Argentine stingless bee honey: bioactive compounds and health-promoting properties

Despite all the advantages of consuming meliponid honey, meliponiculture has not been sufficiently promoted in Argentina yet, and published studies on these species of bees are very scarce. <i>Tetragonisca fiebrigi</i> honey (<b>TfH</b>) or Yateí honey has recently been incorporated into the Argentine food code. This study assesses antioxidant, anti-inflammatory and analgesic properties and acute toxicity by oral administration of <b>TfH</b> in rats. In addition, we present the melissopalynological analysis and physicochemical characterization. High-performance liquid chromatography identifies and quantifies sugars and phenolic compounds. The <i>T. fiebrigi</i> honey analyzed exhibited ABTS^•+ and DPPH radical scavenging effect (IC₅₀= 98.28 mg/ml and IC₅₀=337.83 mg/ml, respectively). A significant reduction in hind paw edema (44.44%) was observed in rats pretreated with <b>TfH</b> honey (1000 mg/kg b.w.) 3.0 h after dosing and significantly reduced transudative and granuloma weights at all doses tested (27.34%, 35.53% and 47.53% granuloma inhibition). The <b>TfH</b> honey oral administration produced analgesic responses in the three models used (acetic acid, formalin, tail immersion). Ferulic, ellagic, coumaric, gallic, cinnamic acids and the flavonoids quercetin and hesperetin were identified and quantified. Fructose (40.9%), glucose (29.02%) and sucrose (1.06%) were the main sugars. <b>TfH</b> honey administration did not produce lethal effects or clinical signs of disease in the acute toxicity study. The results showed that <i>T. fiebrigi</i> honey could be a good source of bioactive natural compounds with therapeutic and nutritional value.

Antioxidant capacity of blackcurrant (Ribes nigrum L.) leaves and buds

The antioxidant capacity is the combined free radical scavenging effect of all antioxidant compounds found in the studied system. There is a growing need for accurate, numerical determination of this capacity (for easier comparison), so there are many analytical procedures, methods, and measurement systems available to researchers. Neither one is able to model the totality of real, naturally occurring reactions; therefore, conclusions about the antioxidant power of the studied sample can be drawn only after using several methods. In this work, the total phenolic content (TPC) of blackcurrant leaves and buds was determined, and the antioxidant capacity was tested using the DPPH and FRAP assays. 80% methanol was the most effective in the extraction of phenolics followed by 80% ethanol, while for the antioxidant capacity the acetone (50%)/water/acetic acid (2%) mixture proved to be the best. Significant differences were observed between cultivars and sampling dates, but the pattern of variation during the harvest period was similar for all cultivars.

Some bioactive component analysis of herbal capsules

Since the beginning of the evaluation of plants in terms of human health, the bioactivity properties of plants have been studied in the laboratory and thus standards have been brought to the treatment methods with plants. For this purpose, some bioactive component analyzes of 18 herbal capsules and 2 liquid herbal syrups produced by Naturin Company were performed in our current study. In this context, the total oxidant and antioxidant status of these plant mixtures were evaluated. The free radical capacities of the samples were determined by 1, 1-diphenyl-2-picrylhydrazil (DPPH) method and their DNA protective activities were determined using pBR322 plasmid DNA. Total antioxidant level (TAL) and Total oxidant level (TOL) activities were performed using Rel Assay diagnostic kit. All 3 of the stinging nettle samples showed DNA protective activity. The clean sample containing milk thistle extract also showed DNA Protective activity. In both the syrup samples (My guard and DTX-19) results were detected in the direction of positive protection on DNA. When the DPPH radical scavenging capacity was examined, it was determined that the best results were in juniper, nettle and thistle thistle samples, and the samples with syrup had a very good radical scavenging effect, and all of the samples showed antioxidant activity. This study is a preliminary and supportive study in order to elucidate the properties that can be used as drug active ingredients in traditional medicine, especially in the field of pharmacology.

Synthesis and Antioxidant Properties of Novel 2-(2,4-Dioxothiazolidin-5-ylidene)-Acetamides Containing 1,3,4-Thia/Oxadiazole Moieties

A series of novel 1,3,4-thia(oxa)diazole substituted 2-(2,4-dioxothiazolidine-5-ylidene)-acetamides 3a-c, 4 and 5a-k have been synthesized following the acylation reaction of 2-amino-5-aryl-1,3,4-oxadiazoles, 5-amino-1,3,4-thiadiazole-2-thiol and it’s S-alkylated derivatives with 2-(2,4-dioxothiazolidine-5-ylidene)acetyl chloride in dioxane medium. The functionalization of compounds 3b, 3c, 5d and 5e was carried out on their N3 position under N-alkylation conditions with N-aryl-2-chloroacetamides in DMF/ethanol medium yielded the corresponding 2,4-dioxothiazolidine-3,5-diacetic acid diamides 6a-e and 7a-b. The structures of target compounds were confirmed by using 1H NMR spectroscopy and elemental analysis. The antioxidant activity evaluation in vitro of the synthesized compounds was performed by the method of scavenging effect on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals. As a result, the highly active compound 4, namely 2-(2,4-dioxothiazolidin-5-ylidene)-N-(5-mercapto-[1,3,4]thiadiazol-2-yl)acetamide was found to be the most efficient candidate among all compounds with a radical scavenging ability of 88.9%, which was comparable that for ascorbic acid (92.7%). The experimentally calculated IC50 value of 43.1 µM for compound 4 was lower than for ascorbic acid (50.5 µM).

