In-vivo toxicity and therapeutic efficacy of Paeonia emodi-mediated zinc oxide nanoparticles: In-vitro study

A review of history, properties, classification, applications and challenges of natural and synthetic dyes

Natural dyes have been used for centuries for coloring textiles, food, and other materials. Synthetic dyes are particularly popular due to their ease of use, wide range of available colors, and fastness. However, their usage comes with significant environmental and health challenges. In recent years, there has been a renewed interest in natural dyes due to their eco-friendliness, ready availability, affordability, non-toxicity, and sustainability. Hence, natural dyes are fast gaining popularity as better alternatives to synthetic dyes. Nature is blessed with a rich diversity of plant species with varying colors and properties which can be harnessed in textile, printing, cosmetics, and food industries. This paper presents a comprehensive review on natural and synthetic dyes with particular focus on their history, properties, classification, extraction methods, applications, and health challenges. Although many plants have been suggested as potential sources of natural dyes, there is insufficient information on their exploration and application. Additionally, chemical analyses of these dyes have not been extensively done. Overall, the results of studies conducted so far identified a number of promising taxa for further investigation as plant-based dyes with many indigenous plants as potential sources of natural dyes.

Safety assessment of crude aqueous methanol extract of Annona senegalensis stem bark: acute and sub-chronic toxicity studies

Annona senegalensis Pers., (wild custard apple), is a shrub used traditionally to treat respiratory and skin diseases. Previous studies have demonstrated its anti-malaria, anti-snake envenomation and anti-cancer activities. However, its toxicological profile remains limited, particularly in male and female animals. This study aims to evaluate the safety of crude aqueous methanol extract of Annona senegalensis stem bark (AMEAS) through acute and sub-chronic toxicity studies. The stem bark of A. senegalensis was collected, air-dried, pulverized, and extracted using 70% methanol. Phytochemical screening, elemental analysis, and acute toxicity evaluation were carried out on AMEAS. Sub-chronic toxicity study was conducted on Wistar rats of both sexes at different doses administered orally for 28 days. Elemental analysis revealed the presence of heavy metals and essential mineral elements with the highest contents being calcium (59.88%) and potassium (25.39%). Acute toxicity testing showed no mortality up to 5000 mg/kg, suggesting an LD50 greater than 5000 mg/kg. In the sub-chronic toxicity study, no mortality or significant harmful effects were observed. The blood glucose decreased from 13.68 mMol/L at 250 mg/kg to 10.71 mMol/L at 1000 mg/kg, much lower than the distilled water group (17.06 mMol/L). In conclusion, the extract appeared to be well-tolerated, with no obvious adverse effects. AMEAS is rich in Calcium (Ca) and potassium (K). It has been shown to have LD50 greater than 5000 mg/kg and is assumed to be safe. On repeated use, AMEAS may cause hypoglycemia and weight loss which may be useful in managing diabetes and obesity respectively.

A comprehensive review on traditional uses, phytochemistry and pharmacological properties of Paeonia emodi Wall. ex Royle: current landscape and future perspectives

Paeonia emodi Wall. ex Royle is commonly known as Himalayan paeony has great importance as a food and medicine. The practice of Paeonia emodi Wall. ex Royle is very ancient and it is conventionally used for a wide range of illnesses in the folk system of medicine because of its wide beneficial phytochemical profile. The main purpose of the current review was the synthesis of recent data on botany, ethnopharmacology, phytochemistry and potential pharmacological mechanisms of action of Paeonia emodi Wall. ex Royle, thus offering new prospects for the development of new adjuvant natural therapies. Using scientific databases such as PubMed/MedLine, Scopus, Web of Science, ScienceDirect, Google Scholar, Springer, and Wiley, a comprehensive literature search was performed for Paeonia emodi Wall. ex Royle. For searching, we used the next MeSH terms: "Biological Product/isolation and purification", "Biological Products/pharmacology", "Drug Discovery/methods", "Ethnopharmacology, Medicine", "Traditional/methods", "Paeonia/chemistry", "Plant Extracts/pharmacology", "Phytochemicals/chemistry", "Phytochemicals/pharmacology", "Plants, Medicinal". The results of the most recent studies were analyzed and the most important data were summarized in tables and figures. Phytochemical research of Paeonia emodi Wall. ex Royle has led to the isolation of triterpenes, monoterpenes, phenolic acids, fatty acids, organic compounds, steroids, free radicals and some other classes of primary metabolites. In addition, diverse pharmacological activities like antibacterial, antifungal, anticoagulant, airway relaxant lipoxygenase and beta-glucuronidase inhibiting activity, radical scavenging activity, phytotoxic and insecticidal activities have been reported for Paeonia emodi Wall. ex Royle. Different bioactive compounds of Paeonia emodi Wall. ex Royle has proven their therapeutic potential in modern pharmacological and biomedical research to cure numerous gastrointestinal and nervous disorders. In future, further in vitro and in vivo therapeutic studies are required to identify new mechanisms of action, pharmacokinetics studies, and new pharmaceutical formulations for target transport and possible interaction with allopathic drugs. Also, new research regarding quality evaluation, toxicity and safety data in humans is needed.

Where Is Nano Today and Where Is It Headed? A Review of Nanomedicine and the Dilemma of Nanotoxicology

Worldwide nanotechnology development and application have fueled many scientific advances, but technophilic expectations and technophobic demands must be counterbalanced in parallel. Some of the burning issues today are the following: (1) Where is nano today? (2) How good are the communication and investment networks between academia/research and governments? (3) Is there any spotlight application for nanotechnology? Nanomedicine is a particular arm of nanotechnology within the healthcare landscape, focused on diagnosis, treatment, and monitoring of emerging (such as coronavirus disease 2019, COVID-19) and contemporary (including diabetes, cardiovascular diseases, neurodegenerative disorders, and cancer) diseases. However, it may only represent the bright side of the coin. In fact, in the recent past, the concept of nanotoxicology has emerged to address the dark shadows of nanomedicine. The nanomedicine field requires more nanotoxicological studies to identify undesirable effects and guarantee safety. Here, we provide an overall perspective on nanomedicine and nanotoxicology as central pieces of the giant puzzle of nanotechnology. First, the impact of nanotechnology on education and research is highlighted, followed by market trends and scientific output tendencies. In the next section, the nanomedicine and nanotoxicology dilemma is addressed through the interplay of in silico, in vitro, and in vivo models with the support of omics and microfluidic approaches. Lastly, a reflection on the regulatory issues and clinical trials is provided. Finally, some conclusions and future perspectives are proposed for a clearer and safer translation of nanomedicines from the bench to the bedside.