Screening of Chinese medicinal plants for inhibition against clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA)

The geranium genus: A comprehensive study on ethnomedicinal uses, phytochemical compounds, and pharmacological importance

The geranium genus consists of about 400 species, which have been utilized for a long time in ancient medical practices throughout the world. As a result, herbal medications based on species are commonly utilized to treat a range of illnesses. This investigation aims to provide an extensive assessment of the literature on the phytochemistry, ethnomedicinal and pharmacological importance of the genus Geranium. Data were collected through systemic computer searches among the most reputable scientific databases, Web of Science, Google Scholar, and Scopus. Occasionally, information published as peer-reviewed literature was added to data from sources that these databases do not include. This review includes all published works through the end of 2022. The assessment of the biological characteristics of medicinal plant species in the genus Geranium has received a great deal of attention, primarily in the last 20 years, in tandem with the growing interest in herbal remedies in general. The detailed and systematic comparative analysis presented here provides valuable information on the current Geranium species. It paves the way for other beneficial species of Geranium to be studied in the fields of ethnobotany, phytochemistry, and new drug discovery.

Carboxymethyl cellulose/poly (vinyl alcohol) based active film incorporated with tamarind seed coat waste extract for food packaging application

Incorporating a bioactive food waste extract into biodegradable polymers is a promising green approach to producing active films with antioxidant and antibacterial activity for food packaging. Active packaging films from carboxymethyl cellulose (CMC) and polyvinyl alcohol (PVA) incorporated with tamarind seed coat waste extract (TS) were prepared by solvent casting method using citric acid as a crosslinking agent. The effect of TS content on the film properties was determined by measuring the optical, morphology, mechanical, water vapor transmission rate (WVTR), antioxidant, and antimicrobial attributes. The CMC/PVA-TS films were also tested on fresh pork. The addition of TS did not significantly affect the film structure and WVTR but it improved the mechanical and UV barrier properties. The films possessed antioxidant and antimicrobial ability against bacteria (S. aureus and E. coli). Thus, CMC/PVA packaging was successfully prepared, and the incorporation of TS enhanced the antioxidant and antimicrobial properties of the film, which extended the shelf-life of fresh pork.

Identification and pathogenicity of multidrug-resistant Elizabethkingia miricola isolated from farmed American bullfrogs Rana catesbeiana in China with in vitro screening of herbal antimicrobial agents

OBJECTIVE

In 2021, an outbreak of an infectious disease characterized by torticollis, cataracts, and neurological disorders caused massive mortality in farmed American bullfrogs Rana catesbeiana in Hubei province, China. We identified the causal agent in this outbreak, characterized its pathogenicity, and screened candidate antimicrobial agents for future disease control.

METHODS

Bacterium was isolated from the diseased American bullfrogs and identified based on biochemical tests, sequence analyses (16S ribosomal RNA; DNA gyrase subunit B), and experimental challenge. Furthermore, antibiotic sensitivity of the isolated strain was detected with Kirby-Bauer paper diffusion method, and the antibacterial activity of 60 traditional Chinese herbal extracts against the isolated strain was evaluated by agar disc diffusion and broth dilution assays.

RESULT

We identified Elizabathkingia miricola strain FB210601 as the causative agent of this disease. The isolated E. miricola strain FB210601 exhibited extensive antibiotic resistance to all tested quinolones, β-lactam antibiotics, and aminoglycosides. Eight herbal extracts exhibited excellent antimicrobial activity against E. miricola FB210601, especially Caesalpinia sappan and Rhus chinensis, with minimal inhibitory concentrations less than 0.2 mg/mL. Additionally, the combined effects of two-component herbal mixtures containing C. sappan or R. chinensis were greater than those of the individual extracts.

CONCLUSION

Our results provide a reference for understanding the pathogenesis of Elizabethkingia infection in frogs. Furthermore, this study will aid in the application of herbal extracts for protection against infections caused by multidrug-resistant Elizabathkingia in the future.

Phenolics Profiling by HPLC-DAD-ESI/MSn of the Scientific Unknown Polygonum hydropiperoides Michx. and Its Antioxidant and Anti-Methicillin-Resistant Staphylococcus aureus Activities

Polygonum hydropiperoides Michx. is an Asian native plant species that is also widely distributed in the Americas. Despite its traditional uses, P. hydropiperoides is scarcely scientifically exploited. This study aimed to chemically characterize and investigate the antioxidant and antibacterial activities of hexane (HE-Ph), ethyl acetate (EAE-Ph), and ethanolic (EE-Ph) extracts from aerial parts of P. hydropiperoides. The chemical characterization was performed through HPLC-DAD-ESI/MSⁿ. The antioxidant activity was assessed by the phosphomolybdenum reducing power, nitric oxide inhibition, and the β-carotene bleaching assays. The antibacterial activity was determined by the minimal inhibitory concentration (MIC) and the minimal bactericidal concentration followed by the classification of the antibacterial effect. Chemical characterization revealed the expressive presence of phenolic acids and flavonoids in EAE-Ph. An increased antioxidant capacity was revealed in EAE-Ph. Regarding antibacterial activity, EAE-Ph showed weak to moderate property against 13 strains tested with MIC values ranging from 625 to 5000 µg/mL, with bactericidal or bacteriostatic effects. Glucogallin and gallic acid stand out as the most relevant bioactive compounds. These results suggest that P. hydropiperoides is a natural source of active substances, supporting this species' traditional use.

Herbal Products and Their Active Constituents Used Alone and in Combination with Antibiotics against Multidrug-Resistant Bacteria

The purpose of this review is to summarize the current knowledge acquired on herbal products and their active constituents with antimicrobial activity used alone and in combination with antibiotics against multidrug-resistant bacteria. The most promising herbal products and active constituents used alone against multidrug-resistant bacteria are Piper betle (methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus, extended-spectrum beta-lactamase, Acinetobacter baumannii, Pseudomonas aeruginosa), Glycyrrhiza glabra (methicillin-resistant S. aureus, vancomycin-resistant Enterococcus, P. aeruginosa), and berberine (methicillin-resistant S. aureus, A. baumannii, P. aeruginosa), respectively. The synergistic effect of the combination of herbal products and their active constituents with antibiotics against multidrug-resistant bacteria are also described. These natural antibacterial agents can be promising sources of inhibitors, which can modulate antibiotic activity against multidrug-resistant bacteria, especially as efflux pump inhibitors. Other possible mechanisms of action of herbal therapy against multidrug-resistant bacteria including modification of the bacterial cell wall and/or membrane, inhibition of the cell division protein filamenting temperature sensitive Z-ring, and inhibition of protein synthesis and gene expression, all of which will also be discussed. Our review suggests that combination herbal therapy and antibiotics can be effectively used to expand the spectrum of their antimicrobial action. Therefore, combination therapy against multidrug-resistant bacteria may enable new choices for the treatment of infectious diseases and represents a potential area for future research.

MRSA compendium of epidemiology, transmission, pathophysiology, treatment, and prevention within one health framework

Staphylococcus aureus is recognized as commensal as well as opportunistic pathogen of humans and animals. Methicillin resistant strain of S. aureus (MRSA) has emerged as a major pathogen in hospitals, community and veterinary settings that compromises the public health and livestock production. MRSA basically emerged from MSSA after acquiring SCCmec element through gene transfer containing mecA gene responsible for encoding PBP-2α. This protein renders the MRSA resistant to most of the β-lactam antibiotics. Due to the continuous increasing prevalence and transmission of MRSA in hospitals, community and veterinary settings posing a major threat to public health. Furthermore, high pathogenicity of MRSA due to a number of virulence factors produced by S. aureus along with antibiotic resistance help to breach the immunity of host and responsible for causing severe infections in humans and animals. The clinical manifestations of MRSA consist of skin and soft tissues infection to bacteremia, septicemia, toxic shock, and scalded skin syndrome. Moreover, due to the increasing resistance of MRSA to number of antibiotics, there is need to approach alternatives ways to overcome economic as well as human losses. This review is going to discuss various aspects of MRSA starting from emergence, transmission, epidemiology, pathophysiology, disease patterns in hosts, novel treatment, and control strategies.

