In vitro antimicrobial and antioxidant activity of commercial rosemary extract formulations

Effects of rosmarinic acid esters on the oxidation kinetic of organogel and emulsion gel

Rosmarinic acid was esterified with ethanol, butanol, and hexanol to produce ethyl rosmarinate, butyl rosmarinate, and hexyl rosmarinate, respectively. The antioxidant capacities of the rosmarinic acid esters were evaluated in linseed oil, organogel, and emulsion gel during the initiation and propagation phases of peroxidation. Organogel control sample showed higher induction period and propagation period than those of linseed oil and emulsion gel control samples. Among linseed oil and organogel samples containing antioxidants, samples containing rosmarinic acid exhibited the highest antioxidant activity during the initiation phase, while rosemary extract containing butyl rosmarinate showed the highest antioxidant activity in the propagation phase. In emulsion gel, rosemary extract containing butyl rosmarinate showed higher antioxidant activity than those of rosemary extract containing ethyl rosmarinate or hexyl rosmarinate in the initiation and propagation phases. In addition, the investigated antioxidants showed lower efficiency in organogel and emulsion gel samples than those in linseed oil samples.

Priming crop plants with rosemary (Salvia rosmarinus Spenn, syn Rosmarinus officinalis L.) extract triggers protective defense response against pathogens

Plant bioactive compounds provide novel straightforward approaches to control plant diseases. Rosemary (Salvia rosmarinus)-derived extracts carry many prominent pharmacological activities, including antimicrobial and antioxidant, mainly due to its phenolic compounds, rosmarinic acid (RA), carnosic acid and carnosol. However, the effects of these extracts on plant diseases are still unknown, which constrains its potential application as bioprotectant in the agricultural production. In this study we demonstrate the antiviral effect of the aqueous rosemary extract (ARE) against tobacco necrosis virus strain A (TNVA) in ARE-treated tobacco (Nicotiana tabacum) plants. Our results show that ARE-treatment enhances plant defense response, contributing to reduce virus replication and systemic movement in tobacco plants. RA, the main phenolic compound detected in this extract, is one of the main inducers of TNVA control. The ARE-induced protection in TNVA-infected plants was characterized by the expression of H₂O₂ scavengers and defense-related genes, involving salicylic acid- and jasmonic acid-regulated pathways. Furthermore, treatment with ARE in lemon (Citrus limon) and soybean (Glycine max) leaves protects the plants against Xanthomonas citri subsp. citri and Diaporthe phaseolorum var. meridionalis, respectively. Additionally, ARE treatment also promotes growth and development, suggesting a biostimulant activity in soybean. These results open the way for the potential use of ARE as a bioprotective agent in disease management.

Evaluation of Rosmarinic Acid on Broiler Growth Performance, Serum Biochemistry, Liver Antioxidant Activity, and Muscle Tissue Composition

The aim of the present study was to investigate the effects of dietary supplementation with different doses of rosmarinic acid (RA) on the growth performance, serum biochemical indices, liver antioxidant activity, and muscle nutritional component of broiler chickens during 1-20 days of age. A total of 1000 1-day-old Cobb 500 white-feathered broilers were divided into five groups. Each group included four replicates and 50 birds per replicate. The control group was the basic fodder group fed with a basal diet. The experimental groups included four levels of RA (100, 200, 300, and 400 mg/kg RA added to the basal diet, respectively). The results showed that a quadratic increase in final body weight (BW) and average daily gain (ADG) and a quadratic decrease in the feed/gain (F/G) ratio were observed with increasing dietary RA levels. At 200 mg/kg RA supplementation, growth performance was significantly improved. Moreover, under this RA treatment, the highest levels of total protein and globulin were detected in the serum, the activities of total superoxide dismutase and catalase in the liver of broilers were significantly increased, and the malondialdehyde content was significantly decreased, indicating a higher antioxidant capacity of the liver when 200 mg/kg RA was added to the basal diet. The flavor of the muscle meat was improved by dietary supplementation with 200 mg/kg RA. Therefore, adding 200 mg/kg of RA to the diet could significantly improve the growth performance of broilers, improve liver antioxidant capacity, and improve muscle quality, etc. The addition of RA to broiler feed as a natural antioxidant has great prospects.

Hydrogels, Oleogels and Bigels as Edible Coatings of Sardine Fillets and Delivery Systems of Rosemary Extract

Edible coatings provide an alternative way to reduce packaging requirements and extend the shelf life of foods by delaying oxidation and microbial spoilage. Hydrogels, oleogels and bigels were applied as coatings on fresh sardine fillets. The effectiveness of these coatings as delivery systems of rosemary extract (RE) was also evaluated. Three groups of sardine fillet treatments were prepared: (i) the control (C), which comprised sardine fillets without coating, (ii) sardine fillets with plain hydrogel (H), oleogel (O) or bigel (BG) coatings, and (iii) sardine fillets with RE incorporated into the H, O and BG coatings. The different treatments were evaluated for lipid oxidation (TBA test), total volatile basic nitrogen (TVB-N) and microbiological growth during cold storage at 4 °C. Results showed that hydrogel, oleogel and bigel coatings delayed oxidation. The incorporation of RE into coatings significantly retarded lipid oxidation but did not affect the proliferation of microorganisms during storage. When RE was incorporated in the oleogel phase of the bigel coating, it produced significantly lower TVB-N values compared to the control and BG treatments. The incorporation of RE into the oleogel phase of the bigel coating may be a promising method of maintaining the storage quality of the sardine fillets stored at refrigerated temperatures.

Antibacterial Screening, Biochemometric and Bioautographic Evaluation of the Non-Volatile Bioactive Components of Three Indigenous South African Salvia Species

Salvia africana-lutea L., S. lanceolata L., and S. chamelaeagnea L. are used in South Africa as traditional medicines to treat infections. This paper describes an in-depth investigation into their antibacterial activities to identify bioactive compounds. Methanol extracts from 81 samples were screened against seven bacterial pathogens, using the microdilution assay. Biochemometric models were constructed using data derived from minimum inhibitory concentration (MIC) and ultra-performance liquid chromatography-mass spectrometry data. Active molecules in selected extracts were tentatively identified using high-performance thin layer chromatography (HPTLC), combined with bioautography, and finally, by analysis of active zone eluates by mass spectrometry (MS) via a dedicated interface. Salvia chamelaeagnea displayed notable activity towards all seven pathogens, and the activity, reflected by MICs, was superior to that of the other two species, as confirmed through ANOVA. Biochemometric models highlighted potentially bioactive compounds, including rosmanol methyl ether, epiisorosmanol methyl ether and carnosic acid. Bioautography assays revealed inhibition zones against A. baumannii, an increasingly multidrug-resistant pathogen. Mass spectral data of the eluted zones correlated to those revealed through biochemometric analysis. The study demonstrates the application of a biochemometric approach, bioautography, and direct MS analysis as useful tools for the rapid identification of bioactive constituents in plant extracts.

Campylobacter jejuni Biofilm Control with Lavandin Essential Oils and By-Products

The food industry is constantly struggling with one of the most prevalent biofilm-forming and food-borne pathogenic bacteria, Campylobacter jejuni. Different approaches are used to control biofilms in the food production chain, but none is fully effective. In this study, we aim to produce and determine the chemical profile of essential oils (EOs), ethanolic extracts of flowers prior to distillation (EFs), and ethanolic extracts of post-distillation waste material (EWMs) from Lavandula × intermedia 'Bila', 'Budrovka' St Nicholas and 'Budrovka', which were further used to reduce C. jejuni intercellular signaling, adhesion, and biofilm formation, as well as to test their antioxidant activity. Glycosides of hydroxycinnamic acids were the major constituents of both types of lavandin ethanolic extract, while linalool, linalyl acetate, 1,8-cineol, and camphor were the major compounds found in lavandin EOs. Tested EOs showed the best antibacterial activity with a minimal inhibitory concentration of 0.25 mg/mL. Lavandin EFs proved more effective in reducing C. jejuni intercellular signaling and adhesion compared to lavandin EOs and EWMs, while lavandin EOs showed a slightly better effect against biofilm formation. Interestingly, the best antioxidant activity was determined for lavandin EWMs. A positive and moderate correlation was found between the reduction of C. jejuni intercellular signaling and adhesion, as well as between adhesion and biofilm formation. These findings mean novel bacterial targets are of interest for biofilm control with alternative natural agents throughout the whole food production chain.

