The good and the bad: alkaloid screening and brineshrimp bioassays of aqueous extracts of 31 medicinal plants of eastern Nicaragua

Pachira aquatica: biological activity and chemical composition of leaves, flowers, and seeds

The chemical composition of Pachira aquatica crude extracts flowers, leaves, and seeds was obtained by UHPLC-ESI/qTOF and GC/MS. The antiproliferative activity was evaluated against the human tumour cell lines AGS (gastric), CaCo-2 (colorectal), MCF-7 (breast), and NCI-H460 (lung). The anti-inflammatory and cellular antioxidant activities were also studied. Flavonoids, phenolic acids, coumarins, and saturated fatty acids were identified in the samples. The concentration of extracts responsible for inhibiting 50% of nitric oxide production ranged from (149 to > 400 µg mL-1). Antiproliferative activity against the tumour cell lines was: AGS (GI50 175 to > 400 µg mL-1), Caco-2 (GI50 215 to > 400 µg mL-1), MCF7 (GI50 232 to > 400 µg mL-1) and NCI-H460 (GI50 208 to > 400 µg mL-1). Cellular antioxidant activity remained between 73% to > 2000%. The selectivity index (SI) ranged from 1.00 to 2.78, indicating low antiproliferative activity.

Bioactivity of the Genus Turnera: A Review of the Last 10 Years

Turnera is a genus of plants whose biological activity has been widely studied. The importance of this genus, particularly Turnera diffusa, as a source of treatment for various conditions is evidenced by the large number of new studies that have evaluated its biological activity. Accordingly, the objective of this review was to compile the information published in the last ten years concerning the biological activities reported for Turnera spp. The present work includes 92 publications that evaluate 29 bioactivities and toxicological and genotoxic information on five species of this genus. Among the pharmacological effects reported, the antioxidant, hepatoprotective, neuroprotective, hypoglycemic, and aphrodisiac activities seem more promising. Phytochemicals and standardized plant extracts could offer alternative therapeutic remedies for various diseases. Although several flavonoids, cyanogenic glycosides, monoterpenoids, triterpenoids, and fatty acids have been isolated for Turnera plants, future research should focus on the identification of the main active principles responsible for these pharmacological activities, as well as to perform clinical trials to support the laboratory results.

Identification and Evaluation of New Potential Inhibitors of Human Neuraminidase 1 Extracted from Olyra latifolia L.: A Preliminary Study

Sialidases, also called neuraminidases, are involved in several human pathologies such as neurodegenerative disorders, cancers, as well as infectious and cardiovascular diseases. Several studies have shown that neuraminidases, such as neuraminidase 1 (NEU-1), may be promising pharmacological targets. Therefore, the discovery of new selective inhibitors of NEU-1 are necessary to better understand the biological functions of this sialidase. In the present study, we describe the isolation and characterization of nine known compounds from Olyra latifolia L. leaves. This plant, known to have several therapeutic properties, belongs to the family of Poaceae and is found in the neotropics and in tropical Africa and Madagascar. Among the purified compounds, feddeiketone B, 2,3-dihydroxy-1-(4-hydroxy-3,5-diméthoxyphényl)-l-propanone, and syringylglycerol were shown to present structural analogy with DANA, and their effects on membrane NEU-1 sialidase activity were evaluated. Our results show that they possess inhibitory effects against NEU-1-mediated sialidase activity at the plasma membrane. In conclusion, we identified new natural bioactive molecules extracted from Olyra latifolia as inhibitors of human NEU-1 of strong interest to elucidate the biological functions of this sialidase and to target this protein involved in several pathophysiological contexts.

Enzymatic and ultrasonic-assisted pretreatment in the extraction of bioactive compounds from Monguba (Pachira aquatic Aubl) leaf, bark and seed

