Biogenic phytochemicals (cassinopin and isoquercetin) capped copper nanoparticles (ISQ/CAS@CuNPs) inhibits MRSA biofilms.

Purified glycosides, Isoquercetin and Cassinopin from Crotalaria candicans were selected for the synthesis of biogenic copper nanoparticles (CuNPs).The designed biogenic CuNPs was characterized and when evaluated against panel of gram negative and positive bacteria, the biogenic CuNPs were found to be more effective against methicillin resistant Staphylococcus aureus (MRSA). Antibacterial, anti-biofilm effects and time kill studies confirmed the ability of biogenic CuNPs to curtail MRSA. Scanning electron microscopy, Crystal violet staining and fluorescent live-dead imaging showed that treatment with sub lethal levels of glycoside capped CuNPs resulted in greater than 50% decline in biofilm formation by MRSA, which implies that anti-biofilm effect of biogenic CuNPs is not dependent on antibacterial effect. Alizarin red assay implied that prolonged treatment of biogenic CuNPs in presence of MRSA, releases Cu(II) ions and hence antibiofilm effect is primarily mediated by NP and is not due to released Cu(II) ion. The NPs caused altered membrane permeability and reduced surface hydrophobicity, thus accounting for its antibiofilm effect.

Zero valent silver nanoparticles capped with capsaicinoids containing Capsicum annuum extract, exert potent anti-biofilm effect on food borne pathogen Staphylococcus aureus and curtail planktonic growth on a zebrafish infection model.

Food plants Hungarian wax pepper (HWP) and Green Bell pepper (GBP), belonging to Capsicum annuum were utilized for biogenic fabrication of zero valent, nano-silver (AgNPs) through a photo-mediation procedure. In the bacterial strains evaluated, HWP/GBP AgNPs demonstrated effective bacteriostatic and bactericidal effect against Staphylococcus aureus. Time kill results portrayed that HWP/GBP nano-silver exhibited comparable bactericidal potency on S. aureus. Anti-biofilm potential of HWP/GBP AgNPs displayed significant effects at sub MIC levels, by triggering 50% biofilm reduction of the food spoilage microbe S. aureus, inferring that the anti-biofilm outcome is not dependent on antibacterial result, and this was confirmed by SEM and fluorescence studies. Histopathological analyses of S. aureus infected zebrafish liver did not display any abnormality changes such as extensive cell death and degeneration, upon treatment with HWP/GBP AgNPs and the zero-valent silver nanoparticles were comparatively less toxic and more operative in restraining the bioburden in S. aureus infected zebrafish model by a >1.7 log fold. Ability of light reduced HWP/GBP AgNPs to alleviate the in vitro and in vivo planktonic mode of growth and curb the biofilm formation of S. aureus is also demonstrated.

Plant nutraceuticals (Quercetrin and Afzelin) capped silver nanoparticles exert potent antibiofilm effect against food borne pathogen Salmonella enterica serovar Typhi and curtail planktonic growth in zebrafish infection model.

Purified plant nutraceuticals afzelin and quercetrin from an edible plant- Crotolaria tetragona was employed for the fabrication of silver nanoparticles (AgNPs) by a sunlight mediated process. From among a panel of strains tested, AgNPs displayed potent bacteriostatic and bactericidal effect against P. aeruginosa and S. Typhi. Time kill studies revealed green synthesized AgNPs displayed comparable bactericidal effect with chemically synthesized AgNPs against S. Typhi. Antibiofilm potential of AgNPs showed that they were highly effective at sub MIC concentrations in causing 50% biofilm inhibition against food borne pathogen S. Typhi implying that antibiofilm effect is independent of antibacterial effect, which was evidenced by fluorescent imaging and SEM imaging. Mechanistic studies revealed that reduced cell surface hydrophobicity, decreased surface adherence, loss of membrane potential contributed to antibiofilm potential of afzelin/quercetrin AgNPs. Green synthesized afzelin/quercetrin AgNPs were also relatively less toxic and more effective in curtailing bioburden of S. Typhi in infected zebrafish by > 3 log fold. Ability of sunlight reduced afzelin/quercetrin NPs to mitigate planktonic mode of growth in vitro and in vivo and curtail biofilm formation of S. Typhi in vitro demonstrates its potential to curtail food borne pathogen in planktonic and biofilm mode of growth.

