Antioxidant and anti-inflammatory activity through inhibition of NF-κB and sEH of some citrus peel and phytoconstituent characteristics

Unveiling the gastroprotective effect of the ethyl acetate fraction of Cordia africana Lam. roots against ethanol-induced gastric ulcer and Helicobacterpylori

ETHNOPHARMACOLOGICAL RELEVANCE

Traditionally, Cordia africana Lam. roots, have been used in the treatment of gastro-intestinal complaints and the management of peptic ulcer diseases.

AIM OF THE STUDY

Quantitative determination of Cordia africana Lam. roots constituents was performed to investigate their phytochemical composition and their anti-ulcer mechanism.

MATERIALS AND METHODS

Cordia africana Lam. roots were subjected to extraction and fractionation. Antimicrobial activities of the extract and its factions were tested against Helicobacter pylori, and minimum inhibitory concentration (MIC) was measured. Then, an in vivo ethanol-induced model in rats was performed (at two tested doses: 200 mg/kg, 400 mg/kg, and pantoprazol 10 mg/kg against ethanol 5 mL/kg by oral gavage) with subsequent histopathological analysis. Oxidative and gastric inflammatory markers were measured. The phytochemical profile was confirmed using quantitative High-performance liquid chromatography (HPLC). Finally, molecular docking was performed to investigate the binding mode among the most abundant quantified compounds, viz., kaempferol, myricetin, naringenin, quercetin, and rosmarinic acid and three chosen proteins.

RESULTS

Among the tested fractions, Cordia africana ethyl acetate fraction (CAEt) gave the least MIC (7.82 μg/mL). Besides, at its high dose (400 mg/kg; orally), CAEt significantly reduced the ulcer number and severity by 26 % each, lowered malondialdehyde by 39 %, and increased glutathione and prostaglandin E2 levels by 92 % and 27 %, respectively, compared to pantoprazol. It exhibited similar potency to pantoprazol in decreasing tumor necrosis factor-alpha and cytokine-induced neutrophil chemoattractant-1, while it significantly decreased nuclear factor-kappa B more than pantoprazol by 7 %. Nineteen compounds were quantified using HPLC, showing that phenolic compounds and flavonoids were the most abundant phytoconstituents. In-silico molecular docking screening revealed the interaction between the five most quantified compounds and nuclear factor kappa B, prostaglandin E2, and tumor necrosis factor alpha proteins.

CONCLUSION

CAEt possesses potent gastroprotective properties via the reduction of gastric ulcer severity, decreasing oxidative stress, and inflammatory markers in ethanol-induced stomach damage. CAEt could be a promising candidate for gastric ulcer treatment and further studies on gastric-related diseases.

Chartarlactams U-X: Novel Phenylspirodrimanes from a Marine Derived Fungus Stachybotrys sp. SZU-W23 with Anti-Inflammatory Activity Mediated by the NF-κB/ROS Signaling Pathways

In this investigation, the anti-inflammatory potential of phenylspirodrimanes (PSDs) produced by the marine-derived fungal strain Stachybotrys sp. SZU-W23 was systematically explored. A total of 15 PSDs were successfully isolated. Among them, four novel compounds, designated as chartarlactams U-X, were precisely characterized using NMR, HRESIMS, and ECD analyses. Specifically, compound 10 exhibited the most potent inhibitory effect on nitric oxide production in LPS-stimulated RAW 264.7 macrophages within the 0.3-30 μM concentration range, with an IC50 value of 12.4 μM. Additionally, MTT assays revealed no detectable cytotoxicity at these concentrations. Mechanistic studies revealed that compound 10 effectively suppressed ROS generation, likely inactivating the NF-κB signaling pathway and consequently downregulating pro-inflammatory mediators, including iNOS, IL-6, and IL-1β.