Elsholtzia: A genus with antibacterial, antiviral, and anti-inflammatory advantages

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Elsholtzia (family Labiaceae) is an important source of folk traditional Chinese medicine, mainly used to relieve the symptoms of cold, fever, pneumonia and so on. However, currently available data on its traditional and pharmacological advantages have not been comprehensively reviewed.

AIM OF THE REVIEW

This review provides up-to-date and comprehensive information on the ethnopharmacological, phytochemical, pharmacological properties and toxicity of Elsholtzia, highlights the antibacterial, antiviral, and anti-inflammatory advantages of the genus, and explores its therapeutic potential.

MATERIALS AND METHODS

Use Google Scholar, Scifinder, PubMed, Springer, Elsevier, Wiley, Web of Science and other online database search to collect the research literatures on application, chemistry and biological activity of Elsholtzia published before December 2021. Their scientific names have been verified using The Plant List and World Flora Online websites.

RESULTS

A total of 42 species of Elsholtzia are widely distributed all over the world, especially in Yunnan Province (China). Since Elsholtzia genus is commonly used in the folk to treat respiratory infectious diseases such as cold and fever, growing numbers of studies have confirmed their antiviral, antibacterial and anti-inflammatory activities. So far, about 221 non-volatile compounds and 1008 volatile compounds have been identified from Elsholtzia plants, mainly containing flavonoids and terpenoids showing convincing antibacterial, antiviral and anti-inflammatory activities. Further research found that their antibacterial and antiviral spectrums are broad, and volatile oils are considered to be the main antibacterial components. Their anti-inflammatory mechanism is mainly through the inhibition of NF-κB and MAPKs signaling pathways. Toxicological studies have not established its toxicity.

CONCLUSIONS

By summarizing the latest information on genus Elsholtzia, their traditional uses, material basis and mechanisms of action in antiviral, antibacterial and anti-inflammatory aspects were described, providing new insights for the genus and its importance as a potential natural resource of antiviral and anti-inflammatory drugs, giving evidence and new ideas for the development of herbal medicines.

Antimicrobial activities and mechanisms of extract and components of herbs in East Asia

Antibacterial drugs face increasing challenges due to drug resistance and adverse reactions, which has created a pressing need for the discovery and development of novel antibacterial drugs. Herbs have played an important role in the treatment of infectious diseases. This review aims to summarize, analyze and evaluate the antibacterial activities and mechanisms of components from popular herbs in East Asia. In this review, we have searched and summarized the scientific papers published during the past twenty-year period from electronic databases such as PubMed, ScienceDirect, and Web of Science. These herbs and their components, including alkaloids, flavonoids, essential oils, terpenes, organic acids, coumarins and lignans, display potential antimicrobial effects. Herbal medicine formulas (HMFs) usually show stronger antibacterial activity than single herbs. Herbs and HMFs bring forth antibacterial activities by damaging cell membranes and walls, inhibiting nucleic acid and protein synthesis, and increasing intracellular osmotic pressure. These herbs and their components can be developed as potential and promising novel antibacterial herbal products.

GC-MS combined with multivariate analysis for the determination of the geographical origin of Elsholtzia rugulosa Hemsl. in Yunnan province

Elsholtzia rugulosa Hemsl., a Chinese herbal medicine, may have the potential to treat COVID-19. The geographical origin has a significant influence on the quality and application of E. rugulosa. In this paper, gas chromatography-mass spectrometry (GC-MS) combined with principal component analysis (PCA) and hierarchical cluster analysis (HCA) and other multivariate statistical analyses were performed for the identification of E. rugulosa. origins. The results showed that the volatile components of E. rugulosa. from different origins were significantly different. PCA and HCA can clearly distinguish the E. rugulosa of Lijiang and Fumin, and Dali and Yongsheng can be distinguished but with a certain overlap. The correlation of different components of was investigated by Pearson correlation. The results showed that E. rugulosa. characteristic component Elsholtzia ketone is regulated by terpenoid metabolism. The discriminant functions of different origins are constructed by Fisher stepwise discrimination, and its initial verification accuracy and leave-one-out cross-validation accuracy were 100% and 87.5%, respectively.

Elsholtzia rugulosa Hemsl., a Chinese herbal medicine, may have the potential to treat COVID-19, and its geographical origin has been successfully identified by GC-MS combined with multivariate analysis.

Elsholtzia rugulosa: Phytochemical Profile and Antioxidant, Anti-Alzheimer's Disease, Antidiabetic, Antibacterial, Cytotoxic and Hepatoprotective Activities

Elsholtzia rugulosa Hemsl., a species of the Labiatae family, has a long history of use as a honey plant, herbal tea, and folk medicine in China. However, little is known about its composition and biological activities. The present study aimed to investigate the total phenol and flavonoid contents, phytochemical composition, and multiple biological activities of this plant. The total flavonoid content of the ethyl acetate fraction (EAF) was higher than those of the petroleum ether fraction (PEF), n-butanol fraction (NBF), and water fraction (WF). The EAF also had much stronger antioxidant, cytotoxic, hepatoprotective, and acetylcholinesterase (AChE) and α-glucosidase inhibitory activities than the PEF, NBF, and WF. More importantly, the IC₅₀ values of the EAF and NBF against α-glucosidase were much lower than that of the positive control acarbose, indicating their potent α-glucosidase inhibitory activities. The isolation of the EAF led to the acquisition of 9 compounds, four of which (β-daucosterol, methyl rosmarinate, betulinic acid, and oleanolic acid) possessed significant α-glucosidase inhibitory activities. Maltol 6'-O-(5-O-p-coumaroyl)-β-D-apiofuranosyl-β-D-glucopyranoside and rosmarinic acid were the major phenolic compounds in the EAF according to the HPLC-DAD analysis. All these findings indicate that the EAF, NBF, and some isolated compounds have the potential to be developed as antidiabetic drugs. Moreover, the dual inhibition of AChE and butyrylcholinesterase (BChE) of certain fractions indicates their potential in the development of anti-Alzheimer's disease drugs. The present study provides a new understanding of the phytochemistry and bioactivity of E. rugulosa.

Chemical composition, antioxidant, and antimicrobial activity of Elsholtzia beddomei C. B. Clarke ex Hook. f. essential oil

The essential oil of Elsholtzia beddomei C. B. Clarke ex Hook. f. was investigated for its chemical composition and tested for antioxidant and antimicrobial activities. The E. beddomei essential oil was extracted using hydrodistillation for 4 h (yield of 1.38% w/w). Forty-three volatile compounds were identified in the E. beddomei essential oil, including linalool (83.67%), perillaldehyde (4.68%), neral (3.68%), perillene (1.65%), E-caryophyllene (1.55%), and α-zingiberene (1.06%) as the major compounds. The antioxidant activity of the E. beddomei essential oil was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical cation scavenging activity. The IC50 values calculated using the DPPH and ABTS methods were 148.31 and 172.22 µg/mL, respectively. In addition, using disc diffusion and broth microdilution methods, the antimicrobial activities of the E. beddomei essential oil against Escherichia coli, Pseudomonas aeruginosa, Enterobacter aerogenes, Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, and Candida albicans were evaluated. The E. beddomei essential oil possessed an inhibitory effect with the minimum inhibitory concentration in the range of 31.25-250.00 µg/mL among these pathogens. The results indicated that E. beddomei essential oil is an alternative raw material of food, and medicinal products for use in pharmaceutical applications.

Antimicrobial Activity of Polyphenols and Natural Polyphenolic Extracts on Clinical Isolates

Antibiotic resistance is a growing global problem that affects people, animals, the environment, and the economy. Many clinically relevant bacteria have become resistant to antibiotics, and this fact is emerging as one of the major threats to public health. The lack of new antibiotics, which is due to their time-consuming and costly development, exacerbates the problem. Therefore, it is necessary to identify new antimicrobial agents to treat bacterial and fungal infections. Plant extracts, which are valuable sources of bioactive compounds, mainly polyphenols, play an important role as a new strategy to combat pathogenic microorganisms. There is an extensive body of supporting evidence for the potent antibacterial and antifungal activities of polyphenols. Furthermore, some polyphenols show a synergistic effect when combined with antibiotics and antifungals, suggesting a promising alternative for therapeutic strategies against antibiotic resistance. However, only a few articles are found when searching the antibacterial or antifungal activities of polyphenols employing clinical isolates. Hence, this review focuses on the antimicrobial activity of polyphenols and extracts rich in polyphenols on clinical isolates, organized according to the World Health Organization priority pathogens classification.