Ferulic acid derivative inhibits NorA efflux and in combination with ciprofloxacin curtails growth of MRSA in vitro and in vivo.

A series of ferulic acid (FA) derivatives were synthesized and evaluated for its ability to inhibit NorA efflux in methicillin resistant Staphylococcus aureus (MRSA), by in silico docking analysis. Based on prediction from glide scores and ability to reduce EtBr MIC, two of the ten derivatives S3- [4-((E)-2-(diethylcarbamoyl)vinyl)-2-methoxyphenyl acetate] and S6- [(E)-methyl 3-(4-((p-tolylcarbamoyl)methoxy)-3-methoxyphenyl)acrylate] were chosen as putative efflux pump inhibitors (EPI's). Time dependent accumulation studies revealed that S6 caused enhanced EtBr accumulation relative to standard NorA efflux inhibitor reserpine, in clinical isolate of MRSA (CIMRSA) and in NorA overexpressed strain of S. aureus (SA1199B). S6 also exhibited synergy with Ciprofloxacin (CPX) against NorA overexpressed strain (SA1199B) of S. aureus but not in NorA knock out strain (K1758). MIC reversal studies showed that S3 in CIMRSA and S6 in NorA overexpressed strain of S. aureus (SA1199B), caused a 4 fold reduction in CPX MIC. In vitro time kill studies revealed that both S3 and S6 with sub MIC of CPX caused a significant 4 log CFU decline in CIMRSA. A decline of >3 log fold CFU by time kill assay implies synergy between FA derivatives and CPX. When tested in vivo in infected muscle tissue of zebrafish both S3 and S6 with CPX caused >3.2 log decline in CIMRSA cell counts relative to CPX treatment alone. Of the two potent derivatives, S6 probably acts through NorA whereas S3 might exert its effect through pump other than NorA. Greater in vitro and in vivo efficiency of FA derivatives implies its potential to be used as an adjuvant along with CPX to curtail MRSA infection in higher animal models.

A benign alternative process for efficient separation of pure commercially important flavonoid nutraceuticals from edible plants.

The present study signifies the development of a unique, optimized procedure for both selective determination and separation of different flavonoid nutraceuticals from edible plants. Totally ten different flavonoids were determined (HPLC-DAD) and isolated from five different plants using the developed process with a remarkable purity of 91-98% and recovery of 88-95%. Box-Behnken experimental design model yielded a optimized amount of 40.36 mg/g of AI extract (Pinostrobin) and 28.95 mg/g of AI extract (Baicalein) with a high correlation coefficient (0.98-0.99), indicating a good fit between the second order regression model and the experimental observations. The final purity of compounds through optimized process is 97.1% (Pinostrobin) and 93.5% (Baicalein) respectively. The optimized yields depicted a total recovery of 92% for pinostrobin, and 89% for Baicalein respectively. Thus, the developed process worked as a potential alternative which when statistically optimized results in a remarkable recovery of flavonoids from various plants. Being an environmentally friendly protocol the process could be useful in industrial separation of commercially important flavonoids widely applied in food industry.

Synergistic antimicrobial profiling of violacein with commercial antibiotics against pathogenic micro-organisms.

CONTEXT: Chromobacterium violaceum Bergonzini (Neisseriaceae), a Gram-negative bacterium, secretes a spectacular pigment called violacein. Violacein is a quorum-sensing metabolite and is also an active antimicrobial, anticancer agent. However, its efficiency as a potential drug, alone or in synergy with other active principles, has not being completely exploited. With the advent of different multi-drug resistant strains, it becomes essential to find a new natural product(s) that could be effectively used as a therapeutic agent. OBJECTIVE: This work focused on the extraction of violacein from an isolated strain of C. violaceum and determined the combinatory effect of violacein with commercial antibiotics against various pathogens. MATERIALS AND METHODS: Violacein production was optimized and was later extracted using ethanol and characterized by liquid chromatography-mass spectrometry and infrared spectroscopy. Then, individual minimum inhibitory concentration (MIC) values for each of the antibiotics were determined followed by violacein-commercial antibiotics (1:1) combinations, tested at different concentrations starting from 500 to 1 µg/ml against major pathogens. RESULTS AND DISCUSSION: The individual MIC data for violacein was found to be 5.7 µg/ml (Staphylococcus aureus), 15.6 µg/ml (Klebsiella pneumoniae), 18.5 µg/ml (Pseudomonas aeruginosa), 20.0 µg/ml (Vibrio cholerae) and 5.7 µg/ml (Salmonella typhi). Violacein-gentamicin and violacein-cefadroxil combinations had MIC of 1.0 µg/ml against S. aureus. Most violacein-macrolide and violacein--aminoglycoside class combinations revealed fractional inhibitory concentration indices (FICI) of <0.5, thus exhibiting synergism. Furthermore, violacein-azithromycin and violacein-kanamycin combination, exhibited significant synergy (FICI-0.3) against S. typhi. CONCLUSION: Violacein works synergistically with most commercial antibiotics and could be used as drug in combination with other antimicrobial agents.

