Hypotensive effect and endothelium-dependent vascular action of leaves of Alpinia purpurata (Vieill) K. Schum

The aims of this study were to evaluate the chemical profile, vascular reactivity, and acute hypotensive effect (AHE) of the ethanolic extract of leaves of Alpinia purpurata (Vieill) K. Schum (EEAP). Its chemical profile was evaluated using HPLC-UV, ICP-OES, and colorimetric quantification of total flavonoids and polyphenols. The vascular reactivity of the extract was determined using the mesenteric bed isolated from WKY. AHE dose-response curves were obtained for both EEAP and inorganic material isolated from AP (IAP) in WKY and SHR animals. Cytotoxic and mutagenic safety levels were determined by the micronucleus test. Rutin-like flavonoids were quantified in the EEAP (1.8 ± 0.03%), and the total flavonoid and polyphenol ratios were 4.1 ± 1.8% and 5.1 ± 0.3%, respectively. We observed that the vasodilation action of EEAP was partially mediated by nitric oxide (·NO). The IAP showed the presence of calcium (137.76 ± 4.08 μg mg-1). The EEAP and IAP showed an AHE in WKY and SHR animals. EEAP did not have cytotoxic effects or cause chromosomic alterations. The AHE shown by EEAP could result from its endothelium-dependent vascular action. Rutin-like flavonoids, among other polyphenols, could contribute to these biological activities, and the calcium present in EEAP could act in a synergistic way

Screening and Characterization of Antiglycoxidant Anthocyanins from Vaccinium myrtillus Fruit Using DPPH and Methylglyoxal Pre-Column HPLC Assays

International audienceVaccinium myrtillusfruit (bilberry) is well known for its high richness in anthocyanins,which may be responsible for its preventive effects on several oxidative and carbonyl stress-relatedpathologies. However, limited data are available regarding the antioxidant and antiglycativecontributions of its constituents. Spectrometric analyses were performed to evaluate anthocyanincontent, radical scavenging and antiglycative properties of an anthocyanin-rich extract from bilberries.Additionally, original DPPH and methylglyoxal pre-column HPLC methods were instigated to allowstraightforward identification of the main contributors to radical and carbonyl trapping effects.Finally, representative pure anthocyanins were evaluated using classical DPPH and antiglycationassays. Delphinidin, petunidin and cyanidin glycosides were identified as the most effective radicalscavenging constituents in both HPLC and spectrometric DPPH evaluations. Potent antiglycativeactivities were also assessed for cyanidin, delphinidin and petunidin glucosides as attested by theirrespective IC50values of 114.2±7.8, 130.5±2.8, and 132.4±3.7μM. Interestingly, methylglyoxalspiking evaluation demonstrated that all bilberry anthocyanins exerted noticeable and comparableα-dicarbonyl trapping effects. Anthocyanins can be regarded as potent antiglycoxidant agents thatmight account for some health benefits of bilberries consumption. Besides, significant differences intheir contributions were successfully highlighted by the employed pre-column HPLC assays

Impact of Simulated Gastrointestinal Conditions on Antiglycoxidant and α-Glucosidase Inhibition Capacities of Cyanidin-3-O-Glucoside

International audienceCyanidin-3-O-glucoside (C3G) is a widespread anthocyanin derivative, which has been reported in vitro to exert potent antioxidant, antiglycation and α-glucosidase inhibition effects. Nevertheless, the physiological relevance of such properties remains uncertain considering its significant instability in gastrointestinal conditions. A simulated digestion procedure was thus instigated to assess the influence of gastric and intestinal media on its chemical integrity and biological activities. HPLC analyses of digested C3G samples confirmed the striking impact of intestinal conditions, as attested by a decomposition ratio of 70%. In contrast, with recovery rates of around 90%, antiglycation, as well as DPPH and ABTS scavenging assays, uniformly revealed a noteworthy persistence of its antiglycoxidant capacities. Remarkably, a prominent increase of its α-glucosidase inhibition activity was even observed after the intestinal phase, suggesting that classical in vitro evaluations might underestimate C3G antidiabetic potential. Consequently, the present data provide novel and specific insights on C3G’s digestive fate, suggesting that the gastrointestinal tract does not profoundly affect its positive action on oxidative and carbonyl stresses. More specifically, it also tends to support its regulating effects on postprandial hyperglycemia and its potential usefulness for diabetes management

Stability and Antiglycoxidant Potential of Bilberry Anthocyanins in Simulated Gastrointestinal Tract Model

International audienceAnthocyanins from Vaccinium myrtillus fruits have been reported in vitro to exert potent radical scavenging and antiglycation activities. However, the physiological relevance of such properties remains unclear given the potential susceptibility of anthocyanin derivatives to digestive conditions. A simulated gastrointestinal tract model was thus implemented to assess the impact of gastric and intestinal phases on the chemical integrity of bilberry anthocyanins and their antiglycoxidant effects. Results demonstrated that the investigated activities as well as total and individual anthocyanin contents were marginally affected by gastric conditions. By contrast, with recoveries ranging from 16.1 to 41.2%, bilberry anthocyanins were shown to be highly sensitive to the intestinal phase. Of major interest, a much better preservation was observed for radical scavenging and antiglycation activities as attested by recovery rates ranging from 79.1 to 86.7%. Consistently with previous observations, the present study confirms the moderate bioaccessibility of anthocyanin constituents. It does however provide valuable information supporting the persistence of substantial radical scavenging and antiglycation activities at each step of the digestion process. Taken together, these data indicate that digestive conditions might not abolish the potential positive effects of bilberry consumption on both oxidative and carbonyl stresses

The occurrence of triterpenoids from Euphorbia gummifera inside the fairy circles of Garub in the southern Namibian pro-desert

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New insights into the mechanisms of the vasorelaxant effects of apocynin in rat thoracic aorta

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1H NMR-based metabolomics of antimalarial plant species traditionally used by Vha-Venda people in Limpopo Province, South Africa and isolation of antiplasmodial compounds

Please read abstract in the article.The National Research Foundation (South Africa)http://www.elsevier.com/locate/jethpharmhj2020Plant Production and Soil Scienc

Characterization of antioxidants from Detarium microcarpum Guill. et Perr. leaves using HPLC-DAD coupled with pre-column DPPH assay

Characterization of antioxidants from Detarium microcarpum Guill. et Perr. leaves using HPLC-DAD coupled with pre-column DPPH assa