Correction: Biogenic synthesis of silver nanoparticles using Rubus fruticosus extract and their antibacterial efficacy against Erwinia caratovora and Ralstonia solanacearum phytopathogens.

[This corrects the article DOI: 10.1039/D3RA06723H.].

Biogenic synthesis of silver nanoparticles using Rubus fruticosus extract and their antibacterial efficacy against Erwinia caratovora and Ralstonia solanacearum phytopathogens.

In the current research, we produced green, cost-effective, eco-friendly silver nanoparticles using a single-step approach. Plants are considered highly desirable systems for nanoparticle synthesis because they possess a variety of secondary metabolites with significant reduction potential. In the current research, the dried leaf extract of Rubus fruticosus was utilized as a capping and reducing agent for the fabrication of silver nanoparticles, to prepare reliable biogenic silver nanoparticles and subsequently to investigate their potential against some common phytopathogens. The prepared silver nanoparticles were exploited to quantify the total flavonoid content (TFC), total phenolic content (TPC) and DPPH-based antioxidant activity. Different concentrations of aqueous extracts of plant leaves and silver nitrate (AgNO3) were reacted, and the color change of the reactant mixture confirmed the formation of Rubus fruticosus leaf-mediated silver nanoparticles (RFL-AgNPs). A series of characterization techniques such as UV-vis spectroscopy, transmission electron microscopy, energy dispersive X-ray analysis and X-ray diffraction revealed the successful synthesis of silver nanoparticles. The surface plasmon resonance peak appeared at 449 nm. XRD analysis demonstrated the crystalline nature, EDX confirmed the purity, and TEM demonstrated that the nanoparticles are mostly spherical in form. Furthermore, the biosynthesized nanoparticles were screened for in vitro antibacterial activity, antioxidant activity, and total phenolic and flavonoid content. The nanoparticles were used in different concentrations alone and in combination with plant extracts to inhibit Erwinia caratovora and Ralstonia solanacearum. In high-throughput assays used to inhibit these plant pathogens, the nanoparticles were highly toxic against bacterial pathogens. This study can be exploited for planta assays against phytopathogens utilizing the same formulations for nanoparticle synthesis and to develop potent antibacterial agents to combat plant diseases.

Therapeutic potential of natural products and antibiotics against bovine mastitis pathogen of cows and buffaloes.

The present study aims to evaluate the prevalence and antimicrobial sensitivity of Staphylococcus aureus associated with bovine mastitis to selected antibiotics and plant extracts. In the current study, 140 milk samples were collected from cows and buffaloes. Among the 140 samples, 93 samples were positive for sub-clinical mastitis based on the California Mastitis Test (CMT). Out of the total positive samples, 45 were confirmed for S. aureus on a Mannitol salt agar media. The antimicrobial susceptibility test revealed that 44.82% of the isolates were resistant to cefoxitin (oxacillin) confirming methicillin-resistant S. aureus (MRSA) with a higher percentage (51.61%) in the buffalo than in the cow samples. Furthermore, the PCR assay confirmed the presence of the mecA gene in all the MRSA isolates. Among the seven tested antibiotics, sulfamethoxazole + trimethoprim showed high efficacy (71.1%) against methicillin-susceptible S. aureus isolates (MSSA). Oxytetracycline and sulfamethoxazole + trimethoprim showed 20% efficacy against MRSA followed by enrofloxacin (10%). On the other hand, the tested samples from Pistacia chinensis revealed that the ethyl acetate extract of bark showed a maximum zone of inhibition of 21.3 mm against MSSA and MRSA isolates at 3 000 µg/disc. Moreover, the methanol extract of Cotoneaster microphyllus formed a 12.3 mm and 9.1 mm zone of inhibition against the MSSA and MRSA isolates, respectively.

Silver and gold nanoparticles induced differential antimicrobial potential in calli cultures of Prunella vulgaris.

BACKGROUND: Prunella vulgaris is medicinally important plant containing high-valued chemical metabolites like Prunellin which belong to family Lamiaceae and it is also known as self-heal. In this research, calli culture were exposed to differential ratios of gold (Au) and silver (Ag) nanoparticles (1:1, 1:2, 1:3, 2:1 and 3:1) along with naphthalene acetic acid (2.0 mg NAA) to investigate its antimicrobial potential. A well diffusion method was used for antimicrobial properties. RESULTS: Here, two concentrations (1 and 2 mg/6 µl) of all treated calli cultures and wild plants were used against Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, Bacillus atrophaeus, Bacillus subtilis, Agrobacterium tumefaciens, Erwinia caratovora and Candida albicans. Dimethyl sulfoxide (DMSO) and antibiotics were used as negative and positive controls. Here, the calli exposed to gold (Au) nanoparticles (NPs) and 2.0 mg naphthalene acetic acid (NAA) displayed the highest activity (25.7 mm) against Salmonella typhi than other extracts, which was considered the most susceptible species, while Agrobacterium tumefaciens and Candida albicans was the most resistance species. A possible mechanism of calli induced nanoparticles was also investigated for cytoplasmic leakage. CONCLUSION: From the above data it is concluded that Prunella vulgaris is medicinally important plant for the development of anti-microbial drugs using nanotechnology and applicable in various pharmaceutical research.