Phenyl propanoid rich extract of edible plant Halosarcia indica exert diuretic, analgesic, and anti-inflammatory activity on Wistar albino rats.

Halosarcia indica (Amaranthaceae), an Edible food used in Indian traditional folk medicine. The present study aims to evaluate the diuretic, analgesic, and anti-inflammatory properties of Halosarcia indica aqueous extract (HAE) on Wistar albino rats. HAE was found to contain chlorogenic acid, sinapic acid, caffeic acid, ferulic acid, scopoletin, quercetin 3-O-ß-D-glucoside and ß-sitosterol-D-glucopyranoside. HAE increased the urine excreted (Diuretic Index: 1.62-1.96 over 2-10 h) and curbed writhing responses significantly (40%) compared to aspirin (54.56%). It showed significant reduction in carrageenan plantar edema (42%) similar to indomethacin (48%). Anti-inflammatory activity by Cotton Granuloma method proved that HAE significantly reduced weights of pellets (dry weight 44.93 mg, wet weight 127.45 mg) similar to diclofenac sodium (dry weight 33.2 mg, wet weight 123.58 mg). Acute toxicity studies showed HAE to be safe until 2000 mg/kg. The above findings evidently propose that HAE has diuretic, analgesic and anti-inflammatory activity as observed with rodent models.

NMR analysis of a series of substituted pyrazolo[3,4-d] pyrimidines-4-amines.

A series of 21 substituted pyrazolo[3,4-d]pyrimidines-4-amines were studied by (1)H and (13)C NMR. The application of two-dimensional techniques, HMQC and HMBC, allowed the complete assignment of the spectra for all the compounds.

Plant phenyl-propanoids-conjugated silver nanoparticles from edible plant Suaeda maritima (L.) dumort. Inhibit proliferation of K562-human myeloid leukemia cells.

The present study portrays the isolation of four phenylpropanoids - ferulic acid (FA), sinapic acid (SA), caffeic acid (CA), and chlorogenic acid (CHA) from the water extract of Suaeda maritima (L.) Dumort, a phytochemically less explored Indian medicinal plant. Further, synthesis and characterization of silver and gold nanoparticles using the isolated phenylpropanoids were done. The silver nanoparticles synthesized from S. maritima water extract along with silver nano-conjugated forms of the isolated compounds exhibited appreciable anti-leukemic activity against K562 cells (human myeloid leukemia). Especially, the ferulic and CA-conjugated silver nanoparticles showed significant (P < .01) activity against leukemia.

Antimicrobial flavonoids isolated from Indian medicinal plant Scutellaria oblonga inhibit biofilms formed by common food pathogens.

Scutellaria oblonga Benth., a hitherto phytochemically unexplored Indian medicinal folklore plant was extracted with acetone and subjected to chromatography to yield nine flavonoids, for the first time from this plant. Antimicrobial assays were performed against 11 foodborne pathogens, and three molecules (Techtochrysin, Negletein and Quercitin-3-glucoside) depicted significant activity. These molecules were assessed for their rate of antibacterial action using time-kill curves which depicted complete inhibition of most of the bacteria within 12-16 h. The significant biofilm-reducing capability exhibited by these three molecules formed a significant finding of the current study. In most of the experiments, a 90-95% reduction in biofilms was observed. Thus, flavonoids as natural molecules from S. oblonga could be further researched to be used as potent antimicrobial and antibiofilm agents.

Development and extraction optimization of baicalein and pinostrobin from Scutellaria violacea through response surface methodology.