Effects of the Phytochemical Combination PB123 on Nrf2 Activation, Gene Expression, and the Cholesterol Pathway in HepG2 Cells

There has been a long history of human usage of the biologically-active phytochemicals in Salvia rosmarinus, Zingiber officinale, and Sophora japonica for health purposes, and we recently reported on a combination of those plant materials as the PB123 dietary supplement. In the present work we extended those studies to evaluate activation of the nuclear factor erythroid 2-related factor 2 (Nrf2) transcription factor and differential gene expression in cultured HepG2 (hepatocellular carcinoma) cells treated with PB123. We determined transcriptome changes using mRNA-seq methods, and analyzed the affected pathways using Ingenuity Pathway Analysis and BioJupies, indicating that primary effects included increasing the Nrf2 pathway and decreasing the cholesterol biosynthesis pathway. Pretreatment of cultured HepG2 cells with PB123 upregulated Nrf2-dependent cytoprotective genes and increased cellular defenses against cumene hydroperoxide-induced oxidative stress. In contrast, pretreatment of cultured HepG2 cells with PB123 downregulated cholesterol biosynthesis genes and decreased cellular cholesterol levels. These findings support the possible beneficial effects of PB123 as a healthspan-promoting dietary supplement.

Pre-Clinical Evaluation of Proprietary Lutein, Zeaxanthin, and Rosemary Formulation for Its Dermal Protective Activity in Male Swiss Albino Mice

This study aimed to evaluate the efficacy of the proprietary lutein, zeaxanthin, and rosemary formulation for its dermal protection against ultraviolet (UV) irradiated skin dehydration. A total of 48 male Swiss albino mice of 8∼12 weeks of age were divided into eight groups of 6 mice: mice in group 1 (G1) were considered the normal control, without treatment and without skin shaving; mice in G2 had their skins were shaved, but did not receive treatment; mice in G3 were the pathological control; mice in G4 were treated as standard (hyaluronic acid); mice in G5∼G8 were treated with low and high doses of 2 different test substances, respectively. Mice were anaesthetized and then depilatory was applied on the dorsal skin area (2 cm×2 cm) on alternate days, then UV/blue light irradiation was carried out for 15 min for 6 weeks. Collagen type 1 gene expression was determined via densitometric analysis, skin elasticity was assessed, and stratum corneum water contents were measured using a cutometer and corneometer. Skin hydration was assessed through transepidermal water loss, and several serum biochemical parameters (collagenase, hydroxyproline, hyaluronic acid, and ceramide levels) were determined to assess the skin moisturizing activity of the product. Images for assessing photoaging were considered between different groups on day 42. All these subjective parameters reached statistical significance (P<0.05) in groups treated with the proprietary lutein and rosemary formulation compared with the placebo-treated group. In conclusion, the proprietary lutein, zeaxanthin, and rosemary formulation showed better protection of skin subjected to UV irradiated skin dehydration.

Optimized extraction of polyphenols from leaves of Rosemary (Rosmarinus officinalis L.) grown in Lam Dong province, Vietnam, and evaluation of their antioxidant capacity

In the present study, the optimized solvent extraction conditions with regards to the total polyphenol content (TPC) and antioxidant capacity of rosemary leaf extract (RLE) were determined. The one-factor-at-a-time method was used to independently investigate the effect of several extraction parameters, including ethanol concentration (0–100% v/v), extraction temperature (50–80°C), extraction period (15–60 min), material–solvent ratio (1:5–1:10 g/mL), and extraction cycles (1, 2, and 3 times) on polyphenol content. Response surface methodology (RSM), in combination with a central composite design, was used to perform optimization. The following optimal conditions that gave maximal TPC were determined and experimentally verified: ethanol concentration of 65% (v/v), extraction temperature of 65°C, material–solvent ratio of 1:7.5 g/mL, extraction time of 15 min, and 2 cycles of extraction. These parameters corresponded with the TPC yield of 87.42 ± 0.25 mg gallic acid equivalent/g dried feed material (mg GAE/g DW). The optimal conditions gave a high extraction yield (337 ± 6 mg dried extract/g dried feed material) with 197.28 ± 3.11 mg GAE/g dried extract. The estimated models were strongly significant (p < 0.05) for TPC values with significant regression coefficients (R 2) of 0.9979. The obtained RLE was supposed to be the top grade of natural antioxidant with the IC50 (DPPH assays) value of 9.4 ± 0.1 μg/mL, which is higher than that of the vitamin C by just three times (IC50 = 3.2 ± 0.1 μg/mL). Current results justify RLE as a potential agent in food preservation applications.

Revalorization of Cava Lees to Improve the Safety of Fermented Sausages

The revalorization of food processing by-products not only reduces the environmental impact of their disposal, but also generates added economic value. Cava lees consist of inactive cells of Saccharomyces cerevisiae, and though regarded as a valueless winery by-product, they are rich in fiber and phenolic compounds. In this study, a challenge test was performed to assess the effect of cava lees and a phenolic extract (LPE) derived therefrom on the behaviour of technological microbiota (lactic acid bacteria used as a starter culture) and the foodborne pathogens Salmonella spp. and Listeria monocytogenes during the fermentation and ripening of pork sausages. Ten batches of fermented sausages were prepared with and without cava lees or the LPE, and with or without different strains of Latilactobacillus sakei (CTC494 or BAP110). The addition of cava lees reduced the pH values of the meat batter throughout the fermentation and ripening process. No growth-promoting effect on spontaneous lactic acid bacteria (LAB) or the starter culture was observed. In contrast, the presence of cava lees prevented the growth of the tested pathogens (Salmonella and L. monocytogenes), as did the starter culture, resulting in significantly lower counts compared to the control batch. In addition, the combination of cava lees with L. sakei CTC494 had a bactericidal effect on Salmonella. LPE supplementation did not affect the pH values or LAB counts but reduced the mean counts of Salmonella, which were 0.71 log10 lower than the control values at the end of the ripening. The LPE did not exert any additional effect to that of the starters applied alone. The revalorization of cava lees as a natural ingredient to improve the microbiological safety of fermented sausages is a feasible strategy that would promote a circular economy and benefit the environment.

Essential Oils of Sage, Rosemary, and Bay Laurel Inhibit the Life Stages of Oomycete Pathogens Important in Aquaculture

Saprolegnia parasitica, the causative agent of saprolegniosis in fish, and Aphanomyces astaci, the causative agent of crayfish plague, are oomycete pathogens that cause economic losses in aquaculture. Since toxic chemicals are currently used to control them, we aimed to investigate their inhibition by essential oils of sage, rosemary, and bay laurel as environmentally acceptable alternatives. Gas Chromatography-Mass Spectrometry (GC-MS) analysis showed that the essential oils tested were rich in bioactive volatiles, mainly monoterpenes. Mycelium and zoospores of A. astaci were more sensitive compared to those of S. parasitica, where only sage essential oil completely inhibited mycelial growth. EC₅₀ values (i.e., concentrations of samples at which the growth was inhibited by 50%) for mycelial growth determined by the radial growth inhibition assay were 0.031-0.098 µL/mL for A. astaci and 0.040 µL/mL for S. parasitica. EC₅₀ values determined by the zoospore germination inhibition assay were 0.007-0.049 µL/mL for A. astaci and 0.012-0.063 µL/mL for S. parasitica. The observed inhibition, most pronounced for sage essential oil, could be partly due to dominant constituents of the essential oils, such as camphor, but more likely resulted from a synergistic effect of multiple compounds. Our results may serve as a basis for in vivo experiments and the development of environmentally friendly methods to control oomycete pathogens in aquaculture.

