Protective Effect of Portulaca oleracea Extract Against Lipopolysaccharide-Induced Neuroinflammation, Memory Decline, and Oxidative Stress in Mice: Potential Role of miR-146a and miR-let 7

A review on ethnopharmacology, phytochemistry, pharmacology and potential uses of Portulaca oleracea L

ETHNOPHARMACOLOGICAL RELEVANCE

Portulaca oleracea L. (PO), popularly known as purslane, has been documented in ethnopharmacology in various countries and regions. Traditional application records indicated that PO might be used extensively to treat the common cold, dysentery, urinary tract infections, coughing, eye infections, skin problems, gynecological diseases, and pediatric illnesses.

AIM OF THE REVIEW

This paper includes a systematic review of the traditional usage, phytochemicals, pharmacological activity, and potential uses of PO to provide an overview of the research for further exploitation of PO resources.

MATERIALS AND METHODS

This article uses "Portulaca oleracea L." and "purslane" as the keywords and collects relevant information on PO from different databases, including PubMed, Web of Science, Springer, Science Direct, ACS, Wiley, CNKI, Baidu Scholar, Google Scholar, and ancient meteria medica.

RESULTS

PO is a member of the Portulacaceae family and is grown worldwide. Traditional Chinese medicine believes that purslane has the effect of improving eyesight, eliminating evil qi, quenching thirst, purgation, diuresis, hemostasis, regulating qi, promoting hair growth, detoxifying, and avoiding epidemic qi. Recent phytochemical investigations have shown that PO is a rich source of flavonoids, homoisoflavonoids, alkaloids, organic acids, esters, lignans, terpenoids, catecholamines, sterols, and cerebrosides. The purslane extracts or compounds have exhibited numerous biological activities such as anti-inflammatory, immunomodulatory, antimicrobial, antiviral, antioxidant, anticancer, renoprotective, hepatoprotective, gastroprotective, metabolic, muscle relaxant, anti-asthmatic and anti-osteoporosis properties. The significant omega-3 fatty acids, vital amino acids, minerals, and vitamins found in purslane also provide nutritional benefits. Purslane as a food/feed additive in the food industry and animal husbandry has caused concern. Its global wide distribution and tolerance to abiotic stress characteristics make it in the future sustainable development of agriculture a certain position.

CONCLUSIONS

Based on traditional usage, phytochemicals, and pharmacological activity, PO is a potential medicinal and edible plant with diverse pharmacological effects. Due to purslane's various advantages, it may have vast application potential in the food and pharmaceutical industries and animal husbandry.

Effect of quercetin-loaded poly (lactic-co-glycolic) acid nanoparticles on lipopolysaccharide-induced memory decline, oxidative stress, amyloidogenesis, neurotransmission, and Nrf2/HO-1 expression

Neuroinflammation contributes to the pathogenesis of several neurodegenerative disorders. This study examined the neuroprotective effect of quercetin (QUR)-loaded poly (lactic-co-glycolic) acid (PLGA) nanoparticles (QUR NANO) against the neurotoxicity induced by lipopolysaccharide (LPS) in mice. A QUR NANO formulation was prepared and characterized by differential scanning calorimetry, X-ray diffraction, entrapment efficiency (EE), high-resolution transmission electron microscopy, field emission scanning electron microscopy, and in vitro drug release profile. Levels of glutathione, malondialdehyde, catalase, inducible nitric oxide synthase (iNOS), amyloid beta 42 (Aβ42), β-secretase, gamma-aminobutyric acid (GABA), and acetylcholine esterase (AChE) were measured in the mouse brain tissues. The gene expression of nuclear factor erythroid-related factor 2 (Nrf-2) and heme oxygenase-1 (HO-1) were also determined. The prepared QUR NANO formulation showed 92.07 ± 3.21% EE and drug loading of 4.62 ± 0.55. It exhibited clusters of nano-spherical particles with smooth surface areas, and the loading process was confirmed. In vivo, the QUR NANO preserved the spatial memory of mice and protected the hippocampus from LPS-induced histological lesions. The QUR NANO significantly reduced the levels of malondialdehyde, iNOS, Aβ42, β-secretase, and AChE in brain tissue homogenates. Conversely, QUR NANO increased the glutathione, catalase, and GABA concentrations and upregulated the expression of Nrf-2 and HO-1 genes. Remarkably, the neuroprotective effect of QUR NANO was significantly greater than that of herbal QUR. In summary, the prepared QUR NANO formulation was efficient in mitigating LPS-induced neurotoxicity by reducing memory loss, oxidative stress, and amyloidogenesis while preserving neurotransmission and upregulating the expression of Nrf2 and HO-1 genes. This study addresses several key factors in neuroinflammatory disorders and explores the potential of QUR-loaded nanoparticles as a novel therapeutic approach to alleviate these factors.

