Nanoparticle-Based Delivery of Plant Metabolites
Megh R. Goyal, Hafiz Ansar Rasul Suleria, Ademola Olabode Ayeleso, T. Jesse Joel, Sujogya Kumar Panda in The Therapeutic Properties of Medicinal Plants, 2019
Plants are known to produce compounds (such as alcohols, amino acids, carbohydrates, nucleotides, phytosterols, and some organic acids), which are typically key to the maintenance of normal physiology processes and are important in growth, development, and reproduction. These compounds are called primary metabolites. In contrast, plants also produce secondary metabolites (such as: sterols, terpenes, alkaloids, phenols, tannins, carotenoids, flavonoids, waxes, gums), which are not directly linked to actions that effect the growth, reproduction, and development of the living plant, but seem to have some effect on the function of ecology and the mechanism of defense by production of pigments in some cases [24]. These secondary metabolites are known to be produced from the modification of primary metabolite by enzymatic means. Figure 15.4 shows the pathways to produce some secondary metabolites.
Environmental Factors Impacting Bioactive Metabolite Accumulation in Brazilian Medicinal Plants
Luzia Valentina Modolo, Mary Ann Foglio in Brazilian Medicinal Plants, 2019
Both mild abiotic and biotic stresses often result in increased secondary metabolite accumulation, and this response is usually associated with some degree of growth rate reduction. This is expected since the flux of C, N and S toward secondary metabolism drains the pools of primary metabolite precursors supporting growth. The degree of stress exposure must be such that it finds a balance between maximum defense metabolism stimulation and minimal damage. This fine balance can be achieved by appropriate combinations of time and intensity of exposure to stimuli. At the center of several stresses signaling pathways is redox balance, which is a major regulator of secondary metabolism acting as a network hub. Developmental stage is frequently a determinant of response capacity, as is the type of nutrition, heterotrophic (most cell cultures), semi-autotrophic or fully autotrophic. Seasonal and circadian variations of secondary metabolic profiles may also be considered as a factor for optimizing target product yields.
Effect of Elevated CO2 Conditions on Medicinal Plants
Azamal Husen in Environmental Pollution and Medicinal Plants, 2022
Due to anticancerous, antiviral, and diuretic properties, Catharanthus roseus is an important medicinal plant. In an experiment in which the Catharanthus plant was treated with higher carbon dioxide levels, there was an elevation in most secondary metabolites in the plant, including phenolics, alkaloids, flavonoids, and tannin (Yang et al. 2018). It was studied that, with e[CO2], Zingiber officinale showed enhancement in flavonoid and phenolic content (Ghasemzadeh et al. 2018). In Quercus ilicifolia, elevated carbon dioxide increased flavonoid and phenolic contents (Kumar et al. 2017). It was reported that enhanced content of phenols and flavonoids subsequently incremented to phenylalanine (primary metabolite), which acts as a metabolic precursor in the formation of many secondary metabolites. Other studies carried out on Labisia pumila by Ibrahim et al. (2014) also showed elevated levels of flavonoids and phenols under higher carbon dioxide levels. In addition, in the medicinal plant Pseudotsuga manziesii, there was a sudden decline in monoterpenes under e[CO2] conditions (Snow et al. 2003).
In vitro activity of the antimicrobial peptide AP7121 against the human methicillin-resistant biofilm producers Staphylococcus aureus and Staphylococcus epidermidis
Published in Biofouling, 2020
Gastón Delpech, Mónica Ceci, Sabina Lissarrague, Leonardo García Allende, Beatriz Baldaccini, Mónica Sparo
Other differences between antimicrobial peptides and antibiotics highlight their potential uselfuness. Bacteriocins have a primary metabolite nature since they are the products of relatively simple biosynthetic mechanisms compared with antibiotics, which are secondary metabolites. This makes bacteriocins suitable candidates for bioengineering in order to increase their activity and/or specifity towards certain microorganisms. The less probability of resistance expression against bacteriocins already referred to is likely due to their fast acting mechanism, and pore formation in bacterial membranes, even at low concentrations. This mechanism exerts a bactericidal effect by many bacteriocins, such as AP7121. Also, bacteriocins are easily degraded by proteolytic enzymes due to their proteinaceous nature. Hence, these antimicrobial peptides when fragmentated do not persist for a long time in the human body, minimizing the interaction time between them and the target strains, which is the starting point for the development of antimicrobial resistance. Other feature of some bacteriocins that makes them stand out over broad-spectrum antibiotics is their high-specificity against clinical pathogens. Most of these features have already been proven for AP7121 (Sparo et al. 2006; Perez et al. 2014).
A deadly prescription: combination of methotrexate and trimethoprim-sulfamethoxazole
Published in Journal of Community Hospital Internal Medicine Perspectives, 2018
Mohsin Hamid, Bilal Lashari, Irfan Ahsan, Ida Micaily, Usman Sarwar, Joseph Crocetti
After oral administration, MTX is absorbed quickly, the kidneys excrete 80–90% and liver enzymes metabolize the rest. A positive correlation has been noticed between MTX clearance and creatinine clearance and hence abnormal renal function can precipitate MTX toxicity. After filtration by glomeruli, it undergoes both secretion and reabsorption and competes with other drugs during this process. It accumulates in third spaces such as pleura and peritoneum and is eliminated slowly from these spaces as compared to plasma, and the dosage needs to be readjusted in these situations. The primary metabolite is 90% bound to plasma proteins and therefore can have extensive drug interactions. Most commonly co-prescribed drugs with MTX are steroids, aspirin (ASA), and nonsteroidal anti-inflammatory drugs (NSAIDs). Steroids have been shown to be safe with MTX. NSAIDs and high dose ASA decrease the renal excretion of MTX and increase its plasma concentration. However, a systematic review found that concurrent use of most NSAIDs with MTX is safe, yet, anti-inflammatory doses of ASA should not be used with MTX [9]. Folate has been shown to reduce the toxicity of MTX especially GI and liver toxicity without affecting the efficacy of MTX through unknown mechanisms [10,11].
Potential uses of naltrexone in emergency department patients with opioid use disorder
Published in Clinical Toxicology, 2019
Evan Stuart Bradley, David Liss, Stephanie Pepper Carreiro, David Eric Brush, Kavita Babu
Indicated for OUD and alcoholism, oral naltrexone is administered daily. Following oral administration, ∼96% of naltrexone dose is rapidly absorbed through the gastrointestinal tract. Oral naltrexone undergoes significant first-pass metabolism, limiting bioavailability to 5–40%. Metabolism via hepatic cytosolic dihydrodiol enzymes produces its primary metabolite, 6β-naltrexol [14]. Both naltrexone and 6β-naltrexol reach peak plasma concentrations within one hour after ingestion [9]. The metabolite 6β-naltrexol has a longer elimination half-life than naltrexone (∼12 h and 4 h, respectively) [15]. Naltrexone and 6β-naltrexol are primarily renally excreted. Less than 2% of naltrexone is excreted unchanged, and fecal elimination is minimal.