Anti-quorum sensing activity of some medicinal plants

Background: Quorum sensing is the key regulator of virulence factors of Pseudomonas aeruginosa such as biofilm formation, motility, productions of proteases, hemolysin, pyocyanin, and toxins. The aim of this study was to explore the effect of the extracts from some medicinal plants on quorum sensing and related virulence factors of P. aeruginosa.Material and Methods: Quorum sensing inhibitory (OSI) effect of the alcohol extracts of 20 medicinal plants was evaluated by Chromobacterium violaceum reporter using agar cup diffusion method. The efficient QSI extracts were tested for their activity against biofilm synthesis, motility, and synthesis of pyocyanin from P. aeruginosa PA14Results: The extracts of Citrus sinensis, Laurus nobilis, Elettaria cardamomum, Allium cepa, and Coriandrum sativum exhibited potent quorum quenching effect. On the other hand, Psidium guajava and Mentha longifolia extracts showed lower QSI activity. These extracts exhibited significant elimination of pyocyanin formation and biofilm development of Pseudomonas aeruginosa PA14. In addition, they significantly inhibited twitching and swimming motilities of P. aeruginosa PA14.Conclusion: This study illustrated, for the first time, the importance of C. sinensis, L. nobilis, E. cardamomum, A. cepa, and C. sativum as quorum sensing inhibitors and virulence suppressors of P. aeruginosa. Thus, these plants could provide a natural source for the elimination of Pseudomonas pathogenesis.Keywords: Quorum sensing inhibitory activity, P. aeruginosa, Chromobacterium violaceum, virulence factor

Sagitol C, a new cytotoxic pyridoacridine alkaloid from the sponge Oceanapia sp.

AbstractA new pyridoacridine alkaloid named sagitol C (2) together with two known compounds; kuanoniamine C (1) and sagitol (3) were isolated from the EtOAc fraction of the Indonesian sponge Oceanapia sp. Their chemical structures were established on the basis of physical and spectroscopic methods 1D and 2D NMR, in addition to mass spectrometry and comparison with literature data. Sagitol C was found to exhibit cytotoxic activity when tested against different cancer cell lines

Cucumin S, a new phenylethyl chromone from Cucumis melo var. reticulatus seeds

ABSTRACTA new phenylethyl chromenone, cucumin S [(R)-5,7-dihydroxy-2-[1-hydroxy-2-(4-hydroxy-3-methoxyphenyl)ethyl]chromone] (1), along with five known compounds: 5,7-dihydroxy-2-[2-(4-hydroxyphenyl)ethyl]chromone (2), 5,7-dihydroxy-2-[2-(3,4-dihydroxyphenyl)ethyl]chromone (3), luteolin (4), quercetin (5), and 7-glucosyloxy-5-hydroxy-2-[2-(4-hydroxyphenyl)ethyl]chromone (6) were isolated from the EtOAc fraction of Cucumis melo var. reticulatus Ser., Cucurbitaceae, seeds. Their structures were determined by spectroscopic means (1D and 2D NMR), as well as HRESIMS, optical rotation measurement, and comparison with literature data. The isolated compounds 1–6 were assessed for their antioxidant activity using DPPH assay. Compounds 3, 4, and 5 showed potent activities compared to propyl gallate at concentration 100 µM

Pyridoacridine alkaloids from deep-water marine organisms: Structural elucidation

Pyridoacridine alkaloids are unique marine nitrogenous compounds that represent a large family of alkaloids. They have been reported from different marine organisms like sponges, ascidians, anemones, prosobranch mollusk, and tunicates. Attention to pyridoacridines has risen because of their significant biological activities. The present review emphasizes mainly on pyridoacridines isolated marine organisms over the last years. Thus, the synthetic ones were not discussed. Herein, 95 pyridoacridine alkaloids isolated from marine organisms have been retrieved, in addition to their classification, isolation, sources, structures, molecular weight, physical, and (UV, IR, 1H and 13C NMR) spectral data

Natural occurring 2-(2-phenylethyl) chromones, structure elucidation and biological activities

<div><p>2-(2-Phenylethyl) chromone (PEC), an uncommon class of chromones, possesses a phenylethyl substituent at the C2 position. They have been isolated from a few plant species. They have promising biological activities such as neuro-protective, cytotoxic, acetylcholinesterase inhibitory, antibacterial and anti-inflammatory. This review focuses on the naturally occurring PEC derivatives, their sources, physical and spectral data, as well as biological activities.</p></div

Chemical constituents, anti-inflammatory, and antioxidant activities of Anisotes trisulcus

Anisotes trisulcus (Forssk.) Nees. (family Acanthaceae) aerial part is used in folk medicine in the Arabian peninsula for treatment of hepatic conditions. It showed different activities such as antibacterial, hepatoprotective, and cytotoxicity. It is a rich source of alkaloids and is used as an antidiabetic, bronchodilator, hypotensive, and local anesthetic. To the best of our knowledge, there is no report on the phenolic constituents of A. trisulcus. Therefore, this study aims to identify the constituents and establish antioxidant and anti-inflammatory activities of the total methanolic extract and different fractions. One new benzoyl flavonol: 7,8,3′-trihydroxy-5-methoxy-4′-benzoyl flavonol (5), along with eight known compounds: α-amyrin (1), β-sitosterol (2), stigmasterol (3), (2S,3S,4R)-2[(2′R)-2′-hydroxytetracosanoyl amino]-octadecane-1,3,4-triol (4), allopateuletin (6), veratric acid (7), vanillic acid (8), and β-sitosterol-3-O-β-d-glucopyranoside (9) were isolated from A. trisulcus aerial parts. Their structures were established by physical, chemical, and spectral data (UV, IR, MS, and 1D NMR), as well as comparison with authentic samples. The anti-inflammatory activity of the total methanolic extract and different fractions was evaluated using carrageenan-induced paw edema method at a dose of 400 mg/kg. Also, the antioxidant activity was determined using DPPH assay at concentrations 0.25, 0.5, and 1 mg/mL. The total MeOH extract and EtOAc fraction showed high antioxidant activity 75% and 68% (Conc. 1 mg/mL), respectively while, the n-hexane and EtOAc fractions exhibited significant anti-inflammatory effects

Natural anti-obesity agents

Obesity is a complex disease caused by the interaction of a myriad of genetic, dietary, lifestyle, and environmental factors, which favors a chronic positive energy balance, and leads to increased body fat mass. The incidence of obesity is rising at an alarming rate and is becoming a major public health concern with incalculable social costs. Indeed, obesity facilitates the development of metabolic disorders such as diabetes, hypertension, and cardiovascular diseases in addition to chronic diseases such as stroke, osteoarthritis, sleep apnea, some cancers, and inflammation-based pathologies. Recent researches demonstrated the potential of natural products to counteract obesity. Multiple-natural product combinations may result in a synergistic activity that increases their bioavailability and action on multiple molecular targets, offering advantages over chemical treatments. In this review, we discuss the anti-obesity potential of natural products and analyze their mechanisms