In Vivo Analgesic, Anti-Inflammatory, and Anti-Diabetic Screening of Bacopa monnieri-Synthesized Copper Oxide Nanoparticles.

In this work, an ecofriendly approach for biogenic production of copper oxide nanoparticles (CuO-NPs) was proposed by utilizing the Bacopa monnieri leaf extract as a reducing and stabilizing agent. The synthesis of CuO-NPs was instantly confirmed by a shift in the color of the copper solution from blue to dark gray. The use of UV-visible spectroscopy revealed a strong narrow peak at 535 nm, confirming the existence of monoclinic-shaped nanoparticles. The average size of CuO-NPs was 34.4 nm, according to scanning electron microscopy and transmission electron microscopy studies. The pristine crystalline nature of CuO-NPs was confirmed by X-ray diffraction. The monoclinic form of CuO-NPs with a crystallite size of 22 nm was determined by the sharp narrow peaks corresponding to 273, 541, 698, 684, and 366 Bragg's planes at different 2θ values. The presence of different reducing metabolites on the surface of CuO was shown by Fourier transform infrared analysis. The biological efficacy of CuO-NPs was tested against Helicobacter felis, Helicobacter suis, Helicobacter salomonis. and Helicobacter bizzozeronii. H. suis was the most susceptible strain with an inhibition zone of 15.84 ± 0.89 mm at 5 mg/mL of NPs, while the most tolerant strain was H. bizzozeronii with a 13.11 ± 0.83 mm of inhibition zone. In in vivo analgesic activity, CuO-NPs showed superior efficiency compared to controls. The maximum latency time observed was 7.14 ± 0.12 s at a dose level of 400 mg/kg after 90 min, followed by 5.21 ± 0.29 s at 400 mg/kg after 60 min, demonstrating 65 and 61% of analgesia, respectively. Diclofenac sodium was used as a standard with a latency time of 8.6 ± 0.23 s. The results observed in the rat paw edema assays showed a significant inhibitory activity of the plant-mediated CuO-NPs. The percentage inhibition of edema was 74% after 48 h for the group treated with CuO-NPs compared to the control group treated with diclofenac (100 mg/kg) with 24% edema inhibition. The solution of CuO-NPs produced 82% inhibition of edema after 21 days when compared with that of the standard drug diclofenac (73%). CuO-NPs vividly lowered glucose levels in STZ-induced diabetic mice, according to our findings. Blood glucose levels were reduced by about 33.66 and 32.19% in CuO-NP and (CuO-NP + insulin) groups of mice, respectively. From the abovementioned calculations, we can easily conclude that B. monnieri-synthesized CuO-NPs will be a potential antibacterial, anti-diabetic, and anti-inflammatory agent on in vivo and in vitro basis.

Exploring the therapeutic potential of Hibiscus rosa sinensis synthesized cobalt oxide (Co3O4-NPs) and magnesium oxide nanoparticles (MgO-NPs).

Herein, we present a green, economic and ecofriendly protocol for synthesis of cobalt oxide (Co3O4-NPs) and magnesium oxide nanoparticles (MgO-NPs) for multifaceted biomedical applications. In the study, a simple aqueous leaf extract of Hibiscus rosa sinensis, was employed for the facile one pot synthesis of Co3O4-NPs and MgO-NPs. The well characterized NPs were explored for multiple biomedical applications including bactericidal activity against urinary tract infection (UTI) isolates, leishmaniasis, larvicidal, antidiabetic antioxidant and biocompatibility studies. Our results showed that both the NPs were highly active against multidrug resistant UTI isolates as compared to traditional antibiotics and induced significant zone of inhibition against Proteus Vulgaris, Pseudomonas Aurigenosa and E.coli. The NPs, in particular Co3O4-NPs also showed significant larvicidal activity against the Aedes Aegypti, the mosquitoes involve in the transmission of Dengue fever. Similarly, excellent leishmanicidal activity was also observed against both the promastigote and amastigote forms of the parasite. Furthermore, the particles also exhibited considerable antidiabetic activity by inhibiting α-amylase and α-glucosidase enzymes. The biosynthesized NPs were found to be excellent antioxidant and biocompatible nanomaterials. Owing to ecofriendly synthesis, non-toxic and biocompatible nature, the Hibiscus rosa sinensis synthesized Co3O4-NPs and MgO-NPs can be exploited as potential candidates for multiple biomedical applications.

