The antibacterial and antifungal activity of essential oils extracted from Guatemalan medicinal plants

Citrus essential oil: would it be feasible as antimicrobial in the bioethanol industry?

Essential oils (EOs) extracted from Citrus peels contain 85%-99% volatile components (a mixture of monoterpenes, sesquiterpenes, and their oxygenated derivatives) and 1%-15% non-volatile compounds. Citrus EOs have been long known for their antimicrobial properties, owing to which these EOs have a diverse range of applications. However, no studies have reported the applicability of Citrus EOs for the control of bacterial and yeast contaminants in the bioethanol industry. In this regard, the present review aimed to explore the feasibility of Citrus EOs in this industry. The Web of Science database was searched for reports that described the association of Citrus EOs with the most common microorganisms in the bioethanol industry to evaluate the efficacy of these EOs as antimicrobial agents in this context. The objective of the review was to suggest a novel antimicrobial that could replace sulfuric acid and antibiotics as the commonly used antimicrobial agents in the bioethanol industry. Citrus EOs exhibit antibacterial activity against Lactobacillus, which is the main bacterial genus that contaminates this fermentation process. The present report also confirms the selective action of these EOs on the contaminating yeasts and not/less on ethanol-producing yeast Saccharomyces cerevisiae, however further studies should be conducted to investigate the effects of Citrus EOs in yeast-bacterium co-culture.

Antifungal Potential of Canarian Plant Extracts against High-Risk Phytopathogens

Phytopathogens are responsible for great losses in agriculture. In particular, Fusarium, Alternaria and Botrytis are fungal diseases that affect crops worldwide. In the search for eco-friendly solutions to pest control, plants and their chemo-biodiversity are promising sources of biopesticides for integrated pest management. The aim of the present study is to report the evaluation of sixteen plant species from the Canary Islands Archipelago against the phytopathogenic fungi Botrytis cinerea, Fusarium oxysporum, and Alternaria alternata. The plants were selected on the basis of their traditional uses in medicine and/or pest control, as well as on scientific studies reporting their uses in crop protection. Their growth inhibition (% I), in an in vitro test-assay on mycelium, was used to identify six ethanolic plant extracts displaying activity (% I > 30% at 1 mg/mL) against at least one of the assayed fungi. The most effective plant extracts were further fractionated by liquid−liquid partition, using solvents of increasing polarity. This procedure led to an improvement of the bioactivity against the phytopathogens, even affecting the hexane fraction from S. canariensis and achieving an 83.93% of growth inhibition at 0.5 mg/mL on B. cinerea. These findings identified five plant-derived extracts as potential candidates for the future development of new biofungicides, which could be applied in integrated pest management.

Origanum vulgare ethanolic extracts as a promising source of compounds with antimicrobial, anti-biofilm, and anti-virulence activity against dental plaque bacteria

Dental caries and periodontal diseases remain a challenge for oral health, especially given the lack of effective and safe treatment options that are currently available. Against the backdrop of an ongoing antimicrobial resistance crisis, a renewed interest in traditional medicinal plants as a potential source of new bioactive compounds has surfaced. In this context, we systematically screened the antimicrobial and anti-biofilm activities of both ethanolic and aqueous extracts of nine Algerian medicinal plants (Artemisia herba alba, Centaurium erythraea, Juglans regia, Laurus nobilis, Matricaria recutita, Mentha pulegium, Mentha piperita, Origanum vulgare and Taraxacum officinale). To evaluate the activity spectrum of the extracts, the screening was carried out against an extensive collection of Streptococcus, Enterococcus and Lacticaseibacillus isolates recovered from dental plaques of Algerian patients. Broad-spectrum antimicrobial and anti-biofilm properties were observed, especially among ethanolic extracts, which marks them as a promising source for bioactive compounds to control oral biofilms. The ethanolic extract of O. vulgare, which showed the most promising effects in the initial screening, was further characterized. We first verified the biocompatibility of this extract using human oral keratinocytes and selected a range of non-cytotoxic concentrations (0.195-0.781 mg/ml) to further validate its anti-biofilm and anti-virulence potential. At these concentrations, the extract not only prevented biofilm formation (10.04 ± 0.75-87.91 ± 9.08% of reduction) of most dental plaque isolates on a polystyrene surface, but also significantly reduced their adherence to hydroxyapatite (34.58 ± 9.09-62.77 ± 0.95%). Moreover, the extract showed curative potential against mature biofilms grown under conditions mimicking the oral niche. In addition to its anti-biofilm properties, we observed an inhibition of glucosyltransferase activity, a reduction in acidogenesis and a downregulation in the expression of multiple virulence-associated genes for extract-treated samples. Since anti-virulence properties are more robust to the development of resistance, they provide an attractive complementation to the antimicrobial activities of the extract. Thymol was identified as an important active compound of the extract using GC-MS analysis, but synergy with other compounds was also detected, suggesting a potential advantage of using the whole extract over purified thymol. Further research into the bioactive compounds of the O. vulgare ethanolic extract could yield novel products to fight dental caries.