The present study aims to characterize leaf, bark and seed of monguba in terms of their physicochemical and bioactive composition, and to determine total phenolic compounds (TPC) and total flavonoids (TF), well as their antioxidant activities (AA), of three organic solvent extracts with and without enzyme pretreatment by ultrasonic assisted extraction. Physicochemical composition was measured by pH, total titratable acidity, total soluble solids, moisture, ashes, lipids, crude protein, raw fiber, total carbohydrates, and water activity as well as, phytochemical composition analysis constituted of sugars, condensed (CT) and hydrolysable tannins (HT), carotenoids, total anthocyanins (TA), and organic acids contents. TPC and TF contents, and UHPLC/PDA/QDa flavonoids and phenolic acids quantification were performed for the solvent extracts. Antioxidant activity was determined by radical scavenging capacity assays (ABTS, DPPH, and ORAC), and reducing power assay (FRAP). Results showed that the leaf stood out with higher concentrations of ash, HT, TA and carotenoids; the bark with higher concentrations of raw fiber, total carbohydrates and organic acids (tartaric, quinic and 3.4-dihydroxybenzoic acids); in contrast, the seeds showed high concentrations of lipids, crude protein, sugars (fructose and sucrose), CT, and high values in all AA. The solvents significantly influenced the extraction of TPC and TF, highlighting ethanol. In general, the enzymatic treatments empowered the phenolic extraction and AA. The monguba seed extracts showed higher concentrations of hydroxycinnamic acids (chlorogenic acid, mainly), and flavanols (catechin and epicatechin), whereas the leaf extracts, flavanones (narigenin), flavonols (rutin, mainly) and flavones (acacetin). The bark extracts stood out for the presence of vanillin. The monguba seed extract can be used in functional foods production.

Chemical Composition and Antioxidant Activity of Monguba (Pachira aquatica) Seeds

Monguba fruit has a seed with a chestnut-like flavor that can be consumed boiled, fried, and roasted. These nutritious seeds also have been used in popular medicine to treat several diseases. Nevertheless, the nutritional and functional potential of monguba seed is still underexploited. In this sense, we investigated the nutritional and functional components of monguba seeds. These seeds showed high total content of sugars, mainly sucrose, whereas the content of the raffinose family oligosaccharides was low. The mineral assay showed high amount of minerals, namely potassium, calcium, magnesium and zinc, which indicate that monguba seeds can be a new source of these minerals. UHPLC-ESI-MS/MS analysis showed caffeic, ferulic and 4-hydroxybenzoic acids as the main phenolic compounds, mainly in the esterified form, in these seeds. Monguba seed showed high lipid content, in which the main compounds were palmitic acid and γ-tocopherol. The soluble and insoluble phenolic fractions from monguba seeds showed high antioxidant activity measured by the oxygen radical absorption capacity (ORAC) and the trolox equivalent antioxidant capacity (TEAC) assays. Therefore, the monguba seeds have great potential to be explored by food, pharmaceutical and cosmetic industries due to their chemical composition.

The Selective Interaction of Pistacia lentiscus Oil vs. Human Streptococci, an Old Functional Food Revisited with New Tools

Pistacia lentiscus berry oil (LBO) represents a typical vegetal product of the Mediterranean basin that has been formally used in traditional cuisine for 100s of years. In addition to its interesting alimentary properties, this product could represent an interesting candidate in the field of research on the study of new anti-infective agents. In fact, in Mediterranean countries, lentisk oil still continues to be widely used in folk medicine for oral and skin affections, in particular, acute gingivitis, pediatric skin infections such as impetigo and foot plaques, and biofilm related infections often associated with Streptococcus spp. Following these observations, we have hypothesized a “lentisk oil-bacteria” interaction, placing particular emphasis on the different Streptococcal species involved in these oral and skin diseases. In accordance with this hypothesis, the use of standard antimicrobial-antibiofilm methods (MIC, MBC, MBIC) allowed the interesting behavior of these bacteria to be observed and, in this context, the response to lentisk oil appears to be correlated with the pathogenic profile of the considered microorganism. Two probiotic strains of S. salivarius K12/M18 appeared to be non-sensitive to this product, while a set of five different pathogenic strains (S. agalactiae, S. intermedius, S. mitis, S. mutans, S. pyogenes) showed a response that was correlated to the fatty acid metabolic pathway of the considered species. In fact, at different times of bacteria development, selective High Performance Liquid Chromatography analysis of the growth medium containing LBO detected a significant increase in free unsaturated fatty acids (UFAs) in particular oleic, palmitic and linoleic acids, which are already known for their antibacterial activity. In this context, we have hypothesized that LBO could be able to modulate the pathogen/probiotic rate in a Streptococcal population using the fatty acid metabolic pathway to help the probiotic strain. This hypothesis was strengthened by performing antibacterial testing with oleic acid and an in silico evaluation of the Streptococcal MCRA protein, an enzyme involved in the production of saturated fatty acids from UFA. These results show that LBO may have been used in ancient times as a “natural microbial modulating extract” in the prevention of biofilm- associated diseases.