Antimicrobial constituents of Rhus glabra

Three complete chloroplast genomes from two north American Rhus species and phylogenomics of Anacardiaceae

BACKGROUND

The suamc genus Rhus (sensu stricto) includes two subgenera, Lobadium (ca. 25 spp.) and Rhus (ca. 10 spp.). Their members, R. glabra and R. typhina (Rosanae: Sapindales: Anacardiaceae), are two economic important species. Chloroplast genome information is of great significance for the study of plant phylogeny and taxonomy.

RESULTS

The three complete chloroplast genomes from two Rhus glabra and one R. typhina accessions were obtained with a total of each about 159k bp in length including a large single-copy region (LSC, about 88k bp), a small single-copy regions (SSC, about 19k bp) and a pair of inverted repeats regions (IRa/IRb, about 26k bp), to form a canonical quadripartite structure. Each genome contained 88 protein-coding genes, 37 transfer RNA genes, eight ribosomal RNA genes and two pseudogenes. The overall GC content of the three genomes all were same (37.8%), and RSCU values showed that they all had the same codon prefers, i.e., to use codon ended with A/U (93%) except termination codon. Three variable hotspots, i.e., ycf4-cemA, ndhF-rpl32-trnL and ccsA-ndhD, and a total of 152-156 simple sequence repeats (SSR) were identified. The nonsynonymous (Ka)/synonymous (Ks) ratio was calculated, and cemA and ycf2 genes are important indicators of gene evolution. The phylogenetic analyses of the family Anacardiaceae showed that the eight genera were grouped into three clusters, and supported the monophyly of the subfamilies and all the genera. The accessions of five Rhus species formed four clusters, while, one individual of R. typhina grouped with the R. glabra accessions instead of clustering into the two other individuals of R. typhina in the subgenus Rhus, which showed a paraphyletic relationship.

CONCLUSIONS

Comparing the complete chloroplast genomes of the Rhus species, it was found that most SSRs were A/T rich and located in the intergenic spacer, and the nucleotide divergence exhibited higher levels in the non-coding region than in the coding region. The Ka/Ks ratio of cemA gene was > 1 for species collected in America, while it was < 1 for other species in China, which dedicated that the Rhus species from North America and East Asia have different evolutionary pressure. The phylogenetic analysis of the complete chloroplast genome clarified the Rhus placement and relationship. The results obtained in this study are expected to provide valuable genetic resources to perform species identification, molecular breeding, and intraspecific diversity of the Rhus species.

Bioassay-guided isolation and characterization of lead antimicrobial compounds from Acacia hydaspica plant extract

Acacia hydaspica possesses varied pharmacological attributes. We aimed to examine the antimicrobial potential and isolate the active antimicrobial metabolites. The plant extract was fractionated and the antimicrobial activity of the crude extract, fractions and compounds was tested by agar well diffusion and agar tube dilution and broth dilution methods. Bacterial strains selected for bioactivity testing were Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Acinetobacter baumannii while selected strains from kingdom fungi were Candida albicans, Cryptococcus neoformans, Fusarium solani and Aspergillus. The active compounds were isolated from Acacia hydaspica by bioassay-guided fractionation and identified by nuclear magnetic resonance and spectroscopic techniques. S. aureus cell surface proteins, Autolysins (Atl), Clumping factor A (ClfA), and Fibronectin Binding Proteins (FnBP), were molecularly docked with Catechin 3-O-gallate (CG) and Methyl gallate (MG) and binding energy and molecular interactions between the proteins and compounds were analyzed. Ethyl acetate (AHE) and Butanol (AHB) fractions of A. hydaspica were the most active fractions against tested microbial strains. Therefore, both were subjected to bioassay-directed fractionation which led to the isolation of one pure active antimicrobial AHE and one active pure compound from AHB fraction besides active enriched isolates. Methyl-gallate (MG) and catechin-3-gallate (CG) are active compounds extracted from AHE and AHB fractions respectively. In antibacterial testing MG significantly inhibited the growth of E. coli (MIC₅₀ = 21.5 µg/ml), B. subtilus (MIC₅₀ = 23 µg/ml) and S. aureus (MIC₅₀ = 39.1 µg/ml) while moderate to low activity was noticed against other tested bacterial strains. Antifungal testing reveals that MG showed potent antifungal activity against F. solani (MIC₅₀ = 33.9 µg/ml) and A. niger (MIC₅₀ = 41.5 µg/ml) while lower antifungal activity was seen in other tested strains. AHB fractions and pure compound (CG) showed specific antibacterial activity against S. aureus only (MIC₅₀ = 10.1 µg/ml) while compound and enriched fractions showed moderate to no activity against other bacterial and fungal strains respectively. Molecular docking analysis revealed that CG interacted more strongly with the cell surface proteins than MG. Among these proteins, CG made a stronger complex with ClfA (binding affinity - 9.7) with nine hydrophobic interactions and five hydrogen bonds. Methyl gallate (MG) and catechin 3-O-gallate (CG) are the major antimicrobial compound from A. hydaspica that inhibit the growth of specific microbes. The occurrence of MG and CG endorse the traditional antimicrobial applicability of A. hydaspica, and it can be a legitimate alternative to control specific microbial infections.

Dry powder inhalation, part 1: ancient history and precursors to modern dry powder inhalers

INTRODUCTION

Inhalation of herbs and other compounds has a long history but habits for medical treatment are intertwined with rituals to obtain hallucinatory effects and pleasurable sensations. Several examples of inhaled herbs, and the diseases they were used for, based on early translations of ancient manuscripts related to inhalation were found to be speculative and inconsistent with each other in literature. They needed to be reconsidered and verified with the original sources of information.

AREAS COVERED

Examples of ancient inhalation and the development of early dry powder inhalers up to and including the first half of the twentieth century. Databases used for literature about historic events, ancient habits, and ancient science, included SmartCat, JSTOR, and ANDAT; various facts were verified via personal communication with historians and custodians of historic manuscripts and artifacts.

EXPERT OPINION

Inhalation does not necessarily require active creation of inhalable aerosols, smokes or fumes. Inhaling 'healthy air' with volatile and gaseous components, or fine aerosols in pine forests, on volcano slopes and at the seaside must be considered as inhalation therapy too. From this viewpoint, inhalation therapy may have been much more common and widespread and have a longer history than is currently known from written evidence.

