In vitro synergistic antibacterial activity of Salvia officinalis L. and some preservatives

Microbial Transformation of Hesperidin and Biological Evaluation

The main aim of the study was the biotransformation evaluation of hesperidin for functionalization by 25 different nonhuman pathogenic microorganisms. As a result, four metabolites were identified and characterized. The structure of pinocembrin and naringenin from the microbial transformation of hesperidin was determined initially with LC/MS-MS. The metabolites eriodictyol and hesperetin were isolated, and their molecular structure was determined by NMR and MS. Pinocembrin, eriodictyol, and naringenin were characterized as new hesperidin microbial transformation metabolites, to the best of our knowledge. In order to evaluate the bioactivity, in vitro 5-lipoxygenase (5-LOX) enzyme inhibition, antioxidant, antimicrobial, and acute toxicity evaluations using the brine shrimp assay of hesperidin and its metabolites were performed comparatively. According to antioxidant and anti-inflammatory activity results, hesperetin metabolite was more active than naringenin and hesperidin. The antimicrobial activity of hesperetin and naringenin against the human pathogenic Staphylococcus aureus strain was relatively higher when compared with the substrate hesperidin. In line with this result, biofilm activity of hesperetin and naringenin against S. aureus with combination studies using biofilm formation methods was carried out. The checkerboard combination method was utilized for biofilm layering, also for the first time in the present study. As an initial result, it was observed that hesperidin and naringenin exerted a synergistic activity with a fractional inhibitory concentration index (FICI) value of 1.063. Considering the bioactivity of hesperidin, hesperetin, and naringenin used as substrates are relatively nontoxic. The microbial and enzymatic biotransformation of natural products such as hesperetin and its new bioactive metabolites still have pharmacological potential, which needs further experimentation at the molecular level..

Anti-Heliobacter pylori and Anti-Inflammatory Potential of Salvia officinalis Metabolites: In Vitro and In Silico Studies

Due to its rising antibiotic resistance and associated inflammations, Helicobacter pylori poses a challenge in modern medicine. Salvia officinalis, a member of the Lamiaceae family, is a promising medicinal herb. In this regard, a phytochemical screening followed by GC-MS and LC-MS was done to evaluate the chemical profile of the total ethanolic extract (TES) and the essential oil, respectively. The anti-H. pylori and the anti-inflammatory activities were evaluated by a micro-well dilution technique and COX-2 inhibition assay. Potential anti-H. pylori inhibitors were determined by an in silico study. The results revealed that the main metabolites were flavonoids, sterols, volatile oil, saponins, and carbohydrates. The LC-MS negative ionization mode demonstrated 12 compounds, while GC-MS showed 21 compounds. Carnosic acid (37.66%), epirosmanol (20.65%), carnosol1 (3.3%), and 12-O-methyl carnosol (6.15%) were predominated, while eucalyptol (50.04%) and camphor (17.75%) were dominant in LC-MS and GC-MS, respectively. TES exhibited the strongest anti-H. pylori activity (3.9 µg/mL) asymptotic to clarithromycin (0.43 µg/mL), followed by the oil (15.63 µg/mL). Carnosic acid has the best-fitting energy to inhibit H. pylori (-46.6769 Kcal/mol). TES showed the highest reduction in Cox-2 expression approaching celecoxib with IC50 = 1.7 ± 0.27 µg/mL, followed by the oil with IC50 = 5.3 ± 0.62 µg/mL. Our findings suggest that S. officinalis metabolites with anti-inflammatory capabilities could be useful in H. pylori management. Further in vivo studies are required to evaluate and assess its promising activity.

In Vitro Effects of Lemon Balm Extracts in Reducing the Growth and Mycotoxins Biosynthesis of Fusarium culmorum and F. proliferatum

The objectives of this research were to obtain the extracts of lemon balm (Melissa officinalis) using supercritical CO2 (SC-CO2) and methanol as co-solvent and evaluate the antifungal activity of those extracts against two selected strains of Fusarium species (Fusarium culmorum and Fusarium proliferatum). The extraction conditions were set at 40 and 60 °C and 250 bar. The obtained extracts were characterized in terms of antifungal activity on potato dextrose agar media (PDA). The results showed that the extraction parameters had different effects on mycelium growth and mycotoxins biosynthesis reduction. All studied lemon balm extracts (1, 2.5, 5, 7.5, and 10%) inhibited the growth of F. proliferatum and F. culmorum mycelia compared to the control. The lemon balm extracts significantly reduced ergosterol content and synthesized mycotoxins in both tested strains. These findings support the antifungal activity of lemon balm extracts against F. proliferatum and F. culmorum. However, more research on other Fusarium species is needed, as well as in vivo applications, before considering lemon balm extracts as a natural alternative to synthetic fungicides.