The Current Antimicrobial and Antibiofilm Activities of Synthetic/Herbal/Biomaterials in Dental Application

Herbal and chemical products are used for oral care and biofilm treatment and also have been reported to be controversial in the massive trials conducted in this regard. The present review is aimed at evaluating the potential of relevant herbal and chemical products and comparing their outcomes to conventional oral care products and summarizing the current state of evidence of the antibiofilm properties of different products by evaluating studies from the past eleven years. Chlorhexidine gluconate (CHX), essential oils (EOs), and acetylpyridinium chloride were, respectively, the most commonly studied agents in the included studies. As confirmed by all systematic reviews, CHX and EO significantly control the plaque formation and gingival indices. Fluoride is another interesting reagent in oral care products that has shown promising results of oral health improvement, but the evidence quality needs to be refined. The synergy between natural plants and chemical products should be targeted in the future to accede to the formation of new, efficient, and healthy anticaries strategies. Moreover, to discover their biofilm-interfering or biofilm-inhibiting activities, effective clinical trials are needed. In this review article, therapeutic applications of herbal/chemical materials in oral biofilm infections are discussed in recent years (2010-2022).

Preliminary Study of the Antimicrobial, Anticoagulant, Antioxidant, Cytotoxic, and Anti-Inflammatory Activity of Five Selected Plants with Therapeutic Application in Dentistry

The usefulness of traditional plants in Mexico to treat human ailments has been known since ancient times. This work evaluated the antimicrobial, anticoagulant, antioxidant, cytotoxic, and anti-inflammatory potential of ethanolic extracts of Aloe vera, Equisetum arvense, Mimosa tenuiflora, Lippia graveolens, and Syzygium aromaticum. The antimicrobial activity of the extracts was evaluated against Streptococcus mutans and Streptococcus sorbinus; a significant inhibitory effect of the L. graveolens extract on both bacteria was observed at concentration levels of 250 µg/mL and greater. The anticoagulant activity was evaluated in terms of prothrombin time (PT) and activated partial thromboplastin time (APTT), A. vera and M. tenuiflora extracts showed no significant difference (p ˂ 0.05) in PT compared with the control, and for APTT the extracts of A. vera, L. graveolens, and S. aromaticum decreased the APTT significantly (p ˂ 0.05) compared with the control. The antioxidant potential by DPPH assay indicated that the E. arvense extract behaved statistically the same as the control. The cytotoxic activity was evaluated in HGF-1 cells using the fluorometric microculture cytotoxicity assay technique, and none of the extracts was toxic at 125 and 250 µg/mL concentrations. Finally, the anti-inflammatory activity was evaluated using ELISA, where the A. vera extract showed the best anti-inflammatory capacity. Further research on the search for bioactive metabolites and elucidation of action mechanisms of the most promising extracts will be carried out.

