Quantification of toxic heavy metals, trace elements and essential minerals contents in traditional herbal medicines commonly utilized in Khyber Pakhtunkhwa, Pakistan.

Traditional herbal medicines and health supplements have been empirically used to treat various disorders but most of them are not standardized and have not been experimentally validated for safety and efficacy. In the present study, various dosage forms of traditional herbal medicines prescribed for specific diseases were collected from local practitioners at different districts of Khyber Pakhtunkhwa, Pakistan. The collected samples were analyzed for heavy metal, trace elements, and minerals using atomic absorption spectroscopy. All the tested samples contained heavy metals, trace elements and minerals in different concentrations. All the samples were tested positive for the presence of toxic heavy metals such as arsenic (As), cadmium (Cd) and lead (Pb). The trace elements like cobalt (Co), iron (Fe), zinc (Zn) and chromium (Cr) were also detected in acceptable range. Similarly, the samples analyzed were rich in some of the essential minerals such as sodium (Na), magnesium (Mg) and calcium (Ca) which are necessary for the proper functioning of the body. The hazard quotient (HQ) values were measured for toxic heavy metals to determine their safe ranges for human body. The HQ values were above the permissible range for arsenic (As) in all detected samples while for cadmium (Cd) and lead (Pb), the values ware above in 50 % of the analyzed samples. The detection of toxic metals and their HQ values beyond the permissible limits in different dosage forms raised questions about their quality. This study suggests that evaluation of traditional herbal remedies for the metals contents and their standardization are strongly recommended for quality assurance and protection of public health.

A novel room-temperature formaldehyde gas sensor based on walnut-like WO3 modification on Ni-graphene composites.

Ternary composite with great modulation of electron transfers has attracted a lot of attention from the field of high-performance room-temperature (RT) gas sensing. Herein, walnut-like WO3-Ni-graphene ternary composites were successfully synthesized by the hydrothermal method for formaldehyde (HCHO) sensing at RT. The structural and morphological analyses were carried out by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). SEM and TEM studies confirmed that walnut-like WO3 nanostructures with an average size of 53 ± 23 nm were functionalized. The Raman and XPS results revealed that, due to the deformation of the O-W-O lattice, surface oxygen vacancies Ov and surface-adsorbed oxygen species Oc were present. The gas-sensing measurement shows that the response of the WO3-Ni-Gr composite (86.8%) was higher than that of the Ni-Gr composite (22.7%) for 500 ppm HCHO at RT. Gas-sensing enhancement can be attributed to a p-n heterojunction formation between WO3 and Ni-Gr, Oc, spill-over effect of Ni decoration, and a special walnut-like structure. Moreover, long term stability (%R = 61.41 ± 1.66) for 30 days and high selectivity in the presence of other gases against HCHO suggested that the proposed sensor could be an ideal candidate for future commercial HCHO-sensing in a real environment.

A p-n Heterojunction Based Pd/PdO@ZnO Organic Frameworks for High-Sensitivity Room-Temperature Formaldehyde Gas Sensor.

As formaldehyde is an extremely toxic volatile organic pollutant, a highly sensitive and selective gas sensor for low-concentration formaldehyde monitoring is of great importance. Herein, metal-organic framework (MOF) derived Pd/PdO@ZnO porous nanostructures were synthesized through hydrothermal method followed by calcination processes. Specifically, porous Pd/PdO@ZnO nanomaterials with large surfaces were synthesized using MOFs as sacrificial templates. During the calcination procedure, an optimized temperature of 500°C was used to form a stable structure. More importantly, intensive PdO@ZnO inside the material and composite interface provides lots of p-n heterojunction to efficiently manipulate room temperature sensing performance. As the height of the energy barrier at the junction of PdO@ZnO exponentially influences the sensor resistance, the Pd/PdO@ZnO nanomaterials exhibit high sensitivity (38.57% for 100 ppm) at room temperature for 1-ppm formaldehyde with satisfactory selectivity towards (ammonia, acetone, methanol, and IPA). Besides, due to the catalytic effect of Pd and PdO, the adsorption and desorption of the gas molecules are accelerated, and the response and recovery time is as small as 256 and 264 s, respectively. Therefore, this MOF-driven strategy can prepare metal oxide composites with high surface area, well-defined morphology, and satisfactory room-temperature formaldehyde gas sensing performance for indoor air quality control.