A Possibility to Use Selected Crop Post-Extraction Wastes to Improve the Composition of Cultivated Mushroom Pleurotus citrinopileatus

A cultivated mushroom species, Pleurotus citrinopileatus, is becoming increasingly popular thanks to its attractive colour and medicinal properties. In this study, P. citrinopileatus was grown in a cultivation medium enriched with wheat bran (WB), thymus post-extraction waste (TPEW) and pumpkin post-extraction waste (PPEW) products. The study showed that the post-extraction wastes are a crucial factor determining the accumulation of minerals, the content/profile of low-molecular-weight organic acids (LMWOAs) and phenolic compounds in fruit bodies, thereby increasing their nutritional value. The use of the waste materials significantly increased LMWOAs contents. The sum of LMWOAs under all cultivation mediums increased, especially quinic, malic and citric acids under the 20% PPEW, 25 and 50% TPEW addition. Total phenolic content, phenolic content, as well as the composition and scavenging effect on DPPH radicals, were strongly dependent on the used substrate. The control variant was poor in phenolic compounds, while the supplementation increased the contents and diversity of these metabolites. In the control, only four phenolic compounds were quantified (chlorogenic, gallic, syringic and vanillic acids), while in the supplemented substrates up to 14 different phenolic compounds (caffeic, chlorogenic, p-coumaric, 2,5-dihydroxybenzoic acid, ferulic, gallic, protocatechuic, salicylic, sinapic, syringic, trans-cinnamic and vanillic acids, catechin and rutin).

Chemical and biological investigations of Limonium axillare reveal mechanistic evidence for its antidiabetic activity

Root and bark of Limonium axillare (Forssk) Kuntze are used as antidiabetic remedies in parts of East Africa, but this activity has never been fully investigated. To validate its ethnobotanical use, we compared the chemical and pharmacological profiles of the ethanolic extracts of L. axillare root (REE) and aerial parts (AEE). Administration of REE (500 mg kg-1) reduced streptozotocin-induced hyperglycemia by 44%, restored serum insulin levels, reestablished Glut2 and Glut4 expression and ameliorated pancreatic tissue damage in diabetic rats. In vitro studies revealed a strong radical scavenging effect, α-glucosidase, and α-amylase inhibition activity of REE at IC50 at 25.2, 44.8 and 89.1μg/mL, respectively. HPLC analysis identified ten phenolic compounds in REE with umbelliferone as the major constituents at 10 ± 0.081 mg/g of extract. Additionally, six compounds were isolated from REE including, β-sitosterol-3-palmitate, β-sitosterol, myricetin and gallic acids with two new tetrahydrofuran monoterpenes; 2-isopropyl- 3,4,4, trimethyl-tetrahydrofuran (3), and 2-isopropyl-4-methyl-tetrahydrofuran-3,4 dicarboxylic acid (4), the latter was revealed by molecular docking to be a good ligand to glycerol-3-phosphate dehydrogenase a key enzyme in glycolysis.

Comparative EPR Study on the Scavenging Effect of Methotrexate with the Isomers of Its Photoswitchable Derivative

The scavenging effect of the antimetabolite dihydrofolate reductase inhibitor methotrexate (MTX) and the isomers of its photoswitchable derivate, cis- and trans-phototrexate (PHX), have been compared by ESR spectroscopy, with the application of a cyclic hydroxylamine spin probe. The results showed the most pronounced scavenging effect in the presence of trans-phototrexate (trans-PHX). At a low concentration (100 µM) cis-PHX also showed a greater scavenging effect than the parent molecule MTX. Direct antioxidant properties of the investigated molecules were measured by ABTS scavenging assay, which showed no significant difference between trans-PHX and cis-PHX, but both of the isomers of PHX showed a higher antioxidant capacity than MTX. These findings imply that trans-PHX may have more pronounced anti-inflammatory and tissue-protective effects than MTX, despite the lack of its cytotoxic, antineoplastic effect.

A review on medicinal properties of Pleurotus ostreatus

Mushroom are eaten and liked by people all over the world not only because of their taste, aroma or nutritive values in food but also because of their medicinal properties. They are beneficial for human or animal health due to presence of active polysaccharide which boosts our immune system as well as prevent cell or microorganism growth which is harmful for our body. The extracted drug and oral doses both are efficient in prevention of many harmful biological effects like HIV, polio, inflammation, cancer, tumor, or virus growth. With their potential value and scavenging effect they are most significant functional food and can be used us food supplement.