Effects of dietary rosemary extract supplementation on growth performance, nutrient digestibility, antioxidant capacity, intestinal morphology, and microbiota of weaning pigs

Rosemary (Rosmarinus officinalis L.) extract (RE) has multiple pharmacological and biological activities, including the use as a food additive and medicine. This study was conducted to investigate the effects of dietary RE supplementation on the growth performance, nutrient digestibility, antioxidant capacity, intestinal morphology, and microbiota of weaning piglets. A total of 192 crossbred weaned piglets [Duroc × (Large White × Landrace)] (initial body weight = 6.65 ± 0.33 kg, weaned days = 23 ± 1 d) were group housed (six pigs per pen; n = 8 pens/treatment). Pigs were fed a corn-soybean meal-based control diet or the basal diet supplemented with 100, 200, or 400 mg/kg RE. Pigs were allowed ad libitum access to fed for 21 d. The growth performance and apparent total tract digestibility of nutrients, and intestinal morphology and antioxidant status were evaluated. The components of the microbial microflora were also determined in the cecal samples. Compared with the control, dietary supplementation with RE increased the final body weight, average daily gain, and average daily feed intake (linear, P = 0.038, 0.016, and 0.009, respectively), and decreased the diarrhea ratio in piglets (linear, P < 0.05). The digestibility of crude protein (linear, P = 0.034) and gross energy (linear, P = 0.046) increased with treatment with RE. Piglets fed RE showed longer villus height (linear, P = 0.037 and 0.028, respectively) and villus height/crypt depth (linear, P = 0.004 and 0.012; quadratic, P = 0.023 and 0.036, respectively) in the jejunum and ileum, in addition to a lesser crypt depth in the jejunum (linear, P = 0.019) and ileum (quadratic, P = 0.042). The addition of RE increased the activity of superoxide dismutase (linear, P = 0.035 and 0.008, respectively) and glutathione peroxidase activity (linear, P = 0.027 and 0.039, respectively) and decreased the content of malondialdehyde (linear, P = 0.041 and 0.013; quadratic, P = 0.023 and 0.005, respectively) in the serum and liver. Dietary RE supplementation, compared with the control, increased the number of Bifidobacterium (linear, P = 0.034) and Bacteroidetes (linear, P = 0.029), while decreased Escherichia coli (linear, P = 0.008; quadratic, P = 0.014) in the cecal contents. Thus, dietary RE supplementation can improve growth performance, nutrient digestibility, antioxidant capacity, intestinal morphology, and the microbiota in weaned piglets, and 200 mg/kg may be considered the optimum dosage.

Anti-biofilm potential of Lavandula preparations against Campylobacter jejuni

New approaches for the control of Campylobacter jejuni biofilms in the food industry are being studied intensively. Natural products are promising alternative antimicrobial substances to control biofilm production, with particular emphasis on plant extracts. Dried flowers of Lavandula angustifolia were used to produce LEO, LEF, and LEW. The chemical compositions determined for these Lavandula preparations included seven major compounds that were selected for further testing. These were tested against C. jejuni, for biofilm degradation and removal. Next-generation sequencing was used to study the molecular mechanisms underlying LEO actions against C. jejuni adhesion and motility. Analysis of LEO revealed 1,8-cineol, linalool and linalyl acetate as the main components. For LEF and LEW, the main components were phenolic acid glycosides, with flavonoids rarely present. The minimal inhibitory concentrations of the Lavandula preparations and pure compounds against C. jejuni ranged from 0.2 mg/mL to 1 mg/mL. LEO showed the strongest biofilm degradation. The reduction of C. jejuni adhesion was by ≥1 log₁₀ CFU/mL, which satisfies European Food Safety Authority recommendations. Lavandula preparations reduced C. jejuni motility by almost 50%, which consequently can impact upon biofilm formation. These data are in line with the transcriptome analysis of C. jejuni, where LEO down-regulated genes important for biofilm formation. LEW also showed good antibacterial and anti-biofilm effects, particularly against adhesion and motility mechanisms. This defines an innovative approach using alternative strategies and novel targets to combat bacterial biofilm formation, and hence the potential to develop new effective agents with biofilm-degrading activities. Importance The Lavandula preparations used in this study are found to be effective against C. jejuni, a common foodborne pathogen. They show anti-biofilm properties at sub-inhibitory concentrations in terms of promoting biofilm degradation and inhibiting cell adhesion and motility, which are involved in the initial steps of biofilm formation. These results are confirmed by transcriptome analysis, which highlights the effect of Lavandula essential oil on C. jejuni biofilm properties. We show that the waste material from the hydrodistillation of Lavandula has particular anti-biofilm effects, suggesting that it may find reuse for industrial purposes. This study highlights the need for efforts directed towards such innovative approaches and alternative strategies against biofilm formation and maintenance by developing new naturally derived agents with anti-biofilm activities.

PCL and PCL/bioactive glass biomaterials as carriers for biologically active polyphenolic compounds: Comprehensive physicochemical and biological evaluation

In this work, polymeric and bioactive glass (BG)-modified composite films were successfully loaded with polyphenols (PPh) extracted from sage. It was hypothesized that PPh, alone and in combination with BGs particles, would affect physicochemical and biological properties of the films. Furthermore, sol-gel-derived BG particles would serve as an agent for control the release of the polyphenolic compounds, and other important properties related to the presence of PPh. The results showed that polyphenolic compounds significantly modified numerous material properties and also acted as biologically active substances. On the one hand, PPh can be considered as plasticizers for PCL, on the other hand, they can act as coupling agent in composite materials, improving their mechanical performance. The presence of PPh in materials improved their hydrophilicity and apatite-forming ability, and also provided antioxidant activity. What is important is that the aforementioned properties and kinetics of PPh release can be modulated by the use of various concentrations of PPh, and by the modification of PCL matrix with sol-gel-derived BG particles, capable of binding PPh. The films containing the lowest concentration of PPh exhibited cytocompatibility, significantly increased alkaline phosphatase activity and the expression of bone extracellular matrix proteins (osteocalcin and osteopontin) in human normal osteoblasts, while they reduced intracellular reactive oxygen species production in macrophages. Furthermore, materials loaded with PPh showed antibiofilm properties against Gram positive and Gram negative bacteria. The results suggest that obtained materials represent potential multifunctional biomaterials for bone tissue engineering with a wide range of tunable properties.

Antimicrobial Resistance Profiles, Virulence Genes, and Genetic Diversity of Thermophilic Campylobacter Species Isolated From a Layer Poultry Farm in Korea

Thermophilic Campylobacter species are among the major etiologies of bacterial enteritis globally. This study aimed at assessing the antimicrobial resistance (AMR) profiles, virulence genes, and genetic diversity of thermophilic Campylobacter species isolated from a layer poultry farm in South Korea. One hundred fifty-three chicken feces were collected from two layer poultry farms in Gangneung, South Korea. The Campylobacter species were isolated by cultural techniques, while PCR and sequencing were used for species confirmation. Antimicrobial susceptibility testing for six antimicrobials [ciprofloxacin (CIP), nalidixic acid (NAL), sitafloxacin (SIT), erythromycin (ERY), tetracycline (TET), and gentamicin (GEN)] was carried out by broth microdilution. Three AMR and nine virulence genes were screened by PCR. Genotyping was performed by flaA-restriction fragment length polymorphism (RFLP) and multilocus sequence typing (MLST). Of the 153 samples, Campylobacter spp. were detected in 55 (35.9%), with Campylobacter jejuni and Campylobacter coli being 49 (89.1%) and six (10.9%), respectively. High-level resistance was observed for CIP (100%), NAL (100%), and TET (C. jejuni, 93.9%; C. coli: 83.3%). No resistance was observed for SIT. The missense mutation (C257T) in gyrA gene was confirmed by sequencing, while the tet(O) gene was similar to known sequences in GenBank. The rate of multidrug-resistant (MDR) strains was 8.2%, and they all belonged to C. jejuni. All Campylobacter isolates possessed five virulence genes (cdtB, cstII, flaA, cadF, and dnaJ), but none possessed ggt, while the rates for other genes (csrA, ciaB, and pldA) ranged between 33.3 and 95.9%. The flaA-RFLP yielded 26 flaA types (C. jejuni: 21 and C. coli: five), while the MLST showed 10 sequence types (STs) for C. jejuni and three STs for C. coli, with CC-607 (STs 3611) and CC-460 (ST-460) being predominant. Among the 10 STs of C. jejuni, three were newly assigned. The findings of this study highlight the increased resistance to quinolones and TET, the virulence potential, and the diverse genotypes among Campylobacter strains isolated from the layer poultry farm.