Elicitation of Submerged Adventitious Root Cultures of Stevia rebaudiana with Cuscuta reflexa for Production of Biomass and Secondary Metabolites.

Stevia rebaudiana is an important medicinal plant that belongs to the Asteraceae family. The leaves of Stevia rebaudiana are a rich source of many health-promoting agents such as polyphenols, flavonoids, and steviol glycoside, which play a key role in controlling obesity and diabetes. New strategies such as the elicitation of culture media are needed to enhance the productivity of active components. Herein, the Cuscuta reflexa extracts were exploited as elicitors to enhance the productivity of active components. Cuscuta reflexa is one of the parasitic plants that has the ability to elongate very fast and cover the host plant. Consequently, it may be possible that the addition of Cuscuta reflexa extracts to adventitious root cultures (ADR) of Stevia rebaudiana may elongate the root more than control cultures to produce higher quantities of the desired secondary metabolites. Therefore, the main objective of the current study was to investigate the effect of Cuscuta reflexa extract as a biotic elicitor on the biomass accumulation and production of antioxidant secondary metabolite in submerged adventitious root cultures of Stevia rebaudiana. Ten different concentrations of Cuscuta reflexa were added to liquid media containing 0.5 mg/L naphthalene acetic acid (NAA). The growth kinetics of adventitious roots was investigated for a period of 49 days with an interval of 7 days. The maximum biomass accumulation (7.83 g/3 flasks) was observed on medium containing 10 mg/L extract of Cuscuta reflexa on day 49. As the concentration of extract increases in the culture media, the biomass gradually decreases after 49 days of inoculation. In this study, the higher total phenolics content (0.31 mg GAE/g-DW), total flavonoids content (0.22 mg QE/g-DW), and antioxidant activity (85.54%) were observed in 100 mg/L treated cultures. The higher concentration (100 mg/L) of Cuscuta reflexa extract considerably increased the total phenolics content (TPC), total phenolics production (TPP), total flavonoids content (TFC), total flavonoids production (TFP), total polyphenolics content (TPPC), and total polyphenolics production (TPPP). It was concluded that the extract of Cuscuta reflexa moderately improved biomass accumulation but enhanced the synthesis of phenolics, flavonoids, and antioxidant activities. Here, biomass's independent production of secondary metabolites was observed with the addition of extract. The present study will be helpful to scale up adventitious roots culture into a bioreactor for the production of secondary metabolites rather than biomass accumulation in medicinally important Stevia rebaudiana.

Vitamin D exerts neuroprotection via SIRT1/nrf-2/ NF-kB signaling pathways against D-galactose-induced memory impairment in adult mice.

Vitamin D (Vt. D) is one of the vital hormone having multiple functions in various tissues, including brain. Several evidences reported that Vt. D plays a significant part in memory and cognition as its inadequate amount may accelerate cognitive impairment. This study shows for the first time the antioxidant potential of Vt. D against D-Galactose (D-gal) induced oxidative stress mediated Alzheimer disease (AD) pathology in male adult albino mice. The result reveals that the mice exposed to D-gal (120 mg/kg) for eight weeks have pre-and post-synaptic dysfunction and impaired memory investigated through Morris water maze and Y-maze tests. This is followed by the suppressed Nuclear factor erythroid 2-related factor 2 (NRF2), Heme Oxygenase-1 (HO-1) and elevated expressions of Nuclear Factor kappa B (NF-kB), Tumor Necrosis Factor alpha (TNF-α) and Interleukin 1 beta (IL-1ß) proteins in the brain homogenates evaluated through western blotting technique. On the other hand Vt. D (100 µg/kg) administration (three times a week for 4 weeks) activated Silent mating type information regulation 2 homolog 1 (SIRT1) and significantly improved both the neuronal synapse and memory, reduced oxidative stress by upregulating NRF-2 and HO-1 and downregulating NF-kB, TNF-α and IL-1ß proteins expression. Most importantly, Vt. D significantly abrogate the amyloidogenic pathway of amyloid beta (Aß) production against D-gal in the brains of adult male albino mice. These results reveal that Vt. D being an antioxidant agent plays a vital role in reducing the AD pathophysiology in D-gal induced animal model of aging, therefore act as a potential drug candidate in neurodegenerative diseases.

