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.

Determination of thermal, molecular changes, and functional properties in stabilized rice bran

In this study, stabilization was performed using three different oven temperatures (110, (T1) 130 (T2) and 150 °C(T3)) in the oven set at 10% moisture. The effect of stabilization on lipase activity, functional, and thermal properties of rice bran. Lipase activity of control (27.92 U/g) was to be higher than stabilized rice bran samples. Starch gelatinization peak temperature ranged from 70.05 (T3) to 85.09 °C (control). DPPH scavenging effect of control was 12.99 mmol TE. The highest DPPH radical scavenging effect value (15.72 mmol TE) was determined in the T3 sample. ABTS radical scavenging effect of stabilized samples significantly increased (p < 0.05) and the increase for T1, T2, and T3 was found to be 73, 75, and 77%, respectively. The highest ferulic (4284 μg/g) and p-coumaric acid (1180 μg/g) contents were determined in T3 and T1 samples, respectively. The content of bound ferulic and p-coumaric acids of stabilized rice bran samples was 2.41 and 2.33 times higher than control samples. While prolamine content was 3.38–4.18 mg/mL; glutelin content ranged from 4.45 to 5.11 mg/mL. An obvious state change during stabilization was observed in all samples around 70–85.9 °C. The results of the study revealed that stabilization might change the functional and thermal properties of rice bran.

Design, Synthesis and Biological Evaluation of Novel Thiazolidinone Derivatives

In present study, the novel thiazolidinone derivatives were designed and synthesized. The formation of the target compounds was confirmed by the elemental analyses, FT-IR, mass spectroscopy and 1H NMR spectroscopy. These derivatives were subjected to antibacterial and antioxidant activities. The antibacterial results revealed that these derivatives were selectively active against Gram-negative Pseudomonas aeruginosa bacteria. Also, these derivatives displayed a good DPPH radical scavenging effect. Drosophila melanogaster flies were used for evaluating the toxic impact of novel thiazolidinone derivatives.