Metabolomic profiling and quantification of polyphenols from leaves of seven Acacia species by UHPLC-QTOF-ESI-MS

The genus Acacia (Fabaceae) comprises >1350 species and has been used in traditional medicine as infusions and decoctions to treat wounds, sores, headaches, diarrhea, and cough. The leaf methanolic extracts of seven Acacia species growing in Egypt namely: Acacia saligna, Acacia seyal, Acacia xanthophloea, Acacia tortilis subsp. raddiana., Acacia tortilis, Acacia laeta, Acacia albida were analyzed using UPLC-QTOF-ESI-MS. A total of 37 polyphenols were identified and discussed in detail. They included phenolic acids, flavonoids, and procyanidins, among which sixteen polyphenols were identified in Acacia for the first time. Folin-ciocalteau assay and ferric reducing antioxidant power, cupric reducing antioxidant capacity, 2,20 -azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) cation radical and the scavenging capacity against 2,2-diphenyl-1- picrylhydrazyl radical were performed to investigate the total phenolic content and the antioxidant activity of the Acacia extracts, respectively. Furthermore, the absolute quantification of eighteen polyphenols common to most of the species was performed using UPLC-MS. It was evident that the differences in the chemical composition among the species accounted for the difference in antioxidant activity which was in line together with the total phenolic content.

Differential Impact of Zinc Salt Precursors on Physiognomies, Anticancerous, and Antibacterial Activities of Zinc Oxide Nanoparticles

Zinc oxide nanoparticles (ZnONPs) are enormously popular semi-conductor metal oxides with diverse applications in every field of science. Many physical and chemical methods applied for the synthesis of ZnONPs are being rejected due to their environmental hazards. Therefore, ZnONPs synthesized from plant extracts are steered as eco-friendly showing more biocompatibility and biodegradability. Additionally, various synthesis conditions such as the type of precursor salt also play a role in influencing the physicochemical and biological properties of ZnONPs. In this study, green synthesis of ZnONPs from Acacia nilotica was carried out using zinc acetate (ZA-AN-ZNPs), zinc nitrate (ZN-AN-ZNPs), and zinc sulfate (ZS-AN-ZNPs) precursor salts. Surprisingly, characterization of ZnONPs using UV-visible spectroscopy, TEM, XRD, and EDX revealed the important role precursor salts played in influencing the size and shape of ZnONPs, i.e., 20-23 nm spherical (ZA-AN-ZNPs), 55-59 nm triangular (ZN-AN-ZNPs), and 94-97 nm nano-flowers (ZS-AN-ZNPs). FTIR analysis showed the involvement of alkaloids, alcohols, carboxylic acid, and phenolic compounds present in Acacia nilotica extract during the synthesis process. Since different precursor salts showed different morphology of ZnONPs, their biological activities were also variable. ZN-AN-ZNPs showed the highest cytotoxicity towards HepG2 cells with the lowest cell viability (28.92 ± 0.99%), highest ROS/RNS production (3425.3 ± 184.58 relative DHR123 fluorescence), and loss of mitochondrial membrane potential (1645.2 ± 32.12 relative fluorescence unit) as well as induced significant caspase-3 gene expression. In addition to this, studying the zone of inhibitions and minimum bactericidal and inhibitory concentrations of ZnONPs showed their exceptional potential as antibacterial agents. At MIC as low as 8 µg/mL, ZA-AN-ZNPs and ZN-AN-ZNPs exhibited significant bactericidal activities against human pathogens Klebsiella pneumoniae and Listeria monocytogenes, respectively. Furthermore, alkaline phosphatase, DNA/RNA leakage, and phosphate ion leakage studies revealed that a damage to the bacterial cell membrane and cell wall is involved in mediating the antibacterial effects of ZnONPs.