An Astragalus membranaceus based eco-friendly biomimetic synthesis approach of ZnO nanoflowers with an excellent antibacterial, antioxidant and electrochemical sensing effect.

Nowadays featuring outstanding eco-friendliness, the phytochemical fabrication method of nanostructures is very popular. Here, we propose to utilize the Astragalus membranaceus extract as the reducing and capping agent to stabilize the metal and to avoid the aggregations of nanoparticles during ZnO nanoflowers synthesis procedure. As a result, the whole fabrication procedure was highly efficient and cost-effective without requiring a special environment of high pressure or elevated temperature and without chemical hazards used or produced. After the fabrication, detailed characterization about material morphology and crystal structure was carried out, including scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscope (FTIR). Moreover, the ZnO nanoflowers demonstrated distinctive antibacterial, antioxidant and electrochemical sensing effect. Specifically, ZnO nanoflowers had an antibacterial inhibition zone of 19(±0.7) and 15(±0.8) mm in diameter against the concentration of 50 µL (1 mg/mL) Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), which is greatly improved compared to the reference drug (Kanamycin). Besides, antioxidant activity was also tested using H2O2 free radical scavenging assay and 60% 2,2-diphenyl-1-picrylhydrazyl (DPPH) inhibition of 0.5 mg/mL was reported. Finally, controlled by the diffusion process during the charge transfer procedure, 4-nitorphenol was dramatically reduced and a limit of detection of 0.08 µM by ZnO nanoflowers modified electrode was observed during the cyclic voltammetry (CV) experiment. Because the phenolic compounds originating from Astragalus membranaceus helped to facilitate the electron transfer, the limit of detection was lower compared to other materials, such as copper oxide nanoparticles (Cu2O-NPs), silicon dioxide/silver nanoparticles (SiO2/Ag-NPs), zinc oxide nanoparticles (ZnO-NPs), activated carbon (AC) and cobalt oxide nanocubes (Co3O4). Therefore, featuring easy operation, low-cost and eco-friendliness, our proposed ZnO nanoflowers fabrication method will have a great potential in biomedical and electro-catalytic fields.

Greener synthesis of zinc oxide nanoparticles using Trianthema portulacastrum extract and evaluation of its photocatalytic and biological applications.

Synthesis of nanoparticles (NPs) through "green" chemistry is an exciting area of research with wide applications. Trianthema portulacastrum's extract containing greater amount of reducing agents has been explored first time for the synthesis of ZnO-NPs that characterized with UV/Vis, XRD, FT-IR, SEM,EDX, HR-TEM and XPS. The particles of ZnO-NPs are crystalline and having the size in the range of 25-90 nm. The cell viability of ZnO-NPs was studied using Mouse pre-osteoblast cell line MC3T3-E1 sub-clone 14 cells which confirmed its biocompatibility that render for biomedical applications. The antibacterial properties were evaluated against Staphylococcus aureus and Escherichia coli which showed high potency of synthesized ZnO-NPs against these species. The antifungal activities of ZnO-NPs were screened against Aspergillus niger, Aspergillus flavus, Aspergillus fumigatus of fungal species. The antioxidant activity of the as-synthesized NPs was also studied using DPPH (2, 2-diphenyl-1-picrylhydrazyl) substrate. The ZnO-NPs were evaluated for catalytic activity through degradation of Synozol Navy Blue-KBF textile dye using solar irradiation that causes 91% degradation of the dye in 159 min. Mechanistic pathways for the degradation of Synozol Navy Blue-KBF dye using ZnO-NPs were also proposed from the pattern of the degradation of the dye and the resulting by-products. The results concluded that the ZnO-NPs synthesized by green method have high biological and photocatalytic applications.

An eco-benign synthesis of AgNPs using aqueous extract of Longan fruit peel: Antiproliferative response against human breast cancer cell line MCF-7, antioxidant and photocatalytic deprivation of methylene blue.