Arnica Montana L. Supercritical Extraction Optimization for Antibiotic and Anticancer Activity

Arnica montana L. flower heads are known for their antioxidant, antimicrobial, and anticancer activity. The aim of this work was to optimize the process of supercritical CO₂ extraction, to achieve high extraction yield and high content of biologically active components, and to confirm the antimicrobial and anticancer activity of the extract. The influence of pressure and temperature on the total phenolic content, antioxidant activity, and proanthocyanidin content was evaluated. The pressure and temperature were found to be interdependent. A temperature of 60°C and a pressure of 30 MPa resulted in a high extraction yield, antioxidant activity and phenolic content. The content of proanthocyanidins was highest at a pressure between 18 and 24 MPa. The extracts inhibited three different microorganisms successfully; Staphylococcus aureus, Escherichia coli and Candida albicans, at concentrations ranging from 0.1 to 5.16 mg/ml and showed anticancer activity decrease up to 85% at a concentration of 0.5 mg/ml.

Microbial Deterioration of the Archaeological Nujoumi Dome (Egypt-Aswan): Identification and Suggested Control Treatments by Natural Products

Biodeterioration plays a significant role in the damage and loss of monuments including gypsum work. Bacteria and fungi are mainly responsible for the biodeterioration of gypsum work. Thus, the present study aimed to evaluate the effects of essential oils (Thyme, clove, cinnamon, garlic, castor, and olive) on the growth of the main fungi and bacteria which isolated from the Nujoumi Dome which is also called the Dome of the Toshka Martyrs and is located in Aswan, Egypt. Microbial swabs were taken from these infected objects, and the isolated microorganisms were characterized. The next genera were identified: four fungal isolates were isolated and identified as Aspergillus japonicas, Aspergillus terrus, Penicillium commune, and Cladosporium elatum while two species of bacteria were isolated, identified as Bacillus cereus and Listeria monocytogenes. Garlic oil had the best effect on all isolates, showing 35 and 33 mm inhibition of growth of Bacillus cereus and Listeria monocytogenes, respectively, while 28 mm inhabitation of growth of Penicillium commune, 25 mm inhibition of Aspergillus japonicas, and finally 20 mm inhibition of both Aspergillus terrus and Cladosporium elatum. In conclusion, garlic oil could be an effective natural product for controlling the biodeterioration.

Bixa orellana L. (Achiote, Annatto) as an antimicrobial agent: A scoping review of its efficiency and technological prospecting

ETHNOPHARMACOLOGICAL RELEVANCE

Bixa orellana L. is reported to have numerous applications in traditional medicine and pharmacological properties such as wound healing, analgesic, hemostatic, and antioxidant activities. Recently, the literature has shown scientific interest of its antimicrobial properties aiming the development of cost-effective phytotherapeutic agents. However, no literature are available in witch the antimicrobial and technological prospecting are summarized.

AIM OF STUDY

This study aimed to systematically review articles and patents related to the antimicrobial activity of B. orellana.

METHODS

The review followed the guidelines proposed by The Joanna Briggs Institute and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Two reviewers performed a literature search up to November 2021 in eight databases: Medline (PubMed), Scopus, Scifinder, Web of Science, Cochrane, Embase, Scielo, and Biblioteca Virtual em Saúde. The following databases for the patent search were analyzed: United States Patent and Trademark Office (USPTO), Google Patents, National Institute of Industrial Property (INPI), World Intellectual Property Organization (WIPO), and Espacenet (European Patent Office, EPO). The grey literature was searched using the ProQuest Dissertations and Periódicos Capes Theses database. The methodological quality and risk of bias in the included studies were carried out using Review Manager (RevMan) 5.3.5.

RESULTS

After analyzing the 47 studies and five patents fulfilled all the criteria and were included in the present investigation. The evidence suggests that this herbal medicine is effective against several fungi, Gram-positive and Gram-negative bacteria, being more effective to Gram-negative bacteria. Regarding the risk of bias and methodological quality analysis, most studies a high risk of bias related to random sequence generation and allocation concealment.

