Isolation and seasonal variation of fruticin in fruits of false indigo-bush (Amorpha fruticosa L. Fabaceae) from Serbia

Fruticin (amorphin) is a constituent of the fruit of the false indigo-bush (Amorpha fruticosa L.), which belongs to the class of rotenoid glycosides, and shows several interesting pharmacological activities. The aim of this study was to isolate and chemically characterize this natural product, as well as to determine the optimal period of the year for A. fruticosa fruits collection. Fruticin was obtained by re-crystallization of the precipitate that formed after partial evaporation of the extract, prepared by 3fold extraction of powdered plant material by chloroform - ethanol (1:1, v/v). The structure of the final product was determined by various techniques of instrumental analysis (NMR, UV and MS), and confirmed by comparing the obtained spectra with corresponding data in available literature. The content of fruticin in A. fruticosa fruit was determined by LC-DAD-MS, using the external standard method based on the constructed calibration curve. Limits of detection (LOD) and quantification (LOQ) were also determined. A substantial increase in fruticin content was observed during the ripening period (>50 %). It has also been established that the optimal time for fruit collection is mid-December. Obtained results indicate that the content of fruticin in the A. fruticosa fruit is highly dependable on the time of collection. Since the biosynthesis of secondary plant metabolites is influenced not only by the time of collection, but by numerous other factors as well, additional studies are needed to define, with greater certainty, the conditions that are necessary for design of prospective efficient and sustainable production process.

Phyto-pharmacological aspects of Nepeta nuda L.: A systematic review

Nepeta nuda L. (syn. N. pannonica L.) is a herbaceous perennial plant that is the most widespread species of the genus Nepeta, the largest genera in Lamiaceae family. N. nuda is divided into four subspecies according to morphological differences which occur within large geographical range of distribution: subsp. nuda, subsp. albiflora, subsp. lydiae, and subsp. glandulifera. In this review, previous reports on N. nuda concerning its botanical description and systematics, phytochemistry, use in traditional medicine, pharmacology, and posibilities for other applications were summarized. All of these data indicate N. nuda as a highly promising species for application in food and pharmaceutical industries, as well as in agriculture for the development of natural pesticides.

Antifungal activity of the essential oil from Artemisia santonicum and its constituent isogeranic acid

This study represents a continuation of exploring of the biological activities of the Artemisia santonicum essential oil. The previous investigation was focused on the antibacterial, antibiofilm, and antiquorum activities of A. santonicum essential oil and isogeranic acid as the main antibacterial constituent. The present study describes its antifungal activity. The antifungal activity of the A. santonicum essential oil was tested against eight fungi isolates, whereas antifungal effects of isogeranic acid were studied using four fungi species, because of the limited quantities of the isolated compound. The results were compared to the commercial antimycotics, bifonazole and ketoconazole. Antifungal activity of isogeranic acid against all tested fungi was significantly higher in comparison to the essential oil and the both controls.

GC/MS chemical analysis of lavandin (Lavandula x intermedia) hydrolat: Successive extraction fractions

Hydrolats are valuable co-products of the essential oil distillation process, whose volatile compounds can be quantified by various methods. In this paper, we have tried to estimate the liquid-liquid extraction cycle number threshold for volatile compounds quantification of lavandin (Lavandula x intermedia) hydrolat. For this purpose, ten consecutive hydrolat extractions with n-hexane were analyzed GC/MS with hexadecane (C16) as an internal standard and compared with the lavandin essential oil. The chemical composition of the lavandin hydrolat showed similarity with its essential oil to the great extent, while volatile compounds dissolved in hydrolat exclusively belonged to the class of oxygenated monoterpenes. The total amount of extracted compounds has been estimated to 2174.2 mg/L, where the most dominant compounds in lavandin hydrolat were cisand trans-furanoid linalool oxide (676.3 and 634.1 mg/L, respectively), followed by much smaller amounts of linalool, camphor, and 1,8-cineole (167.6, 157.0, and 148.2 mg/L, respectively). Cumulative recoveries of total compounds yield after the third, fifth, and eighth extractions were 88 %, 96 %, and 99 %, respectively. Combined fraction analysis confirmed that in the first 5 cycles more than 95 % of the total yield (from 10 cycles) of extracted volatile compounds can be collected. Based on the results of this study, for volatile compounds quantification in lavandin hydrolat, 5 cycles of n-hexane liquid-liquid extraction can be recommended.

