Mineral Analysis, In Vitro Evaluation of Alpha-Amylase, Alpha-Glucosidase, and Beta-Galactosidase Inhibition, and Antibacterial Activities of Juglans regia L. Bark Extracts

Abstract

In traditional medicine, various parts of the plant Juglans regia L. are used to treat several pathological conditions including diabetes and infectious and periodontal diseases. This includes the bark of Juglans regia. The present study is aimed at evaluating for the first time the mineral composition, investigating the antidiabetic and antibacterial properties of Moroccan J. regia bark, and finally determining the correlations between the chemical composition of the tested extracts and their biological activities. The mineral composition was determined using inductively coupled plasma atomic emission spectroscopy. Then, nine extracts were prepared by different methods and modalities of extractions and investigated for their antidiabetic activities, via tests of inhibition of alpha-amylase, alpha-glucosidase, and beta-galactosidase enzymes, and for their antibacterial activities against six strains involved in infectious diseases and periodontology. Finally, the correlation between the chemical compositions of the different extracts prepared and their antidiabetic and antibacterial potencies was determined by Principal Component Analysis (PCA). J. regia is an important source of mineral elements, mainly Fe (19849.8), K (3487.8), Mg (2631.03), and P (691.02) mg/kg plant material. All the extracts of J. regia possess antidiabetic activity, and in particular, the macerated acetone extract gave the highest inhibitory activity against alpha-amylase ( I C 50 value of 5445.33 ± 82.58 μ g / mL ), alpha-glucosidase ( I C 50 value of 323.7 ± 1.71 μ g / mL ), and beta-galactosidase ( I C 50 value of 811.2 ± 8.32 μ g / mL ). For the results of antibacterial activity, the macerated acetone extract at the concentration of 80 mg/mL was found to be the most active by inducing inhibition diameters of 12, 17, 18, 11, 14.5, and 16 mm against Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis, and Listeria innocua, respectively. PCA allowed us to deduce that the extracts richer in polyphenols, in particular, the two acetone and ethanol macerates, have a better antidiabetic activity against alpha-glucosidase as well as a better antibacterial activity. The results of the present study revealed that the aqueous and organic macerate extracts showed a better antidiabetic activity and justified the use of J. regia bark as an antibacterial and antiseptic agent in traditional Moroccan medicine in the treatment of dental affections.

Juglans regia kernel meal; a prospective nutraceutical feed supplement

“…The nutraceutical properties of JKM, when used as food/feed supplements or ingredients, are revealed by the alpha-amylase inhibition (61.06%) and alpha-glucosidase inhibition (67.76%) capacities of JKM, as reported in this study (Figure 4). Previous research showed that phytogens had alpha-amylase and alpha-glucosidase inhibitory activities (Boulfia et al, 2021;Oloruntola & Ayodele, 2022). The phytochemical makeup of JKM may be responsible for its alpha-amylase and alpha-glucosidase inhibitory capabilities; for example, peptides derived from cereals, phenolic compounds, non-starch polysaccharides, and lipids were confirmed to inhibit alpha-glucosidase and alpha-amylase activities (Gong et al, 2020).…”

Ethnopharmacological Survey, Mineral and Chemical Content, In Vitro Antioxidant, and Antibacterial Activities of Aqueous and Organic Extracts of Chamaerops humilis L. var. argentea Andre Leaves

“…Studies conducted on plants collected in the region of Taza, Morocco, have also revealed the richness of the said plants in mineral elements that are involved in their biological properties: Juglans regia has a high level of Fe (19849.8), K (3487.8), Mg (2631.03), and P (691.02 mg/kg), Leopoldia comosa is rich in Fe (33552), K (1843.14), P (756.36), Na (439.65), Cu (303.9), Mg (272.37), and Ca (20.55 mg/kg), and Ajuga iva has contents of 112.00 mg/l Fe, 44.071 mg/l K, and 16.572 mg/l Na [ 44 , 90 , 91 ].…”

“…In this sense, Singh and collaborators found that the highest antibacterial capacity was observed for sterols in E. hirta fruits (21 mm) [ 113 ]. In addition, studies conducted on plants from Taza region reported that Ajuga iva had the highest inhibition diameter for petroleum ether extract against Proteus mirabilis strain (14 mm) [ 91 ]; Juglans regia acetone macerate was found to be the most active with an inhibition diameter of 17 and 18 mm against Proteus mirabilis and Pseudomonas aeruginosa [ 90 ].…”

Phytochemicals and Biological Activities of Walnut Septum: A Systematic Review

“…Besides J. regia septum, the effects on blood glucose of other matrices from this species were also evaluated. Boulfia et al showed that macerated acetone and ethanol extracts from walnut bark inhibited the activities of alpha-amylase and alpha-glucosidase [ 58 ]. These effects may be due to the various polyphenolics that were reported in walnut husk, buds, and bark [ 59 ].…”