Zia-Ur-Rehman Mashwani

Synthesis in plants and plant extracts of silver nanoparticles with potent antimicrobial properties: current status and future prospects.

Synthesis of silver nanoparticles by plants and plant extracts (green synthesis) has been developed into an important innovative biotechnology, especially in the application of such particles in the control of pathogenic bacteria. This is a safer technology, biologically and environmentally, than synthesis of silver nanoparticles by chemical or physical methods. Plants are preferable to microbes as agents for the synthesis of silver nanoparticles because plants do not need to be maintained in cell culture. The antibacterial activity of bionanoparticles has been extensively explored during the past decade. This review examines studies published in the last decade that deal with the synthesis of silver nanoparticles in plants and their antibacterial activity.

An ethno botanical perspective of traditional medicinal plants from the Khattak tribe of Chonthra Karak, Pakistan.

ETHNO PHARMACOLOGICAL RELEVANCE The present study was carried out with an aim to gather, evaluate and analyze the ethno botanical information of medicinal uses of the plant species possessed by the native Khattak tribe of the Chonthra, district Karak Pakistan. The region with poor documentation of traditional knowledge, preserving the local traditional knowledge, reporting new as well as rarely reported medicinal properties of medicinal plants, to be tested experimentally for validation. MATERIAL AND METHOD The medicinal uses of existing plant species were documented by oral communication with 103 people, all over above 60 years of age, born and residing in Chonthra. Information was gathered by semi-structured interviews with further analysis by indices like Relative frequency citation RFC and Medicinal use value MUV. RESULTS The study resulted with medicinal information on 66 plants species belonging to 34 families (using against 58 health related problems with 83 different preparations mainly administered orally and topical). The dominant families include Brasicaceae and Limiaceae. Withania coagulans and Pegnum harmala were the plant species quoted 100% by the informants with RFC values 1 each. The MUV were scattered between 1.24 and 0.03. The highest MUV were W. coagulans 1.24, Pegnum harmala 1.18, Fagonia cretica 1.14. This study for the first time include Nepeta lagopsis to the ethnobotanical wealth. CONCLUSIONS This study was an extension to the ethnobotanical research conducted in Khyber Pakhtunkhwa (KPK) Pakistan. The target area being small and less number of plants with limited traditional knowledge can serve basis for further work focusing on rarely or non- reported plant species of pharmacological and phytochemical importance with active metabolite capable of broadening the sources of new drugs.

Applications of plant terpenoids in the synthesis of colloidal silver nanoparticles.

Green chemistry is the design of chemical products and processes that reduce or eliminate the generation of hazardous substances. Since the last few years, natural products especially plant secondary metabolites have been extensively explored for their potency to synthesize silver nanoparticles (AgNPs). The plant-based AgNPs are safer, energy efficient, eco-friendly, and less toxic than chemically synthesized counterparts. The secondary metabolites, ubiquitously found in plants especially the terpenoid-rich essential oils, have a significant role in AgNPs synthesis. Terpenoids belong to the largest family of natural products and are found in all kinds of organisms. Their involvement in the synthesis of plant-based AgNPs has got much attention in the recent years. The current article is not meant to provide an exhaustive overview of green synthesis of nanoparticles, but to present the pertinent role of plant terpenoids in the biosynthesis of AgNPs, as capping and reducing agents for development of uniform size and shape AgNPs. An emphasis on the important role of FTIR in the identification and elucidation of major functional groups in terpenoids for AgNPs synthesis has also been reviewed in this manuscript. It was found that no such article is available that has discussed the role of plant terpenoids in the green synthesis of AgNPs.

Effect of silver nanoparticles and silver nitrate on growth of rice under biotic stress

This study was organised to check the effect of silver nanoparticles and silver nitrate on rice growth against biotic stress. Silver nanoparticles were synthesised by using plant extract as reducing agent, followed by characterisation through UV Vis spectroscopy, XRD, EDS and SEM. Aspergillus application significantly reduced rice plant fresh mass (0.9%), dry mass (0.21%), root length (2.3%), shoot length (5.2%) and root number (1%) in comparison to control. Similarly, leaf area, leaf fresh mass, dry mass and leaf number were also reduced by 23.1, 0.02, 0.11 and 0.9%, respectively. AgNPs and AgNO3 treatments increased the root length (16.2 & 12.8%), shoot length (21 & 20%), root number (8.1 & 6.8%), plant fresh weight (6.4 & 5%) and plant dry weight (4.6 & 3.5%) in 75mg/l treatment of AgNPs and AgNO3 respectively. Similarly, AgNPs and AgNO3 treatment (75 mg/l concentrations) reflected remarkable increase in leaf area (58.8 & 57.2 %), leaf number (4.3 & 3.7 %), leaf fresh weight (1.7 & 1.4 %) and leaf dry weight (0.9 & 0.8 %). Overall AgNPs showed more significant results as compared to AgNO3. The quantity of aflatoxins ranged from 3.1 to 7.7 μg/kg against tolerable limit (4 µg/kg). Overall AgNPs and AgNO3 treatments showed significant results and it could be considered as a strategy for aflatoxin management in rice plants.

Green synthesis and characterisation of silver nanoparticles and their effects on antimicrobial efficacy and biochemical profiling in Citrus reticulata

The synthesis of nanoparticles by utilising plant extract has revolutionised the field of nanotechnology. In the present study, AgNPs were synthesised by utilising the leaves of Moringa oleifera as reducing and stabilising agent. UV-visible spectroscopy showed characteristic surface plasmon band in the range of 413-420 nm. Scanning electron microscopy (SEM) elucidated rectangular segments fused together. X-ray diffraction (XRD) analysis confirmed the crystalline nature of AgNPs and presence of metallic silver ions was confirmed by energy dispersive X-ray (EDX). The different concentrations (10, 20, 30 and 40 ppm) of AgNPs were exogenously applied on Citrus reticulata to record the disease incidence at different day intervals. The disease intensity was progressively increased in all the applied treatments with the passage of time. The 30 ppm concentration of AgNPs was found to be most suitable concentration for creating the resistance against brown spot disease. Moreover, the effects of AgNPs were also assessed for biochemical profiling in C. reticulata. The enhanced production of endogenous enzymes and non-enzymatic components was observed in response to 30 ppm concentration of AgNPs. The present work highlighted that green synthesised AgNPs can be as used as biological control of citrus diseases and the enhanced production of secondary metabolites antioxidants.