Antimicrobial activities evaluation and phytochemical screening of some selected medicinal plants: A possible alternative in the treatment of multidrug-resistant microbes

BACKGROUND

Four out of five individuals rely on traditional medicine for their primary healthcare needs. Medicinal plants are endowed with diverse bioactive compounds to treat multidrug-resistant (MDR) microbes. So far, a less thorough examination has been made in this regard. This study aimed to evaluate antimicrobial activity and phytochemical screening of selected medicinal plants against MDR microbes.

METHODS

In vitro experimental study was carried out to evaluate antimicrobial effects and phytochemical screening of Rumex abyssinicus, Cucumis pustulatus, Discopodium penninervium, Lippia adoensis, Euphorbia depauperata, Cirsium englerianum, and Polysphaeria aethiopica against MDR bacteria and fungi. Aqueous and 80% methanolic extraction methods were employed for extraction. The susceptibility test, minimum inhibitory concentration, and minimum bactericidal or fungicidal concentration were measured using disc diffusion or broth micro-dilution as per the CLSI protocols.

RESULT

The 80% methanolic extraction method was a preferred method to aqueous. The phytochemical constituents identified were alkaloids, flavonoids, saponins, phenolic, tannins, terpenoidss, and cardiac glycosides. The hydroalcoholic extract demonstrated an appreciable antimicrobial role against MDR microbes with an MIC value of 1.0-128.0μg/ml and 11-29mm inhibition zone (IZ) in diameter. Extracts obtained from C. englerianum and E. depauperata showed a significant IZ ranged of 26-29mm on MRSA and Streptococcus pyogenes. MDR E. coli and K. pneumoniae showed 12-25mm and 23-28mm IZ in diameter, respectively. T. mentagraphytes was susceptible to all tested extracts. Moreover, S. pyogenes and K. pneumoniae were found the most susceptible bacteria to C. englerianum. Cirsium englerianum, L. adoensis, D. penninervium, and R. abyssinicus demonstrated remarkable antifungal effect against C. albicans and T. mentagrophytes, while R. abyssinicus showed the leading antifungal effect with 32 to 64μg/ml MIC values.

CONCLUSION

The plant extracts have shown appreciable antimicrobial activities comparable to the currently prescribed modern drugs tested. Accordingly, further studies on clinical efficacy trial, safety, toxicity and affordability analyses have to be instigated promptly, so as to head to the final step to synthesize precursor molecules for new effective antimicrobials.

Recent phytochemical and pharmacological advances in the genus Potentilla L. sensu lato - An update covering the period from 2009 to 2020

ETHNOPHARMACOLOGICAL RELEVANCE

Potentilla plants are still common herbal medicines used in folk medicine. This review provides an update of research undertaken on Potentilla from 2009 until 2020.

AIM OF THE STUDY

This comprehensive review considers biological updates, recent advances in phytochemical and pharmacological research, and toxicological reports on Potentilla sensu lato based on available data since 2009.

METHODS

A literature search was conducted using available databases including ScienceDirect, PubMed, Scopus, Web of Science, China National Knowledge Infrastructure and Google Scholar.

RESULTS

Until now, more than 210 new and known compounds, including flavonoids, tannins, triterpenes and phenolic compounds, have been confirmed and elucidated for numerous Potentilla species, i.e., in the underground and aerial parts of this genus. Modern pharmacology studies have revealed that those structures are responsible for a broad spectrum of pharmacological activities, such as anti-neoplastic, antihyperglycemic, anti-inflammatory, antioxidant, hepatoprotective, neuroprotective, antibacterial and anti-yeast effects.

CONCLUSIONS

However, in vitro studies must be re-considered due to the discovery of urolithins and their origins, including microbiota, which can lead to different results when applying Potentilla species and their extracts to in vivo conditions. Thus, future research should focus more on in vivo and particularly clinical studies to confirm the validity and safety of traditional uses. Particularly, the use of Potentilla alba extracts in the treatment of thyroid gland disorders should be further explored to confirm the underlying mechanism of their action, efficacy and safety. In addition, more clinical studies should focus on Potentilla erecta rhizome extracts for application as herbal remedies against dysentery, diarrhoea and inflammation of the skin.

Synergistic effects of anti-MRSA herbal extracts combined with antibiotics

MRSA is a super drug-resistant bacterium. Developing new drug or therapeutic strategies against MRSA is urgently needed. Increasing evidence has shown that herbal extracts and antibiotics can have synergistic effects against MRSA. This review focuses on commonly used antibiotics combined with herbal extracts against MRSA and the corresponding mechanisms. Through systematic analysis, we found that herbal extracts combined with antibiotics, such as β-lactams, quinolones, aminoglycosides, tetracyclines and glycopeptides, could greatly enhance the antibacterial effects of the antibiotics, reduce the dosage and toxic side effects, and reverse MRSA resistance. Therefore, we conclude that herbal extracts combined with antibiotics may be a promising strategy to combat MRSA. This review provides a novel idea for overcoming antibiotic resistance.

Bioactivity of the Geranium Genus: A Comprehensive Review

BACKGROUND

Plants from the Geranium genus, which comprises about 400 species, have been used since ancient times in the practice of traditional medicines throughout the world. Therefore, herbal preparations based on Geranium species have found wide usage for the treatment of a variety of ailments. The aim of this work is to present a review, as comprehensive as possible, of the studies concerning different biological activities of Geranium species.

METHODS

Relevant data were obtained through systematic computer searches from major reputed scientific databases, particularly Web of Science and Scopus. Occasionally, information issued in primary sources not covered by these databases was also included provided published as peer-reviewed literature. This review covers the literature disclosed till the end of 2018.

RESULTS

Accompanying the increasing interest in herbal medicines in general, the evaluation of the biological properties of medicinal plants from the Geranium genus has been addressed thoroughly, mostly over the last two decades. Geranium species are endowed with a number of different biological activities. Herein, we present a survey of the results of the studies concerning these different biological activities.

CONCLUSION

Most studies found in the literature effectively contribute to scientifically validate the beneficial properties of Geranium plants claimed by traditional medicines and medical herbalism and demonstrate that many of them possess evident therapeutic properties.

Comparison of In Vitro Antibacterial Activity of Epaltes divaricata and Vetiveria zizanioides against Methicillin-Resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus (MRSA) is a major cause of hospital- and community-acquired infections worldwide. Therefore, this study was conducted to explore the antibacterial activity of the two medicinal plants Epaltes divaricata and Vetiveria zizanioides against strains of MRSA which were isolated from patients with skin and soft tissue infections. Hexane, ethanol, and water extracts of E. divaricata (whole plant) and V. zizanioides (roots) were prepared. Clinical isolates of MRSA strains (n = 20) were used for the study. Bacterial susceptibility was tested using a disc diffusion assay. Minimum inhibitory concentration (MIC) was determined by a broth microdilution method. Vancomycin was used as the positive control. Hexane, ethanol, and water extracts of E. divaricata showed inhibitory zones against MRSA. Except for water extract, both hexane and ethanol extracts of V. zizanioides showed inhibitory zones. MIC ranges of hexane, ethanol, and water extracts in E. divaricata were 0.012-0.32 mg/mL, 0.019-2.4 mg/mL, and 0.019-0.48 mg/mL, respectively. Respective MIC ranges of hexane and ethanol extracts of V. zizanioides were 0.003-0.032 mg/mL and 0.019-2.4 mg/mL. The hexane extract of V. zizanioides inhibited 55% of the selected MRSA strains at a relatively low MIC value of 0.012 mg/mL. The hexane extract of both plants demonstrated inhibition of 75% of MRSA strains at a MIC value of 0.064 mg/mL. Ethanol extract of V. zizanioides and E. divaricata, respectively, inhibited 70% and 45% of MRSA strains at the MIC of 0.096 mg/mL, whereas water extract of E. divaricata inhibited 80% of MRSA strains at the same MIC. Both E. divaricata and V. zizanioides were equally effective against MRSA at a MIC of 0.064 mg/mL. But V. zizanioides was more effective since the hexane extract inhibited more than 50% of MRSA strains at significantly a lower MIC value of 0.012 mg/mL. Fractionation, purification, and identification of active compounds will warrant further evaluation of the therapeutic potential of both plant extracts.