A new ent-clerodane diterpene from Detarium microcarpum Guill. & Perr. and its protective potential for osteoporosis

A new clerodane diterpene, named 6α-hydroxy-3,13E-clerodien-15-oic acid (1), together with a known clerodane diterpene (2), four known labdane diterpenes (3-6), a triterpenoid (7), a known steroid (8), and two benzenoid compounds (9 and 10) were isolated from Detarium microcarpum Guill. & Perr. The structures of all obtained compounds were determined by chemical properties and spectroscopic evidence, accompanied by comparisons with data in the literature. Electronic circular dichroism (ECD) was performed for compounds 1-4 to confirm the absolute configuration. Compounds 1-3 and 8-10 were evaluated for the protective effect on osteoblasts. Compound 1 was observed to increase the proliferation of dexamethasone (DEX)-treated MC3T3-E1 cells significantly at 1 μM, which was comparable with the positive control geniposide at 10 μM. The results were further confirmed by flow cytometry analysis. In addition, compound 1 increased the level of alkaline phosphatase (ALP) and mineralization in osteoblasts inhibited by DEX. Moreover, Compound 9 (vanillic acid) showed a pronounced inhibition (IC₅₀ 6.5 ± 0.6 μM) on reactive oxygen species (ROS) production, and 10 (4-O-methyl gallic acid) showed a good inhibition with IC₅₀ as 103.3 ± 2.2 μM, compared with the standard drug ibuprofen (IC₅₀ 54.2 ± 9.2 μM). Besides, compounds 1-3 and 8-10 were non-cytotoxic against MCF-7, NCI-H460, Hela, and BJ cell lines.

Exhaustive Plant Profile of “Dimocarpus longan Lour” with Significant Phytomedicinal Properties: A Literature Based-Review

Background: “Dimocarpus longan Lour” is a tropical and subtropical evergreen tree species mainly found in China, India, and Thailand; this plant, found naturally in Bangladesh, even locally, is used as “kaviraj” medication for treating different diseases, such as gastrointestinal disorders, wounds, fever, snake bites, menstrual problem, chickenpox, bone fractures, neurological disorders, and reproductive health. Different parts of this plant, especially juice pulp, pericarp, seeds, leaves, and flowers, contain a diverse group of botanical phytocompounds, and nutrient components which are directly related to alleviating numerous diseases. This literature-based review provides the most up-to-date data on the ethnomedicinal usages, phytochemical profiling, and bio-pharmacological effects of D. longan Lour based on published scientific articles. Methodology: A literature-based review was conducted by collecting information from various published papers in reputable journals and cited organizations. ChemDraw, a commercial software package, used to draw the chemical structure of the phytochemicals. Results: Various phytochemicals such as flavonoids, tannins, and polyphenols were collected from the various sections of the plant, and other compounds like vitamins and minerals were also obtained from this plant. As a treating agent, this plant displayed many biologicals activities, such as anti-proliferative, antioxidant, anti-cancer, anti-tyrosinase, radical scavenging activity, anti-inflammatory activity, anti-microbial, activation of osteoblast differentiation, anti-fungal, immunomodulatory, probiotic, anti-aging, anti-diabetic, obesity, neurological issues, and suppressive effect on macrophages cells. Different plant parts have displayed better activity in different disease conditions. Still, the compounds, such as gallic acid, ellagic acid, corilagin acid, quercetin, 4-O-methyl gallic acid, and (-)-epicatechin showed better activity in the biological system. Gallic acid, corilagin, and ellagic acid strongly exhibited anti-cancer activity in the HepG2, A549, and SGC 7901 cancer cell lines. Additionally, 4-O-methyl gallic acid and (-)-epicatechin have displayed outstanding antioxidant activity as well as anti-cancer activity. Conclusion: This plant species can be considered an alternative source of medication for some diseases as it contains a potential group of chemical constituents.

Phytochemicals of Rhus spp. as Potential Inhibitors of the SARS-CoV-2 Main Protease: Molecular Docking and Drug-Likeness Study

Background

The outbreak of coronavirus disease 2019 (COVID-19) induced by the novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) originated in China and spread to cover the entire world with an ongoing pandemic. The magnitude of the situation and the fast spread of the new and deadly virus, as well as the lack of specific treatment, led to a focus on research to discover new therapeutic agents.

Aim

In this study, we explore the potential inhibitory effects of some active polyphenolic constituents of Rhus spp. (sumac) against the SARS-CoV-2 main protease enzyme (M^pro; 6LU7).

Methods

26 active polyphenolic compounds of Rhus spp. were studied for their antiviral activity by molecular docking, drug likeness, and synthetic accessibility score (SAS) as inhibitors against the SARS-CoV-2 M^pro.

Results

The results show that all tested compounds of sumac provided good interaction with the main active site of SARS-CoV-2 M^pro, with better, lower molecular docking energy (kcal/mol) compared to the well-known drugs chloroquine and favipiravir (Avigan). Only six active polyphenolic compounds of Rhus spp. (sumac), methyl 3,4,5-trihydroxybenzoate, (Z)-1-(2,4-dihydroxyphenyl)-3-(3,4-dihydroxyphenyl)-2-hydroxyprop-2-en-1-one, (Z)-2-(3,4-dihydroxybenzylidene)-6-hydroxybenzofuran-3(2H)-one, 3,5,7-trihydroxy-2-(4-hydroxyphenyl)chroman-4-one, 2-(3,4-dihydroxyphenyl)-3,5-dihydroxy-7-methoxy-4H-chroman-4-one, and 3,7-dihydroxy-2-(4-hydroxyphenyl)chroman-4-one, were proposed by drug likeness, solubility in water, and SAS analysis as potential inhibitors of M^pro that may be used for the treatment of COVID-19.

Conclusion

Six phenolic compounds of Rhus spp. are proposed for synthesis as potential inhibitors against M^pro and have potential for the treatment of COVID-19. These results encourage further in vitro and in vivo investigations of the proposed ligands and research on the preventive use of Rhus spp. against SARS-CoV-2.

