Influence of ultrasound-assist and classical extractions on total phenolic, tannin, flavonoids, tocopherol and antioxidant characteristics of Teucrium polium aerial parts

Quercetin-loaded sodium alginate/collagen/h-boron nitride potential wound dressings prepared using the Box-Behnken experimental design

BACKGROUND/AIMS

Natural and synthetic biocompatible polymers have received significant attention in the pharmaceutical industry due to their rapid and effective healing properties in the wound healing process. The aim of this study was to optimize the extraction of onions, the preparation of sodium alginate/collagen/hydrogen boron nitride (NaAlg/Col/h-BN) membranes using the Box-Behnken experimental design, and determine the optimal conditions for quercetin release. The study also aimed to investigate the antimicrobial and antioxidant activities of the prepared membranes and their therapeutic properties.

METHODS AND RESULTS

The prepared membranes were characterized by scanning electron microscopy (SEM), fourier transform infrared (FTIR), differential scanning calorimetry (DSC), and X-ray diffraction (XRD). Antimicrobial activities were tested against Gram-negative (Gr-) Escherichia coli ATCC 25922, Klebsiella pneumonia, Enterobacter aerogenes, Gram-positive (Gr+) Staphylococcus aureus ATCC 25923, and Candida albicans ATCC 10231 pathogens. In vitro release studies were conducted to examine the therapeutic properties of the prepared membranes. The optimum conditions for the extraction of onions and the preparation of NaAlg/Col/h-BN membranes were found to be EtOH = 75 mL, t = 2 h, T = 45°C, and NaAlg = 1.0 g, Col = 2.0 g, and h-BN = 6% wt, respectively. The prepared membranes exhibited serious antimicrobial properties against S. aureus and C. albicans. The membranes also promoted the controlled release of quercetin for 24 h in vitro, indicating their potential as a new approach in wound treatment.

CONCLUSION

The study concludes that quercetin-filled NaAlg/Col/h-BN membranes have promising therapeutic properties for wound healing. The membranes exhibited significant antimicrobial and antioxidant properties, and their controlled release of quercetin suggests their potential for use in wound healing applications.

Phytochemical analysis, antioxidant, and antihyperlipidemic activities of Teucriumtakoumitense

Objective

The main purpose of the present work was to determine the chemical composition, safety, and antioxidant and antihyperlipidemic activities of an aqueous extract of Teucrium takoumitense.

Methods

Phytochemical analysis (total phenolic, total flavonoid, and total hydroxycinnamic acid contents), antioxidant activity (ferric-reducing antioxidant power, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid, 2,2-diphenyl-1-picrylhydrazil, and total antioxidant capacity tests), acute toxicity, and antihyperlipidemic activity were evaluated according to established models. In addition, the phytochemical profile was determined by methylation followed by gas chromatography-mass spectrometry (GC/MS).

Results

The aqueous extract of T. takoumitense had a high content of total polyphenols (87.01 ± 0.31 mg gallic acid equivalent (GAE)/g extract) and hydroxycinnamic acid (2.28 ± 0.1 g/100 g Powdered Material) and a low content of total flavonoids (2.99 ± 0.16 mg GAE/g extract). In addition, the extract demonstrated remarkable antioxidant activity (DPPH IC50 = 76.67 ± 0.56 μg/mL, ABTS IC50 = 89.65 ± 0.27 μg/mL, FRAP EC50 = 296.32 ± 0.86 μg/mL, TAC value = 43 ± 0.27 mg EAA/g extract). The main compounds were identified as benzene, (hexyloxy)- (19.32%), 2,6a-methano-6aH-indeno[4,5-b]oxirene, octahedro-(1a.alpha., 2.beta., 3a.alpha., 6a.beta., 6b.alpha.)- (32.42%), d-fucose (5.47%), 5-hydroxymethylfurfural (5.47%) and guaiacol (3.19%). The LD50 was estimated to be between 500 and 2000 mg/kg. Furthermore, at 500 and 250 mg/kg, the aqueous extract of T. takoumitense exhibited good antihyperlipidemic activity in vivo.

