New Lignanamides with Antioxidant and Anti-Inflammatory Activities Screened Out and Identified from Warburgia ugandensis Combining Affinity Ultrafiltration LC-MS with SOD and XOD Enzymes

Potential antioxidative and anti-hyperuricemic components in Rodgersia podophylla A. Gray revealed by bio-affinity ultrafiltration with SOD and XOD

Rodgersia podophylla A. Gray (R. podophylla) is a traditional Chinese medicine with various pharmacological effects. However, its antioxidant and anti-hyperuricemia components and mechanisms of action have not been explored yet. In this study, we first assessed the antioxidant potential of R. podophylla with 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and ferric ion reducing antioxidant power (FRAP) assays. The results suggested that the ethyl acetate (EA) fraction of R. podophylla not only exhibited the strongest DPPH, ABTS radical scavenging and ferric-reducing activities, but also possessed the highest total phenolic and total flavonoid contents among the five fractions. After that, the potential superoxide dismutase (SOD) and xanthine oxidase (XOD) ligands from the EA fraction were quickly screened and identified through the bio-affinity ultrafiltration liquid chromatography-mass spectrometry (UF-LC-MS). Accordingly, norbergenin, catechin, procyanidin B2, 4-O-galloylbergenin, 11-O-galloylbergenin, and gallic acid were considered to be potential SOD ligands, while gallic acid, 11-O-galloylbergenin, catechin, bergenin, and procyanidin B2 were recognized as potential XOD ligands, respectively. Moreover, these six ligands effectively interacted with SOD in molecular docking simulation, with binding energies (BEs) ranging from -6.85 to -4.67 kcal/mol, and the inhibition constants (Ki) from 9.51 to 379.44 μM, which were better than the positive controls. Particularly, catechin exhibited a robust binding affinity towards XOD, with a BE value of -8.54 kcal/mol and Ki value of 0.55 μM, which surpassed the positive controls. In conclusion, our study revealed that R. podophylla possessed remarkable antioxidant and anti-hyperuricemia activities and that the UF-LC-MS method is suitable for screening potential ligands for SOD and XOD from medicinal plants.

Phytochemical Content and Antidiabetic Properties of Most Commonly Used Antidiabetic Medicinal Plants of Kenya

Traditional medicinal plants have been used for decades in folk medicines in the treatment and management of several ailments and diseases including diabetes, pain, ulcers, cancers, and wounds, among others. This study focused on the phytochemical and antidiabetic activity of the commonly used antidiabetic medicinal species in Kenya. Phytochemical profiling of these species revealed flavonoids and terpenoids as the major chemical classes reported which have been linked with strong biological activities against the aforementioned diseases, among others. However, out of the selected twenty-two species, many of the natural product isolation studies have focused on only a few species, as highlighted in the study. All of the examined crude extracts from thirteen antidiabetic species demonstrated strong antidiabetic activities by inhibiting α-glucosidase and α-amylase among other mechanisms, while nine are yet to be evaluated for their antidiabetic activities. Isolated compounds S-Methylcysteine sulfoxide, quercetin, alliuocide G, 2-(3,4-Dihydroxybenzoyl)-2,4,6-trihydroxy-3 (2H)-benzofuranone, Luteolin-7-O-D-glucopyranoside, quercetin, 1,3,11α-Trihydroxy-9-(3,5,7-trihydroxy-4H-1-benzopyran-7-on-2-yl)-5α-(3,4-dihydroxy-phenyl)-5,6,11-hexahydro-5,6,11-trioxanaphthacene-12-one and [1,3,11α-Trihydroxy-9-(3,5,7-trihydroxy-4H-1-benzopyran-7-on-2-yl)-5α-(3,4-dihydroxy-phenyl)-5,6,11-hexahydro-5,6,11-trioxanaphthacene-12-one]-4'-O-D-gluco-pyranoside from Allium cepa have been found to exhibit significant antidiabetic activities. With the huge number of adults living with diabetes in Kenya and the available treatment methods being expensive yet not so effective, this study highlights alternative remedies by documenting the commonly used antidiabetic medicinal plants. Further, the study supports the antidiabetic use of these plants with the existing pharmacological profiles and highlights research study gaps. Therefore, it is urgent to conduct natural products isolation work on the selected antidiabetic species commonly used in Kenya and evaluate their antidiabetic activities, both in vitro and in vivo, to validate their antidiabetic use and come up with new antidiabetic drugs.