Chemical Profiles and Pharmacological Properties with in Silico Studies on Elatostema papillosum Wedd

The current study attempted, for the first time, to qualitatively and quantitatively determine the phytochemical components of Elatostema papillosum methanol extract and their biological activities. The present study represents an effort to correlate our previously reported biological activities with a computational study, including molecular docking, and ADME/T (absorption, distribution, metabolism, and excretion/toxicity) analyses, to identify the phytochemicals that are potentially responsible for the antioxidant, antidepressant, anxiolytic, analgesic, and anti-inflammatory activities of this plant. In the gas chromatography-mass spectroscopy analysis, a total of 24 compounds were identified, seven of which were documented as being bioactive based on their binding affinities. These seven were subjected to molecular docking studies that were correlated with the pharmacological outcomes. Additionally, the ADME/T properties of these compounds were evaluated to determine their drug-like properties and toxicity levels. The seven selected, isolated compounds displayed favorable binding affinities to potassium channels, human serotonin receptor, cyclooxygenase-1 (COX-1), COX-2, nuclear factor (NF)-κB, and human peroxiredoxin 5 receptor proteins. Phytol acetate, and terpene compounds identified in E. papillosum displayed strong predictive binding affinities towards the human serotonin receptor. Furthermore, 3-trifluoroacetoxypentadecane showed a significant binding affinity for the KcsA potassium channel. Eicosanal showed the highest predicted binding affinity towards the human peroxiredoxin 5 receptor. All of these findings support the observed in vivo antidepressant and anxiolytic effects and the in vitro antioxidant effects observed for this extract. The identified compounds from E. papillosum showed the lowest binding affinities towards COX-1, COX-2, and NF-κB receptors, which indicated the inconsequential impacts of this extract against the activities of these three proteins. Overall, E. papillosum appears to be bioactive and could represent a potential source for the development of alternative medicines; however, further analytical experiments remain necessary.

Biopreservation and Quality Enhancement of Fish Surimi Using Colorant Plant Extracts

The biopreservation, flavoring, and coloration of foodstuffs, e.g., seafoods, with natural plant derivatives are major demands for consumers and overseers. Different colored plant parts, i.e., Hibiscus sabdariffa calyces, Curcuma longa rhizomes, and Rhus coriaria fruits, were extracted and evaluated as biopreservatives, antimicrobial and colorant agents for fish surimi from Oreochromis niloticus. All colorant plant extracts (CPEs) exhibited strong antibacterial activities against screened pathogens, Escherichia coli, Salmonella typhimurium, Staphylococcus aureus, and Pseudomonas aeruginosa. H. sabdariffa extract (HCE) was the most effectual antimicrobial CPEs. S. aureus was the most sensitive strain to CPEs, whereas S. typhimurium and P. aeruginosa were the most resistant strains. The exterior coloration of tilapia surimi with CPEs resulted in great bacterial count reduction in colored products; stored CPEs-colored surimi had enhanced sensorial attributes. HCE-exposed S. aureus indicated bacterial cell lyses in time-dependent manner. CPEs application as colorants and antibacterial and quality enhancing agents is recommended for seafoods’ biopreservation.

Generation Times of E. coli Prolong with Increasing Tannin Concentration while the Lag Phase Extends Exponentially

The current study examines the effect of tannins and tannin extracts on the lag phase duration, growth rate, and generation time of Escherichia coli. Effects of castalagin, vescalagin, gallic acid, Colistizer, tannic acid as well as chestnut, mimosa, and quebracho extracts were determined on E. coli's growth phases using the broth microdilution method and obtained by turbidimetric measurements. E. coli responds to the stress caused by the investigated antimicrobial agents with reduced growth rates, longer generation times, and extended lag phases. Prolongation of the lag phase was relatively small at low tannin concentrations, while it became more pronounced at concentrations above half the MIC. Moreover, for the first time, it was observed that lag time extensions follow a strict exponential relationship with increasing tannin concentrations. This feature is very likely a direct consequence of the tannin complexation of certain essential ions from the growth medium, making them unavailable to E. coli for its growth.

The Effect of Growth Medium Strength on Minimum Inhibitory Concentrations of Tannins and Tannin Extracts against E. coli

In this study the effect of growth medium strength on the minimum inhibitory concentration (MIC) of different tannins and tannin extracts against Escherichia coli was systematically investigated for the first time. Three pure compounds (vescalagin, castalagin and gallic acid) and five extracts (chestnut, quebracho, mimosa, Colistizer and tannic acid) were studied. Broth microdilution was assayed and bacteria were grown using different growth medium strengths varying from half to double the concentration recommended by the producer. MICs were determined using the iodonitrotetrazolium chloride (INT) dye or turbidity measurements. It was observed that MIC values depend on the growth medium strength. With an increase in the growth medium concentration MIC values rose roughly linearly for all samples, while their relative order remained unchanged, indicating that a direct interaction of tannins with growth medium nutrients represents the likely source of their antimicrobial activity. Understanding the effect of growth medium strength can finally yield a plausible explanation for the observed variation in MIC values reported in the scientific literature as well as provide help in planning proper applications of tannins in the livestock production.

Bioactive galloyl flavans from the stems of Helixanthera parasitica

Three new flavans, (2S)-7-O-galloyl-5,3',4'-trihydroxyflavan (1), (2S)-7,3'-O-digalloyl-5,4'-dihydroxyflavan (2), and (2S)-7,4'-O-digalloyl-5,3'-dihydroxyflavan (3), together with four known compounds, (2S)-5,7,3',4'-tetrahydroxyflavan (4), (-)-epicatechin (5), (-)-syringaresinol (6), and methyl gallate (7) have been isolated from the EtOAc extract of the stems of Helixanthera parasitica. Compounds 2 and 3 were obtained as a mixture of positional isomers. The structures of the isolated compounds were established using extensive spectroscopic data. Compound 1 and the mixture of 2 and 3 exhibited significant antimalarial activity against Plasmodium falciparum, with IC₅₀ values of 0.59 and 1.38 μM, respectively. In addition, flavans 1-3 showed cytotoxicity against KB, MCF-7, and NCI-H187 cancer cell lines, with IC₅₀ values in the range of 11.1-30.0 μM.

Phytochemical Diversity and Pharmacological Properties of Rhus coriaria

Rhus coriaria L. (Anacardiaceae), sumac, is a common condiment, appetizer and souring agent in the Mediterranean region that has a long history in traditional medicine. R. coriaria has been prescribed for the treatment of many ailments including diarrhea, ulcer, hemorrhoids, hemorrhage, wound healing, hematemesis, and eye ailments like ophthalmia and conjunctivitis. The plant is also used as diuresis, antimicrobial, abortifacient and as a stomach tonic. Sumac is known to be rich in different classes of phytochemicals including tannins, polyphenols, flavonoids, organic acids and essential oils and continues to be a hot topic for extensive research work designed for revealing its phytochemical constituents and evaluating its bioactive properties. This review summarizes the recent phytochemical and diverse bioactivity studies on R. coriaria, especially those concerned with antitumor, antioxidant, hypoglycemic, antimicrobial, and anti-inflammatory studies.