Harnessing the antibacterial activity of Quercus infectoria and Phyllanthus emblica against antibiotic-resistant Salmonella Typhi and Salmonella Enteritidis of poultry origin

Background and Aim:

In a scenario of the ineffectiveness of the current drugs against antibiotic-resistant pathogens, the herbal extracts can serve as an alternative remedy. This study appraises the antibacterial potency of Quercus infectoria (gall), Phyllanthus emblica (fruit) individually and synergistically against antimicrobial-resistant (AMR) Salmonella Typhi and Salmonella Enteritidis in a time and dose-dependent manner. Further, the antibacterial phytocompounds were identified employing gas chromatography-mass spectrometry (GC-MS).

Materials and Methods:

Preliminary antibacterial activity of the plant extracts was assessed using the agar disk diffusion method. In vitro evaluations of Q. infectoria methanolic extract (QIME) and P. emblica methanolic extract (PEME) against S. Typhi and S. Enteritidis were carried out using plate count method.

Results:

QIME and PEME at a dose rate of 50 mg/ml and 25 mg/ml, respectively, had a complete bactericidal effect on AMR S. Typhi and S. Enteritidis whereas 10 log₁₀ CFU/ml of exponential growth was seen in untreated control groups. At the lower concentrations, QIME and PEME had a significant bacteriostatic effect (3-6 log₁₀ reduction of the test isolates). The synergistic antibacterial effect obtained from the combination of these two plant extracts at 12.5 mg/ml was superior (p<0.001) than the individual treatments. Phytochemical profiling indicated the presence of tannins, flavonoids, saponins, and terpenoids in both the plant extracts. GC-MS analysis of QIME and PEME revealed the presence of 16 and 15 antibacterial phytocompounds, respectively. Further 1, 2, 3 Benzenetriol was found as the prominent active principle.

Conclusion:

The findings validate that QIME and PEME are potential antibacterial agents against AMR S. Typhi, S. Enteritidis and can play a promising role in antimicrobial packaging, poultry feed additives and can also serve as a platform for formulating effective phytotherapeutics.

Antioxidant activity screening and chemical constituents of the essential oil from rosemary by ultra-fast GC electronic nose coupled with chemical methodology

BACKGROUND

Traditional chemical methods were mainly used to evaluate the total antioxidant activity of essential oils. How to determine the bioactivity of each compound in mixtures is an interesting research topic. Nowadays, an ultra-fast gas chromatography electronic nose (E-nose) has been gradually used in the detection of volatile compounds, but the screening of the active components of essential oils has not been reported. E-nose coupled with chemical methodology was established using the essential oil from rosemary (EOR) as a specific application example. The proposed method can both identify the chemical constituents of EOR and quickly screen the antioxidant by comparing the change of chromatographic peak area of every component in EOR before and after reaction with free radicals.

RESULTS

Among all chemical constituents in EOR, verbenone, eucalyptol and o-cymene showed the strongest scavenging abilities in 1,1'-diphenyl-2-picrylhydrazine (DPPH·), 2,2'-azino-bis(3-ethyl-benzothiazoline-6-sulphonate) (ABTS·⁺ ) and hydroxyl (·OH) radicals, respectively, with scavenging rates of 67.9%, 39.5%, and 69.9%. The reliability and feasibility of using E-nose to identify chemical constituents of EOR were verified by gas chromatography-tandem mass spectrometry (GC-MS/MS). The GC-MS/MS results showed that the main components of EOR were α-pinene (422.2 μg g^-1 ), p-cymene (208.4 μg g^-1 ), camphor (203.5 μg g^-1 ), verbenone (160.2 μg g^-1 ), and eucalyptol (129.1 μg g^-1 ).

CONCLUSIONS

The E-nose methods can be used as a complementary method to traditional spectrophotometric techniques. Furthermore, this study will be of great significance for the rapid screening of antioxidant active components in essential oils from natural products. © 2020 Society of Chemical Industry.

Carnosic acid exhibits antiproliferative and proapoptotic effects in tumoral NCI-H460 and nontumoral IMR-90 lung cells

Carnosic acid (CA) is a phenolic diterpene with many important biological activities including antimicrobial, antioxidant, anti-inflammatory properties, and anti-proliferative properties. The aim of the present study was to investigate cytotoxic activity, cell cycle, apoptotic, and molecular effects attributed to CA in non-tumoral IMR-90 (human fetal lung fibroblasts), as well as tumoral NCI-H460 (human non-small-cell lung cancer) cell lines. Cell proliferation was evaluated by Real-Time Cell Analysis system, while apoptosis and cell cycle were assessed using flow cytometry. RT-qPCR was used to estimate the relative expression of genes involved in cell cycle regulation, DNA damage and repair, and apoptosis induction. CA inhibited proliferation of IMR-90 and NCI-H460 cells via cell cycle arrest at G₀/G₁ and G₂/M phases, according to the treatment concentration. The mRNA levels of genes encoding cyclins A2, B1, and B2 were downregulated in response to CA treatment of IMR-90 cells. Apoptosis was induced and proapoptotic gene PUMA was upregulated in both cell lines. mRNA levels of genes ATR, CCND1, CHK1, CHK2, MYC, GADD45A, H2AFX, MTOR, TP53, and BCL2, CASP3 were not markedly changed following CA treatments. Although CA exerted antiproliferative activity against NCI-H460 tumor cells, this phytochemical induced toxic effects in non-tumoral cells, and thus needs to be considered carefully prior to pharmacological use therapeutically.

Impact of ultrasound-assisted extraction and solvent composition on bioactive compounds and in vitro biological activities of thyme and rosemary

Mediterranean herbs, specially thyme and rosemary, are important ingredients in food preparation and more recently have been studied as natural sources of bioactive compounds. This study aimed to study the effect of matrix (thyme vs. rosemary), and extraction protocol (conventional extraction vs. ultrasound assisted extraction) solvent composition (water vs. 50:50 ethanol:water solution) on the extraction of high value compounds (phenolic compounds, flavonoids and carotenoids) and also explore the antioxidant, antimicrobial (Listeria innocua, Staphylococcus aureus, and Salmonella enterica), probiotic (Lactobacillus casei and Bifidobacterium lactis), and anti-inflammatory activities. The phenolic, flavonoid and carotenoid content of extracts was greatly influenced by extraction conditions wherein the ultrasound pre-treatment improved the extraction of carotenoids but induced the opposite effect for polyphenols and flavonoids in both herbs. Only the aqueous extract of thyme obtained from ultrasound pre-treatment was the only extract that inhibited the growth of potentially pathogenic bacteria, stimulated the probiotic bacteria and achieved high anti-inflammatory and antioxidant activity. Moreover, this extract also was rich on phenolic compounds (such as p-coumaric acid 4-O-glucoside, kaempferol 3-O-rutinoside, feruloyl glucose, and 4-vinylguaiacol) and carotenoids. Therefore, ultrasound extraction of bioactive compounds with water as solvent could be explored in food and pharmaceutical applications.