CONCLUSION

Up to now, the evidence in the literature suggests that the use of B. orellana preparations for antimicrobial preparations has some effectiveness. However, further research is needed using standard B. orellana preparations to determine their effectiveness as antimicrobial agents and expanding their application at an industrial level, in addition in vivo studies are needed for this confirmation.

Meta-analysis of the antifungal activities of three essential oils as alternative therapies in dermatophytosis infections

Aims

This work examines the available scientific evidence about the efficiency of essential oils (EO) as an alternative therapy to traditional treatment of fungal infections, including onychomycosis, assessing the effect of the three EO most frequently studied for their antifungal activity (thyme, cinnamon and tea tree EO) against three causative agents of fungal diseases in humans: Trichophyton rubrum, Trichophyton mentagrophytes complex and Candida albicans.

Methods and Results

The PRISMA statement protocol was followed to conduct a bibliographical search and 54 articles that met all the inclusion criteria were retrieved. Differences were observed in the MIC and MFC values depending on the micro‐organism strain and the EO used. The lowest MIC were observed with Cinnamomum zeylanicum EO (0.013–1120 μl ml⁻¹) against the three micro‐organisms. For MFC, the lowest value was found for Thymus vulgaris EO (4.2 μl ml⁻¹) against Trichophyton rubrum.

Conclusions

The antifungal effects of EO could be a very promising solution to overcome the therapeutic shortcomings of antimycotic medication. More experiments are needed to examine the properties of these oils to devise effective and nonaggressive therapies for treatment of dermatophytosis.

Significance and Impact of Study

The results indicate that EO remain good candidates for future treatments and could provide a solution for failed medications and/or adverse reactions to current pharmacological treatments.

Origanum vulgare L. essential oil inhibits virulence patterns of Candida spp. and potentiates the effects of fluconazole and nystatin in vitro

Background

Recurrence and resistance of Candida spp. infections is associated with the ability of these microorganisms to present several virulence patterns such as morphogenesis, adhesion, and biofilm formation. In the search for agents with antivirulence activity, essential oils could represent a strategy to act against biofilms and to potentiate antifungal drugs.

Objective

To evaluate the antivirulence effect of Origanum vulgare L. essential oil (O-EO) against Candida spp. and to potentiate the effect of fluconazole and nystatin.

Methods

The effect of O-EO was evaluated on ATCC reference strains of C. albicans and non-albicans Candida species. Minimum inhibitory concentration (MIC) was determined through broth microdilution assay. Adhesion to microplates was determined by crystal violet (CV) assay. An adapted scratch assay in 24-well was used to determine the effect of essential oil on biofilms proliferation. Viability of biofilms was evaluated by MTT reduction assay and through a checkerboard assay we determined if O-EO could act synergistically with fluconazole and nystatin.

Results

MIC for C. albicans ATCC-90029 and ATCC-10231 was 0.01 mg/L and 0.97 mg/L, respectively. For non-albicans Candida strains MIC values were 2.6 mg/L for C. dubliniensis ATCC-CD36 and 5.3 mg/L for C. krusei ATCC-6258. By using these concentrations, O-EO inhibited morphogenesis, adhesion, and proliferation at least by 50% for the strains assayed. In formed biofilms O-EO decreased viability in ATCC 90029 and ATCC 10231 strains (IC50 7.4 and 2.8 mg/L respectively). Finally, we show that O-EO interacted synergistically with fluconazole and nystatin.

Conclusions

This study demonstrate that O-EO could be considered to improve the antifungal treatment against Candida spp.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-022-03518-z.

Cognizance and Use of Minimally Invasive Dentistry Approach by General Dentists: An Overlooked Companion

Background:

Dental caries begins with the decalcification of the first nonorganic part, followed by the decay of the organic tooth matrix. Minimally invasive dentistry (MID) focuses on using the adhesive technique for restoration as these techniques allow minimum removal of healthy tooth structure.

Objective:

This study aimed to assess the attitude, knowledge, and behavior of the general dentists toward the use of MID and to evaluate if MID is considered as standard care measure among general dentists.