Antifungal Activity of Natural Compounds vs. Candida spp.: A Mixture of Cinnamaldehyde and Eugenol Shows Promising In Vitro Results

Candida spp. are commensal organisms of the skin, mucous membranes, gastrointestinal tract, blood, and vagina of animals and humans. In recent decades, the incidence of human fungal infections has increased, with Candida spp. (mainly C. albicans) infections being the most frequent, and the treatment of fungal infections is still a clinical challenge. Colonization of the human gastrointestinal tract by Candida spp. is significant because infections (e.g., candidemia and vulvovaginal candidiasis) frequently arise from commensal microorganisms. The aim of this study was to test in vitro the antifungal activity and the eventual synergistic effect of five pure components of essential oils: cinnamaldehyde, α-pinene, limonene, eucalyptol, and eugenol. These compounds were tested on 18 Candida strains (15 C. albicans, 2 C. glabrata, and 1 C. lusitaniae) derived from a culture collection of vaginal clinical strains.

METHODS

Fungistatic activity was evaluated using the disk diffusion method. For fungicidal activity, microdilution and time-kill curve protocols were set up. The checkerboard method was chosen to evaluate a possible synergistic effect of these compounds when mixed.

RESULTS

Cinnamaldehyde and eugenol gave the best results, inhibiting all the Candida strains and showing a highly additive effect (FICI 0.625). The cinnamaldehyde inhibition zone (IZ), MIC, and MFC means were 69 mm, 50.05 mg/L, and 109.26 mg/L respectively. Cinnamaldehyde led to the total loss of viable Candida cells within 4 h. Eugenol IZ, MIC, and MFC means were 35.2 mm, 455.42 mg/L, and 690.09 mg/L, respectively. Eugenol led to the total loss of viable fungal cells within 1 h. Treatment with α-pinene inhibited 88.9% of Candida strains, with an IZ mean of 21.2 mm, a MIC mean of 195.41 mg/L, and a MFC mean of 251.27 mg/L; this compound led to the total loss of viable fungal cells only after 24 h. Limonene inhibited only 33.3% of the tested strains and eucalyptol did not produce an inhibition halo, so these compounds were not tested further.

CONCLUSIONS

These characteristics, together with the well-known safety of cinnamaldehyde and eugenol for human use, make these two natural compounds the perfect candidates for the treatment of candidiasis. This was a pilot study, the purpose of which was to evaluate the best composition of a mixture to be used against intestinal and vulvovaginal candidiasis; in vivo studies are needed to confirm these very encouraging results.

Novel strategies of essential oils, chitosan, and nano- chitosan for inhibition of multi-drug resistant: E. coli O157:H7 and Listeria monocytogenes