Betulin and its derivatives as novel compounds with different pharmacological effects

Betulin (B) and Betulinic acid (BA) are natural pentacyclic lupane-structure triterpenoids which possess a wide range of pharmacological activities. Recent evidence indicates that B and BA have several properties useful for the treatment of metabolic disorders, infectious diseases, cardiovascular disorders, and neurological disorders. In the current review, we discuss B and BA structures and derivatives and then comprehensively explain their pharmacological effects in relation to various diseases. We also explain antiviral, antibacterial and anti-cancer effects of B and BA. Finally, we discuss the delivery methods, in which these compounds most effectively target different systems.

Antimicrobial Effects and Mechanisms of Ethanol Extracts of Psoralea corylifolia Seeds Against Listeria monocytogenes and Methicillin-Resistant Staphylococcus aureus

Psoralea corylifolia seeds contain many bioactive compounds commonly used in traditional Chinese medicine. In this study, the antibacterial activity and possible mechanism of P. corylifolia seed ethanol extract (PCEE) against foodborne pathogens were investigated. Both methicillin-resistant Staphylococcus aureus (MRSA) and Listeria monocytogenes had similar minimum inhibitory concentrations and minimum bactericidal concentrations of PCEE at 50 and 100 μg/mL, respectively. Furthermore, elevated OD₂₆₀, protein concentration, and electric conductivity indicated irreversible damage to the cytoplasmic membranes of PCEE-treated cells. Indeed, the treated cells displayed disrupted membranes, incomplete and deformed shapes, and rupture as visualized by scanning electron microscopy. Multidrug-resistance efflux pump gene expression was also analyzed by quantitative reverse transcription PCR. Although the mdrL, mdrT, and lde genes of L. monocytogenes and the mepA gene of MRSA were upregulated, there was no significant difference that indicated an attempt by the efflux pumps to discharge PCEE. MRSA norA expression and abcA expression were significantly downregulated (p < 0.05). A possible mechanism for PCEE may be to cause an energy depletion, either by inhibiting adenosine triphosphate binding or by disturbing the proton gradient, resulting in membrane damage.

Attributes of Polygonum multiflorum to transfigure red biotechnology

A vast array of plant-based compounds has enriched red biotechnology to serve the human health and food. A peculiar medicinal plant which was an element of traditional Chinese medicine for centuries as a liver and kidney tonic, for life longevity and hair blackening, is Polygonum multiflorum Thunb. (PM) which is popularly known as "He shou wu" or "Fo-ti" and is rich in chemical components like stilbenes, quinones, and flavonoids which have been used as anti-aging, anti-alopecia, anti-cancer, anti-oxidative, anti-bacterial, anti-hyperlipidemia, anti-atherosclerosis, and immunomodulating and hepatoprotective agents in the modern medicine. The health benefits from PM are attained since long through commercial products such as PM root powder, extract, capsules, tincture, shampoo, and body sprays in the market. Currently, the production of these pharmaceuticals and functional foods possessing stilbenes, quinones, and flavonoids is through cell and organ cultures to meet the commercial demand. However, hepatotoxic effects of PM-based products are the stumbling blocks for its long-term usage. The current review encompasses a comprehensive account of bioactive compounds of PM roots, their biological activities as well as efficacy and toxicity issues of PM ingredients and future perspectives.

Antimicrobial Effects of Egyptian Local Chicory, Cichorium endivia subsp. pumilum

The discovery of novel and more efficient antimicrobial agents from natural sources like plants is one of the most important ways through which the growing threat of antibiotic-resistant pathogens can be overcome. Herein, we report the potential antimicrobial activity of Cichorium endivia L. subsp. pumilum. Different concentrations of various solvent extracts prepared from several parts of chicory were tested for their antimicrobial effect against a panel of microorganisms. The antimicrobial activity was analyzed using the well diffusion method, where zones of inhibition were used as indicators of antimicrobial activity. The results indicated the superiority of seed extracts over both leaf and root extracts. Methanol extracts showed higher activity compared with chloroform and water extracts. Increased solvent extract concentration was accompanied by a parallel increase in the diameter of the inhibition zone. Gram-positive bacteria were found to be more sensitive than Gram-negative bacteria and fungi. On a whole, the highest observed inhibition zones (21.3 ± 0.6 and 20.1 ± 0.4 mm) were recorded with the methanolic extract of chicory seeds against S. aureus and B. cereus, respectively. These results offer insights into the antimicrobial potency of this Egyptian local plant and provide a basis for further phytochemical and pharmacological research.

Haplotype analysis of the germacrene A synthase gene and association with cynaropicrin content and biological activities in Cynara cardunculus

Cynara cardunculus: L. represents a natural source of terpenic compounds, with the predominant molecule being cynaropicrin. Cynaropicrin is gaining interest since it has been correlated to anti-hyperlipidaemia, antispasmodic and cytotoxicity activity against leukocyte cancer cells. The objective of this work was to screen a collection of C. cardunculus, from different origins, for new allelic variants in germacrene A synthase (GAS) gene involved in the cynaropicrin biosynthesis and correlate them with improved cynaropicrin content and biological activities. Using high-resolution melting, nine haplotypes were identified. The putative impact of the identified allelic variants in GAS protein was evaluated by bioinformatic tools and polymorphisms that putatively lead to protein conformational changes were described. Additionally, cynaropicrin and main pentacyclic triterpenes contents, and antithrombin, antimicrobial and antiproliferative activities were also determined in C. cardunculus leaf lipophilic-derived extracts. In this work we identified allelic variants with putative impact on GAS protein, which are significantly associated with cynaropicrin content and antiproliferative activity. The results obtained suggest that the identified polymorphisms should be explored as putative genetic markers correlated with biological properties in Cynara cardunculus.

Inhibition of Pseudomonas aeruginosa Biofilm Formation by Traditional Chinese Medicinal Herb Herba patriniae

New antimicrobial agents are urgently needed to treat infections caused by drug-resistant pathogens and by pathogens capable of persisting in biofilms. The aim of this study was to identify traditional Chinese herbs that could inhibit biofilm formation of Pseudomonas aeruginosa, an important human pathogen that causes serious and difficult-to-treat infections in humans. A luxCDABE-based reporter system was constructed to monitor the expression of six key biofilm-associated genes in P. aeruginosa. The reporters were used to screen a library of 36 herb extracts for inhibitory properties against these genes. The results obtained indicated that the extract of Herba patriniae displayed significant inhibitory effect on almost all of these biofilm-associated genes. Quantitative analysis showed that H. patriniae extract was able to significantly reduce the biofilm formation and dramatically altered the structure of the mature biofilms of P. aeruginosa. Further studies showed H. patriniae extract decreased exopolysaccharide production by P. aeruginosa and promoted its swarming motility, two features disparately associated with biofilm formation. These results provided a potential mechanism for the use of H. patriniae to treat bacterial infections by traditional Chinese medicines and revealed a promising candidate for exploration of new drugs against P. aeruginosa biofilm-associated infections.

Traditional uses of medicinal plants reported by the indigenous communities and local herbal practitioners of Bajaur Agency, Federally Administrated Tribal Areas, Pakistan

ETHNOPHARMACOLOGICAL RELEVANCE

In the study area, knowledge related to the traditional uses of medicinal plants is totally in the custody of elder community members and local herbalists. The younger generation is unaware of the traditional knowledge, however with only few exceptions. Therefore, this study was planned with objective to document the medicinal importance of plants, conserve this precious indigenous knowledge, and share it among other communities through published literature.

MATERIALS AND METHODS

Data was collected through semi-structured interviews from the community members and local herbalists. The reported plants were collected post interviews and later on pressed on herbarium vouchers for reference. Afterwards, the data was analyzed through Use value (UV) and Relative Frequency of Citation (RFC).