Conclusion

T. takoumitense extract has significant pharmacological potential and a varied chemical composition.

Teucrium montanum L.-Unrecognized Source of Phenylethanoid Glycosides: Green Extraction Approach and Elucidation of Phenolic Compounds via NMR and UHPLC-HR MS/MS

Health-oriented preferences, a demand for innovative food concepts, and technological advances have greatly influenced changes in the food industry and led to remarkable development of the functional food market. Incorporating herbal extracts as a rich source of bioactive compounds (BC) could be an effective solution to meet the high demand of consumers in terms of expanding the high-quality range of functional foods. The aim of this study is the valorization of the bioactive potential of T. montanum L., an understudied Mediterranean plant species, and the in-depth elucidation of a polyphenolic profile with a UHPLC-HR MS/MS and NMR analysis. The total phenolic content (TPC) and antioxidant capacity (AC) were determined on heat-assisted (HAE), microwave-assisted (MAE) and subcritical water (SWE) extracts. In terms of antioxidant capacity, SWE extracts showed the most notable potential (ABTS: 0.402-0.547 mmol eq Trolox g-1 dw, DPPH: 0.336-0.427 mmol eq Trolox g-1 dw). 12 phenolic compounds were identified in the samples of T. montanum from six microlocations in Croatia, including nine phenylethanoid glycosides (PGs) with total yields of 30.36-68.06 mg g-1 dw and 25.88-58.88 mg g-1 dw in HAE and MAE extracts, respectively. Echinacoside, teupolioside, stachysoside A, and poliumoside were the most abundant compounds HAE and MAE extracts, making T. montanum an emerging source of PGs.

Teucrium polium: Potential Drug Source for Type 2 Diabetes Mellitus

Simple Summary

Teucrium polium (also known as Golden Germander) is a herb brewed and drunk as a tea by the locals of the Mediterranean region, used mostly to treat a number of illnesses including diabetes. When consumed regularly, the tea can be problematic since some of its ingredients can be toxic or interfere with other medications taken by the patient. Current anti-diabetic medications are not always suitable nor optimal for all patients living with diabetes and therefore new drugs are constantly being sought after which may be more useful and/or present less side effects. Therefore, identifying the specific constituents that give the desired anti-diabetic effect, isolating them and developing them further may provide new useful anti-diabetic drugs. This paper discusses some key compounds found in Golden Germander that might be valuable for developing a new medication for type 2 diabetics whilst outlining some issues with the research conducted thus far.

Abstract

The prevalence of type 2 diabetes mellitus is rising globally and this disease is proposed to be the next pandemic after COVID-19. Although the cause of type 2 diabetes mellitus is unknown, it is believed to involve a complex array of genetic defects that affect metabolic pathways which eventually lead to hyperglycaemia. This hyperglycaemia arises from an inability of the insulin-sensitive cells to sufficiently respond to the secreted insulin, which eventually results in the inadequate secretion of insulin from pancreatic β-cells. Several treatments, utilising a variety of mechanisms, are available for type 2 diabetes mellitus. However, more medications are needed to assist with the optimal management of the different stages of the disease in patients of varying ages with the diverse combinations of other medications co-administered. Throughout modern history, some lead constituents from ancient medicinal plants have been investigated extensively and helped in developing synthetic antidiabetic drugs, such as metformin. Teucrium polium L. (Tp) is a herb that has a folk reputation for its antidiabetic potential. Previous studies indicate that Tp extracts significantly decrease blood glucose levels r and induce insulin secretion from pancreatic β-cells in vitro. Nonetheless, the constituent/s responsible for this action have not yet been elucidated. The effects appear to be, at least in part, attributable to the presence of selected flavonoids (apigenin, quercetin, and rutin). This review aims to examine the reported glucose-lowering effect of the herb, with a keen focus on insulin secretion, specifically related to type 2 diabetes mellitus. An analysis of the contribution of the key constituent flavonoids of Tp extracts will also be discussed.

