Loranthus micranthus nanoparticles abates streptozotocin-instigated testicular dysfunction in Wistar rats: Involvement of glucose metabolism enzymes, oxido-inflammatory stress, steroidogenic enzymes/protein and Nrf2 pathway.

Loranthus micranthus (African mistletoe)-Loranthaceae family, is used in Nigerian traditional medicine for treating male infertility and lowering diabetic blood sugar levels. We investigated possible mechanism(s) involved in mitigation of L. micranthus leaves nanoparticles (LMLNPs) on streptozotocin (STZ)-induced testicular alterations. Type two diabetes mellitus (T2DM) was induced in male rats following 2 weeks feeding with fructose and single intraperitoneal injection of STZ. Control (nondiabetic) and (diabetic) rats received buffer only. Diabetic rats were treated with metformin or LMLNPs (two different doses) for 28 days. Hormonal profile, oxido-inflammatory stress parameters, glucose metabolism and steroidogenic enzymes/regulatory protein (StAR) and Nuclear factor erythroid 2-related factor 2 (Nrf2) protein in testes and sperm parameters were evaluated. Metformin and LMLNPs treatment significantly reduced blood glucose level in diabetic rats. Furthermore, LMLNPs enhanced glucose metabolism and testicular steroidogenic enzymes/protein, increased reproductive hormone levels and sperm functional parameters in diabetic rats. Additionally, LMLNPs suppressed testicular oxido-inflammatory stress biomarkers and inhibited lipid peroxidation in diabetic rats while augmenting Nrf2 pathway. Conclusively, LMLNPs potently reversed adverse effects of T2DM testicular dysfunction of rats. Use of LMLNPs in abating diabetic consequences proves an acceptable alternative to traditional crude extract preparations, as a result of better packaging and preservation.

Milling the Mistletoe: Nanotechnological Conversion of African Mistletoe (Loranthus micranthus) Intoantimicrobial Materials.

Nanosizing represents a straight forward technique to unlock the biological activity of complex plant materials. The aim of this study was to develop herbal nanoparticles with medicinal value from dried leaves and stems of Loranthus micranthus with the aid of ball-milling, high speed stirring, and high-pressure homogenization techniques. The milled nanoparticles were characterized using laser diffraction analysis, photon correlation spectroscopy analysis, and light microscopy. The average size of leaf nanoparticles was around 245 nm and that of stem nanoparticles was around 180 nm. The nanoparticles were tested for their antimicrobial and nematicidal properties against a Gram-negative bacterium Escherichia coli, a Gram-positive bacterium Staphylococcus carnosus, fungi Candida albicans and Saccharomyces cerevisiae, and a nematode Steinernemafeltiae. The results show significant activities for both leaf and (particularly) stem nanoparticles of Loranthus micranthus on all organisms tested, even at a particle concentration as low as 0.01% (w/w). The results observed indicate that nanoparticles (especially of the stem) of Loranthus micranthus could serve as novel antimicrobial agents with wide-ranging biomedical applications.

Resuspendable Powders of Lyophilized Chalcogen Particles with Activity against Microorganisms.

Many organic sulfur, selenium and tellurium compounds show considerable activity against microorganisms, including bacteria and fungi. This pronounced activity is often due to the specific, oxidizing redox behavior of the chalcogen-chalcogen bond present in such molecules. Interestingly, similar chalcogen-chalcogen motifs are also found in the elemental forms of these elements, and while those materials are insoluble in aqueous media, it has recently been possible to unlock their biological activities using naturally produced or homogenized suspensions of respective chalcogen nanoparticles. Those suspensions can be employed readily and often effectively against common pathogenic microorganisms, still their practical uses are limited as such suspensions are difficult to transport, store and apply. Using mannitol as stabilizer, it is now possible to lyophilize such suspensions to produce solid forms of the nanoparticles, which upon resuspension in water essentially retain their initial size and exhibit considerable biological activity. The sequence of Nanosizing, Lyophilization and Resuspension (NaLyRe) eventually provides access to a range of lyophilized materials which may be considered as easy-to-handle, ready-to-use and at the same time as bioavailable, active forms of otherwise insoluble or sparingly substances. In the case of elemental sulfur, selenium and tellurium, this approach promises wider practical applications, for instance in the medical or agricultural arena.

No time to waste organic waste: Nanosizing converts remains of food processing into refined materials.

Modern food processing results in considerable amounts of side-products, such as grape seeds, walnut shells, spent coffee grounds, and harvested tomato plants. These materials are still rich in valuable and biologically active substances and therefore of interest from the perspective of waste management and "up-cycling". In contrast to traditional, often time consuming and low-value uses, such as vermicomposting and anaerobic digestion, the complete conversion into nanosuspensions unlocks considerable potentials of and new applications for such already spent organic materials without the need of extraction and without producing any additional waste. In this study, nanosuspensions were produced using a sequence of milling and homogenization methods, including High Speed Stirring (HSS) and High Pressure Homogenization (HPH) which reduced the size of the particles to 200-400 nm. The resulting nanosuspensions demonstrated nematicidal and antimicrobial activity and their antioxidant activities exceeded the ones of the bulk materials. In the future, this simple nanosizing approach may fulfil several important objectives, such as reducing and turning readily available waste into new value and eventually closing a crucial cycle of agricultural products returning to their fields - with a resounding ecological impact in the fields of medicine, agriculture, cosmetics and fermentation. Moreover, up-cycling via nanosizing adds an economical promise of increased value to residue-free waste management.

