Liquorice (Glycyrrhiza glabra): the journey of the sweet root from Mesopotamia to England

Hairy Root Cultures as a Source of Polyphenolic Antioxidants: Flavonoids, Stilbenoids and Hydrolyzable Tannins

Due to their chemical properties and biological activity, antioxidants of plant origin have gained interest as valuable components of the human diet, potential food preservatives and additives, ingredients of cosmetics and factors implicated in tolerance mechanisms against environmental stress. Plant polyphenols are the most prominent and extensively studied, albeit not only group of, secondary plant (specialized) metabolites manifesting antioxidative activity. Because of their potential economic importance, the productive and renewable sources of the compounds are desirable. Over thirty years of research on hairy root cultures, as both producers of secondary plant metabolites and experimental systems to investigate plant biosynthetic pathways, brought about several spectacular achievements. The present review focuses on the Rhizobium rhizogenes-transformed roots that either may be efficient sources of plant-derived antioxidants or were used to elucidate some regulatory mechanisms responsible for the enhanced accumulation of antioxidants in plant tissues.

Natural Supplements for COVID19-Background, Rationale, and Clinical Trials

Worldwide, the turmoil of the SARS-CoV-2 (COVID-19) pandemic has generated a burst of research efforts in search of effective prevention and treatment modalities. Current recommendations on natural supplements arise from mostly anecdotal evidence in other viral infections and expert opinion, and many clinical trials are ongoing. Here the authors review the evidence and rationale for the use of natural supplements for prevention and treatment of COVID-19, including those with potential benefit and those with potential harms. Specifically, the authors review probiotics, dietary patterns, micronutrients, antioxidants, polyphenols, melatonin, and cannabinoids. Authors critically evaluated and summarized the biomedical literature published in peer-reviewed journals, preprint servers, and current guidelines recommended by expert scientific governing bodies. Ongoing and future trials registered on clinicaltrials.gov were also recorded, appraised, and considered in conjunction with the literature findings. In light of the controversial issues surrounding the manufacturing and marketing of natural supplements and limited scientific evidence available, the authors assessed the available data and present this review to equip clinicians with the necessary information regarding the evidence for and potential harms of usage to promote open discussions with patients who are considering dietary supplements to prevent and treat COVID-19.

What is the Role of Over 100 Excipients in Over the Counter (OTC) Cough Medicines?

Most medicines are white bitter powders that are formulated as tablets and capsules but cough medicines are an exception where the taste and appearance of the medicine are more important to the patient than the pharmacology of the active ingredient. Excipients are generally defined as any ingredient in a medicine other than the active ingredient. In most medicines excipients play a supportive role in delivering the medicine, but in the case of cough medicines, excipients have more important and complex roles and they can also be the main active ingredient of the cough medicine as menthol, glycerol, and sugars, which are declared as active ingredients. This review searched the United Kingdom electronic medicines compendium (emc) and found over 100 excipients in 60 different liquid formulations of over the counter cough medicines. The excipients were divided into functional groups: sweeteners, thickeners, flavors, colors, antimicrobials, and buffers, and the incidence and function of the different excipients is discussed. When considering the efficacy of a cough medicine, clinicians and pharmacists tend to think of the pharmacology of antitussives such as dextromethorphan or expectorants such as guaifenesin, and they rarely consider the role of excipients in the efficacy of the medicine. This review discusses the functions and importance of excipients in cough medicines and provides some new information for clinicians, pharmacists, and all interested in the treatment of cough when considering the composition and efficacy of a cough medicine.

The Powerful Placebo Effect in Cough: Relevance to Treatment and Clinical Trials

Interest in the placebo effect of medicines has developed from the use of placebo treatments as controls in clinical trials into a whole new area of research around how placebos fit into a psychosocial model of therapeutics. The large placebo effect associated with cough medicines is both a problem and an opportunity for researchers: a problem for clinical trials on new actives as the active must beat the large placebo effect, and an opportunity for harnessing the placebo effect to produce effective cough medicines without any pharmacologically active ingredient. This review discusses the mechanisms associated with the placebo effect of cough medicines and distinguishes between a 'perceived placebo effect' and a true 'placebo effect'. The efficacy of sweeteners in cough syrups is discussed as well as viscosity, mucoadhesion, and flavoring. The complexity of modern cough medicines is demonstrated by an example of a medicine which contains one active ingredient, and eighteen excipients which provide a complex and intense sensory experience to enhance the placebo effect and complement the pharmacological activity of the medicine.