Antioxidant Effects of Moringa oleifera Against Abamectin-Induced Oxidative Stress in the Brain and Erythrocytes of Rats

The current study was conducted to explore the phytochemical composition and in vitro antioxidant activity of Moringa oleifera leaves aqueous extract (MOLE), as well as its in vivo modulatory effects on abamectin (ABM)-induced oxidative stress in rat erythrocytes and brain tissue. Following extraction, the total phenolic, flavonoid, condensed tannin and ortho-diphenolic contents of MOLE were determined. High-performance liquid chromatography (HPLC) analysis allowed the identification and the quantification of 12 bioactive compounds: gallic acid, chlorogenic acid, caffeic acid, vanillic acid, quercetin, ferulic acid, ascorbic acid, alizarin, hesperidin, neohesperidin, resveratrol, and naringin. In vitro study: the assessment of the antioxidant activity of MOLE on the 2,2-diphenyl-1-picrylhydrazyl radical DPPH and the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation (ABTS), its ferric reducing power and its antioxidant effect on the β-carotene bleaching indicated that MOLE exhibited potent antioxidant activity, with an IC50 of 0.125 mg/mL against DPPH radical, and an IC50 of 0.06 mg/mL against ABTS radical. It also demonstrated notable ferric-reducing ability, with an EC50 of 1.4 mg/mL and a strong inhibition of β-carotene bleaching with an IC50 of 1.36 mg/mL. In vivo study: Twenty rats were equally divided into four groups. The first group served as a control and received distilled water by gavage. The second group (negative control) received ABM in drinking water at a dose of 1 mg/kg body weight. The third group received MOLE at a dose of 200 mg/kg of body weight by gavage. The fourth group received a combination of ABM and MOLE in the same manner and doses as described, for 3 weeks. Body weight, brain relative and absolute weights, and nitric oxide levels were not affected by ABM. However, ABM significantly inhibited acetylcholinesterase (AChE) activity (p < 0.001), decreased the activities of antioxidant enzymes, specifically superoxide dismutase (SOD) and glutathione S-transferase (GST) in cerebral tissue, and catalase (CAT) in erythrocytes (p < 0.001). ABM also decreased reduced glutathione (GSH) levels in both the brain (p < 0.001) and erythrocytes (p < 0.05). In addition, malondialdehyde (MDA) levels significantly increased in the brains of ABM-intoxicated rats (p < 0.01) compared to the control group. These results were accompanied by histopathological changes, notably the remarkable vacuolization of neuropil in brain tissue. Supplementation with MOLE in ABM-treated rats significantly ameliorated brain AChE (p < 0.05) and GST activities, decreased MDA content, and improved GSH levels in both brain and erythrocyte homogenates (p < 0.01). MOLE also restored the histopathological alterations observed in the ABM group. Computational modeling revealed that some of the tested molecules, including some present in the studied extract, bound human peroxiredoxin 5, CAT, and glutathione peroxidase with acceptable affinities, which, together with the established molecular interactions and tight embedding satisfactory support the in vivo results. Thus, it may be concluded that ABM impairs brain and erythrocyte function through oxidative damage, and these effects could be prevented by MOLE, likely due to its antioxidant activity.

Identification of Bioactive Compounds from Citri Reticulatae Pericarpium and Evaluation of Their Uric Acid-Lowering Activity

Citri Reticulatae Pericarpium, the dried and mature peel of wild Citrus reticulata Blanco and its cultivated varieties in the rutaceae family, is an important herb and condiment in Chinese medicine. At present, there are few relevant reports, especially in-depth reports, on the discovery of effective anti-gout natural products from CRP. In this study, four compounds were extracted and characterized from CRP using 70% ethanol, RP-C18, thin layer chromatography (TLC), Sephadex LH-20, high performance liquid chromatography (HPLC), and nuclear magnetic resonance spectroscopy (NMR). Additionally, monomer compounds (apigenin, luteolin) in CRP, along with those isolated from CRP, were investigated through molecular docking and in vitro assessment of their XOD inhibitory activity. Notably, the lowest binding energy (-10.3 kcal/mol) and IC50 value (76.24 µg/mL) denoted a strong inhibitory effect of isosakuranetin with XOD. Further studies showed that isosakuranetin could significantly reduce XOD activity and uric acid levels in xanthine-induced BRL-3A cells. This research elucidates, for the first time, the uric acid-lowering effects of isosakuranetin, offering valuable insights into the potential mechanisms underlying its properties. This study provides a basis for the development of uric acid-lowering products from CRP and in-depth mechanism research of uric acid-lowering compounds.