Bioactive polyphenols separated from hemp seed shells ameliorate H2 O2 -induced oxidative stress injury in human umbilical vein endothelial cells

In the present study, we investigated the protection of hemp seed polyphenols on human umbilical vein endothelial cells (HUVEC) from H₂ O₂ -mediated oxidative stress injury. Fractions with different polarities were obtained by separating the hemp seed extract using HPD300 macroporous resin-packed column. The fraction, desorbed by 50% ethanol, is rich in polyphenol (789.51 ± 21.92 mg GAE/g) and has the highest antioxidant activity in vitro. HPLC-QTOF-MS/MS identified the main polyphenol components in hemp seed shells: 4 hydroxycinnamic acid amides and 15 lignanamides. The protective effects of hemp seed polyphenol against oxidative-stress injury in HUVEC cells were evaluated by cell viability, intracellular antioxidant parameters, and cell apoptosis assay. After HUVEC cells were precultured with 50 µg/ml hemp seed polyphenols, the cell viability increased significantly from 53.07 ± 2.46% (model group) to 80.65 ± 1.32% (p < 0.01). In addition, the pretreatment of HUVEC cells with polyphenol could substantially increase their intracellular superoxide dismutase activity and reduce their intracellular reactive oxygen species level, malondialdehyde content, and lactate dehydrogenase leakage index. These findings demonstrate the defensive potential of hemp seed polyphenol in reducing the incidence of cardiovascular disease. PRACTICAL APPLICATION: Hemp seed shell waste is produced while producing hemp seed kernel and has abundant phenolic compounds. This research showed that hemp seed polyphenol has potent antioxidant activity in vitro and protects HUVEC cells against H₂ O₂ -induced oxidative stress injury, suggesting that hemp seed polyphenol has the defensive potential to reduce the incidence of cardiovascular disease. These results indicated that polyphenol separated from hemp seed shells is valuable for further research and development, which will improve the utilization rate of hemp seed.

Anti-Alzheimer's disease active components screened out and identified from Hedyotis diffusa combining bioaffinity ultrafiltration LC-MS with acetylcholinesterase

ETHNOPHARMACOLOGICAL RELEVANCE

Hedyotis diffusa is a traditional ethnomedicinal plant in local communities in northeastern Asia and used to treat inflammation, nervous breakdown, among others. In recent years, it has been applied in the treatment of Alzheimer's disease (AD), while the specific chemical components responsible for the activity remain need to be explored.

AIM OF THE STUDY

To prepare, screen and identify the potential anti-AD active components from Hedyotis diffusa.

MATERIALS AND METHODS

The acetylcholinesterase (AChE) inhibitory activity of four different extracts of Hedyotis diffusa were initially assessed using a spectrophotometric Ellman's method. A more accurate LC-MS/MS screening method combining functional enzyme assay and affinity ultrafiltration (AU) screening assay was developed and applied for the screening of natural compound inhibitors of AChE from Hedyotis diffusa. The binding mode was further investigated between protein and ligands via molecular docking. Subsequently, CL4176, a transgenic nematode model for AD, was used for activity validation of one of these components.

RESULTS

N-butanol extract of Hedyotis diffusa (NHD) appeared significant inhibitory activities on AChE, were chosen to delve deeper. Five bioactive components targeting AChE were screened out and identified using AU coupled to liquid chromatography-mass spectrometry. Molecular docking technique further confirmed the results of the screening assay. Finally, quercetin-3-O-sophoroside (QS) was confirmed as a potent anti-AD agent by in vivo experiments in C. elegans.