Materials and Methods:

This was a cross-section observational survey and included 285 practicing dentists. The survey questions were divided into two parts. The question related to the use of sharp explorer utilized response categories (1–5), with options of always, most of the time, often, sometimes, and never or rarely. The independent variables collected were age, gender, years of practice, clinical hours, type of practice, postgraduate education, and clinic environment. The data collected were tabulated and were statistically analyzed.

Results:

The results of the present study showed that MID meets the standard of care for the treatment of both primary teeth 85.96% (n = 245) as well as permanent teeth 78.24% (n = 223). ART, sandwich technique, in-office, and at-home topical fluoride application were considered active for treating dental caries. The use of sharp explorers, nonsharp explorers, radiographs, and magnification were considered common for caries detection.

Conclusion:

The more dentists who listened to about MID in the past responded that the MID concept is the standard of care for the treatment of primary and permanent teeth than dentists who have heard little or nothing about MID.

Cariostatic Efficacy of Cinnamon Water Extract on Streptococcus mutans: An In vitro Study

Background:

Dental caries is a chronic, widespread, and infectious disease affecting the large population. Anticariogenic effects of different herbs and natural products are observed, cinnamon among these, showed the ability to inhibit Streptococcus mutans biofilm.

Objectives:

The aim of this study was to assess the cinnamon water extract use on nicotine exposed S. mutans biolfilms.

Materials and Methods:

Microtiter plates having S. mutans culture were treated using varying nicotine concentration range (0–32 mg/ml). These were then either subjected to cinnamon water (2.5 mg/ml) extract or no treatment and analyzed using a spectrophotometer to see planktonic growth, total growth absorbance, and biofilm formation.

Results:

About 2.5 mg/ml of cinnamon water inhibits the S. mutans biofilm (nicotine-induced) considerably at various nicotine levels (0–32 mg/ml).

Conclusion:

Cinnamon water extract has a powerful inhibitory effect for S. mutans growth. Nicotine-induced S. mutans growth is markedly reduced by treating with cinnamon water extract.

Flavored Olive Oil as a Preservation Means of Reduced Salt Spanish Style Green Table Olives (cv. Chalkidiki)

Reformulation of products fermented in brine is a challenging area of research. Continuing the efforts toward the establishment of table olives as a healthy food for all population groups, this study aimed at examining whether olive oil flavored with essential oils can be used as a preservation means for reduced salt Spanish style green table olives (cv. Chalkidiki). Response surface methodology was applied to organize experimentation and assess data. As independent factors, concentrations of the essential oils used (oregano, lemon balm and bay laurel) and time of storage under vacuum were set. Microbiological parameters (pathogens and fermentation-related microbes), color and firmness attributes were used as responses. Models indicated that each essential oil exerted a preservative role to maintain microbiological quality of reduced salt table olives. Concurrently, appearance attributes of the latter were retained at desirable values. Oregano essential oil had a profound role against pathogens. Lemon balm and bay laurel essential oils were found to be important for yeast population control. The results are promising toward the use of flavored olive oil as a preservation means for tailor-made reduced salt table olives, a practice that may enhance local industry innovative activity in a practical and effective way.

Antifungal Efficacy of Four Different Concentrations of the Essential Oil of Cinnamomum zeylanicum (Canela) against Candida albicans: An In Vitro Study

Objective:

The objective of this study was to compare in vitro the antifungal efficacy of the essential oil of Cinnamomum zeylanicum (Canela) (EOC) at 25%, 50%, 75%, and 100% against strains of Candida albicans ATCC 10231.

Materials and Methods:

The design was experimental, in vitro, prospective, and longitudinal study, having a sample of n = 30 petri dishes per six groups. The test was conducted in the microbiology laboratory of the Universidad Nacional Federico Villarreal. The essential oil was prepared by steam distillation, which means that the pressure steam enters in connection with the plant cells and breaks them, releasing the essence and trapping it in drops of water. Cinnamon essential oil was obtained using the hydrodistillation method, subsequently the oil obtained was dehydrated with sodium sulfate and then filtered at 0.22 µm. Then the vials were stored at a temperature of 4°C. Finally, Candida albicans ATCC 10231 was used as the biological material. Antifungal efficacy was measured by the Kirby–Bauer method (disk diffusion).

