Antioxidant, anti-cholinesterase, anti-α-glucosidase and prebiotic properties of beta-glucan extracted from Algerian barley

Beta-glucan, such as barley-derived beta-glucan (BBG), are homopolysaccharides that have attracted attention by their nutritional and therapeutic properties. The aim of this study was to evaluate the antioxidant power of BBG extracted from local Algerian variety of barley (SAIDA 183), and its acetylcholinesterase, alpha glucosidase inhibitory activity as well as its prebiotic potential by fermentation with lactic acid bacteria isolated from camel’s milk, namely lactococcuslactisssplactis (Lc.l.l) and leuconostocmesenteroidesspmesenteroides (Ln.m.m). The results revealed that BBG exhibited low activity against DPPH and ferric-reducing power (IC50 4018.61 ± 656.69 and A0.5 at 359.88 ±63.64 µg/mL respectively), in contrast to other antioxidant tests (ABTS, Beta-carotene and CUPRAC) where BBG demonstrated a moderate activity (IC50 529.91 ±26.37, IC50 161.013±13.322, A0.5 529.79 ± 48.65 µg/mL). The scavenging ability of hydroxyl radical and superoxide radical by BBG with an IC50 at 2268.38±101.57 µg/mL and IC50 345.26± 62.32 µg/mL, respectively, while enzymatic inhibition by  BBG exhibited for AChE at IC50 859.164 ±64.46 μg/mL , BChE at IC50 at 725.470 ±30.95 , α-Amylase inhibitory activity at IC50 2986.785 ± 37.046  . The bacterial growth of the two strains used in this study is favorably affected by the use of BBG as the only carbon source, in comparison with glucose as a control. In light of these findings, it can be concluded that BBG have shown moderate antioxidant and enzyme inhibitory activities and can be used as a prebiotic by acting synergistically with probiotics in functional food matrices

Anticholinesterase, anti-α-glucosidase, antioxidant and antimicrobial effects of four Algerian propolis

This study aimed to investigate the functional properties of four Algerian propolis collected from El-Menia, Oum el Bouaghi, El Harrouch and Collo regions. The total bioactive content, antioxidant, anti-enzymatic and antimicrobial effects of the four propolis methanolic extracts were evaluated using in vitro assays. The highest amount of total phenolic (561.99 ± 3.50 μg GAE/mg E) and flavonoid content (76.98 ± 0.26 μg QE/mg E) was found in propolis from El-Menia. Antioxidant tests (DPPH, ABTS, CUPRAC and ferric reducing power) revealed the strong scavenging and reducing abilities of the extracts. Anti-enzymatic assays against acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and α-glucosidase showed that all extracts possessed a potent inhibitory effect on α-glucosidase better than acarbose and revealed the ability of extracts to inhibit BChE more effectively than AChE. However, the extract of propolis from El Menia was the best inhibitor of the three key enzymes with IC50 values of 11.40 ± 0.58 µg/mL 16.06 ± 0.85 µg/mL and 71.29 ± 2.73 µg/mL against α-glucosidase, BChE and AChE, respectively. The antimicrobial assay indicated that all extracts were mainly active against Gram-positive bacteria and yeast and had bactericidal action in certain bacteria and bacteriostatic action in other ones. However, they had all fungistatic effect on C. albicans ATCC 10231. According to these results, Algerian propolis can be considered as a source of natural bioactive principles for dietary, pharmacological and medicinal applications