RESULTS

In total, 79 medicinal plant species were used for the treatment of different ailments in the study region. Out of the total plant species, 28 species were not reported from any other mountainous communities across the country. In this study, the ethno-medicinal value of Opuntia littoralis (Engelm.) Cockerell and Viola indica W.Becker was reported for the first time, which have moderate confidential level in terms of their medicinal uses in the study area. Important medicinal plants of the region with high UV are Berberis lycium Royle (0.94), V. indica (0.90), Isodon rugosus (Wall. ex Benth.) Codd (0.88), Foeniculum vulgare Mill. (0.87), Peganum harmala L (0.86), Solanum virginianum L. (0.85), and Cassia fistula L. (0.79). Medicinal plants with higher RFC values are Calotropis procera (Aiton) Dryand. (0.86), Cannabis sativa L. (0.82), Mentha piperita L. (0.82), Mentha longifolia (L.) Huds. (0.76), Allium sativum L. (0.73), Coriandrum sativum L. (0.73), and F. vulgare (0.72).

CONCLUSIONS

Traditional knowledge on folk medicines is directly linked to the local culture, faith and perception. This knowledge is gaining high threat of extinction because of its limitation to a small portion of the society in the region. Therefore, future studies are recommended in similar regions for the documentation of this precious knowledge. Moreover, our study has also identified some important and newly reported medicinal plants from the ethno-medicinal perspective, which needs to be studied pharmacologically and toxicologically.

Botanicals With Dermatologic Properties Derived From First Nations Healing: Part 1—Trees

Introduction:

First Nations people have a long history of working with medicinal plants used to treat skin diseases. The purpose was to assess the dermatologic therapeutic potential of western red cedar, white spruce, birch, balsam poplar, and black spruce.

Methods:

Based on expert recommendations, 5 trees were selected that were used in First Nations medicine for cutaneous healing and have potential and/or current application to dermatology today. We searched several databases up to June 12, 2014.

Results:

Western red cedar’s known active principal compound, β-thujaplicin, has been studied in atopic dermatitis. White spruce’s known active principal compound, 7-hydroxymatairesinol, has anti-inflammatory activity, while phase II clinical trials have been completed on a birch bark emulsion for the treatment of actinic keratoses, epidermolysis bullosa, and the healing of split thickness graft donor sites. Balsam poplar has been used clinically as an anti-aging remedy. Black spruce bark contains higher amounts of the anti-oxidant trans-resveratrol than red wine.

Discussion:

North American traditional medicine has identified important botanical agents that are potentially relevant to both cosmetic and medical dermatology. This study is limited by the lack of good quality evidence contributing to the review. The article is limited to 5 trees, a fraction of those used by First Nations with dermatological properties.

Synergism of coumarins from the Chinese drug Zanthoxylum nitidum with antibacterial agents against methicillin-resistant Staphylococcus aureus (MRSA)

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) poses a serious therapeutic challenge in current clinic and new drug development. Natural coumarins have diverse bioactivities and the potential of resistance modifying effects.

PURPOSE

This study is to present in-depth evaluations of in vitro antimicrobial activities of four natural coumarins 5-geranyloxy-7-methoxycoumarin (Gm, 1), (5,7-dimethoxy-8-prenyloxycoumarin (artanin, Ar, 2)), isopimpinellin (Is, 3) and phellopterin (Ph, 4) from Zanthoxylum nitidum (Roxb.) DC. (Rutaceae) extracts, focusing on their potential restoration the activity of conventional antibacterial agents against clinical MRSA strains.

METHODS

Bioactivity-guided fractionation and spectral analyses were used to isolate the coumarins and identify the structures, respectively. The double broth microdilution method was used to assay the coumarins' alone activity. The classic checkerboard microdilution and dynamic time-killing methods were used to evaluate combinatory effects.

RESULTS

The four plant coumarins Gm (1), Ar (2), Is (3) and Ph (4) were isolated and identified from Z. nitidum extracts. Coumarins 1-4 displayed promising inhibition against both MSSA and MRSA with minimal inhibitory concentrations (MICs) of 8-64µg/ml, but very weak against Gram-negative pathogen and yeast with MICs of 256 to ≥1024µg/ml. The geranyloxy and prenyloxy substitutions showed to be more active than the methoxy substitution on the coumarin skeletons. 1-4 also showing different extent of synergism with a total of eight conventional antibacterial agents, i.e. chloramphenicol (CL), gentamicin (CN), fosfomycin (FF), levofloxacin (LE), minocycline (MI), piperacillin/tazobactam (P/T), teicoplanin (TE) and vancomycin (VA) against ten clinical MRSA strains. Four to ten of the tested MRSA strains showed bacteriostatic synergy in the eleven combinations. The anti-MRSA modifying effects were related to different arrangement in the combinations with fractional inhibitory concentration indices (FICIs) from 0.187 to 1.125 and the three combinations CN (Is), CL (Ph) and MI (Gm) were the best ones. The enhancement of activity was also shown by 2-64 of dose reduction indices (DRIs) of the combined MICs, with VA (Ph) combination resulted the biggest DRI. The resistance of MRSA to antibacterial agents could be reversed in the combinations of CL (Gm or Ph), LE (Ph) and MI (Is) following the Clinical and Laboratory Standards Institute (CLSI) criteria. Six combinations P/T (Gm), TE (Ar), CN (Is), VA (Ph) and CL (Gm or Ph) also showed bactericidal synergy with Δlog₁₀CFU/ml >2 at 24h incubation.

CONCLUSIONS

The coumarins showed high potentiating effects of the antibacterial agents against multi-drug resistant SA. The resistance reversal effect of CL, LE and MI warrants further pharmacological investigation on combinatory therapy for the sake of fighting against MRSA infections.

Microbiological Assessment of Moringa Oleifera Extracts and Its Incorporation in Novel Dental Remedies against Some Oral Pathogens

AIM:

To assess the antibacterial and antifungal potentials of different parts of Moringa oleifera plant using different extraction methods in attempts to formulate natural dental remedies from this plant.

MATERIAL AND METHODS:

Three solvents extracts (Ethanol, acetone, and ethyl acetate) of different parts of Egyptian Moringa tree were prepared and tested against oral pathogens: Staphylococcus aureus, Streptococcus mutans, and Candida albicans using disc diffusion method; As well as to incorporate the plant extract to formulate experimental toothpaste and mouthwash. The two dental remedies were assessed against the same microbial strains. Statistical analysis was performed using One-Way ANOVA test to compare the inhibition zone diameter and t-test.

RESULTS:

Ethanol extracts as well as leaves extracts demonstrated the highest significant mean inhibition zone values (P ≤ 0.05) against Staphylococcus aureus and Streptococcus mutans growth. However, all extracts revealed no inhibition zone against Candida albicans. For dental remedies, experimental toothpaste exhibited higher mean inhibition than the mouthwash against Staphylococcus aureus, Streptococcus mutans and only the toothpaste revealed antifungal effect against Candida albicans.

CONCLUSION:

The different extracts of different parts of Moringa showed an antibacterial effect against Staphylococcus aureus and Streptococcus mutans growth. The novel toothpaste of ethanolic leaves extract has antimicrobial and antifungal potential effects all selected strains.

Potentiation activity of multiple antibacterial agents by Salvianolate from the Chinese medicine Danshen against methicillin-resistant Staphylococcus aureus (MRSA)

Salvianolate (SAL) is a prescribed medicine from the Chinese herb Danshen (Salvia miltiorrhiza Bunge). It has been widely used in treatment of coronary and other diseases with significant effects. The in vitro antimicrobial activities of SAL against infectious pathogens were assayed and its combined effects on 10 clinical isolates of SCCmec III type methicillin-resistant Staphylococcus aureus (MRSA) with ten antibiotics were evaluated. Susceptibility to each agent alone was tested using a broth microdilution method, and the chequerboard and time-kill experiments were used for the combined activities. The results showed MIC was 128-256 mg/L for SAL used alone against MRSA. Significant synergies were observed for SAL/Ampicillin (Fosfomycin, Erythromycin, Piperacillin-tazobactam or Clindamycin) combination against over half of the isolates, with their MICs reduced by times of dilution (TOD) to 4-32 (FICIs 0.375-0.5), respectively. SAL/AMP combination showed the best combined effect of synergy on bacteriostatic and bactericidal activities, while SAL/AMK combination reversed the resistance of MRSA to AMK. The results demonstrated that SAL enhanced widely the in vitro anti-MRSA efficacy of the ten antibacterial agents, which had potential for combinatory therapy of patients infected with MRSA and warrants further investigations.