Plants mediated synthesis of noble metal nanoparticles is encountered as a clean, environment friendly, lucrative and benign loom. The current study consists of clean and green synthesis of Silver nanoparticles (AgNPs). Phytoconstituents from Longan (Euphorbia longana Lam.) fruit peel were used to reduce Ag+ into AgNPs. Different analytical techniques i.e. UV-vis Spectroscopy, X-ray diffraction spectroscopy (XRD), electron dispersive X-ray (EDX), High-resolution transmission electron microscopy (HRTEM) and Fourier transform infrared spectroscopy (FTIR) were used to analyze the synthesized AgNPs. AgNPs have localized surface plasmon resonance (LSPR) peak at 445 nm which is confirmed by UV-vis spectroscopy. HRTEM showed that the prepared AgNPs are spheroid in shape and well dispersed while XRD results showed that the AgNPs are face centered cubic crystalline. EDX confirmed the elemental composition of AgNPs. The antiproliferative response of AgNPs was assayed by an exhaustive MTT assay. AgNPs showed potent anticancer activity (88%) against breast cancer cells MCF-7. Moreover, the green produced AgNPs effectively scavenged 91% of the stable and harmful 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical which confirms its' efficient antioxidant nature. AgNPs have profound photocatalytic degradation (99%) of methylene blue in a short period of time (7 min). The noteworthy biological and photocatalytic responses of the green and cleanly produced AgNPs are encountered to their well dispersion, petite volume and round shaped structure.

New natural product -an efficient antimicrobial applications of new newly synthesized pyrimidine derivatives by the electrochemical oxidation of hydroxyl phenol in the presence of 2-mercapto-6-(trifluoromethyl) pyrimidine-4-ol as nucleophile.

Some new pyrimidine derivatives have been synthesised by electrochemical oxidation of catechol (1a) in the existence of 2-mercapto-6-(trifluoromethyl) pyrimidine-4-ol (3) as a nucleophile in aqueous solution using Cyclic Voltammetric and Controlled Potential Coulometry. The catechol has been oxidised to o-quinone through electrochemical method and participative in Michael addition reaction, leading to the development of some new pyrimidine derivatives. The products were achieved in good yield with high pureness. The mechanism of the reaction has been conformed from the Cyclic Voltammetric data and Controlled Potential Coulometry. After purification, the compounds were characterised using modern techniques. The synthesised materials were screened for antimicrobial actions using Gram positive and Gram negative strain of bacteria. These new synthesised pyrimidine derivatives showed very good antimicrobial activity.

Biomedical applications of green synthesized Nobel metal nanoparticles.

Synthesis of Nobel metal nanoparticles, play a key role in the field of medicine. Plants contain a substantial number of organic constituents, like phenolic compounds and various types of glycosides that help in synthesis of metal nanoparticles. Synthesis of metal nanoparticles by green method is one of the best and environment friendly methods. The major significance of the green synthesis is lack of toxic by-products produced during metal nanoparticle synthesis. The nanoparticles, synthesized by green method show various significant biological activities. Most of the research articles report the synthesized nanoparticles to be active against gram positive and gram negative bacteria. Some of these bacteria include Escherichia coli, Bacillus subtilis, Klebsiella pneumonia and Pseudomonas fluorescens. The synthesized nanoparticles also show significant antifungal activity against Trichophyton simii, Trichophyton mentagrophytes and Trichophyton rubrum as well as different types of cancer cells such as breast cancer cell line. They also exhibit significant antioxidant activity. The activities of these Nobel metal nano-particles mainly depend on the size and shape. The particles of small size with large surface area show good activity in the field of medicine. The synthesized nanoparticles are also active against leishmanial diseases. This research article explores in detail the green synthesis of the nanoparticles and their uses thereof.

Visible light inactivation of E. coli, Cytotoxicity and ROS determination of biochemically capped gold nanoparticles.