Rhus and Safflower Extracts as Potential Novel Food Antioxidant, Anticancer, and Antimicrobial Agents Using Nanotechnology

Green synthesis of metal nanoparticles using plant extracts offers a safe and attractive alternate to the chemical methods. The present work aims at preparing metal nanoparticles of rhus (Rhus coriaria L.) and safflower (Carthamus tinctorius L.) extracts using Fe²⁺, Cu²⁺, Zn²⁺, and Ag⁺ ions. The water extracts were prepared, and the total polyphenols and flavonoids contents were determined. The safflower extract contained the highest number of total polyphenols and total flavonoids (87.20 mg GAE/g and 36.32 mg QE/g), respectively. The synthesized nanoparticles were characterized using UV-Visible (UV-Vis) spectroscopy and Transmission Electron Microscope (TEM). The studied extracts and their nanoparticles were evaluated as an antioxidant, antimicrobial, and anticancer agents. The plant extracts and their nanoparticles showed significant antioxidant activity using (3-ethylbenzothiazoline-6-sulfonic acid (ABTS^•+) and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assays. Safflower silver nanoparticles (AgNPs) were the most powerful antimicrobial agent compared to the other nanoparticles. The Sulforhodamine B (SRB) cytotoxic activity was evaluated against three cancer cell lines. The results revealed that CuNP safflower nanoparticles displayed the highest activity as anticancer agent with values (98.94% with T47D, 97.68% with HEPG2, and 89.33% against Caco-2). The data revealed that rhus and safflower extracts and their nanoparticles possess high potential activity as antimicrobial, antioxidant, and anticancer agents.

The Phytochemistry of Cherokee Aromatic Medicinal Plants

Background: Native Americans have had a rich ethnobotanical heritage for treating diseases, ailments, and injuries. Cherokee traditional medicine has provided numerous aromatic and medicinal plants that not only were used by the Cherokee people, but were also adopted for use by European settlers in North America. Methods: The aim of this review was to examine the Cherokee ethnobotanical literature and the published phytochemical investigations on Cherokee medicinal plants and to correlate phytochemical constituents with traditional uses and biological activities. Results: Several Cherokee medicinal plants are still in use today as herbal medicines, including, for example, yarrow (Achillea millefolium), black cohosh (Cimicifuga racemosa), American ginseng (Panax quinquefolius), and blue skullcap (Scutellaria lateriflora). This review presents a summary of the traditional uses, phytochemical constituents, and biological activities of Cherokee aromatic and medicinal plants. Conclusions: The list is not complete, however, as there is still much work needed in phytochemical investigation and pharmacological evaluation of many traditional herbal medicines.

Phytochemical Screening of Quaking Aspen (Populus tremuloides) Extracts by UPLC-QTOF-MS and Evaluation of their Antimicrobial Activity

The continual emergence of pathogen resistance is a recurring challenge and pushes for the development of antimicrobial compounds. Here, we investigated compounds from quaking aspen trees (Populus tremuloides) as potential antimicrobial agents. Several extractions using different solvents were realized, and corresponding antimicrobial activity was tested against eight microorganisms. Results revealed that polar extraction solvents including water, ethanol and methanol gave the best extraction yields (>15.07%). Minimal inhibition concentration (MIC) and minimal bactericidal/fungicidal concentration (MBC/MFC) demonstrated that water extracts had the best antimicrobial activity by a weak to moderate inhibition of growth of all eight tested microorganisms in addition to having a bactericidal effect on three of them. The quaking aspen methanol extract also displayed antimicrobial activity but to a lower level than the water extract. Ultra-performance liquid chromatography quadrupole time-of flight mass spectrometry (UPLC-QTOF-MS) analysis led to the identification of 92 compounds, mainly polyphenols in both extracts, with 22 molecules previously known for their antimicrobial properties. According to the relative abundance, 4-hydroxybenzaldehyde (5.44% in methanol extract) and kaempferol (5.03% in water extract) were the most abundant antimicrobial compounds. Among antimicrobial molecules identified, nine were from the flavonoid family. The results of our study demonstrate the interest of using quaking aspen as source of antimicrobial compounds.

Evaluation of Antioxidant and Antimicrobial Activities of Ethanol Extracts of Three Kinds of Strawberries

The antioxidant and antimicrobial activities of three kinds of strawberry ethanol extracts from Robus corchorifolius L. f. (RCL), Rubus parvifolius L. var. parvifolius (RPL), and Duchesnea chrysantha Miq. (DCM) were investigated. The RPL was highest (P<0.05) in phenolic, flavonoid, and anthocyanin contents. 2,2-Diphenyl-1-picrylhydrazyl and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging activities of RPL and DCM extracts were higher than that of RCL (P<0.05). Hydrogen peroxide scavenging activity of RPL was high compared to DCM and RCL (P<0.05). RCL exhibited a significant (P<0.05) potent antioxidant activity in nitric oxide radical inhibition. Inhibition diameter zone (nearest mm) of extracts against the test bacteria ranged from 11.5 in RCL to 12.5 in DCM against Staphylococcus aureus, from 10.5 in RCL to 13.5 in DCM against Streptococcus pneumoniae, from 8.5 in DCM to 10.5 in RCL against Escherichia coli, and the same inhibition of 10 mm in three of the extracts against Klebsiella pneumoniae. However, there was no inhibition against fungi Aspergillus niger and Candida albicans. Three of the extracts had the same minimum inhibitory concentration values of 12.50, 12.50, and 6.25 μg/mL against S. aureus, K. pneumoniae, and S. pneumoniae, respectively. On the other hand, MIC values of 12.50, 12.50, and 6.50 μg/mL were recorded for RPL, DCM, and RCL against E. coli, respectively. The result of present study revealed that extracts from three kinds of strawberries could be potential candidates as antioxidant and antimicrobial sources for functional food industries.