Despite the wide range of available antibiotics, food borne bacteria demonstrate a huge spectrum of resistance. The current study aims to use natural components such as essential oils (EOs), chitosan, and nano-chitosan that have very influential antibacterial properties with novel technologies like chitosan solution/film loaded with EOs against multi-drug resistant bacteria. Two strains of Escherichia coli O157:H7 and three strains of Listeria monocytogenes were used to estimate antibiotics resistance. Ten EOs and their mixture, chitosan, nano-chitosan, chitosan plus EO solutions, and biodegradable chitosan film enriched with EOs were tested as antibacterial agents against pathogenic bacterial strains. Results showed that E. coli O157:H7 51,659 and L. monocytogenes 19,116 relatively exhibited considerable resistance to more than one single antibiotic. Turmeric, cumin, pepper black, and marjoram did not show any inhibition zone against L. monocytogenes; Whereas, clove, thyme, cinnamon, and garlic EOs exhibited high antibacterial activity against L. monocytogenes with minimum inhibitory concentration (MIC) of 250–400 μl 100⁻¹ ml and against E. coli O157:H7 with an MIC of 350–500 μl 100⁻¹ ml, respectively. Among combinations, clove, and thyme EOs showed the highest antibacterial activity against E. coli O157:H7 with MIC of 170 μl 100⁻¹ ml, and the combination of cinnamon and clove EOs showed the strongest antibacterial activity against L. monocytogenes with an MIC of 120 μl 100⁻¹ ml. Both chitosan and nano-chitosan showed a promising potential as an antibacterial agent against pathogenic bacteria as their MICs were relatively lower against L. monocytogenes than for E. coli O157:H7. Chitosan combined with each of cinnamon, clove, and thyme oil have a more effective antibacterial activity against L. monocytogenes and E. coli O157:H7 than the mixture of oils alone. Furthermore, the use of either chitosan solution or biodegradable chitosan film loaded with a combination of clove and thyme EOs had the strongest antibacterial activity against L. monocytogenes and E. coli O157:H7. However, chitosan film without EOs did not exhibit an inhibition zone against the tested bacterial strains.

Antimicrobial Potential of Plastic Films Incorporated with Sage Extract on Chicken Meat

The function of packaging is crucial in the maintenance of fresh meat product quality. This study aimed to assess the efficiency of six films added with coatings 2379L/220 and 2379L/221 (containing sage extracts) to inhibit Salmonella typhimurium, Staphylococcus aureus, and Escherichia coli, which showed that two of the six films had a significant effect. Additionally, the effects of the films on refrigerated skinless chicken breast meat were evaluated based on microbiological content, colour, weight loss, texture and pH. Four of the six films were examined could extend the storability of refrigerated chicken breast fillets for up to seven days. All six treated films improved the pH, colour stability, weight loss, and texture of the chicken fillets. Therefore, these findings suggested that the coatings containing sage extracts having different viscosities (2379L/220 and 2379L/221) were effective as antimicrobial adhesives in food packaging films and can be commercially applied in prolonging the storage of chicken breast meat without affecting their quality.

Individual and synergistic protective properties of Salvia officinalis decoction extract and sulfasalazine against ethanol-induced gastric and small bowel injuries

The present study was carried out to determine the phytochemical composition of Salvia officinalis flowers decoction extract (SOFDE) as well as its individual and/or synergistic actions with sulfasalazine against ethanol (EtOH)-induced peptic ulcer in Wistar rats. In this respect, rats were divided into six groups of eight animals each: control, EtOH, EtOH + sulfasalazine (SULF, 100 mg kg^-1, b.w., p.o.), mixture: MIX (SOFDE, 50 mg kg^-1 b.w., p.o. + SULF, 50 mg kg^-1, b.w., p.o.) and EtOH + two doses of SOFDE (100 and 200 mg kg^-1 b.w., p.o.). In vitro, the phytochemical and the antioxidant properties were determined using colorimetric analysis. HPLC-PDA/ESI-MS assay was used to identify the distinctive qualitative profile of phenolic compounds. Our results firstly indicated that SOFDE is rich in total tannins, flavonols, anthocyanins and a moderate concentration of total carotenoids. Chromatographic techniques allowed the identification of 13 phenolic compounds and the major ones are quinic acid, protocatechuic acid, gallic acid and salviolinic acid. SOFDE also exhibited an important in vitro antioxidant activity using the β-carotene bleaching method. In vivo, SOFDE and the mixture provide significant protection against ethanol-induced gastric and duodenal macroscopic and histological alterations. Also, SOFDE alone or in combination with SULF, showed a significant protection against the secretory profile disturbances, lipid peroxidation, antioxidant enzyme activities and non-enzymatic antioxidant level depletion induced by alcohol administration. Importantly, we showed that EtOH acute intoxication increased gastric and intestinal calcium, free iron, magnesium and hydrogen peroxide (H₂O₂) levels, while SOFDE/MIX treatment protected against all these intracellular mediators' deregulation. We also showed that alcohol treatment significantly increased the C-reactive protein (CRP) and alkaline phosphatase (ALP) activities in plasma. The SOFDE and MIX treatment significantly protected against alcohol-induced inflammation. More importantly, we showed in the present work that the mixture exerted a more important effect than SOFDE and SULF each alone indicating a possible synergism between these two molecules. In conclusion, our data suggests that SOFDE and SULF exerted a potential synergistic protective effect against all the macroscopic, histological and biochemical disturbances induced by EtOH intoxication. This protection might be related in part to its antioxidant and anti-inflammatory properties as well as by negatively regulating Fenton reaction components such as H₂O₂ and free iron.