Review of clinical studies of Polygonum multiflorum Thunb. and its isolated bioactive compounds

Polygonum multiflorum Thunb. (PMT), officially listed in the Chinese Pharmacopoeia, is one of the most popular perennial Chinese traditional medicines known as He shou wu in China and East Asia, and as Fo-ti in North America. Mounting pharmacological studies have stressed out its key benefice for the treatment of various diseases and medical conditions such as liver injury, cancer, diabetes, alopecia, atherosclerosis, and neurodegenerative diseases as well. International databases such as PubMed/Medline, Science citation Index and Google Scholar were searched for clinical studies recently published on P. multiflorum. Various clinical studies published articles were retrieved, providing information relevant to pharmacokinetics-pharmacodynamics analysis, sleep disorders, dyslipidemia treatment, and neurodegenerative diseases. This review is an effort to update the clinical picture of investigations ever carried on PMT and/or its isolated bio-compounds and to enlighten its therapeutic assessment.

Antibacterial activity of native California medicinal plant extracts isolated from Rhamnus californica and Umbellularia californica

Background

Antimicrobial resistance (AMR) is a major threat to global public health. Medicinal plants have long been used as remedies for infectious diseases by native cultures around the world and have the potential for providing effective treatments for antibiotic-resistant infections. Rhamnus californica (Rhamnaceae) and Umbellularia californica (Lauraceae) are two indigenous California plant species historically used by Native Americans to treat skin, respiratory and gastrointestinal infections. This study aimed to assess the in vitro antimicrobial activity of methanolic extracts of leaves and bark of R. and U. californica against methicillin-resistant Staphylococcus aureus (MRSA) and other Gram-positive and Gram-negative bacteria.

Methods

Methanolic extracts of leaves and bark of R. and U. californica were prepared by soxhlet extraction and evaluated for their antimicrobial activity against Bacillus cereus, Streptococcus pyogenes, Mycobacterium smegmatis, Staphylococcus aureus, MRSA, Escherichia coli and Pseudomonas aeruginosa using disc diffusion and minimal inhibitory concentration (MIC) assays. Chemical profiling of the extracts was performed using standard methods.

Results

All extracts inhibited the growth of MRSA and other Gram-positive bacteria with MICs of 3.3-6.0 mg/ml. Gram-negative organisms were unaffected by these extracts. U. californica extracts (leaves and bark) had the lowest MIC values. Chemical profiling detected the presence of quinones, alkaloids, flavonoids, cardenolides, tannins and saponins in these extracts. Our study is the first to report the antimicrobial properties of R. and U. californica and illustrates their promising anti-MRSA potential.

Conclusions

Our results give scientific credence to the traditional medicinal uses of these plants by the indigenous peoples of California. Further investigation of the secondary metabolites responsible for the antimicrobial activity of these extracts against MRSA is warranted.

Antimicrobial activity and synergy of antibiotics with two biphenyl compounds, protosappanins A and B from Sappan Lignum against methicillin-resistant Staphylococcus aureus strains

OBJECTIVES

This study aims to investigate antimicrobial ingredients from Sappan Lignum and to evaluate their synergy on methicillin-resistant Staphylococcus aureus strains with antibiotics.

METHODS

Bioactivity-guided phytochemical procedures were used to screen the active compounds. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) were assayed by broth microdilution. The synergy was evaluated through checkerboard microdilution and loss of viability assays.

KEY FINDINGS

Protosappanins A (PsA) and B (PsB) were identified from Sappan Lignum extracts. They showed active against both S. aureus and MRSA with MIC or MIC50 at 64 (PsA) and 128 (PsB) mg/L alone. When they were used in combination with antibiotics, they showed best synergy with amikacin and gentamicin with MIC50 (mg/L) of amikacin reduced more significantly from 32 to four (with PsA) and eight (with PsB), and the fractional inhibitory concentration index (FICI) ranged between 0.078 and 0.500 (FICI50  = 0.375). Moreover, the resistance of MRSA towards amikacin and gentamicin could be reversed by the Clinical and Laboratory Standards Institute criteria. The combined bactericidal mode could as well be synergy. PsA and PsB showed very low cytotoxicity in comparison with their promising activity against MRSA.

CONCLUSIONS

Protosappanins A and B showed both alone activities and resistance reversal effects of amikacin and gentamicin against MRSA, which warrant further investigations for potential combinatory therapy of MRSA infection.

Bio-synthesis of silver nanoparticles using Potentilla fulgens Wall. ex Hook. and its therapeutic evaluation as anticancer and antimicrobial agent

The present study aims to develop an easy and eco-friendly method for the synthesis of silver nanoparticles using extracts from the medicinal plant, Potentilla fulgens and evaluation of its anticancer and antimicrobial properties. The various parts of P. fulgens were screened and the root extract was found to have the highest potential for the synthesis of nanoparticles. The root extracts were able to quickly reduce Ag(+) to Ag(0) and stabilized the nanoparticles. The synthesis of nanoparticles was confirmed by UV-Visible spectrophotometry and further characterized using Zeta sizer, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD). Electron microscopic study showed that the size of the nanoparticle was in the range of 10 to 15 nm and spherical in shape. The studies of phytochemical analysis of nanoparticles indicated that the adsorbed components on the surface of nanoparticles were mainly flavonoid in nature. Furthermore, nanoparticles were evaluated as cytotoxic against various cancer cell lines and 0.2 to 12 μg/mL nanoparticles showed good toxicity. The IC50 value of nanoparticles was found to be 4.91 and 8.23 μg/mL against MCF-7 and U-87 cell lines, respectively. Additionally, the apoptotic effect of synthesized nanoparticles on normal and cancer cells was studied using trypan blue assay and flow-cytometric analysis. The results indicate the synthesized nanoparticle ability to kill cancer cells compared to normal cells. The nanoparticles also exhibited comparable antimicrobial activity against both Gram-positive and Gram-negative bacteria.

Emodin induces neurite outgrowth through PI3K/Akt/GSK-3β-mediated signaling pathways in Neuro2a cells

In this study, a neurite outgrowth-inducing substance was isolated from the ethylacetate extract of the Polygonum multiflorum roots and identified as emodin by gas-liquid chromatography-mass spectrometry and (1)H NMR and (13)C NMR. Emodin displayed remarkable neurite outgrowth-inducing activity in Neuro2a cells, as demonstrated by morphological changes and immunocytochemistry for class III β-tubulin. Emodin exhibited a stronger neutrophic activity than retinoic acid (RA) known as inducer of neurite outgrowth in Neuro2a cells. Emodin treatment resulted in marked increases in phosphorylation of Akt a direct downstream signaling molecule of phosphatidylinositol 3-kinase (PI3K), but upstream of glycogen synthase kinase-3β (GSK-3β) and cAMP response element-binding protein (CREB). These augmentations and neurite-bearing cells induced by emodin were remarkably reduced by the addition of PI3K inhibitor LY294002. These results demonstrate that emodin induces neuronal differentiation of Neuro2a cells via PI3K/Akt/GSK-3β pathway.

Study of the anti-MRSA activity of Rhizoma coptidis by chemical fingerprinting and broth microdilution methods

AIM

Methicillin-resistant Staphylococcus aureus (MRSA) is a pathogenic bacterium that causes both hospital- and community-acquired infections, and for which single-drug treatments are becoming less efficient. Rhizoma coptidis has been used for more than two thousand years in China to treat diarrhea, fever, and jaundice. In this study, the anti-MRSA activity of Rhizoma coptidis is examined and its effective components sought.

METHODS

The mecA and norA genes were determined by PCR amplification and sequencing. Drug susceptibility of Staphylococcus aureus ATCC43300 was performed using the VITEK2 compact system. The chemical fingerprint of Rhizoma coptidis was investigated using HPLC and preparative liquid chromatography, and the anti-MRSA activity was determined using an improved broth microdilution method.