Structure-Activity Relationships of Antimicrobial Gallic Acid Derivatives from Pomegranate and Acacia Fruit Extracts against Potato Bacterial Wilt Pathogen

Bacterial wilts of potato, tomato, pepper, and or eggplant caused by Ralstonia solanacearum are among the most serious plant diseases worldwide. In this study, the issue of developing bactericidal agents from natural sources against R. solanacearum derived from plant extracts was addressed. Extracts prepared from 25 plant species with antiseptic relevance in Egyptian folk medicine were screened for their antimicrobial properties against the potato pathogen R. solancearum by using the disc-zone inhibition assay and microtitre plate dilution method. Plants exhibiting notable antimicrobial activities against the tested pathogen include extracts from Acacia arabica and Punica granatum. Bioactivity-guided fractionation of A. arabica and P. granatum resulted in the isolation of bioactive compounds 3,5-dihydroxy-4-methoxybenzoic acid and gallic acid, in addition to epicatechin. All isolates displayed significant antimicrobial activities against R. solanacearum (MIC values 0.5-9 mg/ml), with 3,5-dihydroxy-4-methoxybenzoic acid being the most effective one with a MIC value of 0.47 mg/ml. We further performed a structure-activity relationship (SAR) study for the inhibition of R. solanacearum growth by ten natural, structurally related benzoic acids.

The antimicrobial activity of Liquidambar orientalis mill. against food pathogens and antioxidant capacity of leaf extracts

BACKGROUND

Medicinal plants are an important source of substances which are claimed to induce antimicrobial, antimutagenic and antioxidant effects. Many plants have been used due to their antimicrobial treatments. Antimicrobial and antioxidant activities of L. orientalis have not been reported to the present day. The aim of this work was to investigate of the antimicrobial and antioxidant potentials of different extracts from L. orientalis.

MATERIALS AND METHODS

The extracts were screened for antimicrobial activity against different food pathogens. These bacteria include 4 Gram positive and 3 Gram negative bacteria and one fungi. The leaf extracts of plant were tested by disc diffusion assay. The MIC was evaluated on plant extracts as antimicrobial activity. In addition to, the plant extracts were tested against the stable DPPH (2,2-diphenyl-1-picryl-hydrazylhydrate) free-radical.

RESULTS

The acetone, ethanol and methanol extracts of L. orientalis showed maximum inhibition zone of 12 mm against Yersinia enterocolitica, Listeria monocytogenes and Staphylococcus aureus. In addition to, the methanol extract displayed a strong antioxidant activity (trolox equivalent = 2.23 mM).

CONCLUSION

L. orientalis extracts have antimicrobial, and antioxidant potential. Our results support the use of this plant in traditional medicine and suggest that some of the plant extracts possess compounds with good antibacterial properties that can be used as antibacterial agents in the search for new drugs.

Anti-inflammatory effects of phenolic compounds isolated from the flowers of Nymphaea mexicana Zucc

Nymphaea mexicana Zucc. is an aquatic plant species which belongs to the family Nymphaea and is commonly known as the yellow water lily. The aim of this work was to study the in vitro antiinflammatory effects of phenolic compounds isolated from the flowers of Nymphaea mexicana Zucc. Seven phenolic compounds including vanillic acid, 4-methoxy-3,5-dihydroxybenzoic acid, (2R,3R)-3,7-dihydroxyflavanone, naringenin (4), kaempferol 3-O-(3-O-acetyl-a-L-rhamnopyranoside), kaempferol 3-O-(2-O-acetyl-a-L-rhamnopyranoside), and quercetin 3-(30 0-acetylrhamnoside) (7) were isolated from the flowers of Nymphaea mexicana Zucc. These results revealed that compound 4 has the most prominent inhibitory effect on the LPS-stimulated nitric oxide (NO), monocyte chemotactic protein-1 (MCP-1), and tumor necrosis factor-alpha (TNF-a) production in RAW 264.7 macrophages. In addition, compound 4 also inhibited LPS-mediated induction of protein expressions of inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX-2), and phospho-ERK in RAW 264.7 macrophages. Thus, compound 4 from the flowers of Nymphaea mexicana Zucc. may provide a potential therapeutic approach for inflammation-associated disorders.

A study on antimicrobial, antioxidant and antimutagenic activities of Elaeagnus angustifolia L. leaves

BACKGROUND

[corrected] The aim of this work was to investigate the antimicrobial, antioxidant, and antimutagenic potentials of methanol extracts from E. angustifolia.

MATERIALS AND METHODS

Methanol extracts were screened for antimicrobial activity against different species of 4 Gram positive and 3 Gram negative bacteria and one fungus. These bacteria included food pathogens. The leaf extract was tested using disc diffusion assay.

RESULTS

The methanol extract of E. angustifolia showed maximum inhibition zone of 16 mm against Yersinia enterocolitica. Whereas, the inhibition zone was not determined by methanol extract against Escherichia coli ATCC 1122 and Candida albicans RSKK 02029. The MIC was evaluated on plant extracts as antimicrobial activity. All of bacterial strains showed the lowest sensitivity to methanol extract of E. angustifolia (3.5 mg/mL), except Yersinia enterocolitica NCTC 11174. In addition, the plant extracts were tested against the stable DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) free-radical. Finally, the methanol extract displayed a strong antioxidant activity (Trolox equivalent = 1.49 mM). Also, E. angustifolia methanol extracts were screened for their antimutagenic activity against sodium azide by Ames test in absence of rat microsomal liver enzyme (-S9). The results showed that E. angustifolia methanol extracts can inhibit mutagenic agents of sodium azide. The plant leaf extracts with the inhibition of 36% sodium azide showed moderate potential in decreasing mutagenic agents in Salmonella typhimurium TA100.

CONCLUSION

E. angustifolia methanol extracts have antimicrobial, antioxidant and antimutagenic potential.

Screening of anti-obesity agent from herbal mixtures

Globally, one in three of the World's adults are overweight and one in 10 is obese. By 2015, World Health Organization (WHO) estimates the number of chubby adults will balloon to 2.3 billion--Equal to the combined populations of China, Europe and the United States. The discovery of bioactive compounds from herbs is one possible way to control obesity and to prevent or reduce the risks of developing various obesity-related diseases. In this study, we screened anti-obesity agents such as methyl gallate from the herbal composition known as HemoHIM that actively inhibits lipid formation as evidenced by Oil Red O staining and triglyceride (TG) contents in 3T3-L1 adipocytes, suggesting their use as an anti-obesity agent. Furthermore, the amount of glycerol released from cells into the medium had increased by treatment of methyl gallate in a concentration-dependent manner. The present study suggests that a promising anti-obesity agent like methyl gallate might be of therapeutic interest for the treatment of obesity.