Micro-Executor of Natural Products in Metabolic Diseases

Obesity, diabetes, and cardiovascular diseases are the major chronic metabolic diseases that threaten human health. In order to combat these epidemics, there remains a desperate need for effective, safe, and easily available therapeutic strategies. Recently, the development of natural product research has provided new methods and options for these diseases. Numerous studies have demonstrated that microRNAs (miRNAs) are key regulators of metabolic diseases, and natural products can improve lipid and glucose metabolism disorders and cardiovascular diseases by regulating the expression of miRNAs. In this review, we present the recent advances involving the associations between miRNAs and natural products and the current evidence showing the positive effects of miRNAs for natural product treatment in metabolic diseases. We also encourage further research to address the relationship between miRNAs and natural products under physiological and pathological conditions, thus leading to stronger support for drug development from natural products in the future.

Phytochemical Analysis and Profiling of Antioxidants and Anticancer Compounds from Tephrosia purpurea (L.) subsp. apollinea Family Fabaceae

Tephorosia purpurea subsp. apollinea was extracted with methanol and n-hexane to obtain sub-fractions. The chemical compounds identified with GC-MS and HPLC in T. purpurea subsp. apollinea extracts showed antioxidant and anticancer properties. The antioxidant and anticancer activities were investigated using DDPH and ABTS assays, and MTT assay, respectively. Stigmasta-5,24(28)-dien-3-ol, (3 β,24Z)-, 9,12,15-octadecatrienoic acid methyl ester, phytol, chlorogenic acid, and quercetin were the major chemical compounds detected in T. purpurea subsp. apollinea. These compounds possessed antioxidant and anticancer properties. The methanol extract showed antioxidant properties with DDPH and ABTS radical scavenging of 84% and 94%, respectively, relative to ascorbic acid and trolox. The anticancer effects of T. purpurea subsp. apollinea against the cancer cell lines MCF7 (IC₅₀ = 102.8 ± 0.6 μg/mL), MG63 (IC₅₀ = 118.3 ± 2.5 μg/mL), T47D (IC₅₀ = 114.7 ± 1.0 μg/mL), HeLa (IC₅₀ = 196.3 ± 2.3 μg/mL), and PC3 (IC₅₀ = 117.7 ± 1.1 μg/mL) were greater than its anticancer effects against U379 (IC₅₀ = 248.4 ± 7.5 μg/mL). However, it had no adverse effects on the normal cells (WI38) (IC₅₀ = 242.9 ± 1.8 μg/mL). Therefore, the major active constituents presented in T. purpurea subsp. apollinea can be isolated and studied for their potential antioxidant and anticancer effects against breast, cervical, and prostate cancers and osteosarcoma.

Oleracone F Alleviates Cognitive Impairment and Neuropathology in APPswe/PSEN1dE9 Mice by Reducing the Expression of Vascular Cell Adhesion Molecule and Leukocyte Adhesion to Brain Vascular Endothelial Cells

Alzheimer's disease (AD) is the most common neurodegenerative disease and the blood-brain barrier dysfunction has been suggested as a key pathological feature of the disease. Our research group successfully established a synthetic protocol for oleracones, a novel series of flavonoids isolated from the plant extract of Portulaca oleracea L. (PO). PO extract was reported to have anti-inflammatory and antioxidant effects, enhancing cognitive function. Thus, we investigated the effects and mechanism of oleracones on cognition using AD model transgenic mice (Tg; APPswe/PSEN1dE9). Oleracone F treatment significantly improved memory dysfunction in Tg mice. Oleracone F decreased the number, burden, and immunoreactivity of amyloid plaques and amyloid precursor protein (APP) protein levels in the brains of Tg mice compared to wild-type mice. Oleracone F also alleviated inflammation observed in Tg mice brains. In vitro studies in human microvascular endothelial cells (HBMVECs) demonstrated that oleracones D, E, and F blocked the elevations in VCAM-1 protein induced by tumor necrosis factor-α (TNF-α), hindering leukocyte adhesion to HBMVECs. Taken together, our results suggest that oleracones ameliorated cognitive impairment by blocking TNF-α-induced increases in VCAM-1, thereby reducing leukocyte infiltration to the brain and modulating brain inflammation.