Combination of rosemary extract and buffered vinegar inhibits Pseudomonas and Shewanella growth in common carp (Cyprinus carpio)

BACKGROUND

Aquaculture is the fastest growing food-production sector, and common carp (Cyprinus carpio) is one of the most cultivated fish species in the world. Due to its intrinsic characteristics, fish meat is highly susceptible to microbiological spoilage. Pseudomonas and Shewanella are the primary and secondary occurring microbiota during storage of fish meat, with significant contribution to spoilage with the formation of hydrolytic enzymes (lipases and proteases).

RESULTS

With in vitro testing, we show that rosemary extract (Inolens4), buffered vinegar and their combination (SyneROX) exhibit antimicrobial effects against P. fragi, P. psychrophila, S. putrefaciens and S. xiaemensis at concentrations of 3.13 and 1.56 mg mL^-1 . The combination was the most effective in inhibiting growth of selected bacteria in food model, and production of lipases and proteases during 9 days at 5 °C. In situ testing of antimicrobial dip treatment of carp meat determined that aerobic mesophilic, total psychrotrophic, Pseudomonas and hydrogen sulfide producer counts were reduced in all treatments, with the most prominent influence being shown by the combination and buffered vinegar.

CONCLUSIONS

Our study highlights the importance of a multilevel assessment of the antimicrobial potential of biopreservatives under conditions comparable to those of the selected food. Investigation with bacteria and food model provided coherent and consistent data for the evaluation of the antimicrobial potential for carp meat. Combination of buffered vinegar (as active antimicrobial) and rosemary extract, with well-known and researched antioxidant properties but low in situ antimicrobial activity, represents a good potential for combined effect in preservation of fish meat. © 2020 Society of Chemical Industry.

Antimicrobial and Antioxidant Properties of Four Lycopus Taxa and an Interaction Study of Their Major Compounds

The compositions of leaf infusions of three genotypes of Lycopus europaeus L. with origins in central Europe, namely L. europaeus A (LeuA), L. europaeus B (LeuB), and L. europaeus C (LeuC), and one genotype of L. exaltatus (Lex), were examined by LC-MS-DAD (Liquid Chromatography Mass Spectrometry and Diode Array Detection) analysis. This revealed the presence of thirteen compounds belonging to the groups of phenolic acids and flavonoids, with a predominance of rosmarinic acid (RA) and luteolin-7-O-glucuronide (LGlr). The antimicrobial activity of leaf infusions was tested on the collection strains of Gram-positive and Gram-negative bacteria, and on the clinical Staphylococcus aureus strains. We detected higher activity against Gram-positive bacteria, of which the most susceptible strains were those of Staphylococcus aureus, including methicillin-resistant and poly-resistant strains. Furthermore, we examined the antioxidant activity of leaf infusions using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) methods, and on NIH/3T3 cell lines using dichlorodihydrofluorescein diacetate (DCFH-DA). We also studied the mutual interactions between selected infusions, namely RA and/or LGlr. In the mixtures of leaf infusion and RA or LGlr, we observed slight synergism and a high dose reduction index in most cases. This leads to the beneficial dose reduction at a given antioxidant effect level in mixtures compared to the doses of the parts used alone. Therefore, our study draws attention to further applications of the Lycopus leaves as a valuable alternative source of natural antioxidants and as a promising topical antibacterial agent for medicinal use.

Rosmarinus plants: Key farm concepts towards food applications

Rosmarinus species are aromatic plants that mainly grow in the Mediterranean region. They are widely used in folk medicine, food, and flavor industries and represent a valuable source of biologically active compounds (e.g., terpenoids, flavonoids, and phenolic acids). The extraction of rosemary essential oil is being done using three main methods: carbon dioxide supercritical extraction, steam distillation, and hydrodistillation. Furthermore, interesting antioxidant, antibacterial, antifungal, antileishmanial, anthelmintic, anticancer, anti-inflammatory, antidepressant, and antiamnesic effects have also been broadly recognized for rosemary plant extracts. Thus the present review summarized data on economically important Rosmarinus officinalis species, including isolation, extraction techniques, chemical composition, pharmaceutical, and food applications.

Protective Role of Nutritional Plants Containing Flavonoids in Hair Follicle Disruption: A Review

Hair loss is a disorder in which the hair falls out from skin areas such as the scalp and the body. Several studies suggest the use of herbal medicine to treat related disorders, including alopecia. Dermal microcirculation is essential for hair maintenance, and an insufficient blood supply can lead to hair follicles (HF) diseases. This work aims to provide an insight into the ethnohistorical records of some nutritional compounds containing flavonoids for their potential beneficial features in repairing or recovering from hair follicle disruption. We started from a query for “alopecia” OR “hair loss” AND “Panaxginseng C.A. Mey.“ (or other six botanicals) terms included in Pubmed and Web of Sciences articles. The activities of seven common botanicals introduced with diet (Panaxginseng C.A. Mey., Malus pumila Mill cultivar Annurca, Coffea arabica, Allium sativum L., Camellia sinensis (L.) Kuntze, Rosmarinum officinalis L., Capsicum annum L.) are discussed, which are believed to reduce the rate of hair loss or stimulate new hair growth. In this review, we pay our attention on the molecular mechanisms underlying the bioactivity of the aforementioned nutritional compounds in vivo, ex vivo and in vitro studies. There is a need for systematic evaluation of the most commonly used plants to confirm their anti-hair loss power, identify possible mechanisms of action, and recommend their best adoption.

Carvacrol ameliorates acute campylobacteriosis in a clinical murine infection model

BACKGROUND

The prevalence of human infections with the zoonotic pathogen Campylobacter jejuni is rising worldwide. Therefore, the identification of compounds with potent anti-pathogenic and anti-inflammatory properties for future therapeutic and/or preventive application to combat campylobacteriosis is of importance for global health. Results of recent studies suggested carvacrol (4-isopropyl-2-methylphenol) as potential candidate molecule for the treatment of campylobacteriosis in humans and for the prevention of Campylobacter colonization in farm animals.

RESULTS

To address this in a clinical murine infection model of acute campylobacteriosis, secondary abiotic IL-10-/- mice were subjected to synthetic carvacrol via the drinking water starting 4 days before peroral C. jejuni challenge. Whereas at day 6 post-infection placebo treated mice suffered from acute enterocolitis, mice from the carvacrol cohort not only harbored two log orders of magnitude lower pathogen loads in their intestines, but also displayed significantly reduced disease symptoms. Alleviated campylobacteriosis following carvacrol application was accompanied by less distinct intestinal apoptosis and pro-inflammatory immune responses as well as by higher numbers of proliferating colonic epithelial cells. Remarkably, the inflammation-ameliorating effects of carvacrol treatment were not restricted to the intestinal tract, but could also be observed in extra-intestinal organs such as liver, kidneys and lungs and, strikingly, systemically as indicated by lower IFN-γ, TNF, MCP-1 and IL-6 serum concentrations in carvacrol versus placebo treated mice. Furthermore, carvacrol treatment was associated with less frequent translocation of viable C. jejuni originating from the intestines to extra-intestinal compartments.

CONCLUSION

The lowered C. jejuni loads and alleviated symptoms observed in the here applied clinical murine model for human campylobacteriosis highlight the application of carvacrol as a promising novel option for both, the treatment of campylobacteriosis and hence, for prevention of post-infectious sequelae in humans, and for the reduction of C. jejuni colonization in the intestines of vertebrate lifestock animals.