CONCLUSION

This study explores a new idea for screening anti-AD active components from traditional medicine. The findings provide a molecular structure and bioactivity basis for future potential applications of Hedyotis diffusa in medical industries.

Potential Antioxidative and Anti-Hyperuricemic Components Targeting Superoxide Dismutase and Xanthine Oxidase Explored from Polygonatum Sibiricum Red

Polygonatum sibiricum Red. (P. sibiricum) has been used as a traditional Chinese medicine with a wide range of pharmacology effects. However, the responsible bioactive compounds and their mechanisms of action concerning its antioxidative and anti-hyperuricemic activities remain unexplored. In this work, the antioxidant capacity of P. sibiricum was firstly evaluated with the 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2’-azinobis-(3ethylbenzthiazoline)-6-sulfonic acid (ABTS) and ferric-reducing antioxidant power (FRAP) assays, from which the ethyl acetate (EA) fraction exhibited the highest DPPH, ABTS radical scavenging, and ferric-reducing capacities. Meanwhile, the EA fraction displayed the highest total phenolic and flavonoid contents among the four fractions. Next, the potential ligands from the EA fraction were screened out by bio-affinity ultrafiltration liquid chromatography-mass spectrometry (UF-LC-MS) with superoxide dismutase (SOD) and xanthine oxidase (XOD). As a result, N-trans-p-coumaroyloctopamine, N-trans-feruloyloctopamine, N-trans-feruloyltyramine were identified as potential SOD ligands, while N-cis-p-coumaroyltyramine was determined as potential XOD ligand. Additionally, these four ligands effectively interact with SOD and XOD in the molecular docking analysis, with binding energies (BEs) ranging from –6.83 to –6.51 kcal/mol, and the inhibition constants (Ki) from 9.83 to 16.83 μM, which were better than the positive controls. In conclusion, our results indicated that P. sibiricum has good antioxidative and anti-hyperuricemic activities, and its corresponding active ligands targeting SOD and XOD could be explored by the UF-LC-MS method.

Flavonoids from Selaginella doederleinii Hieron and Their Antioxidant and Antiproliferative Activities

Selaginella doederleinii Hieron. (S. doederleinii) is a traditional herb that is widely used in China to treat several ailments, but mainly cancer. Studies have been carried out to determine the phytochemicals ascribed to its pharmacological activity. However, both phytochemical and pharmacological profiles have not been fully explored as few compounds have been reported. This study evaluated the flavonoid content of the ethanol extract and its four fractions (petroleum ether, dichloromethane, ethyl acetate, and n-butanol) together with their antioxidant activity (DPPH and FRAP assays). Further, the antiproliferative activity was evaluated. Two new secondary metabolites (1 and 3) were isolated from S. doederleinii, which comprised of an apigenin skeleton with a phenyl attached at C-8 of ring A and an acetyl group. Additionally, other known metabolites 2 and 4–16 were isolated, whereby compounds 2, 4, 5, 8, 12, 15, and 16 were reported for the first time in this species. These compounds were evaluated for their antioxidative potentials by both DPPH and FRAP assays, and for their antiproliferative activities by the MTT assay on three human cancer cell lines: colon cancer (HT-29), cervical cancer (HeLa), and lung cancer (A549). Compound 7 exhibited the best activity on the three cancer cell lines (HT-29, HeLa, A549) by inhibiting the rate of growth of the cancer cells in a dose-dependent manner with IC₅₀ values of 27.97, 35.47, and 20.71 µM, respectively. The structure–activity relationship of the pure compounds was highlighted in this study. Hence, the study enriched both the phytochemical and pharmacological profiles of S. doederleinii.