Role of Biotransformation of Acacia nilotica Metabolites by Aspergillus subolivaceus in Boosting Lupinus termis Yield: A Promising Approach to Sustainable Agriculture

Biotransformation plays a significant role in sustainable agriculture. This process involves utilizing microorganisms, such as bacteria and fungi, to transform organic compounds and metabolites into bioactive compounds which have beneficial effects on plant growth, yield, and soil characters. Accordingly, the present study aims to explore the role of biotransformation of Acacia nilotica metabolites by Aspergillus subolivaceus in boosting L. termis yield, as an important strategy in agricultural sustainability. A pilot experiment was performed on five fungal strains (Fusarium oxysporium A. aculeatus, Aspergillus. subolivaceus, Rhizopus oryzae and Trichoderma viride) which were grown on different parts of plants (A. nilotica leaves; green tea leaves, green pepper fruits and pomegranate fruits), and the results indicated that the most active metabolite for the growth of L. termis seeds was the fungal metabolite of A. subolivaceus growing on A. nilotica. More specifically, we assess how metabolites produced by Aspergillus subolivaceus using A. nilotica leaves affect the biochemical properties and chemical composition of L. termis seeds. A. subolivaceus was grown on leaves from A. nilotica to obtain metabolites and fractionated into four extracts. Two concentrations of each extract were examined by pretreating the seeds of L. termis. The study found that all four extracts contributed to an increase in yield and some biochemical properties of the yielded seeds. The best results were obtained by treating the L. termis seeds with an extract obtained from diethyl ether, which led to a significant increase in total nitrogen, amino nitrogen, glucose and protein contents of the seeds. According to 1H NMR guided GC/MS analysis, our results showed an increase in phytochemicals such as terpenes, fatty materials, and flavonoids including 3′,4′,7-trimethoxyquercetin and 4-methyl-p-menth-8-en-3-one, which have not been stated before from A. nilotica suggesting that biotransformation may have occurred due to the presence of A. subolivaceus.

Flowers and Leaves Extracts of Stachys palustris L. Exhibit Stronger Anti-Proliferative, Antioxidant, Anti-Diabetic, and Anti-Obesity Potencies than Stems and Roots Due to More Phenolic Compounds as Revealed by UPLC-PDA-ESI-TQD-MS/MS

The present work aims to assess the biological potential of polyphenolic compounds in different parts (flowers, leaves, stems, and roots) of Stachys palustris L. Towards secondary metabolites profile, 89 polyphenolic compounds (PCs) were identified by UPLC-PDA-ESI-TQD-MS/MS, with a total average content of 6089 mg/100 g of dry matter (d.m.). In terms of biological activity, antioxidant activity (radical activity, reducing power), digestive enzyme inhibitory (α-glucosidase, α-amylase, pancreatic lipase) effect, and antiproliferative activity (inhibition of cell viability and induction of apoptosis in different human cancer cell lines) were explored. Leaves, flowers, stems, and roots of S. palustris L. have not been studied in this regard until now. Vescalagin and cocciferin d2, isoverbascoside (verbascoside), luteolin 6-C-glucoside, luteolin 6-C-galactoside, apigenin 6-C-glucoside, (−)-epicatechin, ellagic acid, and malvidin 3-O-diglucoside were detected as main ingredients in the studied parts. Methanolic extract of S. palustris L. leaves and flowers revealed the highest amount of PCs with the strongest antiradical (18.5 and 15.6 mmol Trolox equivalent (TE)/g d.m., respectively) and reducing power effects (7.3 and 5.6 mmol TE/g d.m.). Leaf extracts exhibited better α-amylase and pancreatic lipase inhibition effects, while flower extracts exhibited better α-glucosidase inhibition effect. Regarding antiproliferative activity, extracts of the leaves and flowers significantly reduced cell viability and induced a high level of apoptosis in human lung, pancreatic, bladder, and colon cancer cell lines, as well as in human acute myeloid leukemia; whereas the extracts from stems and roots revealed the weaker effects. The results of this work showed anti-proliferative and potentially anti-diabetic, anti-obesity properties of S. palustris L., especially for flowers and leaves, which may have wide potential applications in the functional food, special food, pharmaceutical, cosmetics industries, and/or in medicine.