About this Research Topic
Plants produce and accumulate a vast array of compounds through their secondary metabolism, and more than 200,000 defined structures have been identified to date. Many of these compounds are found to possess antibacterial, antifungal, antiviral, anti-inflammatory, hepatoprotective, antidepressant, antioxidant, neuroprotective, and anticancer activities due to their bioactivities. Throughout history, human beings have benefited from these compounds by taking them internally or applying them externally as crude extracts, decoctions, infusions etc., as practiced in Ayurveda, Siddha, Unani, Chinese and other traditional medicines. A large number of impressive modern drugs have been derived from natural sources particularly from plants based on their traditional uses. The majority of drug candidates available today are natural products or structural analogues of natural products.
Controlled pharmacological studies and clinical trials have confirmed the traditional knowledge in many instances and revealed that the pharmacological properties of crude extracts could either be attributed to a single compound or to a synergistic action of many compounds. Although a number of natural compounds with therapeutic potential have been identified, in many cases their use as therapeutic agents is constrained by poor bioavailability, low absorption, fast metabolism, and rapid systemic elimination. In this context, encapsulation of these compounds or extracts in nanoparticles offers several advantages, including protection against degradation, enhanced solubility and bioavailability. Correspondingly, plant secondary metabolites like flavanoids, tannins, and terpenoids have shown better therapeutic effect than their native form after incorporating them into nanocarriers. Recent advances in the understanding of the molecular biology of disease progression and associated signaling mechanisms have offered us several clues for functionalizing nanoparticles to target specific cells, tissues and organs. These nanoparticles can deliver the cargo in a pre-determined rate at a particular site of action, providing high bioavailability and low toxicity.
Today, Herbal medicine for the prevention and treatment of diseases and ailments is gaining attention as the extracts and compounds obtained from natural sources are considered safe. The boom in natural or alternative medicine prompted scientists to design various nanoformulations containing herbal extracts or phytochemicals in the recent years. We intend to bring the current knowledge and future trends in this area of pharmacology together. Submissions on the development of nanoparticles containing herbal extracts/ compounds, their physicochemical characterization, pharmacological and toxicological evaluation are welcomed. Articles describing biogenic nanoparticles with enhanced bioactivities or reduced toxicity in cell/ animal models will be considered. Although articles debating on the risks and limitations of using nanotechnologies are equally welcomed, manuscripts with limited or no nanotechnology focus are outside the scope of this Research Topic.
Frontiers in Pharmacology (section Ethnopharmacology) focuses on biological and pharmacological activities of plants, fungi and other organisms used locally or traditionally as a medicine or to improve health. Studies with the specific aim to either improve local healthcare by developing products based on such knowledge or studies in the context of drug discovery / development from natural sources will be considered if they are based on biological resources with a clear and well-defined local or traditional use. Purely biodiversity-based screening studies and studies of established natural products and their mechanism of action are outside the scope of this section. Studies reporting such local and traditional uses will only be accepted if the comply with the ConSEFS standards (Heinrich et al. 2017 ) . Toxicological research and clinical studies on medicinal plants are welcome.
Manuscripts which are highly specific, lack breadth and often are very similar to previous papers (often by the same group) are not acceptable and this will be assessed.
The following basic guidelines, focused on best practice in ethnopharmacology, should be followed by all submissions:
- This Specialty Section of Frontiers in Pharmacology subscribes to the taxonomic standards laid down most importantly at the Kew MPNS portal (http://mpns.kew.org/mpns-portal/) and also the Royal Botanic Gardens/Kew/Missouri Botanical Garden `The Plant List` initiative (www.theplantlist.org). Of course, full botanical documentation is essential (i.e. a voucher specimen deposited in a recognized herbarium).
- Antioxidant activity: here in vivo or in vitro studies using generally accepted pharmacological models are essential. Simple in silico and pharmacologically irrelevant assays for antioxidant activity (e.g. the DPPH assay, FRAP (Ferric Reducing Ability of Plasma), ABTS (2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)) are not acceptable as a main tool for assessing an extract or a compound for activity. Such assays are commonly used in food chemistry and other fields, but are not of pharmacological relevance.
- Dose ranges must be pharmacologically relevant. While impossible to define an exact cut-off, studies testing extracts at implausibly high doses are increasingly common in the literature.
- Positive and negative controls must be included.
- Models must be pharmacologically relevant and plausible - a complex question depending on the specific goals of the study. Authors must consider the ethical acceptability of further in vivo studies on an already well-studied species, demonstrating some common activity (e.g. an anti-inflammatory effect studied in the rat-paw oedema).
- The composition of the study material must be described in sufficient detail
- If ‘pure’ compounds are used information on the level of purity must be included
In case of ethnopharmacological field studies you must follow the ConSEFS standards: https://www.ncbi.nlm.nih.gov/pubmed/28818646
Keywords: Phytochemicals, Herbal extracts, Pharmacology, Toxicology, Nanoformulation
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.