Potential Antioxidative Components in Azadirachta indica Revealed by Bio-Affinity Ultrafiltration with SOD and XOD

Azadirachta indica (A. indica) has been widely used due to its diverse pharmacological activities. However, there are currently few studies on its responsible antioxidant ingredients against superoxide dismutase (SOD) and xanthine oxidase (XOD). In this study, the antioxidant activities of A. indica were evaluated by a 2,2′-azinobis-(3-ethyl-benzthiazoline)-6-sulfonic acid) and ferric-ion-reducing antioxidant power method. Meanwhile, total polyphenol and flavonoid content were determined to reveal that they were the highest in ethyl acetate (EA) fraction. Next, compounds with the most antioxidant activity were screened out from EA fraction by bio-affinity ultrafiltration liquid chromatography–mass spectrometry (UF-LC-MS) with SOD and XOD. As a result, gallic acid, protocatechuic acid and (−)-epicatechin were identified as potential SOD ligands with relative binding affinity (RBA) values of 2.15, 1.78 and 1.61, respectively. Additionally, these three ligands could effectively interact with SOD in molecular docking with binding energies (BEs) ranging from −3.84 ± 0.37 to −5.04 ± 0.01 kcal/mol. In addition, carnosic acid exhibited a strong binding affinity to XOD with an RBA value of 2.05 and BE value of −8.24 ± 0.71 kcal/mol. In conclusion, these results indicated that A. indica might have good antioxidant activity and antigout potential, and the UF-LC-MS method is suitable and efficient for screening both SOD and XOD ligands from A. indica.

Optimization of the extraction conditions of Nypa fruticans Wurmb. using response surface methodology and artificial neural network

In this study, we conducted response surface methodology (RSM) and artificial neural network (ANN) to predict and estimate the optimized extraction condition of Nypa fruticans Wurmb. (NF). The effect of ethanol concentration (X₁; 0-100%), extraction time (X₂; 6-24 h), and extraction temperature (X₃; 40-60 °C) on the antioxidant potential was confirmed. The optimal conditions (57.6% ethanol, 19.0 h extraction time, and 51.3 °C extraction temperature) of 2,2-diphenyl-1-1picrylhydrazyl (DPPH) scavenging activity, cupric reducing antioxidant capacity (CUPRAC) and ferric reducing antioxidant power (FRAP), total phenolic content (TPC), and total flavonoid contents (TFC) resulted in a maximum value of 62.5%, 41.95 and 48.39 µM, 143.6 mg GAE/g, and 166.8 CAE/g, respectively. High-resolution mass spectroscopic technique was performed to profile phenolic and flavonoid compounds. Upon analyzing, total 48 compounds were identified in NF. Altogether, our findings can provide a practical approach for utilizing NF in various bioindustries.

Future Directions for the Discovery of Natural Product-Derived Immunomodulating Drugs

Drug discovery from natural sources is going through a renaissance, having spent many decades in the shadow of synthetic molecule drug discovery, despite the fact that natural product-derived compounds occupy a much greater chemical space than those created through synthetic chemistry methods. With this new era comes new possibilities, not least the novel targets that have emerged in recent times and the development of state-of-the-art technologies that can be applied to drug discovery from natural sources. Although progress has been made with some immunomodulating drugs, there remains a pressing need for new agents that can be used to treat the wide variety of conditions that arise from disruption, or over-activation, of the immune system; natural products may therefore be key in filling this gap. Recognising that, at present, there is no authoritative article that details the current state-of-the-art of the immunomodulatory activity of natural products, this in-depth review has arisen from a joint effort between the International Union of Basic and Clinical Pharmacology (IUPHAR) Natural Products and Immunopharmacology, with contributions from a Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation number of world-leading researchers in the field of natural product drug discovery, to provide a "position statement" on what natural products has to offer in the search for new immunomodulatory argents. To this end, we provide a historical look at previous discoveries of naturally occurring immunomodulators, present a picture of the current status of the field and provide insight into the future opportunities and challenges for the discovery of new drugs to treat immune-related diseases.

