Search Results (6)

In this research, the antioxidant and antibacterial activities of active films based on potato starch containing Viola odorata extract (VOE) were investigated both in vitro and in chicken fillets. The VOE was added to the starch film formulation at 0, 1, 2, and 3% (w/v). The results showed that by increasing the extract level, the total phenol content and antioxidant and antibacterial activity of the films against Escherichia coli, Staphylococcus aureus, and Salmonella typhimurium improved remarkably. The results of the meat tests indicated the significant antioxidant and antimicrobial activity of active films containing different levels of VOE in chicken fillets, and a direct relationship was observed between the concentration of the extract and the functional activity of the films, so with the increase in the concentration of the extract in the films, the rate of lipid oxidation and growth of microorganisms in the chicken fillets decreased significantly during the storage period, and less volatile nitrogen bases, metmyoglobin, and oxidation products were produced in the fillets. In general, the results of this research demonstrated that an active film based on potato starch containing VOE (especially 2 and 3% levels) has the ability to extend the oxidative and microbiological shelf life of chicken fillets during cold storage for at least eight days. Full article

Viola odorata L. oil is frequently recommended in the aromatherapeutic literature for treating respiratory, urinary, and skin infections; however, antimicrobial evidence is lacking. In addition, in aromatherapy, combinations of essential oils are predominantly utilized with the goal of achieving therapeutic synergy, yet no studies investigating the interaction of essential oil combinations with V. odorata oil exists. This study thus aimed to address these gaps by investigating the antimicrobial activity of three Viola odorata oil samples, sourced from different suppliers, independently and in combination with 20 different commercial essential oils, against micro-organisms involved in respiratory, skin, and urinary tract infections associated with global resistance trends. These pathogens include several of the ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter spp.) The chemical profile of the oils was determined using gas chromatography coupled with mass spectrometry. The minimum inhibitory concentrations (MIC) were determined using the broth micro-dilution method. The interactive profiles for the combinations were assessed by calculating the fractional inhibitory concentration index (ΣFIC). The main compounds varied across the three samples, and included phenethyl alcohol, isopropyl myristate, 2-nonynoic acid, methyl ester, α-terpineol, α-cetone, and benzyl acetate. The V. odorata oil samples displayed overall poor antimicrobial activity when tested alone; however, the antimicrobial activity of the combinations resulted in 55 synergistic interactions where the combination with Santalum austrocaledonicum resulted in the lowest MIC values as low as 0.13 mg/mL. The frequency of the synergistic interactions predominantly occurred against Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, and Enterococcus faecium with noteworthy MIC values ranging from 0.25–1.00 mg/mL. This study also reports on the variability of V. odorata oils sold commercially. While this warrants caution, the antimicrobial benefit in combination provides an impetus for further studies to investigate the therapeutic potential. Full article

Exceptional components of the cultural landscape of Central Europe include archaeological sites, e.g., castle ruins, prehistoric or medieval fortified settlements, other settlements and burial mounds. The plants associated with them help us explain the processes of species persistence on habitat islands as well as the process of naturalization of crop species, which escape from fields or are abandoned. This study describes the flora of a medieval fortified settlement in Giecz (Wielkopolska region, western Poland), presents plant indicators of former settlements (relics of cultivation), species of high conservation value, and transformations of the vascular flora of this settlement over a few decades. Field research was conducted in 1993–1994, 1998–1999, and 2019. At the study site, 298 species of vascular plant species were recorded, and nearly 70% of them (201 species) have persisted there over the last 20 years. The flora includes seven relics of cultivation (Artemisia absinthium, Leonurus cardiaca, Lycium barbarum, Malva alcea, Pastinaca sativa, Saponaria officinalis, and Viola odorata), 5 species threatened with extinction in Poland and/or Wielkopolska, and 53 species of least concern (LC) according to the European red list. We have attempted to explain the floristic changes. The archaeological site in Giecz is of high conservation value, very distinct from the surrounding cultural landscape because of its specific flora, and composed of species from various habitats (e.g., dry grasslands, wooded patches, meadows, aquatic and ruderal habitats), including threatened, protected, and relic species. Full article

