 Editura Academiei Romane. All rights reserved.