Results:

It was found that in the 24-h group the concentration that had the greatest antifungal effect was 100% EOC with a mean of 22.1 ± 11 mm; however, the lowest antifungal activity was seen in the 25% EOC with 17.9 ± 1.6 mm. On the contrary, in the 48-h group, it was shown that the highest antifungal efficacy was also observed in the 100% EOC with an average of 31.2 ± 3.2 mm, but the lowest antifungal activity was in the 25% EOC with 22.6 ± 1.7 mm. Although in both groups, both at 24 and 48h, nystatin was the one with the lowest antifungal efficacy 15.1 ± 1.0 and 19.9 ± 0.1 mm, respectively.

Conclusions:

EOC had a better statistically significant antifungal effect compared to nystatin. Otherwise, on analysis of the results in different concentrations, the EOC showed a directly proportional antifungal effectiveness as the concentration against the strains of C. albicans ATCC 10231 increased, compared to nystatin, suggesting its potential use as a possible attractive therapeutic alternative for the control of diseases caused by strains of C. albicans resistant to nystatin.

Traditional Herbal Medicine in Mesoamerica: Toward Its Evidence Base for Improving Universal Health Coverage

The quality of health care in Mesoamerica is influenced by its rich cultural diversity and characterized by social inequalities. Especially indigenous and rural communities confront diverse barriers to accessing formal health services, leading to often conflicting plurimedical systems. Fostering integrative medicine is a fundamental pillar for achieving universal health coverage (UHC) for marginalized populations. Recent developments toward health sovereignty in the region are concerned with assessing the role of traditional medicines, and particularly herbal medicines, to foster accessible and culturally pertinent healthcare provision models. In Mesoamerica, as in most regions of the world, a wealth of information on traditional and complementary medicine has been recorded. Yet these data are often scattered, making it difficult for policy makers to regulate and integrate traditionally used botanical products into primary health care. This critical review is based on a quantitative analysis of 28 survey papers focusing on the traditional use of botanical drugs in Mesoamerica used for the compilation of the "Mesoamerican Medicinal Plant Database" (MAMPDB), which includes a total of 12,537 use-records for 2188 plant taxa. Our approach presents a fundamental step toward UHC by presenting a pharmacological and toxicological review of the cross-culturally salient plant taxa and associated botanical drugs used in traditional medicine in Mesoamerica. Especially for native herbal drugs, data about safety and effectiveness are limited. Commonly used cross-culturally salient botanical drugs, which are considered safe but for which data on effectiveness is lacking constitute ideal candidates for treatment outcome studies.

In vitro Cariostatic effects of cinnamon water extract on nicotine-induced Streptococcus mutans biofilm

Background

Dental caries is one of the most prevalent chronic oral diseases worldwide. Dental caries is mainly associated with Streptococcus mutans and the Lactobacillus species. A specific relationship was found between nicotine and S. mutans growth as the presence of nicotine increased S. mutans biofilm formation. Nicotine is able to increase the number of S. mutans and extracellular polysaccharide (EPS) synthesis. Among the widely used herbs and spices is cinnamon which demonstrated a strong antibacterial activity against a wide variety of bacteria including S. mutans and showed the ability to inhibit S. mutans biofilm formation. Cinnamon essential oil, obtained from the leaves of C. zeylanicum, has been demonstrated to be effective against S. mutans and Lactobacillus acidophilus, which are partially responsible for dental plaque formation and caries development. The aim of this study was to identify the effects of nicotine exposure on the inhibitory effects of cinnamon water extract on S. mutans biofilm formation.

