Catecholic alkaloid sulfonates and aromatic nitro compounds from Portulaca oleracea and screening of their anti-inflammatory and anti-microbial activities

A Survey of Recently Discovered Naturally Occurring Organohalogen Compounds

The discovery of naturally occurring organohalogen compounds has increased astronomically in the 55 years since they were first discovered─from fewer than 50 in 1968 to a combined 7,958 described examples in three comprehensive reviews. The present survey, which covers the period 2021-2023, brings the number of known natural organohalogens to approximately 8,400. The organization is according to species origin, and coverage includes marine and terrestrial plants, fungi, bacteria, marine sponges, corals, cyanobacteria, tunicates, and other marine organisms.

Identification of Novel Alkaloids from Portulaca oleracea L. and Characterization of Their Pharmacokinetics and GLP-1 Secretion-Promoting Activity in STC-1 Cells

Six new alkaloids (compounds 1-6) were isolated from Portulaca oleracea L. The compounds were triple pair (1 and 2, 3 and 4, and 5 and 6) enantiomers, with 1, 3, and 5 in the R-configuration and 2, 4, and 6 in the S-configuration, and all could bind to SUR1 according to molecular docking analysis. Treatment of STC-1 cells with each compound led to an influx of intracellular Ca2+, eventually leading to the secretion of glucagon-like peptide-1 (GLP-1), with compound 3 giving the highest secretion, resulting in 24.3 ± 7.03% more GLP-1 than nateglinide-treated cells, suggesting that these alkaloids may be able to reduce blood glucose based on their ability to stimulate the release of GLP-1. Furthermore, compound 3 also exhibited slightly faster absorption than nateglinide, as shown by pharmacokinetic analysis conducted in rats. Therefore, the results showed that some purslane alkaloids (such as compound 3) had good pharmacological activity in vivo and may have preventive and therapeutic effects on diabetes.

Catecholamine Derivatives: Natural Occurrence, Structural Diversity, and Biological Activity

Catecholamines (CAs) are aromatic amines containing a 3,4-dihydroxyphenyl nucleus and an amine side chain. Representative CAs included the endogenous neurotransmitters epinephrine, norepinephrine, and dopamine. CAs and their derivatives are good resources for the development of sympathomimetic or central nervous system drugs, while they also provide ligands important for G-protein coupled receptor (GPCR) research. CAs are of broad interest in the fields of chemical, biological, medical, and material sciences due to their high adhesive capacities, chemical reactivities, metal-chelating abilities, redox activities, excellent biocompatibilities, and ease of degradability. Herein, we summarize CAs derivatives isolated and identified from microorganisms, plants, insects, and marine invertebrates in recent decades, alongside their wide range of reported biological activities. The aim of this review is to provide an overview of the structural and biological diversities of CAs, the regularity of their natural occurrences, and insights toward future research and development pertinent to this important class of naturally occurring compounds.

Inhibitory effect of Portulaca oleracea L. aqueous extract and juice on NLRP3 inflammasome activation in an ulcerative colitis mouse model

Portulaca oleracea L. (PO) is an edible and medicinal plant used for treating gastrointestinal diseases. However, the effects of PO on ulcerative colitis (UC) and underlying mechanisms remain unclear. This study investigated the effects of PO aqueous extract (POE) and PO juice (PJ) on dextran sulfate sodium (DSS)-induced UC in a mouse model and attempted to unravel their underlying mechanisms. The results revealed that PJ contains more bioactive compounds and has more overlapping targets with UC than POE. Both POE and PJ effectively reduced Disease Activity Index scores and inflammatory cell infiltration in the UC mouse model, but PJ had a better effect than POE. Furthermore, PJ inhibited pyroptosis by decreasing the expression of the NLRP3 inflammasome, while also repairing the dysfunction of the intestinal barrier by upregulating the expression of tight junction proteins. Therefore, based on the study findings, we concluded that PJ can improve DSS-induced UC and may suppress pyroptosis by interfering with the activation of the NLRP3 inflammasome.

Portulaca oleracea L. organic acid extract inhibits persistent methicillin-resistant Staphylococcus aureus in vitro and in vivo

Staphylococcus aureus continues to be one of the most important pathogens capable of causing a wide range of infections in different sites of the body in humans and livestock. With the emergence of methicillin-resistant strains and the introduction of strict laws on antibiotic usage in animals, antibiotic replacement therapy has become increasingly popular. Previous studies have shown that Portulaca oleracea L. extract exerts a certain degree of bacteriostatic effect, although the active ingredients are unknown. In the present study, the antibacterial activity of the organic acid of P. oleracea (OAPO) against S. aureus was examined using a series of experiments, including the minimum inhibitory concentration, growth curve, and bacteriostasis curve. In vitro antibacterial mechanisms were evaluated based on the integrity and permeability of the cell wall and membrane, scanning electron microscopy, and soluble protein content. A mouse skin wound recovery model was used to verify the antibacterial effects of OAPO on S. aureus in vivo. The results showed that OAPO not only improved skin wound recovery but also decreased the bacterial load in skin wounds. Moreover, the number of inflammatory cells and cytokines decreased in the OAPO-treated groups. In summary, this study reports a botanical extract that can inhibit S. aureus in vitro and in vivo, indicating the potential use of OAPO to prevent and control S. aureus infection in the near future.

A review on bioactive phytochemicals and ethnopharmacological potential of purslane (Portulaca oleracea L.)

The Portulaca oleracea L. commonly known as purslane is distributed all over the world and easily grows in diverse soil and climatic conditions. It has been traditionally used as a nutritious and ethnomedicinal food across the globe. Various studies have shown that the plant is a rich source of various important phytochemicals such as flavonoids, alkaloids, terpenoids, proteins, carbohydrates, and vitamins such as A, C, E, and B, carotenoids and minerals such as phosphorus, calcium, magnesium and zinc. It is particularly very important because of the presence of a very high concentration of omega-3- fatty acids especially α-linolenic acid, gamma-linolenic acid and linoleic acid, which are not generally synthesized in terrestrial plants. Various parts of purslane are known for ethnomedicinal and pharmacological uses because of its anti-inflammatory, antidiabetic, skeletal muscle relaxant, antitumor, hepatoprotective, anticancer, antioxidant, anti-insomnia, analgesic, gastroprotective, neuroprotective, wound healing and antiseptic activities. Due to multiple benefits of purslane, it has become an important wonder crop and various scientists across the globe have shown much interest in it as a healthy food for the future. In this review, we provide an update on the phytochemical and nutritional composition of purslane, its usage as nutritional and an ethnomedicinal plant across the world. We further provide a detailed account on ethnopharmacological studies that have proved the ethnomedicinal properties of purslane.

Antimicrobial Effect of Phytochemicals from Edible Plants

Current strategies of combating bacterial infections are limited and involve the use of antibiotics and preservatives. Each of these agents has generally inadequate efficacy and a number of serious adverse effects. Thus, there is an urgent need for new antimicrobial drugs and food preservatives with higher efficacy and lower toxicity. Edible plants have been used in medicine since ancient times and are well known for their successful antimicrobial activity. Often photosensitizers are present in many edible plants; they could be a promising source for a new generation of drugs and food preservatives. The use of photodynamic therapy allows enhancement of antimicrobial properties in plant photosensitizers. The purpose of this review is to present the verified data on the antimicrobial activities of photodynamic phytochemicals in edible species of the world’s flora, including the various mechanisms of their actions.