Use composite coating of chitosan-chia seed gum enriched with microliposomes of Bay laurel essential oil to increase the shelf life of quail fillets

In this study, the effect of composite chitosan-chia seed coating (CH-CG) with Bay laurel (Laurus nobilis) essential oil (BE) in two forms including free and nanocapsulated on the shelf life of quail fillets during the 16-day refrigeration (4 ± 1℃) period was investigated. For this purpose, first, BE was extracted by Clevenger apparatus. Then, nanoliposomes BE were produced, and the properties of BE and nanoliposomes BE were investigated. In order to investigate the shelf life of quail, 6 treatments were produced including 1: control (C), 2: CH-CG, CH-CG+BE at 800 ppm, 3: CH-CG+BE at 1600 ppm, 4: CH-CG+nano BE at 800 ppm, 5: CH-CG+nano BE at 1600 ppm, and periodically chemical parameters (peroxide value, free fatty acid, total volatile basic nitrogen, texture firmness, and chewing ability) and microbial (total viable bacteria (TVC) and psychrotrophic bacteria), and the effect of different treatments on control in Escherichia coli and Staphylococcus aureus inoculated populations in quail was also investigated. The BE had high antioxidant and antimicrobial properties. The particle size and microencapsulation efficiency of BE nanoliposome were 98.3 nm and 75.95%, respectively. The results of chemical and microbial analysis showed that in general, the coating with essential oil slowed down the increasing trend of oxidation and microbial indices compared to the control treatment and nanocapsulation of essential oil has increased its antimicrobial and antioxidant properties (p < .05). At the end of storage period, in all tests, treatments of 3, 4, and 5 had the allowed microbial and chemical range and they also inhibited the growth of these bacteria (p < .05). Overall, considering the higher sensory score of treatment 4 and economic efficiency, it seems that this treatment can be used as a natural preservative in the meat industry.

Extraction of phenol compound from Mentha piperita by ultrasonic waves based on a response surface methodology

In this study, optimization of the extraction of phenol compounds from Mentha piperita using ultrasonic waves with response surface methodology (RSM) was assessed. In this regard, a central composite design with three independent variables of time (5, 27.5, and 50 min), temperature (25, 45, and 65°C), and concentrations of ethanol in the water-ethanol solution (0%, 50%, and 100%) was used. Besides, the antioxidant activity tests (DPPH radical scavenging assay, ferric reducing antioxidant power [FRAP], and oxidative stability indexes [OSI]) were examined. Significant effects of independent variables on the extraction of phenol compound, DPPH radical scavenging power, and OSI of M. piperita extract, with the regression coefficients of 0.89, 0.92, and 0.94, respectively, were noted. However, no significant difference in terms of the FRAP among different treatments was noted. Also, the best antioxidant activity of M. piperita was obtained by using the ultrasonic wave for 50 min at 65°C and 59.6% v/v ethanol/water solution. While the findings of RSM confirmed the experimental results, due to the favored properties of M. piperita extract by the proposed method, further research to investigate possible applications in the food industry is recommended.

Changes in chemical composition and biological activity of essential oil from Thomson navel orange (Citrus sinensis L. Osbeck) peel under freezing, convective, vacuum, and microwave drying methods

Thomson navel orange peel is a by-product of citrus processing, which contains high levels of bioactive compounds advantageous to human health, nevertheless due to its high moisture content it is exceedingly perishable. Drying is among the most common preservation methods, which could prolong the plants shelf-life via reducing their moisture value. Taking this into account, depending on their type and conditions, drying techniques could degrade plant heat-sensitive metabolites and lead to quality decline. Therefore, the goal of this paper was to investigate the influence of seven drying methods named sun, shade, oven, vacuum oven, microwave, and freeze-drying with different drying conditions on the physical properties, for example, bulk density and color (L*, a*, b*, ΔE, and browning index (BI)) and essential oil characteristics such as extraction yield, chemical composition, antioxidant (total phenolic content (TPC), DPPH, and FRAP essays), and antimicrobial (MIC and MBC) activities of Thomson peel and determine the superior drying procedure. Results showed that freeze-dried sample had the highest retention of L* (48.54) and b* (49.00) values, lowest BI (216.11) as well as highest EO extraction yield (6.90%), TPC (60.10 GAE/100 g), FRAP (0.52% at 80 mg/ml), and lowest IC50 (5.00 mg/ml), MIC and MBC compared with other drying treatments. Therefore, it could be inferred that freeze-drying is the most efficient drying approach in respect of preserving both physical and EO attributes of Thomson peel.