Characterization and storage stability of the extract of Thai mango (Mangifera indica Linn. Cultivar Chok-Anan) seed kernels

Qualitative analysis of hydrolysable extract from mango (Mangifera indica Linn. cultivar Chok-Anan) seed kernel was performed by means of reversed phase high-performance liquid chromatography coupled to diode array detection and electrospray ionization mass spectrometry (RPHPLC-DAD-ESI-MS). The main phenolic compound was identified as methyl gallate by comparing their retention time, UV-vis absorption spectra and mass spectra with a reference standard. Quantification of phenolic compounds was performed by HPLC-DAD, which revealed that the extract contained total phenolics at a concentration of 194.1 mg GAE/g dry weight of mango seed kernel (MSK), of which 85.7% was identified as methyl gallate. In addition, the antioxidant activities of the extract and the main compound were assessed by the 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) assays, by the ferric thiocyanate method and by an assay of metal chelating activity. Tyrosinase inhibition was also investigated. Furthermore, the antioxidant capacity and the total phenolic content of MSK extract stored in a plastic (polyethylene) PE bag decreased during storage at freezing (-20 °C), refrigerated (7 °C) and room (28-32 °C) temperature for 182 days. The loss of antioxidant capacity and total phenolic content increased at higher storage temperatures for more than 182 days.

Traditional use of medicinal plants in the boreal forest of Canada: review and perspectives

BACKGROUND

The boreal forest of Canada is home to several hundred thousands Aboriginal people who have been using medicinal plants in traditional health care systems for thousands of years. This knowledge, transmitted by oral tradition from generation to generation, has been eroding in recent decades due to rapid cultural change. Until now, published reviews about traditional uses of medicinal plants in boreal Canada have focused either on particular Aboriginal groups or on restricted regions. Here, we present a review of traditional uses of medicinal plants by the Aboriginal people of the entire Canadian boreal forest in order to provide comprehensive documentation, identify research gaps, and suggest perspectives for future research.

METHODS

A review of the literature published in scientific journals, books, theses and reports.

RESULTS

A total of 546 medicinal plant taxa used by the Aboriginal people of the Canadian boreal forest were reported in the reviewed literature. These plants were used to treat 28 disease and disorder categories, with the highest number of species being used for gastro-intestinal disorders, followed by musculoskeletal disorders. Herbs were the primary source of medicinal plants, followed by shrubs. The medicinal knowledge of Aboriginal peoples of the western Canadian boreal forest has been given considerably less attention by researchers. Canada is lacking comprehensive policy on harvesting, conservation and use of medicinal plants. This could be explained by the illusion of an infinite boreal forest, or by the fact that many boreal medicinal plant species are widely distributed.

CONCLUSION

To our knowledge, this review is the most comprehensive to date to reveal the rich traditional medicinal knowledge of Aboriginal peoples of the Canadian boreal forest. Future ethnobotanical research endeavours should focus on documenting the knowledge held by Aboriginal groups that have so far received less attention, particularly those of the western boreal forest. In addition, several critical issues need to be addressed regarding the legal, ethical and cultural aspects of the conservation of medicinal plant species and the protection of the associated traditional knowledge.

Toxicity of Hydnora johannis Becca. dried roots and ethanol extract in rats

AIM OF THE STUDY

Hydnora johannis Becca. (Hydnoraceae) commonly is used for the treatment of dysentery, diarrhoea, cholera and swelling tonsillitis in the folk medicine of Sudan and other African countries. This study evaluates the toxicological effects of Hydnora johannis roots on Wistar rats.

MATERIALS AND METHODS

Rats were randomized into control, groups fed with 2, 10, 20% of dried roots for 8 weeks and other groups given ethanol extract (50, 100, 200 and 400mg/kg/day) through oral and intramuscularly administration for 2 weeks. Toxicity was evaluated using biochemical and histopathological assays.

RESULTS

Alterations in the levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, cholesterol and urea were observed. Histopathological analysis revealed that the toxic effect were mainly on the liver, kidney and spleen on all treated groups. However, the impact of the dried roots was mild compared to the ethanol extract. Remarkably, there was a drop in cholesterol level in all treatment groups suggesting the antiartherogenic effect of Hydnora johannis roots.

CONCLUSION

The results from this study suggest that the powder preparation as well as ethanolic extract of Hydnora johannis roots induced toxic effect on Wistar rats. The observed toxic effect might be due to the dose and/or frequency of administration. Although in traditional medicine the extract is administrated in low dose, the results suggest the necessity of standardization of the drug.

Chewing-stick practices using plants with anti-streptococcal activity in a ugandan rural community

Background: The high dental disease burden in developing countries has created a need to explore and develop cheap and accessible methods of dental disease prevention. Traditional toothbrushes (chewing-sticks) prepared from specific plants have been used for dental hygiene for generations. When properly used, chewing-sticks may be as effective as synthetic toothbrushes. This study set out to describe traditional chewing-stick practices in a Ugandan rural community, and evaluate the antibacterial activity of two most commonly used plants. Methods: Interviews were done to identify chewing-stick plants and obtain socio-cultural information relating to the practice in two villages in rural Uganda. Field walks were done to pick and voucher the plants, for taxonomical identification and storage. For the two most reported plants, aqueous extracts were prepared and tested for antibacterial activity against Streptococcus mutans using the agar-well diffusion method. Results: Of the 21 key informants interviewed, all were using or had used chewing-sticks in the past. A total of eight plants were identified as sources of chewing-sticks, with Rhus vulgaris and Lantana trifolia most commonly mentioned. Chewing-sticks were preferred over synthetic tooth brushes because they were less likely to traumatize the gums. Their use has been limited of recent due to scarcity of some plants. R. vulgaris and L. trifolia aqueous extracts showed antibacterial activity against S. mutans with mean diameters of inhibition of 24.33 ± 0.58 and 14.17 ± 0.29 mm on Blood agar respectively, compared to benzyl penicillin control 30.67 ± 0.29 mm. Conclusion: R. vulgaris and L. trifolia are the most common sources of chewing-sticks for cleaning teeth in this community. The plants contain compounds that are active against S. mutans. These plants merit further studies as they are possible sources of cheap dental health care for the rural poor.

Antibacterial activity of Alpinia galanga (L) Willd crude extracts

Methanol, acetone and diethyl ether extracts of Alpinia galanga have been evaluated against pathogens viz. Bacillus subtilis MTCC 2391, Enterobacter aerogene, Enterobacter cloacae, Enterococcus faecalis, Escherichia coli MTCC 1563, Klebsiella pneumoniae, Pseudomonas aeruginosa MTCC 6642, Salmonella typhimurium, Staphylococcus aureus and Streptococcus epidermis using Agar well diffusion method. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of all the extracts were determined using the macrodilution method. Methanol extracts have shown excellent activity towards all the pathogens with MIC and MBC values ranging from 0.04-1.28 mg/ml and 0.08-2.56 mg/ml, respectively. The GC-MS analysis of methanol extracts have yielded compounds like 5-hydroxymethyl furfural (59.9%), benzyl alcohol (57.6%), 1,8 cineole (15.65%), methylcinnamate (9.4%), 3-phenyl-2-butanone (8.5%) and 1,2 benzenedicarboxylic acid (8.9%), which could be responsible for its broad spectrum activity. So, A. galanga can be quite resourceful for the development of new generation drugs.