Biosynthesis of antioxidative enzymes and polyphenolics content in calli cultures of Prunella vulgaris L. in response to auxins and cytokinins.

Prunella vulgaris L. is one of the therapeutic herbs containing various polyphenolics, which is used for multiple medicinal purposes. In this study, plant growth regulators (PGRs)-induced calli cultures from seed-derived leaf explants were exploited for the production of stress enzymes and polyphenolics. A growth curve was plotted for each PGR for 49 days period, which showed a distinct lag, log and decline phases. Here, the combination of naphthalene acetic acid (NAA) and 6-benzyleadenine (BA; 0.5 and 2.0 mg l-1) produced maximum fresh (6.32 FW-g/100 ml) and dry biomass (0.75 DW-g/100 ml) in contrast to control. The maximum synthesis of SOD (0.0154 FW-nM/min/mg) was detected on media comprising mixture of NAA and BA (1.5 mg l-1), while POD enzyme (0.366 FW-nM/min/mg) was higher at 0.5 mg l-1 NAA and 2, 4-dichlorophenoxy acetic acid. Further, NAA and BA (1.5 and 2.0 mg l-1) boosted up the synthesis of phenolics (18.83 GAE-mg/g-DW) and flavonoids content (18.05 RE-mg/g-DW) than control. Moreover, NAA of 1.0 and 2.0 mg l-1 were found supportive for maximum antioxidant activity (87.4%) and total protein (716 µg BSAE/mg-DW). This study will contribute in the development of cell culture in fermenter and synthesis of antioxidant secondary metabolites for commercial uses.

Monitoring Bioaccumulation (in Gills and Muscle Tissues), Hematology, and Genotoxic Alteration in Ctenopharyngodon idella Exposed to Selected Heavy Metals.

Health and environmental problems arising from metals present in the aquatic ecosystem are very well known. The present study investigated toxicological effects of LC15 of metals such as copper, chromium, and lead for 24, 48, 72, and 96 h on hematological indices, RBC nucleus and cell morphology, and gill and muscle tissues of grass carp (Ctenopharyngodon idella). Experimental dose concentrations of copper were 1.5, 1.4, 1.2, and 1 mgL-1. Similarly, dose concentrations of chromium were 25.5, 22.5, 20, and 18 mgL-1 while those of lead were 250, 235, 225, and 216 mgL-1, respectively. Maximum decrease in the concentration of Hb, RBCs, and monocytes was observed against chromium, while maximum increase in the concentration of lymphocytes was reported against lead. Abnormalities such as single and double micronuclei, deformed nucleus, nuclear shift, irregular nucleus, deformed cells, microcyte cells, and vacuolated and swollen cells were observed. Gill tissues absorbed maximum concentration of lead followed by chromium and copper. Muscle tissues also absorbed maximum concentration of lead followed by chromium and copper, respectively. Histological alterations such as epithelial lifting, interlamellar spaces, club gill filaments, gill bridging, curling filaments, swelling and fusion of cells, irregular cells, destruction of epithelial cells, cellular necrosis, and inflammatory cells were observed in gill tissues while inflammation and necrosis of muscle fibers, degeneration of muscle fibers, edema of muscle bundles, zig-zag of muscle fibers, and lesions were observed in muscle tissues of fish exposed with different doses of these heavy metals, indicating the toxicity of metals to aquatic fauna as well as to human being via food chain.

Extraction and isolation of important bioactive compounds from the fruit of Physalis ixocarpa.

The current study investigates pharmaceutically important bioactive compounds in the fruits of Physalis ixocarpa. Two different extractions methods were used to study its effect on percent extract yield, recovery of bioactive compounds and antioxidant activity of the extracts. The data indicated that Soxhlet extraction had high efficiency of recovery than maceration method for extracting compounds; percent extract yield and antioxidant activity of the extracts. In maceration, the percent extract yield was found to be in order of water >methanol >ethyl acetate whereas in Soxhlet extraction, it was in order of methanol >water >ethyl acetate. Ethyl acetate extract produced by Soxhlet extraction showed strong antioxidant activity of 59.7% (250ppm) as compared to other extracts. Analysis of ethyl acetate extract showed the presence of Triglyceride. GC-MS study of triglyceride revealed the presence of trilinoleinic acid (9,12-Octadecdienoic acid), tripalmitin (hexadecanoic acid) and trioleinic acid (9-Octa decenoic acid). Four impure and three pure compounds were isolated from crude methanol extract of the fruit. The structure of pure compounds were identified by NMR and characterized as sugar, glucose and fructose.