The Anti-Campylobacter Activity and Mechanisms of Pinocembrin Action

We investigated the anti-Campylobacter activity of pinocembrin and its mechanism of action, as well as Campylobacter responses to pinocembrin treatment at the genetic and phenotypic levels, using C. jejuni NCTC 11168 and a multidrug efflux system repressor mutant (11168ΔcmeR). At its minimal inhibitory concentration, pinocembrin significantly increased cell membrane permeability of Campylobacter. Interestingly, at sub-inhibitory concentrations, pinocembrin did not significantly alter membrane functionality and it increased bacterial fitness. Treatment with pinocembrin evoked decreased expression of ribosomal proteins and down-regulation of several NADH dehydrogenase I chain subunits and proteins involved in iron uptake. This suggests altered protein production and redox cycle and iron metabolism. Interestingly, the chelation of Fe ions during the treatment with pinocembrin increased C. jejuni survival, although there was no increase in the formation of reactive oxygen species. Pre-treatment of C. jejuni with sub-inhibitory concentrations of pinocembrin for 2 h resulted in a 1 log decrease in C. jejuni colony forming units in mice liver at 8 days post-infection, compared to untreated C. jejuni. These findings suggest that pinocembrin modulates the metabolic activity of C. jejuni and that pre-treatment of C. jejuni with pinocembrin influences its virulence potential in mice. This anti-Campylobacter potential of pinocembrin warrants further investigation.

Antibacterial effects of extracts obtained from plants of Argentina: Bioguided isolation of compounds from the anti-infectious medicinal plant Lepechinia meyenii

ETHNOPHARMACOLOGICAL RELEVANCE

The mostly native species from Argentina are used in traditional medicine generally for the treatment of pain and inflammation, respiratory, gastro-intestinal and urinary disorders and as antiseptics.

AIM OF THE STUDY

Since these ailments may be associated with bacterial infections and that it is necessary to discover alternative compounds with antibacterial activity, 69 extracts from these plants were screened for their activity against pathogenic bacteria. The most effective extract was then submitted to bioguided isolation to obtain the compounds responsible for this activity.

MATERIALS AND METHODS

Extracts and fractions were screened using agar dilution, and compounds using microbroth dilution methods. A large panel of pathogenic bacteria was used, especially methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA). Bioguided fractionation was performed using successive chromatographic techniques, while the chemical structures of the isolated compounds were determined by nuclear magnetic resonance (NMR). Additionally, a series of derivatives of the most active compound were prepared in order to study the chemical features required for achieving the antibacterial effect.

RESULTS

Lepechinia meyenii (Walp.) Epling (Lamiaceae) extract showed itself the most effective, with minimum inhibitory concentration (MIC) against Gram positive and negative bacteria ranging from 62.5 to 500 μg/mL, and showing better activity on MRSA than on MSSA. Activity-guided fractionation yielded the abietanes carnosol (1), rosmanol (2) and carnosic acid (3) as active principles, with MICs ranging from 15.6-31.2, 15.6-62.5 and 7.8-15.6 μg/mL, respectively against 15 MRSA strains, and 15.6-31.2, 31.2-62.5 and 7.8-15.6 μg/mL, respectively against 11 MSSA strains, maintaining higher activity against the resistant bacteria, as does the extract. In addition, Enterococcus faecalis was sensitive to 1-3 with MICs of 15.6-62.5 μg/mL. The structure activity analysis showed that 12-OH is necessary for remarkable activity, but methylation in C-20 significantly increased this, as observed with 20-methyl carnosate (5) displaying the greatest effect, even more so than 3, with MICs of 3.9 μg/mL against all the tested MRSA and 3.9-7.8 μg/mL against the MSSA.

CONCLUSIONS

The results of this study contribute to validate the traditional antibacterial use of species native to Argentina, particularly of L. meyenii. The chemical structures of the compounds obtained may aid the design of antibacterial agents, especially those effective against MRSA.

Functionalization of Polyethylene (PE) and Polypropylene (PP) Material Using Chitosan Nanoparticles with Incorporated Resveratrol as Potential Active Packaging

The present paper reports a novel method to improve the properties of polyethylene (PE) and polypropylene (PP) polymer foils suitable for applications in food packaging. It relates to the adsorption of chitosan-colloidal systems onto untreated and oxygen plasma-treated foil surfaces. It is hypothesized that the first coated layer of chitosan macromolecular solution enables excellent antibacterial properties, while the second (uppermost) layer contains a network of polyphenol resveratrol, embedded into chitosan nanoparticles, which enables antioxidant and antimicrobial properties simultaneously. X-ray photon spectroscopy (XPS) and infrared spectroscopy (FTIR) showed successful binding of both coatings onto foils as confirmed by gravimetric method. In addition, both attached layers (chitosan macromolecular solution and dispersion of chitosan nanoparticles with incorporated resveratrol) onto foils reduced oxygen permeability and wetting contact angle of foils; the latter indicates good anti-fog foil properties. Reduction of both oxygen permeability and wetting contact angle is more pronounced when foils are previously activated by O2 plasma. Moreover, oxygen plasma treatment improves stability and adhesion of chitosan structured adsorbates onto PP and PE foils. Foils also exhibit over 90% reduction of Staphylococcus aureus and over 77% reduction of Escherichia coli as compared to untreated foils and increase antioxidant activity for over a factor of 10. The present method may be useful in different packaging applications such as food (meat, vegetables, dairy, and bakery products) and pharmaceutical packaging, where such properties of foils are desired.

Essential Oils as an Intervention Strategy to Reduce Campylobacter in Poultry Production: A Review

Campylobacter is a major foodborne pathogen and can be acquired through consumption of poultry products. With 1.3 million United States cases a year, the high prevalence of Campylobacter within the poultry gastrointestinal tract is a public health concern and thus a target for the development of intervention strategies. Increasing demand for antibiotic-free products has led to the promotion of various alternative pathogen control measures both at the farm and processing level. One such measure includes utilizing essential oils in both pre- and post-harvest settings. Essential oils are derived from plant-based extracts, and there are currently over 300 commercially available compounds. They have been proposed to control Campylobacter in the gastrointestinal tract of broilers. When used in concentrations low enough to not influence sensory characteristics, essential oils have also been proposed to decrease bacterial contamination of the poultry product during processing. This review explores the use of essential oils, particularly thymol, carvacrol, and cinnamaldehyde, and their role in reducing Campylobacter concentrations both pre- and post-harvest. This review also details the suggested mechanisms of action of essential oils on Campylobacter.

Phytochemical Combination PB125 Activates the Nrf2 Pathway and Induces Cellular Protection against Oxidative Injury

Bioactive phytochemicals in Rosmarinus officinalis, Withania somnifera, and Sophora japonica have a long history of human use to promote health. In this study we examined the cellular effects of a combination of extracts from these plant sources based on specified levels of their carnosol/carnosic acid, withaferin A, and luteolin levels, respectively. Individually, these bioactive compounds have previously been shown to activate the nuclear factor erythroid 2-related factor 2 (Nrf2) transcription factor, which binds to the antioxidant response element (ARE) and regulates the expression of a wide variety of cytoprotective genes. We found that combinations of these three plant extracts act synergistically to activate the Nrf2 pathway, and we identified an optimized combination of the three agents which we named PB125 for use as a dietary supplement. Using microarray, quantitative reverse transcription-PCR, and RNA-seq technologies, we examined the gene expression induced by PB125 in HepG2 (hepatocellular carcinoma) cells, including canonical Nrf2-regulated genes, noncanonical Nrf2-regulated genes, and genes which appear to be regulated by non-Nrf2 mechanisms. Ingenuity Pathway Analysis identified Nrf2 as the primary pathway for gene expression changes by PB125. Pretreatment with PB125 protected cultured HepG2 cells against an oxidative stress challenge caused by cumene hydroperoxide exposure, by both cell viability and cell injury measurements. In summary, PB125 is a phytochemical dietary supplement comprised of extracts of three ingredients, Rosmarinus officinalis, Withania somnifera, and Sophora japonica, with specified levels of carnosol/carnosic acid, withaferin A, and luteolin, respectively. Each ingredient contributes to the activation of the Nrf2 pathway in unique ways, which leads to upregulation of cytoprotective genes and protection of cells against oxidative stress and supports the use of PB125 as a dietary supplement to promote healthy aging.