Studies of the in vitro anticancer, antimicrobial and antioxidant potentials of selected Yemeni medicinal plants from the island Soqotra

Background

Recent years have witnessed that there is a revival of interest in drug discovery from medicinal plants for the maintenance of health in all parts of the world. The aim of this work was to investigate 26 plants belonging to 17 families collected from a unique place in Yemen (Soqotra Island) for their in vitro anticancer, antimicrobial and antioxidant activities.

Methods

The 26 plants were extracted with methanol and hot water to yield 52 extracts. Evaluation for in vitro anticancer activity was done against three human cancer cell lines (A-427, 5637 and MCF-7) by using an established microtiter plate assay based on cellular staining with crystal violet. Antimicrobial activity was tested against three Gram-positive bacteria, two Gram-negative bacteria, one yeast species and three multiresistant Staphylococcus strains by using an agar diffusion method and the determination of MIC against three Gram-positive bacteria with the broth micro-dilution assay. Antioxidant activity was investigated by measuring the scavenging activity of the DPPH radical. Moreover, a phytochemical screening of the methanolic extracts was done.

Results

Notable cancer cell growth inhibition was observed for extracts from Ballochia atro-virgata, Eureiandra balfourii and Hypoestes pubescens, with IC₅₀ values ranging between 0.8 and 8.2 μg/ml. The methanol extracts of Acanthospermum hispidum, Boswellia dioscorides, Boswellia socotrana, Commiphora ornifolia and Euphorbia socotrana also showed noticeable antiproliferative potency with IC₅₀ values < 50 μg/ml. The greatest antimicrobial activity was exhibited by extracts from Acacia pennivenia, Boswellia dioscorides, Boswellia socotrana, Commiphora ornifolia, Euclea divinorum, Euphorbia socotrana, Leucas samhaensis, Leucas virgata, Rhus thyrsiflora, and Teucrium sokotranum with inhibition zones > 15 mm and MIC values ≤ 250 μg/ml. In addition, the methanolic extracts of Acacia pennivenia, Boswellia dioscorides, Boswellia socotrana and Commiphora ornifolia showed good antioxidant potential at low concentrations (more than 80% at 50 μg/ml).

Conclusion

Our results show once again that medicinal plants can be promising sources of natural products with potential anticancer, antimicrobial and antioxidative activity. The results will guide the selection of some plant species for further pharmacological and phytochemical investigations.

Methyl gallate

THE CRYSTAL STRUCTURE OF THE TITLE COMPOUND (SYSTEMATIC NAME: methyl 3,4,5-trihydroxy-benzoate), C(8)H(8)O(5), is composed of essentially planar mol-ecules [maximum departures from the mean carbon and oxygen skeleton plane of 0.0348 (10) Å]. The H atoms of the three hydroxyl groups, which function as hydrogen-bond donors and acceptors simultaneously, are oriented in the same direction around the aromatic ring. In addition to two intra-molecular hydrogen bonds, each mol-ecule is hydrogen bonded to six others, creating a three-dimensional hydrogen-bonded network.

Mutiniside, new antioxidant phenolic glucoside from Abutilon muticum

Mutiniside (1), new phenolic glucoside, and the flavonoidal glucoside cephacoside (2) have been isolated from the n-BuOH soluble fraction, along with lupeol (3), beta-sitosterol (4), stigmasterol (5), methyl-4-hydroxybenzoate (6), taraxacin (7), ursolic acid (8), and beta-sitosterol-3-O-beta-D-glucopyranoside (9), have been isolated from the EtOAc soluble fraction of Abutilon muticum. Compounds 2-9 are reported for the first time from this species. Compound 1 showed significant antioxidant activity while moderate inhibitory activity was observed against the enzyme lipoxygenase.

Inhibitory effect of methyl gallate and gallic acid on oral bacteria

This study examined the ability of methyl gallate (MG) and gallic acid (GA), the main compounds of gallo-tannins in Galla Rhois, to inhibit the proliferation of oral bacterial and the in vitro formation of Streptococcus mutans biofilms. The antimicrobial activities of these compounds were evaluated in vitro using the broth microdilution method and a beaker-wire test. Both MG and GA had inhibitory effects on the growth of cariogenic (MIC<8 mg/ml) and periodontopathic bacteria (MIC=1 mg/ml). Moreover, these compounds significantly inhibited the in vitro formation of S. mutans biofilms (MG, 1 mg/ml; GA, 4 mg/ml; P<0.05). MG was more effective in inhibiting bacterial growth and the formation of S. mutans biofilm than GA. In conclusion, MG and GA can inhibit the growth of oral pathogens and S. mutans biofilm formation, and may be used to prevent the formation of oral biofilms.

Biological activities of extracts from sumac (Rhus spp.): a review

Sumac is the common name for a genus (Rhus) that contains over 250 individual species of flowering plants in the family Anacardiaceae. These plants are found in temperate and tropical regions worldwide, often grow in areas of marginal agricultural capacity, and have a long history of use by indigenous people for medicinal and other uses. The research efforts on sumac extracts to date indicate a promising potential for this plant family to provide renewable bioproducts with the following reported desirable bioactivities: antifibrogenic, antifungal, antiinflammatory, antimalarial, antimicrobial, antimutagenic, antioxidant, antithrombin, antitumorigenic, antiviral, cytotoxic, hypoglycaemic, and leukopenic. As well, the bioactive components can be extracted from the plant material using environmentally benign solvents that allow for both food and industrial end-uses. The favorable worldwide distribution of sumac also suggests that desirable bioproducts may be obtained at the source, with minimal transportation requirements from the source through processing to the end consumer. However, previous work has focussed in just a few members of this large plant family. In addition, not all of the species studied to date have been fully characterized for potential bioactive components and bioactivities. Thus, there remains a significant research gap spanning the range from lead chemical discovery through process development and optimization in order to better understand the full potential of the Rhus genus as part of global green technology based on bioproducts and bioprocesses research programs.