Materials and methods

A 24-h culture of S. mutans UA159 in microtiter plates was treated with varying nicotine concentrations (0–32 mg/ml) in Tryptic Soy broth supplemented with 1% sucrose (TSBS) with or without a standardized concentration (2.5 mg/ml) of cinnamon water extract. A spectrophotometer was used to determine total growth absorbance and planktonic growth. The microtiter plate wells were washed, fixed and stained with crystal violet dye and the absorbance measured to determine biofilm formation.

Results

The presence of 2.5 mg/ml cinnamon water extract inhibits nicotine-induced S. mutans biofilm formation from 34 to 98% at different concentrations of nicotine (0–32 mg/ml).

Conclusion

The results demonstrated nicotine-induced S. mutans biofilm formation is decreased from 34 to 98% in the presence of 2.5 mg/ml cinnamon water extract. This provides further evidence about the biofilm inhibitory properties of cinnamon water extract and reconfirms the harmful effects of nicotine.

Endophytic fungal extracts: evaluation as photosynthesis and weed growth inhibitors

A central pillar of modern weed control is the discovery of new herbicides which are nontoxic to humans and the environment and which have low application dosage. The natural products found in plants and microorganisms are well suited in this context because they are generally nontoxic and have a wide variety of biological activities. In this work, Diaporthe phaseolorum (Dp), Penicillium simplicissimum (Ps) and Trichoderma spirale (Ts) (methanolic extracts) were evaluated as photosynthesis and plant growth inhibitors in Senna occidentalis and Ipomoea grandifolia. The most significant results were observed for Ts and Dp in S. occidentalis and I. grandifolia, respectively. Ts reduced PI_(abs), ET₀/CS₀, PHI(E₀) and PSI₀ parameters by 64, 28, 40 and 38%, respectively, indicating a reduction on electron transport efficiency. Additionally, Ts decreased shoot length by 9%, affecting the plant growth. Dp reduced PI_(abs), ET₀/CS₀ and PHI(E₀) parameters by 50, 20, 26 and 22%, respectively, revealing the inhibition competency on PSII acceptor site. Furthermore, Dp decreased by 50% the shoot length on germination assay. Thus, the phytotoxic behaviors based on endophytic fungal extracts may serve as a valuable tool in the further development of a bioherbicide since natural products represent an interesting alternative to replace commercial herbicides.

Extraction of essential oil from Citrus reticulate Blanco peel and its antibacterial activity against Cutibacterium acnes (formerly Propionibacterium acnes)

Citrus is one of the largest output fruits in the word. In China, the major orange variety is the Citrus reticulate Blanco (Ponkan). The peels are discarded as waste material, its comprehensive utilization is urgently needed. In this work, hydrodistillation method was developed to extract citrus essential oil (EO) from Blanco peel. With the optimal extraction conditions, the EO yield was more than 3%. By GC-MS analysis, 53 compounds were identified from the citrus EO. Terpenes compounds accounted for 71.2%, especially d-limonene (major composition) accounted for 58.9%. The obtained citrus EO showed remarkable antibacterial activity against Cutibacterium acnes (C. acnes, Formerly P. acnes) and common microorganisms such as S. aureus, B. subtilis, and E. coli. Even compared with the common antibiotics (such as erythromycin, clindamycin, and tetracycline) for acne therapy, its antibacterial activity against C. acnes is more excellent. This work provides a potential therapy material for the treatment of acne.

Antifungal potential of eugenyl acetate against clinical isolates of Candida species