The formation of metal nanoparticles is one of the most vast and intensifying research areas in favor of prospective applications for the advancement of new technologies. It is a well-founded, significant feature of green chemistry that making marvelous interconnection between nano-biotechnology and microbial biotechnology. In the present research, the aqueous extract of medicinally important plant Coptis Chinensis (in Chinese called "gold thread") was applied for the synthesis of gold nanoparticles (Au-NPs). The crystalline structure, size, shape and dispersion of Au-NPs were confirmed by using various characterization techniques i.e. X-ray Diffraction (XRD), High Resolution Transmission Electron Microscope (HRTEM) and Energy Dispersive X-ray (EDX). Well dispersed face centered cubic crystalline structures were obtained in the this contribution. The possible phyto-chemicals involved in the reduction and stabilization of Au-NPs were confirmed by Fourier Transform Infrared Spectroscopy (FT-IR). The prepared NPs were tested against highly drug resistance bacterium Escherichia coli both in light and dark. The results illustrated that the antibacterial efficiency of photo irradiated Au-NPs was several times higher than in dark Au-NPs. The zone of inhibition for irradiated Au-NPs was19 ± 0.5 mm, which was higher than in dark 14 ± 0.4 mm. This high antibacterial activity of photo irradiated Au-NPs are due to the production of reactive oxygen species which is responsible for the inhibition of bacteria.

Biophysical and molecular docking approaches for the investigation of biomolecular interactions between amphotericin B and bovine serum albumin.

Exogenous drug as an antidote to treat various infections get absorbed in the blood circulatory system of a human can directly contact with transporter proteins such as serum albumin. Therefore, for rational drug discovery, understanding the biomolecular interaction between drugs and protein is highly important. In this contribution, we describe the possible interactions between an antifungal drug Amphotericin B (AmB) and Bovine Serum Albumin (BSA) using multi-spectroscopic techniques and further confirmed through in-silico approaches. Binding effects of AmB on BSA conformation, surface morphology, topology, and stability were determined by Ultraviolet-visible spectroscopy (UV), Fourier transform infrared spectroscopy (FT-IR), Circular Dichroism (CD), Transmission Electron Microscopy (TEM), Dynamic Light Scattering (DLS), Fluorescence Spectroscopy and Molecular dynamic simulations. The Stern-Volmer equation was used to determine the binding site (0.4) and binding constant (8.16×105M-1). The intrinsic intensity of the native BSA was quenched by AmB through static quenching mechanism. The calculated Gibbs free energy value (-8.70kcal/mol) indicated the involvement of hydrogen bonding and hydrophobic contacts in BSA-AmB interaction. The hydrodynamic radii and surface contact area of BSA-AmB molecules are decreasing which can strongly support the stabilizing action of complex particles. Moreover, the finding of this work will provide information for the drug designers to further study the AmB binding mechanism and their pharmacodynamics and pharmacokinetics features in order to achieve better therapeutic efficacy.

Facile and green synthesis of phytochemicals capped platinum nanoparticles and in vitro their superior antibacterial activity.

The increase in the severe infectious diseases and resistance of the majority of the bacterial pathogens to the available drug is a serious problem now a day. In order to overcome this problem it is necessary to develop new therapeutic agents which are non-toxic and more effective to inhibit these microbial pathogens. For this purpose the plant extract of highly active medicinal plant, Taraxacum laevigatum was used for the synthesis of platinum nanoparticles (PtNPs) to enhance its bio-activities. The surface plasmon resonance peak appeared at 283nm clearly represent the formation of PtNPs. The results illustrate that the bio-synthesized PtNPs were uniformly dispersed, small sized (2-7nm) and spherical in shape. The green synthesized PtNPs were characterized by UV-vis spectroscopy, XRD, TEM, SEM, EDX, DLS and FTIR. These nanoparticles were tested against gram positive bacteria (Bacillus subtilis) and gram negative bacteria (Pseudomonas aeruginosa). The bio-synthesized PtNPs were examined to be more effective against both of the bacteria. The results showed, that the zone of inhibition of PtNPs against P. aeruginosa was 15 (±0.5) mm and B. subtilis was 18 (±0.8) mm. The most significant outcome of this examination is that PtNPs exhibited strong antibacterial activity against P. aeruginosa and B. subtilis which have strong defensive system against several antibiotics.

Antioxidant and catalytic applications of silver nanoparticles using Dimocarpus longan seed extract as a reducing and stabilizing agent.