Stimulation of ROS Generation by Extract of Warburgia ugandensis Leading to G0/G1 Cell Cycle Arrest and Antiproliferation in A549 Cells

Warburgia ugandensis Sprague (WU) is a traditional medicinal plant used for the treatment of various diseases, including cancer, in Africa. This study aimed to evaluate the anti-non-small cell lung cancer (NSCLC) activities of WU against A549 cells and to reveal potential molecular mechanisms. The cytotoxicity of various WU extracts was evaluated with HeLa (cervical cancer), HepG2 (liver cancer), HT-29 (colorectal cancer), and A549 (non-small cell lung cancer) cells by means of Sulforhodamine B (SRB) assay. Therein, the dimethyl carbonate extract of WU (WUD) was tested with the most potent anti-proliferative activity against the four cancer cell lines, and its effects on cell viability, cell cycle progression, DNA damage, intracellular reactive oxygen species (ROS), and expression levels of G₀/G₁-related proteins in A549 cells were further examined. First, it was found that WUD inhibited the proliferation of A549 cells in a time- and dose-dependent manner. In addition, WUD induced G₀/G₁ phase arrest and modulated the expression of G₀/G₁ phase-associated proteins Cyclin D1, Cyclin E1, and P27 in A549 cells. Furthermore, WUD increased the protein abundance of P27 by inhibiting FOXO3A/SKP2 axis-mediated protein degradation and also significantly induced the γH2AX expression and intracellular ROS generation of A549 cells. It was also found that the inhibitory effect of WUD on the proliferation and G₀/G₁ cell cycle progression of A549 cells could be attenuated by NAC, a ROS scavenger. On the other hand, phytochemical analysis of WUD with UPLC-QTOF-MS/MS indicated 10 sesquiterpenoid compounds. In conclusion, WUD exhibited remarkable anti-proliferative effects on A549 cells by improving the intracellular ROS level and by subsequently modulating the cell proliferation and G₀/G₁ cell cycle progression of A549 cells. These findings proved the good therapeutic potential of WU for the treatment of NSCLC.

Identification of Anti-Inflammatory and Anti-Proliferative Neolignanamides from Warburgia ugandensis Employing Multi-Target Affinity Ultrafiltration and LC-MS

Previous reports have illustrated that the incidence and mortality of cancer are increasing year by year worldwide. In addition, the occurrence, development, recurrence and metastasis of cancer are closely related to inflammation, which is a kind of defensive response of human body to various stimuli. As an important medicinal plant in Africa, Warburgia ugandensis has been reported to have certain anti-inflammatory and anti-proliferative activities, but its specific components and mechanisms of action remain elusive. To tackle this challenge, affinity ultrafiltration with drug targets of interest coupled to high-performance liquid chromatography-mass spectrometry (AUF-HPLC-MS/MS) could be utilized to quickly screen out bioactive constituents as ligands against target enzymes from complex extracts of this plant. AUF-HPLC-MS/MS with four drug targets, i.e., cyclooxygenase-2 (COX-2), 5-lipoxygenase (5-LOX), topoisomerase I (Top I) and topoisomerase II (Top II) were used to rapidly screen and characterize the anti-inflammatory and anti-proliferative natural ligands from W. ugandensis, and the resulting potential active compounds as ligands with specific binding affinity to COX-2, 5-LOX, Top I and Top II, were isolated with modern separation and purification techniques and identified with spectroscopic method like NMR, and then their antiinflammatory and anti-proliferative activities were tested to verify the screening results from AUF-HPLC-MS/MS. Compounds 1 and 2, which screened out and identified from W. ugandensis showed remarkable binding affinity to COX-2, 5-LOX, Top I and Top II with AUF-HPLC-MS/MS. In addition, 1 new compound (compound 3), together with 5 known compounds were also isolated and identified from W. ugandensis. The structure of compound 3 was elucidated by extensive 1D, 2D NMR data and UPLC-QTOF-MS/MS. Furthermore, compounds 1 and 2 were further proved to possess both anti-inflammatory and anti-proliferative activities which are in good agreement with the screening results using AUF-HPLC-MS/MS. This work showcased an efficient method for quickly screening out bioactive components with anti-inflammatory and anti-proliferative activity from complex medicinal plant extracts using AUF-HPLC-MS/MS with target enzymes of interest, and also demonstrated that neolignanamides (compounds 1 and 2) from W. ugandensis would be the active components responsible for its anti-inflammatory and anti-proliferative activity with the potential to treat cancer and inflammation.