Antifungal activity of aqueous and corn steep liquor extract of Ficus exasperata, Anonna muricata and Azadiractha indica

This study investigated the activity of aqueous and corn steep liquor (CSL) extracts of Ficus exaperasta, Annona muricata and Azadirachta indica against Candida spp. isolated from high vaginal swab samples. Phytochemical screening of the plants was done using standard methods, the antifungal activity of the plant's extracts and standard drugs were tested against isolates of Candida spp. using the agar well diffusion method; the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) were also determined using microdilution standardized techniques. Phytochemical screening of the aqueous and CSL extracts of the plants revealed the presence of tannin, saponin, flavonoids, and terpenoids. Among the five Candida strain isolates, the zone of inhibition produced by the plant extracts against C. albicans shows a range of 0-18.3 mm; C. krusei (strain A): 5.1-24.5 mm; C. krusei (strain B): 0-18.0 mm; C. kefyr (strain A): 6.1-27.5 mm; and C. kefyr (strain B): 0-22.0 mm. The CSL extract had higher inhibitory action compared with aqueous extract, also F. exasperata and A. muricata gave better antifungal activity against the tested Candida strains. The MIC of the aqueous and CSL extracts of the F. exasperata ranged between 6.25-12.50 mg/mL; A. muricata: 3.125-12.500 mg/mL, while the aqueous and CSL extracts of A. indica was found to have no activity at all the tested concentrations against C. albicans, C. krusei (strain A) and C. krusei (strain B), similar observation for the MFC. This study proved the antifungal efficacy of aqueous and CSL extracts of F. exasperata, A. muricata, and A. indica against isolates of Candida species which are usually implicated in candidiasis.

In vitro antineurodegenerative activity and in silico predictions of blood-brain barrier penetration of Helichrysum plicatum flower extract

This study aimed to assess the antineurodegenerative and antioxidant activity of Helichrysum plicatum flower extract, as well as to identify extract ingredients with acceptable pharmacokinetic parameters such as gastrointestinal absorption, blood-brain barrier permeation, and P-glycoprotein-mediated effusion for optimal therapeutic brain exposure. Antioxidant activity was evaluated by ABTS, FRAP, and b-carotene bleaching assays, while antineurodegenerative activity was tested using acetylcholinesterase (AChE) and tyrosinase (TYR) inhibitory activity assays. In the ABTS test, the dry extract at the highest applied concentration (500 µg/mL) showed better or similar antioxidant activity compared to the standards. In the b-carotene assay, all applied concentrations of the extract showed significantly higher activity than vitamin C. No concentration-dependent activity was observed in the AChE assay, while in the TYR assay the lowest extract concentration (100 µg/mL) showed the highest percentage of inhibition (27.92 %). Pharmacokinetic parameters of compounds were predicted by in silico SwissADME online tool in accordance by the rules of drug-likeness. According to the pharmacokinetic properties, we concluded that pentoxymethoxylated flavones may represent CNS drug candidates for further studies.

Extraction of sweet wormwood (Artemisia annua L.) by supercritical carbon dioxide

In this study, supercritical carbon dioxide was applied for the extraction of Artemisia annua L. Moreover, the impact of different parameters of supercritical extraction on total yield was investigated and the obtained yields were compared to the ones obtained by conventional procedures, hydrodistillation and Soxhlet extraction. Supercritical fluid extraction at 40 °C and different pressures (100, 200, and 300 bar) resulted in extraction yields that were in the 2.23-5.18 % range, while the yields at 60 °C and the same pressures were in the range 2.43-3.35 %. The yields obtained by the Soxhlet extraction and hydrodistillation were 10.28 % and 0.10 %, respectively. Although supercritical fluid extraction is inferior to Soxhlet extraction in terms of the recovery of lipophilic components of A. annua, the Soxhlet extraction is not the method of choice for obtaining sweet wormwood extracts due to its numerous disadvantages that include the use of toxic solvents, extended extraction time, health safety of the product, the need for further processing, the impossibility of adjusting the selectivity and thus the composition of the product.