Natural Nanoparticles: A Particular Matter Inspired by Nature.

During the last couple of decades, the rapidly advancing field of nanotechnology has produced a wide palette of nanomaterials, most of which are considered as "synthetic" and, among the wider public, are often met with a certain suspicion. Despite the technological sophistication behind many of these materials, "nano" does not always equate with "artificial". Indeed, nature itself is an excellent nanotechnologist. It provides us with a range of fine particles, from inorganic ash, soot, sulfur and mineral particles found in the air or in wells, to sulfur and selenium nanoparticles produced by many bacteria and yeasts. These nanomaterials are entirely natural, and, not surprisingly, there is a growing interest in the development of natural nanoproducts, for instance in the emerging fields of phyto- and phyco-nanotechnology. This review will highlight some of the most recent-and sometimes unexpected-advances in this exciting and diverse field of research and development. Naturally occurring nanomaterials, artificially produced nanomaterials of natural products as well as naturally occurring or produced nanomaterials of natural products all show their own, particular chemical and physical properties, biological activities and promise for applications, especially in the fields of medicine, nutrition, cosmetics and agriculture. In the future, such natural nanoparticles will not only stimulate research and add a greener outlook to a traditionally high-tech field, they will also provide solutions-pardon-suspensions for a range of problems. Here, we may anticipate specific biogenic factories, valuable new materials based on waste, the effective removal of contaminants as part of nano-bioremediation, and the conversion of poorly soluble substances and materials to biologically available forms for practical uses.

Natural selenium particles from Staphylococcus carnosus: Hazards or particles with particular promise?

Various bacteria, including diverse Staphylococci, reduce selenite to yield red selenium particles with diameters in the high nanometer to low micrometer range. Formation and accumulation of such particles in bacteria often results in cell death, triggered by a loss of thiols and formation of disruptive deposits inside the cell. Hence certain pathogenic bacteria are rather sensitive to the presence of selenite, whilst other organisms, such as small nematodes, do not employ this kind of nanotechnology, yet become affected by micromolar concentrations of such naturally generated materials. Selenium particles extracted from cultures of Staphylococcus carnosus and apparently stabilized by their natural protein coating, for instance, show considerable activity against the nematode Steinernema feltiae, Escherichia coli and Saccaromyces cerevisiae. Such natural nano- and micro-particles are also more active than mechanically generated selenium particles and may be applied as antimicrobial materials in Medicine and Agriculture.

Turning Waste into Value: Nanosized Natural Plant Materials of Solanum incanum L. and Pterocarpus erinaceus Poir with Promising Antimicrobial Activities.

Numerous plants are known to exhibit considerable biological activities in the fields of medicine and agriculture, yet access to their active ingredients is often complicated, cumbersome and expensive. As a consequence, many plants harbouring potential drugs or green phyto-protectants go largely unnoticed, especially in poorer countries which, at the same time, are in desperate need of antimicrobial agents. As in the case of plants such as the Jericho tomato, Solanum incanum, and the common African tree Pterocarpus erinaceus, nanosizing of original plant materials may provide an interesting alternative to extensive extraction and isolation procedures. Indeed, it is straightforward to obtain considerable amounts of such common, often weed-like plants, and to mill the dried material to more or less uniform particles of microscopic and nanoscopic size. These particles exhibit activity against Steinernema feltiae or Escherichia coli, which is comparable to the ones seen for processed extracts of the same, respective plants. As S. feltiae is used as a model nematode indicative of possible phyto-protective uses in the agricultural arena, these findings also showcase the potential of nanosizing of crude "waste" plant materials for specific practical applications, especially-but not exclusively-in developing countries lacking a more sophisticated industrial infrastructure.

Inspired by Nature: The Use of Plant-derived Substrate/Enzyme Combinations to Generate Antimicrobial Activity in situ.

The last decade has witnessed a renewed interest in antimicrobial agents. Plants have received particular attention and frequently rely on the spontaneous enzymatic conversion of an inactive precursor to an active agent. Such two-component substrate/enzyme defence systems can be reconstituted ex vivo. Here, the alliin/alliinase system from garlic seems to be rather effective against Saccharomyces cerevisiae, whilst the glucosinolate/myrosinase system from mustard appears to be more active against certain bacteria. Studies with myrosinase also confirm that enzyme and substrate can be added sequentially. Ultimately, such binary systems hold considerable promise and may be employed in a medical or agricultural context.