OBJECTIVE: To develop a process that involves optimization of the amount of baicalein and pinostrobin from the hydro-methanolic extract of the leaves of Scutellaria violacea by response surface methodology (RSM). MATERIALS AND METHODS: The combinatorial influence of various extraction parameters on the extraction yield was investigated by adopting Box-Behnken experimental design. Preliminary experiments carried out based on the traditional one variable at a time optimization revealed four such operational parameters to play a crucial role by influencing the yield. These four process parameters at three levels were considered to obtain the Box-Behnken experimental design. RESULTS: RSM based model fitted to the resulting experimental data suggested that 52.3% methanol/water, 12.46:1 solvent-solid ratio, 285 rpm agitation and 6.07 h of extraction time are the optimal conditions which yielded a maximized amount of baicalein and pinostrobin of 2.9 and 4.05 mg/g DM. Analysis of variance revealed a high correlation coefficient (R (2) = 0.999 for baicalein and 0.994 for pinostrobin), signifying a good fit between the regression model (second order) and the experimental observations. CONCLUSION: The present study signifies that both the metabolites have been extracted from S. violacea for the first time. Further, this study developed an optimized extraction procedure to obtain maximum yield of the metabolites, which is unique and better than conventional extraction methodology. The operational parameters under optimized conditions accounts for the lowest cost in extraction process thus, providing an efficient, rapid and cost-effective method for isolation and scale up of these commercially vital flavonoids.

Complete reduction of 2H-pyran-2-one moiety of coumarin and 6-methyl coumarin by Colletotrichum capsici.

The microbial transformation of coumarin (1) and 6-methyl coumarin (2) using Colletotrichum capsici gave 2-(3'-hydroxypropyl) phenol (3) and 2-(3'-hydroxypropyl)-4-methyl phenol (4). The phytopathogenic fungi effectively reduced the 2H-pyran-2-one moiety of both parent coumarins to respective alcohols.

Preparation of gold nanoparticles using Salicornia brachiata plant extract and evaluation of catalytic and antibacterial activity.

The current study deals with the synthesis of gold nanoparticles (AuNPs) using Salicornia brachiata (Sb) and evaluation of their antibacterial and catalytic activity. The SbAuNPs showed purple color with a characteristic surface plasmon resonance peak at 532 nm. Scanning electron microscopy and transmission electron microscopy revealed polydispersed AuNPs with the size range from 22 to 35 nm. Energy dispersive X-ray and thin layer X-ray diffraction analysis clearly shows that SbAuNPs was pure and crystalline in nature. As prepared gold nanoparticles was used as a catalyst for the sodium borohydride reduction of 4-nitro phenol to 4-amino phenol and methylene blue to leucomethylene blue. The green synthesized nanoparticles exhibited potent antibacterial activity against the pathogenic bacteria, as evidenced by their zone of inhibition. In addition, we showed that the SbAuNPs in combination with the regular antibiotic, ofloxacin, exhibit superior antibacterial activity than the individual.

Spectroscopy investigation on chemo-catalytic, free radical scavenging and bactericidal properties of biogenic silver nanoparticles synthesized using Salicornia brachiata aqueous extract.

Nanosized silver have been widely used in many applications, such as catalysis, photonics, sensors, medicine etc. Thus, there is an increasing need to develop high-yield, low cost, non-toxic and eco-friendly procedures for the synthesis of nanoparticles. Herein, we report an efficient, green synthesis of silver nanoparticles utilizing the aqueous extract of Salicornia brachiata, a tropical plant of the Chenopodiaceae family. Silver nanoparticles have been characterized by ultraviolet-visible spectroscopy, scanning electron microscopy and transmission electron microscopy. The morphology of the particles formed consists of highly diversified shapes like spherical, rod-like, prism, triangular, pentagonal and hexagonal pattern. However, addition of sodium hydroxide to the extract produces mostly spherical particles. The stable nanoparticles obtained using this green method show remarkable catalytic activity in the reduction of 4-nitro phenol to 4-amino phenol. The reduction catalyzed by silver nanoparticles followed the first-order kinetics, with a rate constant of, 0.6×10(-2) s(-1). The bactericidal activity of the synthesized silver nanoparticles against the pathogenic bacteria, Staphylococcus aureus, Staphylococcus aureus E, Bacillus subtilis and Escherichia coli, was also explored using REMA. The obtained results showed that the minimum inhibitory concentration required to induce bactericidal effect is lower than the control antibiotic, ciprofloxacin. In addition to these, the biogenic synthesized nanoparticles also exhibited excellent free radical scavenging activity.