Ethnomedicinal application of species from genus Thymus in the Pirot County (Southeastern Serbia)

The species from genus Thymus are polymorphous plants from the family Lamiaceae, spread in Serbia in many species, subspecies, varieties, and forms. The aerial parts of species from genus Thymus have a long tradition of being used worldwide. The subject of this study was the research of ethnomedicinal application of thyme in Pirot County (Southeastern Serbia). Ethnomedicinal surveys were conducted among the population in four municipalities: Pirot, Babušnica, Bela Palanka, and Dimitrovgrad. It was noticed that 56.9 % of interviewed persons use the species of genus Thymus in the Pirot County. They are usually used in the county's folk medicine in the form of herbal tea against colds to relieve dry and spastic cough, especially in bronchitis and asthma, and for sedation.

Antibacterial and antibiofilm activity of selected polyphenolic compounds: An in vitro study on Staphylococcus aureus

Staphylococcus aureus is a human pathogen that causes serious infections with high mortality rates. The antimicrobial activities of eight phenolic compounds (caffeic acid, chlorogenic acid, ferulic acid, morin, quercetin, isoquercitrin, rutin and hesperidin) were evaluated against planktonic and biofilm forming Staphylococcus aureus cells. Their ability to prevent biofilm formation via interference with bacterial cell adhesion and to reduce biomass of 24 h old biofilms has been addressed in this study. The antibacterial activities (MIC/MBC) were demonstrated using the microdilution method and the investigated compounds showed good activity against S. aureus isolates, with MICs in the range 0.05-0.4 mg/mL. Also, they exhibited promising antibiofilm potential in dose depended manner. Among all tested compounds, morin and quercetin showed the best antibiofilm activity at MIC values. The observed antimicrobial potential of the studied natural products can serve as a starting point towards development of novel plant-based therapeutics for the treatment of common infections such as the ones caused by S. aureus.

Development of gastroretentive floating granules with gentian root extract by hot-melt granulation

The roots of yellow gentian, Gentiana lutea L. (Gentianaceae) are used in traditional medicine for the treatment of gastrointestinal disorders, with the literature data indicates a local gastric effect of gentian root extract (GRE) and support the use of the solid pharmaceutical forms. Gentiopicroside, as a dominant secoiridoid in the GRE, has a short elimination half-life and low bioavailability and, consequently, its bioactivity is limited. The aim of the study was to develop gastroretentive floating delivery system with GRE, and to provide prolonged release of gentiopicroside. Floating granules with dry GRE (DGRE) were prepared by the hot-melt granulation technique, while formulations included effervescent components (citric acid and sodium bicarbonate), hydroxypropyl methylcellulose (HPMC) and meltable binders (Compritol® 888 ATO and Gelucire® 50/13). The flowability of the DGRE and prepared formulations was determined by calculating the Carr index and Hausner ratio. Floating properties and in vitro dissolution rate of gentiopicroside from investigated formulations were examined. Floating granules were characterized with improved flowability (Carr index 14-22 %; Hausner ratio 1.16-1.28) in comparison to the DGRE (Carr index 28.99 %; Hausner ratio of 1.41). Furthermore, the floating granules exhibited immediate and long-lasting buoyancy and prolonged-release of gentiopicroside (over 8 h). Compritol® 888 ATO has provided sustained release of gentiopicroside from floating granules, while HPMC has decreased release rate additionally. On the other hand, Gelucire® 50/13 has increased gentiopicroside release rate. The results have shown that hot-melt granulation technique, as a green granulation method was successfully employed for obtaining gastroretentive floating granules with DGRE.