Evaluation of Anti-Propionibacterium Acnes and Anti-Inflammatory Effects of Polyphenolic Extracts of Medicinal Herbs in Jordan

Acne vulgaris is one of the most common health problem where medical treatment is sought in adults worldwide. It has been long described the integral role of Propionibacterium acnes in the pathogenesis of this disease. In this study, a group of local herbs known for their antimicrobial effects were selected for the evaluation of potential anti-acnes effects in vitro. Phenolics and flavonoid contents of methanolic extracts of Eucalyptus globulus, Mentha rotundifolia, Inula viscosa, Utrica dioica, Malva sylvestris, Quercus calliprinos, Arum palaestinum and Achille aodorata collected from different regions in Jordan during 2016-2017 were screened for antimicrobial activity against Propionibacterium acnes by disc diffusion and by broth microdilution method. Measurement of release of interleukin 1 alpha from human skin explants by ELISA was used for the evaluation of anti-inflammatory effects of the herbal preparations and extracts. M. rotundifolia and E. globulus, showed the highest phenolic and flavonoid contents in contrast to M. sylvestris which showed the least phenolic contents. Moreover, polyphenolic fractions exhibited modest anti-acne activity of herbal extracts of E. globulus and A. palaestinum (MIC 0.125 mg/ml), U. dioica (0.25 mg/ml) and I. viscosa (0.5 mg/ml), compared to not significant antimicrobial activity for others (MIC >1mg/ml). Regarding anti-inflammatory effects of the tested fractions, E. globulus and A. palaestinum extracts showed inhibition of interleukin 1 alpha release by more than 60 % for concentrations of 0.5 mg/ml respectively. The presence of anti-inflammatory and anti-acne activities in the polyphenolic extracts of local medicinal plants would increase the potential of using these herbs in the control of Acne vulgaris.

Effects of in vitro gastrointestinal digestion and colonic fermentation on a rosemary (Rosmarinus officinalis L) extract rich in rosmarinic acid

The potential phytochemical losses occurring throughout the sequential steps of in-vitro gastrointestinal digestion and colonic fermentation of a rosemary aqueous extract were investigated. Crude (CE), digested (DE) and fermented (FE) extracts were characterized in terms of their phenolic profile and biological activities. Rosmarinic acid was the phytochemical that underwent the most significate transformation during digestion and fermentation, which amounted to 60% compared to the 26% degradation of the total phenolics. Overall, the simulated digestion step decreased the antioxidant activity estimated by DPPH, ABTS, FRAP, ORAC and TBARS assays. Both CE and DE did not present antiproliferative potential, however, FE exhibited a pronounced cytotoxic activity (GI50 = 116 µg/mL) against HeLa cells. CE and DE showed to be moderate inhibitors of methicillin-resistant Staphylococcus aureus (MRSA), methicillin-susceptible S. aureus (MSSA), S. aureus, Listeria monocytogenes, whilst the FE acted as a moderate inhibitor of MRSA and MSSA.

Extraction of Carnosic Acid and Carnosol from Sage (Salvia officinalis L.) Leaves by Supercritical Fluid Extraction and Their Antioxidant and Antibacterial Activity

Sage (Salvia officinalis L.) is a good source of antioxidant compounds, carnosic acid and carnosol being the prominent ones. Both are soluble in CO₂, and our goal was to investigate the application of supercritical CO₂ extraction to obtain sage extracts rich in these compounds. The effect of pressure, temperature, and CO₂ flow rate on the carnosic acid and carnosol yield was studied. These variables were optimized by response surface methodology (RSM). The pressure significantly affected carnosol extraction, while the extraction of carnosic acid was affected by the pressure, temperature, and CO₂ flow rate. Carnosic acid content varied from 0.29–120.0 µg mg⁻¹, and carnosol content from 0.46–65.5 µg mg⁻¹. The optimal conditions according to RSM were a pressure of 29.5 MPa, a temperature of 49.1 °C, and a CO₂ flow rate of 3 kg h⁻¹, and the sage extract yield was calculated to be 6.54%, carnosic acid content 105 µg mg⁻¹, and carnosol content 56.3 µg mg⁻¹. The antioxidant activities of the sage extracts were evaluated by the scavenging activities of 2,2-diphenyl-1-picrylhydrazyl (DPPH). Sage extract obtained at 30 MPa and 40 °C with 2 kg h⁻¹ CO₂ flow rate with a carnosic acid content of 72 µg mg⁻¹ and carnosol content of 55 µg mg⁻¹ exhibited the highest antioxidant activity (80.0 ± 0.68%) amongst the investigated supercritical fluid extracts at 25 µg mL⁻¹ concentration. The antimicrobial properties of extracts were tested on four bacterial strains: Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, and Staphylococcus aureus. The extract with a carnosic acid content of 116 µg mg⁻¹ and a carnosol content of 60.6 µg mg⁻¹ was found to be the most potent agent against B. subtilis.

Effect of the Essential Oil of Minthostachys verticillata (Griseb.) Epling and Limonene on Biofilm Production in Pathogens Causing Bovine Mastitis

Bovine mastitis causes large annual economic losses around the world. Different microorganisms are associated with the disease. The capacity of pathogens to adhere to bovine mammary epithelial cells is associated with biofilm production which leads to antibiotic resistance. Research is now leading to search alternative control methods and medicinal plants constitute a natural, safe, effective and inexpensive option. Minthostachys verticillata is an autochthonous medicinal plant of Argentina with multiple ethnobotanical properties. In a previous study, we demonstrated that the essential oil (EO) of this species and limonene, one of its compounds, inhibited the growth of mastitis pathogens. The objective of the present work was to determine the inhibitory effect of the essential oil of M. verticillata and limonene, on biofilm formation and on mature biofilm produced by pathogens isolated from bovine mastitis. Time kill assay and bacterial lysis were also determined. Furthermore, RAPD-PCR assays were performed to determine changes in bacterial DNA after EO and limonene exposition. Bacterial isolates were identified as Escherichia coli (EC3 and EC9), Bacillus pumilus (BP5, BP6, and BP7) and Enterococcus faecium (EF1) by rRNA 16S sequencing and MALDI-TOF MS. All the strains were able to form biofilm. Addition of both lactose and sucrose did not affect biofilm production. MIC values for EO were 3.6 mg/ml for E. faecium; 0.9 mg/ml for E. coli (EC3), 14.5 mg/ml for E. coli (EC9), 1.8 mg/ml for B. pumilus (BP7), 3.63 mg/ml for B. pumilus (BP6) and 29.0 mg/ml for B. pumilus (BP7). MIC values for limonene were 6.6 mg/ml for B. pumilus (BP6) and 105 mg/ml for B. pumilus (BP5). These results demonstrated that EO was more effective than limonene, showing also bactericidal action against E. faecium (minimal inhibitory concentration (MBC) = 29.0 mg/ml). This result was corroborated by time of death assay, observing a cell decrease after at 6 h, and then by bacterial lysis assay. Both EO and limonene affected mature biofilm of isolated strains. The results contribute to the study of EO and limonene which may serve as a therapy against bovine mastitis pathogens inhibiting the development of pathogenic bacteria.

Antimicrobial evaluation of red, phytoalexin-rich sorghum food biocolorant

Sorghum (Sorghum bicolor) extract is traditionally used as red biocolorant in West Africa to colour foods, among which wagashi, a soft cheese. This biocolorant is a source of the phytoalexin apigeninidin and phenolic acids, and users claim that it has preservative effects next to its colouring properties. If such a claim can be scientifically substantiated, it adds a valuable functional property to this natural red colorant, thereby increasing its potential applications in the food industry. Hence, the present study evaluated the antimicrobial properties of dye sorghum extracts using challenge tests in broth and wagashi as a model of a popular food application. The alkaline extract and hot aqueous extract were used for dyeing wagashi by 87.7% and 12.3% of the traders, respectively. The dyeing procedure is perceived as a preservation strategy, and is also a means to maximise the revenues. However, results demonstrated that the application of sorghum biocolorant on wagashi had no inhibitory effect on the growth of fungi (Penicillium chrysogenum, Cladosporium macrocarpum) and Escherichia coli O157:H7. Furthermore, sorghum biocolorant in broth had no effect on growth of Listeria monocytogenes and Escherichia coli O157:H7. Consequently, the commonly used extracts for colouring soft West-African cheese did not show a preservative effect. In addition, dyeing did not affect the physico-chemical properties of wagashi. Still, the red colour hampered visual detection of microbial growth, thus clarifying the preservative effect reported by users.