Antibacterial Activity of Melissa officinalis L., Mentha piperita L., Origanum vulgare L. and Malva mauritiana against Bacterial Microflora Isolated from Fish

The aim of the present study was to detect the antibacterial activity of medicinal plants against fish microflora. A total of 4 ethanolic extracts of 6 plant species were collected from local environments of Slovakia and screened for antibacterial activity against bacterial microflora. Extracts of Melissa officinalis L., Mentha piperita L., Origanum vulgare L. and Malva mauritiana were used. Bacterial strains were isolated from common bleak (Alburnus alburnus) and common rudd (Scardinius erythrophthalmus) of Latvian origin. All bacterial strains were identified with the Matrix- Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS). Among fish microflora, Acinetobacter pittii, A. baumannii, Buttiauxella agrestis, Delftia acidovorans, Enterobacter cloacae, Serratia liquefaciens, Pseudomonas alcaligenes, Ps. oryzihabitans, Staphylococcus epidermidis, St. caprae, Pantoea agglomerans, Lelliottia amnigena, Providencia rettgeri, Escherichia coli and Rahnella aquatilis were identified. It has been shown that all plant extracts exhibit different degrees of antimicrobial activity against the tested bacteria. All bacterial strains in the present study were moderate sensitive to all extracts applied. The strongest antimicrobial effect of Malva mauritiana and Melissa officinalis L. against Pseudomonas oryzihabitans (6.67±1.53 resp. 9.67±0.58 mm) were found. The best antimicrobial activity of Mentha piperita L. was against Staphylococcus epidermis (7.33±0.58 mm) and strongest antimicrobial effect of Origanum vulgare L. was same against two bacterial strains Enterobacter cloacae and Serratia liquefaciens (9.67±0.58 mm).

Chemistry, Pharmacology, and Medicinal Property of Sage (Salvia) to Prevent and Cure Illnesses such as Obesity, Diabetes, Depression, Dementia, Lupus, Autism, Heart Disease, and Cancer

For a long time, sage (Salvia) species have been used in traditional medicine for the relief of pain, protecting the body against oxidative stress, free radical damages, angiogenesis, inflammation, bacterial and virus infection, etc., Several studies suggest that sage species can be considered for drug development because of their reported pharmacology and therapeutic activities in many countries of Asia and Middle East, especially China and India. These studies suggest that Salvia species, in addition to treating minor common illnesses, might potentially provide novel natural treatments for the relief or cure of many serious and life-threatening diseases such as depression, dementia, obesity, diabetes, lupus, heart disease, and cancer. This article presents a comprehensive analysis of the botanical, chemical, and pharmacological aspects of sage (Saliva).

Total Phenolic Content and Antioxidative Properties of Commercial Tinctures Obtained from Some Lamiaceae Plants

The antioxidant level of commercial tinctures from three Lamiaceae plants, Salvia officinalis, Mentha piperita, and Melissa officinalis, have been determined by the Folin-Ciocalteu method, the 2.2-diphenyl-2-picrylhydracyl hydrate (DPPH) radical scavenging technique and ABTS assay. Total phenolic content was expressed as GAE (gallic acid equivalent) and ranged from 0.24 to 3.99 mg/mL. Antioxidant activity in the ABTS assay, calculated as TEAC (Trolox equivalent antioxidant capacity), ranged from 23.5 to 35.6 μmol Trolox/mL, while in the DPPH method, the EC50 value ranged from 0.04 to 0.07 mL/assay. Radical scavenging activity was correlated with total phenolic content. Correlations between ABTS and F-C methods, DPPH and F-C methods and ABTS and DPPH methods were calculated. The obtained results can be useful as additional information about the antioxidant activity of galenical preparations.