A new antifeedant clerodane diterpenoid from Tinospora cordifolia.

Phytochemical investigation of the chloroform extract of Tinospora cordifolia yielded a new clerodane diterpenoid tincordin along with tinosporide, 8-hydroxytinosporide, columbin, 8-hydroxycolumbin and 10-hydroxycolumbin. The structure of the new compound was elucidated comprehensively using 1D and 2D NMR methods. All major clerodane diterpenoids isolated were tested for their efficacy as insect antifeedants against Earias vitella, Plutella xylostella and Spodoptera litura.

Tradition to therapeutics: sacrificial medicinal grasses desmostachya bipinnata and imperata cylindrica of India / De la tradición a la terapéutica: hierbas medicinales votivas, desmostachya bipinnata e imperata cylindrica de la India

Desmostachya bipinnata (L.) Stapf. (Fam. Poaceae) and Imperata cylindrica (L.) P. Beauv. (Fam. Poaceae) also traditionally known as Kusha and Dharbha respectively are two grasses that form vital ingredient in various Vedic sacrifices (Yagnas) and rituals. They are found along river beds and plains throughout India and are well known for their medicinal properties as supported by traditional Ayurvedic scriptures and are a vital component in traditional medicinal formulations such as Tripanchamool, Kusadya-ghrita and Kusablecha, etc. to treat many disorders such as dysentery, diuresis, jaundice, skin infections etc. The current review enlightens the bioactive molecules such as flavonoids, glycosides etc. isolated from these grasses so far. Emphasis is laid on the various therapeutic applications of extracts or biomolecules characterized from these medicinal grasses. Reports of antimicrobial, diuretic, anti-ulcerogenic and other activities from both of these plants suggest involvement of various bioactive principles. Also, the future perspectives concerned with medicinal properties of these sacred grasses is discussed.

Desmostachya bipinnata (L.) Stapf. (Fam. Poaceae) e Imperata cylindrica (L.) P. Beauv. (Fam. Poaceae) también conocida tradicionalmente como Kusha y Dharbha respectivamente, son dos plantas medicinales que forman un ingrediente vital en diversos sacrificios védicos (yagnas) y rituales. Se encuentran a lo largo de cauces y llanuras en toda la India y son bien conocidos por sus propiedades medicinales apoyadas por escrituras ayurvédicas tradicionales y son un componente vital en formulaciones medicinales tradicionales como Tripanchamool, Kusadya-ghrita y Kusablecha, etc. para tratar muchos trastornos tales como la disentería, la diuresis, la ictericia, infecciones de la piel, etc. La revisión actual resalta las moléculas bioactivas como los flavonoides, glucósidos etc., aislados de estas plantas hasta ahora. Se hace hincapié en las diversas aplicaciones terapéuticas de los extractos o biomoléculas caracterizadas de estas hierbas medicinales. Informes de actividades antimicrobianas, diuréticas anti-ulcerogénicas y otras de estas dos plantas sugieren la participación de varios principios bioactivos. Además, se discutieron las perspectivas de futuro que se ocupan de las propiedades medicinales de estas hierbas sagradas.

Synergistic antibacterial action of β-sitosterol-D-glucopyranoside isolated from Desmostachya bipinnata leaves with antibiotics against common human pathogens

Desmostachya bipinnata (L.) Stapf, Poaceae, or Kusha in Sanskrit, is a sacred grass used extensively in Indian Vedic practices. It is well known for its medicinal value and is used in traditional Indian medicine to treat microbial infection in combination with other herbs. An effort has been made to isolate and characterize the bioactive compounds from the hydroalcoholic extract of D. bipinnata through bioassay guided fractionation, column chromatography. Their individual or combined antimicrobial properties were determined by the Resazurin Microtitre Assay, the checkerboard assay in combination with antibiotics, and by time kill curve analysis. β-Sitosterol-D-glucopyranoside was the bioactive compound identified to have the best antimicrobial activity (MIC 6-50 µg/ml) and it works synergistically with most antibiotics, especially with ciprofloxacin. Time kill curves showed that BS kills most of the pathogens within 5-10 h. To our knowledge at its best, this is the first time report of antibacterial synergy of β-sitosterol-D-glucopyranoside from D. bipinnata.