Rosmarinus officinalis L.: an update review of its phytochemistry and biological activity

The worldwide interest in the use of medicinal plants has been growing, and its beneficial effects being rediscovered for the development of new drugs. Based on their vast ethnopharmacological applications, which inspired current research in drug discovery, natural products can provide new and important leads against various pharmacological targets. This work pioneers an extensive and an updated literature review on the current state of research on Rosmarinus officinalis L., elucidating which compounds and biological activities are the most relevant. Therefore, a search was made in the databases PubMed, ScienceDirect and Web of Science with the terms ‘rosemary’, ‘Rosmarinus officinalis’, ‘rosmarinic acid’ ‘carnosol’ and ‘carnosic acid’, which included 286 articles published since 1990 about rosemary's pharmacological activities and their isolated compounds. According to these references, there has been an increasing interest in the therapeutic properties of this plant, regarding carnosic acid, carnosol, rosmarinic acid and the essential oil. The present manuscript provides an updated review upon the most reported activities on R. officinalis and its active constituents.

The worldwide interest in the use of medicinal plants has been growing, and their beneficial effects being rediscovered for the development of new drugs. Actually, current research in drug discovery has been inspired on the vast ethnopharmacological applications of natural products, providing new and important leads against various pharmacological targets.

In this work, an updated literature review is presented to clarify the current state of research on Rosmarinus officinalis L., elucidating its constituents and their most relevant biological activities. Therefore, this work provides an updated review upon the most reported medicinal properties, namely, antitumoral, anti-inflammatory, analgesic, neurodegenerative, endocrinal, anti-infective and antioxidant.

Antiadhesion activity of juniper (Juniperus communis L.) preparations against Campylobacter jejuni evaluated with PCR-based methods

The food-borne pathogen Campylobacter jejuni can cause bacterial gastrointestinal infections. Biofilm formation amplifies the risk of human infection by improving survival and persistence of C. jejuni in food processing environments and its transmission through the food chain. We aimed to control C. jejuni using an alternative strategy of low doses of Juniperus communis fruit preparations to target bacterial adhesion properties in the first step of biofilm formation. First, we defined the anti-Campylobacter activity of a juniper fruit crude extract and its fractionated biflavonoids, flavone glycosides, and purified amentoflavone, of juniper fruit essential oil and of juniper fruit postdistillation waste material extract. For accurate quantification of adherent C. jejuni, we optimised digital Polymerase Chain Reaction (PCR) and quantitative real-time PCR for construction of standard curves and quantification. We show for the first time that juniper fruit formulations can effectively inhibit adhesion of C. jejuni to polystyrene. Furthermore, ≥94% of the antiadhesion activity of juniper fruit crude extract and juniper fruit essential oil remained under food-related conditions: modified culture medium with glucose, or a stainless steel surface, or mixed co-cultures of C. jejuni and Listeria monocytogenes. This study indicates that addition of juniper fruit formulations can control growth and adhesion of C. jejuni and thus limit food chain transmission of campylobacters.

Aqueous Extracts of Wild Mushrooms Show Antimicrobial and Antiadhesion Activities against Bacteria and Fungi

Mushrooms represent promising sources of novel bioactive compounds and can be applied as innovative strategies to control microbial contamination and infection via the food chain. We characterized aqueous extracts from 21 wild basidiomycete mushrooms and the cultivated oyster mushroom, Pleurotus ostreatus, as putative sources of antimicrobial and antiadhesive compounds. Broth microdilutions and adhesion to a polystyrene surface were evaluated on Gram-positive and Gram-negative bacteria and on fungi. The aqueous extracts tested showed antimicrobial and antiadhesive activities against these microorganisms. Biochemical analyses of the P. ostreatus extract indicated the involvement of several compounds with different molecular masses. Copyright © 2017 John Wiley & Sons, Ltd.

The antimicrobial effects of three phenolic extracts from Rosmarinus officinalis L., Vitis vinifera L. and Polygonum cuspidatum L. on food pathogens

In this study three phenolic extracts were examined, without volatile fraction, against common food pathogens. The samples, all suitable for food application, were from the leaves of Rosmarinus officinalis L., Vitis vinifera L., and the root of Polygonum cuspidatum L. The microorganisms tested were Escherichia coli O157:H7, Salmonella Enteritidis, Salmonella Typhi, Yersinia enterocolitica and Listeria monocytogenes, well-known as important food pathogens. The results demonstrated a microbicidal activity of all the tested compounds at different concentrations; the rosemary extract showed greater efficacy than the other compounds against the tested microorganisms. In particular, the best results were obtained with rosemary extract against E. coli O157:H7 and L. monocytogenes with values of 200 and 270 μg/mL, respectively. Our results show that rosemary extract, often present as a natural antioxidant in food, can also be proposed as a natural disinfectant in the food field.

Polyphenol, antioxidant and antimicrobial potential of six different white and red wine grape processing leftovers

BACKGROUND

During winemaking, grape polyphenols are only partly extracted, and consequently unexploited. The main aim was to characterize the phenolic content of freeze-dried grape skin and seed (FDSS) extracts obtained from Slovenian and international grape varieties and to evaluate their antioxidant, antimicrobial and anti-adhesive activities.

RESULTS

FDSS of six Vitis vinifera L. grapevine cultivars from Vipava Valley region (Slovenia) underwent extraction and sonification under different conditions. Flavonols were the predominant content of extracts from white 'Zelen' and 'Sauvignon Blanc' grape varieties, with strong antimicrobial activities against Gram-negative bacteria. 'Pinot Noir' FDSS extracted with 50% aqueous ethanol extraction produced a high phenolic content in the final extract, which was further associated with strong antioxidant and antimicrobial activities against all tested bacteria. Bacterial adhesion to stainless steel surfaces with minimal and maximal surface roughness was significantly inhibited (up to 60%) across a wide FDSS concentration range, with lower concentrations also effective with two types of stainless steel surfaces.

CONCLUSION

FDSS extracts from winery by-products show interesting phenolic profiles that include flavonols, catechins, anthocyanins and hydroxycinnamic acids, with yields influenced by grapevine cultivar and extraction conditions. The antioxidant, antimicrobial and anti-adhesive activities of 50% aqueous ethanol 'Pinot Noir' FDSS extract reveals potential applications in food, pharmaceutical and cosmetic industries for these bioactive residues. © 2016 Society of Chemical Industry.

Effect of sous vide processing on physicochemical, ultrastructural, microbial and sensory changes in vacuum packaged chicken sausages

The processing of sous vide chicken sausages was optimized under vacuum packaging condition and cooking at 100 ℃ for 30 min (SV30), 60 min (SV60) and 120 min (SV120) and compared with aerobically cooked control at 100 ℃ for 30 min. Sous vide processing of chicken sausages (SV30) produced higher ( p < 0.05) cooking yield, Hunterlab a* values and sensory attributes without affecting proximate composition and shear force values relative to control. The sodium dodecyl sulphate-polyacrylamide gel electrophoresis and scanning electron microscopy results revealed no significant changes in protein quality and emulsion ultra-structure due to SV30 processing relative to control sausages. Sous vide processing of chicken sausages enriched with rosemary diterpene phenols retained the freshness and quality up to 120 days during storage at 4 ± 1 ℃ relative to control sausages that were spoiled on 20th day. Lipid oxidation and microbial growth remained below the spoilage levels for all the SV-processed sausages throughout the storage and addition of rosemary diterpene mixture at 0.02% v/w reduced the microbial growth and improved ( p < 0.05) the sensory attributes. Our results demonstrate that sous vide processing minimizes lipid oxidation and microbial growth of chicken sausages with improved product quality and shelf-life at 4 ± 1 ℃.