Background: Coffee is one of the most consumed beverages worldwide and is popular for its characteristic flavor and rich organoleptic properties.
Aim: Based on published articles, the aims of this review are i) study the association between coffee consumption and benefits to human health; ii) the effects of coffee consumption on some pathologies; and iii) provide a description of coffee’s bioactive compounds.
Discussion: Coffee presents bioactive compounds, which include phenolic compounds, especially chlorogenic acid (caffeoylquinic acid), trigonelline, and diterpenes, such as cafestol and kahweol. These compounds are related to the beneficial effects for human health, including high antioxidant activity, antimutagenic activity, hepatoprotective action, reduced incidence of type 2 diabetes mellitus, reduced risk of cardiovascular diseases, decreased incidence of inflammatory diseases, reduced menopausal symptoms, and others. Coffee’s bioactive compounds are caffeine, chlorogenic acid, trigonelline, cafestol and kahweol, which are closely related to coffee’s beneficial effects.
Conclusion: The present review clarified that the benefits of moderate coffee consumption outweigh the associated risks.
Background: Microencapsulation of natural antioxidants in polymeric systems represents a possible strategy for improving the oral bioavailability of compounds that are otherwise poorly soluble.
Objective: α-lipoic acid (ALA) was microencapsulated with polymethacrylate polymers (blends at various ratios of Eudragit® RS100 and RL100 resins).
Method: Microspheres were produced by solvent displacement of an ethanol cosolution of ALA and polymers; the microsuspensions were then freeze-dried, using trehalose as a cryoprotector. Microspheres were characterized in the solid state for micromeritic properties and drug loading, as well as by infrared spectroscopy, powder X-ray diffractometry and differential scanning calorimetry. The antioxidant activity of free and encapsulated ALA was assessed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay.
Results: In vitro release studies, performed in simulated gastric (pH 1.2) and intestinal fluid (pH 6.8), showed that, depending on polymer composition and drug-to-polymer ratio, ALA release can be slowed down, compared to the dissolution pattern of the free drug. Solid-state characterization confirmed the chemical stability of ALA in the microspheres, suggesting that ALA did not develop strong interactions with the polymer and was present in an amorphous or a disordered-crystalline state within the polymer network. As indicated by the DPPH assay, the microencapsulation of ALA in Eudragit® Retard matrices did not alter its antioxidant activity.
Conclusion: ALA was effectively encapsulated in Eudragit® Retard matrices, showing a chemical stability up to 6 months at room conditions and at 40°C. Moreover, since the drug maintained its antioxidant activity in vitro, the potential application of these microparticulate systems for oral administration would deserve further studies.
The Inhibitory Effect of Some Algerian Plants Phenolics Extracts on the α – glucosidase and α – amylase Activities and their Antioxidant Activities
Author(s): Ihcen Khacheba, Amar Djeridane, Abdelkarim Kameli and Mohamed Yousfi
Affiliation: Laboratoire des Sciences Fondamentales, Université Amar Telidji. Laghouat- Algérie.
The aim of this study consisted in extracting and quantifying phenolic and flavonoids compounds of five selected Algerian plants. The second step was devoted to studying the effects of phenolic compounds on the kinetics catalyzed by two enzymes belonging to the class of hydrolase (the α – amylase and the α – glucosidase) responsible for the digestion of sugars. Finally, we assessed the potential antiradical of our extracts.
The results indicate that the phenolic extracts from these plants have inhibitory effects on both enzymes, with Ki values in µg/ml range (18.19-72.14 µg / ml) for the α – amylase and (52.26 – 203.90 µg / ml) for α – glucosidase. The antioxidant activity test shows that our phenolic extracts exhibit good antioxidant capacity comparatively to antioxidants taken as reference with IC50 values which vary from 0.044 µg / ml to 0.452 µg / ml. This work contributes to understanding the role of natural polyphenols in the regulation of oxidative stress and normalization of glycemic disorders.