RESULTS

The drug susceptibility test revealed that the penicillin-binding protein phenotype of the strain changed in comparison to penicillin-sensitive Staphylococcus aureus. Ten batches of Rhizoma coptidis showed anti-MRSA activity on the norA-negative Staphylococcus aureus strain, as well as the strain that contained a norA gene. The spectrum-effect relationship revealed that the berberine alkaloids were the effective components, within which berberine, coptisine, palmatine, epiberberine, and jatrorrhizine were the major components.

CONCLUSION

This study lays a foundation for in vivo studies of Rhizoma coptidis and for the development of multi-component drugs.

Studies of the in vitro antibacterial activities of several polyphenols against clinical isolates of methicillin-resistant Staphylococcus aureus

In this study, we report the antibacterial activities of six polyphenols (i.e., luteolin, quercetin, scutellarin, apigenin, chlorogenic acid, and resveratrol) against 29 clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA), and in vitro antibacterial activities of two-drug combinations. All of the MRSA strains evaluated were clinical isolates from patients with MRSA bacteremia. The antibacterial activities were determined by agar dilution method, and the two-drug antibacterial activities were determined by the checkerboard agar dilution method. It was found that luteolin, quercetin and resveratrol show obvious antibacterial activities against MRSA, and the results of two-drug antibacterial activity show either synergy or additivity, without evidences of antagonistic effects.

Synergy of aminoglycoside antibiotics by 3-Benzylchroman derivatives from the Chinese drug Caesalpinia sappan against clinical methicillin-resistant Staphylococcus aureus (MRSA)

The in vitro antimicrobial activities of three 3-Benzylchroman derivatives, i.e. Brazilin (1), Brazilein (2) and Sappanone B (3) from Caesalpinia sappan L. (Leguminosae) were assayed, which mainly dealt with synergistic evaluation of aminoglycoside and other type of antibiotics against methicillin-resistant Staphylococcus aureus (MRSA) by the three compounds through the Chequerboard and Time-kill curve methods. The results showed that Compounds 1-3 alone exhibited moderate to weak activity against methicillin-susceptible S. aureus (MSSA) and other standard strains by MICs/MBCs ranged from 32/64 to >1024/>1024 μg/ml, with the order of activity as 1>2>3. Chequerboard method showed significant anti-MRSA synergy of 1/Aminoglycosides (Gentamicin, Amikacin, Etimicin and Streptomycin) combinations with (FICIs)50 at 0.375-0.5. The combined (MICs)50 values (μg/ml) reduced from 32-128/16-64 to 4-8/4-16, respectively. The percent of reduction by MICs ranged from 50% to 87.5%, with a maximum of 93.8% (1/16 of the alone MIC). Combinations of 2 and 3 with Aminoglycosides and the other antibiotics showed less potency of synergy. The dynamic Time-killing experiment further demonstrated that the combinations of 1/aminoglycoside were synergistically bactericidal against MRSA. The anti-MRSA synergy results of the bacteriostatic (Chequerboard method) and bactericidal (time-kill method) efficiencies of 1/Aminoglycoside combinations was in good consistency, which made the resistance reversed by CLSI guidelines. We concluded that the 3-Benzylchroman derivative Brazilin (1) showed in vitro synergy of bactericidal activities against MRSA when combined with Aminoglycosides, which might be beneficial for combinatory therapy of MRSA infection.

Potential protection of 2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucoside against staurosporine-induced toxicity on cultured rat hippocampus neurons

The present study explored the effect of 2,3,5,4'-tetrahydroxystilbene-2-O-β-d-glucoside (THSG) on the staurosporine (STS)-induced toxicity in cultured rat hippocampal neurons. The results showed that administration of 200μM of THSG significantly protected against 0.3μM of STS-induced apoptosis in cultured rat hippocampal neurons tested by methyl thiazolyl tetrazolium (MTT) and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assays. Furthermore, when the Akt signaling pathway was blocked by LY294002, an inhibitor of Phosphatidyl Inositol 3-kinase (PI3K), the protective effects of THSG against STS-induced neurotoxicity were abrogated. We further examined the involvement of PI3K/Akt signaling pathway in THSG protection against STS-induced cytotoxicity on cultured neurons and found that administration of THSG significantly inhibited the STS-induced decreases in the content of phosphorylated AKt (p-Akt). Moreover, we found that THSG rescued the down-regulation of B cell lymphoma/lewkmia-2 (Bcl2) and pro-caspase-3 (pro-Csp3) caused by STS in the neurons. These results indicate that THSG protect the cultured rat hippocampal neurons against STS-induced cytotoxicity and the PI3K/Akt signaling and mitochondrial apoptotic pathways are involved in the THSG-induced protective effects.

Ethnobotanical survey of medicinally important wild edible fruits species used by tribal communities of Lesser Himalayas-Pakistan

ETHNOPHARMACOLOGICAL RELEVANCE

Present survey was conducted to explore ethnomedicinal uses and cultural importance of wild edible fruits species by the inhabitants of Lesser Himalayas-Pakistan.

MATERIALS AND METHODS

Information was obtained through informed consent semi-structured interviews, questionnaires, market survey, focus group conversation, unceremonious dialogue and village walks with key informants. Cultural significance of each species was calculated based on use report by participants at each study site.

RESULTS

A total of 35 wild edible fruits belonging to 21 genera and 17 families were used for the treatment of various ailments and consumed. Rosaceae was found dominating family with (8 spp.), followed by Moraceae (6 spp.), Rhamnaceae (5 spp.), Palmae and Vitaceae (2 spp. each) and remaining families were represented by one species each. Fruits (48%) were found highly utilized plant parts, followed by leaves (34%), bark, flowers and seeds (4% each), branches, latex and roots (2% each). Water was used as a medium for preparation while milk, ghee, oil, egg and butter are used for application. Modes of preparation were fall into seven categories like fresh parts eaten raw (38%), powder (24%), decoction (20%), extract (12 %), paste (4%), juice and latex (2% each). Based on cultural important index (CI) Morus nigra was found most significant species within top ten fruit plants followed by Morus alba, Olea ferruginea, Berberis lycium, Pyrus pashia, Ficus carica, Ficus palmata, Ziziphus mauritiana, Diospyros lotus and Ziziphus nummularia.

CONCLUSIONS

Traditional uses of wild edible plant depend mainly on socio-economic factors rather than climatic conditions or wealth of flora. Use reports and citation demonstrated that there is a common cultural heritage regarding the gathered food plants. Further investigation is required for Antioxidant study, essential and toxic components, pharmacological applications; dietary requirements and biotechnological techniques to improve yields.

Multicomponent therapeutics of berberine alkaloids

Although berberine alkaloids (BAs) are reported to be with broad-spectrum antibacterial and antiviral activities, the interactions among BAs have not been elucidated. In the present study, methicillin-resistant Staphylococcus aureus (MRSA) was chosen as a model organism, and modified broth microdilution was applied for the determination of the fluorescence absorption values to calculate the anti-MRSA activity of BAs. We have initiated four steps to seek the optimal combination of BAs that are (1) determining the anti-MRSA activity of single BA, (2) investigating the two-component combination to clarify the interactions among BAs by checkerboard assay, (3) investigating the multicomponent combination to determine the optimal ratio by quadratic rotation-orthogonal combination design, and (4) in vivo and in vitro validation of the optimal combination. The results showed that the interactions among BAs are related to their concentrations. The synergetic combinations included “berberine and epiberberine,” “jatrorrhizine and palmatine” and “jatrorrhizine and coptisine”; the antagonistic combinations included “coptisine and epiberberine”. The optimal combination was berberine : coptisine : jatrorrhizine : palmatine : epiberberine = 0.702 : 0.863 : 1 : 0.491 : 0.526, and the potency of the optimal combination on cyclophosphamide-immunocompromised mouse model was better than the natural combinations of herbs containing BAs.

Elsholtzia: phytochemistry and biological activities

Plants of the genus Elsholtzia (Lamiaceae) have a long history of medicinal use in folk. The phytochemical investigations revealed the presence of flavonoids, phenylpropanoids, terpenoids, and other compounds. Abundant volatile components are also identified. Pure compounds, volatile constituents and crude extracts from the genus exhibited a wide spectrum of in vitro and in vivo pharmacological activities. The aims of this review hopefully provide comprehensive information on the distribution, phytochemistry, volatile components, and pharmacological research of Elsholtzia for exploring the potential and advance researches.