In this study, a simple and environmental friendly method was developed for the synthesis of silver nanoparticles (Ag-NPs) using Dimocarpus longan seed extract as a source of reducing and stabilizing agent. The appearance of a surface plasmon resonance peak at 432nm confirmed the synthesis of silver nanoparticles (UV-visible spectroscopy). The biosynthesized Ag-NPs were face centered cubic structures (XRD) with an approximate particle size of 40nm (TEM). Optimization study revealed that 10mL of plant extract (2mM AgNO3) at 180min of incubation resulted the optimum product synthesis. Poly-phenolic compounds were majorly involved in the reduction of silver ions into Ag-NPs (FT-IR). The catalytic activities of Ag-NPs were assessed against the photo-catalytic degradation of methylene blue and chemo catalytic reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). The results indicated that the prepared Ag-NPs have strong chemo catalytic activity with a complete reduction of 4-NP to 4-AP within 10min. Similarly, Ag-NPs displayed higher photo-catalytic activity (K=0.12) as compared to commercial Ag-NPs (K=0.003). In addition, the silver nanoparticles exhibited a promising antioxidant activity in scavenging DPPH radicals. The findings of this study conclude that the biosynthesized Ag-NPs are promising agent possessing strong catalytic and reducing properties.

Photocatalytic and antibacterial response of biosynthesized gold nanoparticles.

Increase in the bacterial resistance to available antibiotics and water contamination by different toxic organic dyes are both severe problems throughout the world. To overcome these concerns, new methodologies including synthesis of nontoxic, human friendly and efficient nanoparticles is required. These nanoparticles not even inhibit the growth of microorganisms but are also effective in the degradation of toxic organics in waste water thus providing a clean and human friendly environment. The use of plants extracts to synthesize and stabilize noble metal nanoparticles have been considered as safe, cost-effective, eco-benign and green approach nowadays. In the present study, Longan fruit juice proficiently reduced ionic gold (Au(+3)) to gold nanoparticles (AuNPs) as well as mediated the stabilization of AuNPs. The antibacterial activity of AuNPs was carried out against both gram positive and gram negative bacteria using agar well diffusion method, followed by the determination of Minimum inhibitory concentration (MIC) values. AuNPs were found to have significant antibacterial activity against Escherichia coli with MIC values of 75µg/ml while outstanding MIC values of 50µg/ml against Staphylococcus areous and Basilus subtilus. AuNPs revealed significant photocatalytic degradation (76%) of methylene blue in time period of 55min, indicating the effective photocatalytic property of biosynthesized AuNPs (K=0.29/min, r(2)=0.95). The considerable antibacterial and photocatalytic activities of the photosynthesized AuNPs can be attributed towards their small size, spherical morphology and uniform dispersion. Our finding suggests the possible therapeutic potential of biogenic AuNPs in the development of new antibacterial agents as well as in the development of effective photocatalysts.

Isatis tinctoria mediated synthesis of amphotericin B-bound silver nanoparticles with enhanced photoinduced antileishmanial activity: A novel green approach.

After malaria, Leishmaniasis is the most prevalent infectious disease in terms of fatality and geographical distribution. The availability of a limited number of antileishmanial agents, emerging resistance to the available drugs, and the high cost of treatment complicate the treatment of leishmaniasis. To overcome these issues, critical research for new therapeutic agents with enhanced antileishmanial potential and low treatment cost is needed. In this contribution, we developed a green protocol to prepare biogenic silver nanoparticles (AgNPs) and amphotericin B-bound biogenic silver nanoparticles (AmB-AgNPs). Phytochemicals from the aqueous extract of Isatis tinctoria were used as reducing and capping agents to prepare silver nanoparticles. Amphotericin B was successfully adsorbed on the surface of biogenic silver nanoparticles. The prepared nanoparticles were characterized by various analytical techniques. UV-Visible spectroscopy was employed to detect the characteristic localized surface plasmon resonance peaks (LSPR) for the prepared nanoparticles. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) studies revealed the formation of spherical silver nanoparticles with an average particle size of 10-20nm. The cubic crystalline structure of the prepared nanoparticles was confirmed by X-ray diffraction (XRD) study. FTIR spectroscopic analysis revealed that plant polyphenolic compounds are mainly involved in metal reduction and capping. Under visible light irradiation, biogenic silver nanoparticles exhibited significant activity against Leishmania tropica with an IC50 value of 4.2µg/mL. The leishmanicidal activity of these nanoparticles was considerably enhanced by conjugation with amphotericin B (IC50=2.43µg/mL). In conclusion, the findings of this study reveal that adsorption of amphotericin B, an antileishmanial drug, to biogenic silver nanoparticles, could be a safe, more effective and economic alternative to the available antileishmanial strategies.