The study evaluated the efficiency of eugenyl acetate (EA), a phytochemical in clove essential oil, against clinical isolates of Candida albicans, Candida parapsilosis, Candida tropicalis, and Candida glabrata. Minimum inhibitory concentrations (MIC) of EA against Candida isolates were in the range between 0.1% and 0.4% (v/v). Spot assay further confirmed the susceptibility of Candida isolates to the compound upon treatment with respective 1 × MIC. Growth profile measured in time kill study evidence that the compound at 1 × MIC and 1/2 × MIC retarded the growth of Candida cells, divulging the fungicidal activity. Light microscopic observation demonstrated that upon treated with EA, rough cell morphology, cell damage, and fragmented patterns were observed in C. albicans, C. parapsilosis, C. tropicalis, and C. glabrata. Furthermore, unusual morphological changes of the organism were observed in scanning electron microscopic study. Therefore, it is validated that the compound could cause cell damage resulting in the cell death of Candida clinical isolates. Eventually, the compound at sub-MIC (0.0125% v/v) significantly inhibited serum-induced germ tube formation by C. albicans. Eugenyl acetate inhibited biofilm forming ability of the organisms as well as reduced the adherence of Candida cells to HaCaT keratinocytes cells. In addition, upon treatment with EA, the phagocytic activity of macrophages was increased significantly against C. albicans (P < 0.05). The results demonstrated the potential of EA as a valuable phytochemical to fight against emerging Candida infections.

Natural Therapeutic Options in Endodontics - A Review

Complete eradication of microbial biofilms and elimination of the smear layer are the key factors during endodontic treatment. Various chemical irrigants have been proposed in the literature for the same. The major setback with these chemical irrigants is that they are not bio-friendly to the dental and peri-radicular tissues. In the recent years, research to use natural products for root canal disinfection has gained importance. The aim of this article is to compile various herbal products that have been used as an irrigants and intracanal medicaments in the field of Endodontics to eradicate the biofilm and remove smear layer.

Natural Antimicrobials and Oral Microorganisms: A Systematic Review on Herbal Interventions for the Eradication of Multispecies Oral Biofilms

Oral diseases such as caries and periodontitis are mainly caused by microbial biofilms. Antibiotic therapy has reached its limits with regard to antimicrobial resistance, and new therapeutic measures utilizing natural phytochemicals are currently a focus of research. Hence, this systematic review provides a critical presentation of the antimicrobial effects of various medicinal herbs against in vitro, ex vivo, and in situ formed multispecies oral biofilms. Searches were performed in three English databases (PubMed, EMBASE, CAMbase) and the electronic archives of five German journals from the times of their establishment until October 10th, 2014, with the search terms “(plant extracts OR herbal extracts OR plant OR herb) AND (oral biofilm OR dental biofilm OR dental plaque OR oral disease OR dental disease).” The pooled data were assessed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PRISMA). Initially, 1848 articles were identified, out of which 585 full-text articles were screened, 149 articles were reevaluated for eligibility and finally, 14 articles met all inclusion criteria. The data of 14 reports disclosed enhanced antiadhesive and antibiofilm activity by the plant extracts obtained from Vitis vinifera, Pinus spp., Coffea canephora, Camellia sinensis, Vaccinium macrocarpon, Galla chinensis, Caesalpinia ferrea Martius, Psidium cattleianum, representative Brazilian plants and manuka honey. Overall, a positive correlation was revealed between herb-based therapies and elimination rates of all types of multispecies oral biofilms. In that context, integrating or even replacing conventional dental therapy protocols with herbal-inspired treatments can allow effective antimicrobial control of oral biofilms and thus, dental diseases.

Antibacterial Effects of Cinnamon: From Farm to Food, Cosmetic and Pharmaceutical Industries

Herbs and spices have been used since ancient times, because of their antimicrobial properties increasing the safety and shelf life of food products by acting against foodborne pathogens and spoilage bacteria. Plants have historically been used in traditional medicine as sources of natural antimicrobial substances for the treatment of infectious disease. Therefore, much attention has been paid to medicinal plants as a source of alternative antimicrobial strategies. Moreover, due to the growing demand for preservative-free cosmetics, herbal extracts with antimicrobial activity have recently been used in the cosmetic industry to reduce the risk of allergies connected to the presence of methylparabens. Some species belonging to the genus Cinnamomum, commonly used as spices, contain many antibacterial compounds. This paper reviews the literature published over the last five years regarding the antibacterial effects of cinnamon. In addition, a brief summary of the history, traditional uses, phytochemical constituents, and clinical impact of cinnamon is provided.