Flowers of red clover (Trifolium pratense), sweet violet (Viola odorata) and elderflowers (Sambucus nigra) were dried by means of air drying at 30 °C and 50 °C and by freeze drying. The content of polyphenols was determined using the Folin–Ciocalteu reagent, while anthocyanins were quantified by the pH differential method. Antioxidant activities of aqueous and ethanolic extracts of the dried flowers were measured by the DPPH and ABTS assays, as well as FRAP and reducing power methods. The highest amount of polyphenols was determined in the ethanolic extracts of fresh red clover flowers (854.76 mg/100 g), while the highest concentration of anthocyanins was determined in the aqueous extracts of fresh sweet violet flowers (99.41 mg/100 g). The results showed that, in general, the extracts of red clover flower were characterized by the highest antioxidant activity, while the sweet violet extracts had the poorest antioxidant properties, although these values fluctuated depending on the method used. There was strong correlation between antioxidant activity and TPC (r = 0.9196, FRAP method). In most cases, freeze drying was found to be the best conservation method, retaining well the antioxidant properties of the tested flowers and the compounds determining these properties. Full article

The aim of the study was to evaluate the postharvest longevity of cut leaves of Viola odorata and determine their usefulness as a florist green. The research also involved the study of the influence of chemical compounds used as plant preservatives on the longevity of leaves of V. odorata. The leaf stalks of V. odorata were soaked in water or conditioned in a 200 mg·dm⁻³ solution of 8–hydroxyquinoline sulphate, or a 50 or 100 mg·dm⁻³ solution of gibberellic acid. After one day, the leaves were kept in water or 200 mg·dm⁻³ of 8–hydroxyquinoline sulphate. The leaves of V. odorata had a longevity of about 31 days in water. Both the conditioning in gibberellic acid and 8–hydroxyquinoline sulphate and the maintenance in 8–hydroxyquinoline sulphate reduced the vase life of cut V. odorata leaves. The application of conditioners resulted in a significantly greater reduction of the leaf mass. The Soil Plant Analysis Development value of the leaves was best affected by conditioning them in 100 mg·dm⁻³ gibberellic acid followed by keeping them in water. Cut leaves of V. odorata with water treatment may be used as a florist green. Full article

Hypertension is highly prevalent among the Lebanese adult population and is indeed the major cause of mortality in Lebanon. Traditional use of antihypertensive medicinal plants has long been practiced. The aim of this study is to document this traditional knowledge and clinically test the antihypertensive capacity of three of the most commonly used wild plant species Mentha longifolia, Viola odorata and Urtica dioica. Ethno-pharmacological data was collected by personal interviews with herbalists and traditional healers using a semi structured survey questionnaire and assessing relative frequency of citation (RFC). The clinical study was conducted by a randomized, blind, placebo-controlled trial in 29 subjects with mild hypertension distributed in four groups, three plant extract treatments and one placebo. Systolic (SBP) and diastolic blood pressures (DBP) as well as mean arterial blood pressures (MAP) were monitored at weeks 4, 8, 12 and 16 during the treatment with 300 mL/day of plant extract. Results showed that M. longifolia, U. dioica and V. odorata exhibited the highest values of RCF (0.95) followed by Allium ampeloprasum (0.94), Apium graveolens (0.92) and Crataegus azarolus (0.90). The clinical trial revealed dose- and duration-dependent significant reductions in SBP, DBP and MAP of subjects treated with M. longifolia, U. dioica or V. odorata. Our findings indicate that extracts of these plants present an effective, safe and promising potential as a phyto-therapuetical approach for the treatment of mild hypertension. More research on the phytochemistry, pharmacological effects and the underlying mechanisms is necessary. Full article