Antimicrobial potential of the leaves of Citrus grandis (L.) Osbeck collected from Iraq: Bioassay-guided isolation of sinensetin as the anti-MRSA compound

Infections caused by antibiotic-drug-resistant microorganisms are a major global health concern, and they result in millions of deaths every year. Methicillin-resistant Staphylococcus aureus (MRSA) is one of such drug-resistant microbial strains, and new and effective antimicrobial agents are desperately needed to combat infections caused by MRSA. In the search for effective anti-MRSA agents, the leaves of Citrus grandis (Rutaceae), also known as C. maxima, were investigated. Implementing a bioassay-guided approach, sinensetin (2), which is a polymethoxyflavone, was isolated as a promising anti-MRSA compound, showing inhibitory activity against three (EMRSA-15, MRSA340802 and MRSA274819; MIC values 128-256 μg/mL) of five MRSA strains tested in the present study. Five other flavonoids 6,7,8,3',4'-pentamethoxyflavone (1), cirsilineol (3), nobiletin (4), 5-desmethylsinensetin (5) and hesperidin (6) were isolated from the dichloromethane extract of this plant. They displayed varied levels of antimicrobial activities against the tested microbial strains, Micrococcus luteus NCTC 7508, Escherichia coli NCTC 12241 and Pseudomonas aeruginosa NCTC 12903, and a fungal strain, Candida albicans ATCC 90028, but not against Staphylococcus aureus NCTC 12981. Sinensetin (2) also exhibited strong antimicrobial activity against the fungal strain C. albicans with an MIC value of 0.0625 mg/mL. The chemical structures of all isolated compounds were unequivocally elucidated by spectroscopic means (1D and 2D NMR and HR-ESIMS). The present study revealed sinensetin (2) as a potential structural template for generating structural analogues and developing anti-MRSA agents and provided scientific evidence supporting the traditional uses of C. grandis in the treatment of microbial infections.

Recovery, Bioactivity, and Utilization of Bioactive Phenolic Compounds in Citrus Peel

Citrus peels are rich in bioactive phenolic compounds with various health effects including antioxidant, antiobesity, antiinflammatory, antihypertensive, antihypercholesterolemic, antimicrobial, antidiabetic, and anticarcinogenic activities. Both extractable and nonextractable phenolics are present in significant amounts in Citrus peel with diverse bioactivities. While extractable phenolics can be recovered from the fruit peels by conventional extraction methods, nonextractable phenolics remaining in the residues must be released from the cell matrix first by hydrolysis with acid, alkali, or enzymes. Novel processing technologies can help in improvement of extraction efficiency. Extreme process or medium conditions degrade phenolics and their bioactivity where encapsulation can be applied to improve their stability, solubility, and bioactivity. Citrus peel powder including ascorbic acid and dietary fiber besides phenolics or extracts therefrom can be used as functional food ingredients to extend shelf life and provide health benefits. In addition, phenolic extracts can be used as antioxidant and antimicrobial agents in active food packaging applications. Phenolic extracts have also a potential to be used as nutraceuticals and pharmaceuticals. In this review, phenolic compounds in different forms in Citrus peels, their recovery, bioactivity and possible applications for upcycling in the industry are presented.

Impact of plant monoterpenes on insect pest management and insect-associated microbes

The fight against insect pests primarily relies on the utilization of synthetic insecticides. However, improper application of these chemicals can lead to detrimental effects on both the environment and human health, as well as foster the development of insect resistance. Consequently, novel strategies must be implemented to address the challenges stemming from the prolonged use of synthetic insecticides in agricultural and public health environments. Certain strategies involve the combination of crop protectants, which not only enhance insecticidal effectiveness but also reduce application rates. Plant-based natural products emerge as promising alternatives for insect management. Monoterpenes, which are abundant plant compounds produced through the activation of various enzymes, have attracted significant attention for their effectiveness in insect control. Notably, they are prolific in fragrance-producing plants. This review explores the plant defense, insecticidal, and antimicrobial characteristics of monoterpenes against insect pests, shedding light on their potential modes of action and possibilities for commercialization. Emphasizing their role as targeted and environmentally safer, the review highlights the practical viability of monoterpenes within integrated pest management programs.