The homeopathic antiarthitic preparation Zeel comp. N: a review of molecular and clinical data

Zeel comp. N (Zeel) is a homeopathic medication that has been widely used for many years for the treatment of arthritic disorders in a large number of countries worldwide. In recent years, a growing body of clinical and molecular evidence has been accumulating that shed light on the possible antiarthritic effects of this preparation. A number of studies report anti-inflammatory effects from Zeel. In vitro studies have indicated Zeel-mediated inhibition of the pathways involving the enzymes cyclooxygenase-1 and -2, and also the 5-lipoxygenase pathways, affecting levels of both eicosanoids and leukotrienes. Thus, Zeel may reduce the main two classes of molecules responsible for arthritic pain and inflammation. This review describes recent research on Zeel and discusses the need for further studies to clarify the role of the compound in the antiarthritic armamentarium of complementary medicine.

4-O-Methylgallic acid suppresses inflammation-associated gene expression by inhibition of redox-based NF-κB activation

4-O-methylgallic acid (4-OMGA) is an in vivo major metabolite of gallic acid which is abundant in red wine, tea, legumes and fruit. We examined the in vitro and in vivo effects of 4-OMGA on the production and expression of nitric oxide (NO) and prostaglandin E(2) (PGE(2)) as well as the expression of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor-alpha (TNF-alpha), and interleukin-1beta (IL-1beta). 4-OMGA inhibited the expression and production of these inflammatory genes and mediators in RAW264.7 cells and primary macrophages stimulated with lipopolysaccharide (LPS). This compound also reduced the serum levels of these inflammatory mediators in endotoxemic mice. 4-OMGA inhibited iNOS promoter activity and NF-kappaB activation in LPS-treated RAW264.7 cells. 4-OMGA inhibited the LPS-mediated increase in reactive oxygen species production and exogenous H(2)O(2)-induced NF-kappaB activation. Moreover, this compound blocked IkappaBalpha phosphorylation and degradation and nuclear translocation of the cytosolic NF-kappaB p65 subunit, which highly correlated with its inhibitory effect on IkappaB kinase activity and inflammatory mediator production. These results suggest that 4-OMGA suppresses inflammation-associated gene expression by blocking NF-kappaB activation through the inhibition of redox-sensitive IkappaB kinase activity, suggesting that this compound may be beneficial for treating endotoxemia.

Antiangiogenic activity of 4-O-methylgallic acid from Canavalia gladiata, a dietary legume

Development of nontoxic and biologically safe antiangiogenic agent has been highlighted as a promising way to treat angiogenesis related diseases including cancer. Herein, we isolated 4-O-methylgallic acid (4-OMGA) from the seed of Canavalia gladiata, a dietary legume, on the basis of the growth inhibitory activity for bovine aortic endothelial cells (BAECs). The compound potently inhibits endothelial cell invasion and tube formation stimulated with basic fibroblast growth factor (bFGF) at low micromolar concentrations where it shows no cytotoxicity to the cells. In addition, 4-OMGA inhibits vascular endothelial cell growth factor (VEGF) production under hypoxic condition and the production of reactive oxygen species (ROS) in the endothelial cells stimulated with VEGF. These results demonstrate that 4-OMGA is a compound having potential for an antiangiogenic agent.

Antimicrobial effect of water extract of sumac (Rhus coriaria L.) on the growth of some food borne bacteria including pathogens

The antimicrobial effect of water extracts of sumac (Rhus coriaria L.) at concentrations of 0.1%, 0.5%, 1.0%, 2.5% and 5.0% (w/v), non-neutralized and after neutralization to pH 7.2+/-0.1, was studied on the growth of 12 bacterial strains (six Gram positive strains and six Gram negative strains), mostly food borne including pathogens. It was found to be effective against all the test organisms with Gram positive strains being more sensitive than Gram negative strains. Significant differences (P<0.01) were found among the bacteria and between the non-neutralized and neutralized extracts with non-neutralized being more effective against all the bacteria. The minimal inhibitory concentration (MIC) of the extract for each bacterial strain was studied by a gradient plate method. Among the Gram positive organisms, Bacillus species (Bacillus cereus, Bacillus megaterium, Bacillus subtilis, and Bacillus thuringiensis) were found to be the most sensitive showing MICs of 0.25-0.32% (after 24 h incubation) followed by Staphylococcus aureus (0.49%), while Listeria monocytogenes was found to be the least sensitive demonstrating a MIC of 0.67%. Of the Gram negative organisms, Salmonella enteritidis was found to be the most resistant with a MIC of 0.67% followed by Escherichia coli Type I, E. coli O157:H7, Proteus vulgaris and Hafnia alvei having MICs of 0.63%, 0.60%, 0.55% and 0.45%, respectively; whereas Citrobacter freundii was found to be the least resistant surviving up to 0.42%. Some loss of antimicrobial activity was, however, observed after incubation for 3 days. Bacteriostatic/bactericidal effects of sumac, as studied by enumerating survival by the viable count technique after 1 h direct contact of each microorganism with various concentrations of sumac extract, revealed a 4-5 log cycle reduction in Bacillus spp. and 2-3 log cycle reduction in other bacteria tested with 1.0% sumac extract.

In vitro antimicrobial activity of extracts and isolated constituents of Rubus ulmifolius

The antimicrobial activity on bacteria and fungi of increasing polarity extracts of Rubus ulmifolius and that of some isolated constituents, quercetin-3-O-beta-D-glucuronide; kaempferol-3-O-beta-D-glucuronide, gallic acid, ferulic acid and tiliroside was evaluated. The phenolic and tannins fractions showed an high antimicrobial activity.

A weakly antimalarial biflavanone from Rhus retinorrhoea

The biflavanone (2S,2"S)-7,7"-di-O-methyltetrahydroamentoflavone and five known flavonoids, 7-O-methylnaringenin, 7,3'-O-dimethylquercetin, 7-O-methylapigenin, 7-O-methylluteolin, and eriodictyol were isolated from the leaves of Rhus retinorrhoea Steud, Ex Olive. The biflavanone exhibited moderate antimalarial activity with IC50 0.98 microg/ml against Plasmodium falciparum (W2 Clone) and weak activity against P. falciparum (D6 Clone) with IC50 2.8 microg/ml. Nevertheless, it did not display any cytotoxicity. 7-O-Methylnaringenin showed weak antimicrobial activity against Candida albicans, C. krusei, Staphylococcus aureus, Mycobacterium smegmatis, M. intracellulare, and M. xenopi with MIC approximately 100 microg/ml. Characterization of each compound was based on spectral analysis and comparison with reported data.