Antibacterial and synergy of berberines with antibacterial agents against clinical multi-drug resistant isolates of methicillin-resistant Staphylococcus aureus (MRSA)

Antibacterial activity of berberine (Ber) and 8-acetonyl-dihydroberberine (A-Ber) alone and combined uses with antibacterial agents ampicillin (AMP), azithromycin (AZM), cefazolin (CFZ) and levofloxacin (LEV) was studied on 10 clinical isolates of SCCmec III type methicillin-resistant Staphylococcus aureus (MRSA). Susceptibility to each agent alone was tested using a broth microdilution method and the chequerboard and time-kill tests for the combined evaluations, respectively. The alone MICs/MBCs (μg/mL) ranges were 32–128/64–256 (Ber) and 32-128/128-512 (A-Ber). Significant synergies were observed for the Ber (A-Ber)/AZM and Ber (A-Ber)/LEV combinations against 90% of the tested MRSA strains, with fractional inhibitory concentration indices (FICIs) values ranged from 0.188 to 0.500. An additivity result was also observed for the Ber/AZM combination by time-kill curves. These results demonstrated for the first time that Ber and A-Ber enhanced the in vitro inhibitory efficacy of AZM and LEV to a same extent, which had potential for further investigation in combinatory therapeutic applications of patients infected with MRSA.

Isojacareubin from the Chinese herb Hypericum japonicum: potent antibacterial and synergistic effects on clinical methicillin-resistant Staphylococcus aureus (MRSA)

Through bioassay-guided fractionation of the extracts from the aerial parts of the Chinese herb Hypericum japonicum Thunb. Murray, Isojacareubin (ISJ) was characterized as a potent antibacterial compound against the clinical methicillin-resistant Staphylococcus aureus (MRSA). The broth microdilution assay was used to determine the minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs) of ISJ alone. The results showed that its MICs/MBCs ranged from 4/16 to 16/64 μg/mL, with the concentrations required to inhibit or kill 50% of the strains (MIC₅₀/MBC₅₀) at 8/16 μg/mL. Synergistic evaluations of this compound with four conventional antibacterial agents representing different types were performed by the chequerboard and time-kill tests. The chequerboard method showed significant synergy effects when ISJ was combined with Ceftazidime (CAZ), Levofloxacin (LEV) and Ampicillin (AMP), with the values of 50% of the fractional inhibitory concentration indices (FICI₅₀) at 0.25, 0.37 and 0.37, respectively. Combined bactericidal activities were also observed in the time-kill dynamic assay. The results showed the ability of ISJ to reduce MRSA viable counts by log₁₀CFU/mL at 24 h of incubation at a concentration of 1 × MIC were 1.5 (LEV, additivity), 0.92 (CAZ, indifference) and 0.82 (AMP, indifference), respectively. These in vitro anti-MRSA activities of ISJ alone and its synergy with conventional antibacterial agents demonstrated that ISJ enhanced their efficacy, which is of potential use for single and combinatory therapy of patients infected with MRSA.

Investigations of antimicrobial activity of some Cameroonian medicinal plant extracts against bacteria and yeast with gastrointestinal relevance

ETHNOPHARMACOLOGICAL RELEVANCE

Resistance against antibiotics of many bacteria is accumulating. Therefore, searches for new substances with antimicrobial activity have become an urgent necessity. Medicinal plants are frequently used in popular medicine as remedies for many infectious diseases (intestinal infection, malaria, tuberculosis, etc.).

AIM OF THE STUDY

This study aimed to determine the in vitro antimicrobial activity of hexane, ethyl acetate and methanol extracts from different parts (leaves, stem bark, entire plant) of five different plant species against bacteria and yeast of gastrointestinal relevance.

MATERIAL AND METHODS

Twenty-one extracts from all the following plants (Albizia gummifera (leaf), Ficus exasperata (leaf and stem bark), Nauclea latifolia (leaf and stem bark), Ricinodendron heudelotii (stem bark), Senna hirsuta (entire plant) have been screened for their antimicrobial activity against eight bacteria species including Gram-positive bacteria (Staphylococcus aureus and Bacillus cereus), Gram-negative bacteria (Escherichia coli, Shigella dysenteriae, Shigella flexneri, Salmonella typhi, Pseudomonas aeruginosa, and Klebsiella pneumoniae) and one yeast species (Candida albicans) using agar disc-diffusion, and microbroth dilution assays.

RESULTS

Results demonstrated that F. exasperata and N. latifolia were active against the whole set of tested microorganisms. The methanol extract of N. latifolia (leaf and stem bark) was the most active against against C. albicans, E. coli, S. aureus, P. aeruginosa with a minimum inhibitory concentration (MIC) of 2, 32, 64 and 64 μg/ml, respectively. The methanol extract of leaf of F. exasperata was also most active with significant inhibitory activity against E. coli, S. dysenteriae, S. Typhi and P. aeruginosa with MIC values of 128 μg/ml. Only the extract of N. latifolia (stem bark and leaf) showed anticandidal property.

CONCLUSION

The results show that these plant extracts exhibit antimicrobial activity and N. latifolia proved to be most effective as an antibacterial and antifungal.

Total alkaloids from Sophora alopecuroides L. increase susceptibility of extended-spectrum β-lactamases producing Escherichia coli isolates to cefotaxime and ceftazidime

OBJECTIVE

To evaluate the antimicrobial activity of total alkaloids extracted from Sophorea alopecuroides L. (TASA) against clinical isolated extended-spectrum beta-lactamases (ESBLs) producing Escherichia coli (E. coli) strains.

METHODS

The antibacterial activity of TASA either itself or in combination with cefotaxime (CTX) or ceftazidime (CAZ) was investigated by using the microbroth dilution method and phenotypic confirmatory disk diffusion test against three clinical isolated ESBLs-producing E. coli strains; the interactions of TASA and CTX or CAZ were ascertained by evaluating the fractional inhibitory concentration index (FICI).

RESULTS

The antibacterial activity of either TASA itself or in combination with CTX or CAZ was found. The minimum inhibitory concentration (MICs) of TASA against the ESBLs producing isolates was 12.5 mg/mL. In the combinations with a sub-inhibitory concentration of TASA, a synergistic effect on CTX and CAZ against the ESBLs producing isolates was observed. Similarly, the isolates exposed to lower dose of TASA yielded an increased susceptibility to CTX and CAZ by 8-16 folds determined by microdilution assay. Moreover, enzymatic detection of ESBLs demonstrated that TASA induced reversal resistance to CTX and CAZ partially by a mechanism of inhibition of ESBLs activity in these isolates. Additionally, in the tested isolates following the exposure of TASA, molecular analysis verified the SHV-type beta-lactamase encoding ESBL gene in these isolates, and no mutation was introduced into the ESBL gene.

CONCLUSIONS

These results suggest that TASA could be used as a source of natural compound with pharmacological activity of reversal resistance to antimicrobial agent. These findings also indicated that the application of the TASA in combination with antibiotics might prove useful in the control and treatment of infectious diseases caused by the ESBLs producing enterobacteriaceae.

Evaluation of traditional Chinese medicinal plants for anti-MRSA activity with reference to the treatment record of infectious diseases

The in vitro antimicrobial activities of 30 Chinese medicinal plants were evaluated with reference to the treatment record of infectious diseases in the Traditional Chinese Medicine (TCM) literature. The plant materials were extracted with 80% ethanol and the extracts were primarily screened against conventional clinical pathogens like Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans by the agar diffusion method. Their inhibition zone diameters (IZDs, mm, 50 mg/mL) ranged from <8 to 24. The 21 extracts which showed IZDs ≥10 mm against MSSA were also active against methicillin-resistant S. aureus (MRSA) with lower IZDs of 9.0–18.8 mm. They were further subjected to minimal inhibitory concentration and minimal bactericidal concentration (MIC/MBC, μG/mL) assays, which were 8-2,048/32->2,048 by the standard broth microdilution method. The seven extracts from M. yunnanensis, S. sinensis, G. morella, E. daneillii, M. squamulata, S. arborescens and B. hancei were determined as the most active extracts, with MICs of 8–64 μg/mL. The results were in good agreement with their traditional applications in skin and other infections.