Ultra-efficient photocatalytic deprivation of methylene blue and biological activities of biogenic silver nanoparticles.

Phytosynthesis of metal nanoparticles is considered as a safe, cost-effective, and green approach. In this study, silver nanoparticles (AgNPs) were successfully synthesized using the aqueous extract of Lychee (Litchi chinensis) fruit peel and an aqueous solution of silver nitrate (AgNO3). The synthesized nanoparticles were characterized by several analytical techniques i.e. UV-Vis Spectroscopy, XRD (X-ray diffraction spectroscopy), EDX (electron dispersive X-ray), SAED (selected area electron diffraction), HRTEM (high-resolution transmission electron microscopy), and FTIR (Fourier transform infrared spectroscopy). HRTEM and XRD results indicated that the prepared AgNPs are spherical in shape, well dispersed and face centered cubic crystalline. AgNPs showed potent antibacterial properties against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. The minimum inhibitory concentration (MIC) values were 125µg against E. coli and 62.5µg against both S. aureus and B. subtilis. AgNPs induce efficient cell constituent release from bacterial cells, which indicates the deterioration of cytoplasmic membrane. Moreover, antioxidant studies on the as-synthesized nanoparticles reveal efficient scavenging of the stable or harmful DPPH free radical. The cytotoxicity assay confirmed that biosynthesized AgNPs are nontoxic to normal healthy RBCs. AgNPs exhibited consistent release of Ag(+) determined by ICP-AES analysis. AgNPs exhibited extraordinary photocatalytic degradation (99.24%) of methylene blue. On the other hand, commercial silver nanoparticles have moderate biological activities against the tested bacterial strains and negligible photocatalytic degradation of methylene blue. The significant biological and photocatalytic activities of the biosynthesized silver nanoparticles are attributed to their small size, spherical morphology and high dispersion.

Photocatalytic, antimicrobial activities of biogenic silver nanoparticles and electrochemical degradation of water soluble dyes at glassy carbon/silver modified past electrode using buffer solution.

In the present research work a novel, nontoxic and ecofriendly procedure was developed for the green synthesis of silver nano particle (AgNPs) using Caruluma edulis (C. edulis) extract act as reductant as well as stabilizer agents. The formation of AgNPs was confirmed by UV/Vis spectroscopy. The small and spherical sizes of AgNPs were conformed from high resolution transmission electron microscopy (HRTEM) analysis and were found in the range of 2-10nm, which were highly dispersion without any aggregation. The crystalline structure of AgNPs was conformed from X-ray diffraction (XRD) analysis. For the elemental composition EDX was used and FTIR helped to determine the type of organic compounds in the extract. The potential electrochemical property of modified silver electrode was also studied. The AgNPs showed prominent antibacterial motion with MIC values of 125 µg/mL against Bacillus subtilis and Staphylococcus aureus while 250 µg/mL against Escherichia coli. High cell constituents' release was exhibited by B. subtilis with 2 × MIC value of silver nanoparticles. Silver nanoparticles also showed significant DPPH free radical scavenging activity. This research would have an important implication for the synthesis of more efficient antimicrobial and antioxidant agent. The AgNP modified electrode (GC/AgNPs) exhibited an excellent electro-catalytic activity toward the redox reaction of phenolic compounds. The AgNPs were evaluated for electrochemical degradation of bromothymol blue (BTB) dyes which showed a significant activity. From the strong reductive properties it is obvious that AgNPs can be used in water sanitization and converting some organic perilous in to non-hazardous materials. The AgNPs showed potential applications in the field of electro chemistry, sensor, catalyst, nano-devices and medical.