Botanical supplements, herbal remedies, and plant-derived products are used globally. However, botanical dietary supplements are rarely subjected to robust safety testing unless there are adverse reports in post-market surveillance. Botanicals are complex and difficult to assess using current frameworks designed for single constituent substances (e.g. small molecules or discrete chemicals), making safety assessments costly and time-consuming. The liver is a primary organ of concern for potential botanical-induced hepatotoxicity and botanical-drug interactions as it plays a crucial role in xenobiotic metabolism. The NIH-funded Drug Induced Liver Injury Network noted that the number of botanical-induced liver injuries in 2017 nearly tripled from those observed in 2004-2005. New approach methodologies (NAMs) can aid in the rapid and cost-effective assessment of botanical supplements for potential hepatotoxicity. The Hepatotoxicity Working Group within the Botanical Safety Consortium is working to develop a screening strategy that can help reliably identify potential hepatotoxic botanicals and inform mechanisms of toxicity. This manuscript outlines the Hepatotoxicity Working Group's strategy and describes the assays selected and the rationale for the selection of botanicals used in case studies. The selected NAMs evaluated as a part of this effort are intended to be incorporated into a larger battery of assays to evaluate multiple endpoints related to botanical safety. This work will contribute to a botanical safety toolkit, providing researchers with tools to better understand hepatotoxicity associated with botanicals, prioritize and plan future testing as needed, and gain a deeper insight into the botanicals being tested.

The COVID-19 pandemic sparked the development of novel anti-viral drugs that have shown to be effective in reducing both fatality and hospitalization rates in patients with elevated risk for COVID-19 related morbidity or mortality. Currently, nirmatrelvir/ritonavir (Paxlovid™) fixed-dose combination is recommended by the World Health Organization for treatment of COVID-19. The ritonavir component is an inhibitor of cytochrome P450 (CYP) 3A, which is used in this combination to achieve needed therapeutic concentrations of nirmatrelvir. Because of the critical pharmacokinetic effect of this mechanism of action for Paxlovid™, co-administration with needed medications that inhibit or induce CYP3A is contraindicated, reflecting concern for interactions with the potential to alter the efficacy or safety of co-administered drugs that are also metabolized by CYP3A. Some herbal medicines are known to interact with drug metabolizing enzymes and transporters, including but not limited to inhibition or induction of CYP3A and P-glycoprotein. As access to these COVID-19 medications has increased in low- and middle-income countries (LMICs), understanding the potential for herb-drug interactions within these regions is important. Many studies have evaluated the utility of herbal medicines for COVID-19 treatments, yet information on potential herb-drug interactions involving Paxlovid™, specifically with herbal medicines commonly used in LMICs, is lacking. This review presents data on regionally-relevant herbal medicine use (particularly those promoted as treatments for COVID-19) and mechanism of action data on herbal medicines to highlight the potential for herbal medicine interaction Herb-drug interaction mediated by ritonavir-boosted antiviral protease inhibitors This work highlights potential areas for future experimental studies and data collection, identifies herbal medicines for inclusion in future listings of regionally diverse potential HDIs and underscores areas for LMIC-focused provider-patient communication. This overview is presented to support governments and health protection entities as they prepare for an increase of availability and use of Paxlovid™.

Interest in botanicals, particularly as dietary supplement ingredients, is growing steadily. This growth, and the marketing of new ingredients and combination products as botanical dietary supplements, underscores the public health need for a better understanding of potential toxicities associated with use of these products. This article and accompanying template outline the resources to collect literature and relevant information to support the design of botanical toxicity studies. These resources provide critical information related to botanical identification, characterization, pre-clinical and clinical data, including adverse effects and interactions with pharmaceuticals. Toxicologists using these resources should collaborate with pharmacognosists and/or analytical chemists to enhance knowledge of the botanical material being tested. Overall, this guide and resource list is meant to help locate relevant information that can be leveraged to inform on decisions related to toxicity testing of botanicals, including the design of higher quality toxicological studies.

A history of safe use is a backbone of safety assessments for many current probiotic species, however, there is no global harmonization regarding requirements for establishing probiotic safety for use in foods and supplements. As probiotic manufacturers are increasingly seeking to use new strains, novel species, and next-generation probiotics, justification based on a significant history of use may be challenged. There are efforts underway by a variety of stakeholders, including the United States Pharmacopeia (USP), to develop best practices guidelines for assessing the quality and safety of probiotics. A current initiative of the USP seeks to provide expert advice specific to safety considerations for probiotics. Toward this goal, this review provides a helpful summary guide to global regulatory guidelines. We question the suitability of traditional animal toxicology studies designed for testing chemicals for relevance in assessing probiotic safety. This includes discussion of the use of excessive dose levels, the length of repeated dose toxicity studies needed, and the most suitable animal species used in toxicology studies. In addition, the importance of proper manufacturing practices with regard to final product safety are also included. Thus, an outline of essential parameters of a comprehensive safety assessment for a probiotic are provided.

Dietary supplement current good manufacturing practice (cGMP) requires establishment of quality parameters for each component used in the manufacture of a dietary supplement to ensure that specifications for the identity, purity, strength, composition, and limits on contaminants are met. Compliance with botanical extract ingredient specifications is assured by using scientifically valid methods of analysis, the results of which are reported on certificates of analysis (CoAs). However, CoAs routinely include additional data that are not amenable to verification through methods of analysis. Such descriptive information may include Plant to Extract ratios, which are ratios of the quantity of botanical article used in the manufacture of the extract to the quantity of extract obtained. Plant to Extract ratios can be misleading when their meaning is not clearly understood. Plant to Extract ratios do not completely describe botanical extracts because other important factors influence the make-up of final extracts, such as the quality of the raw starting material (as can defined by pharmacopeial standards), extraction solvent(s) used, duration and temperature of extraction, and percentage and type of excipients present. Other important qualitative descriptions may include constituent "fingerprinting." Despite these issues, Plant to Extract ratios are often used as a measure of extract strength for dosage calculations. This article defines and clarifies the meaning of Plant to Extract ratios and their proper use in describing and labeling botanical extract ingredients and finished products containing them.

The dried flower and flower bud of Styphnolobium japonicum (L.) Schott (Japanese Sophora flower and Japanese Sophora flower bud, respectively) have long been used as herbal medicines in Asia. Today, they are marketed as dietary supplements in the United States for their anti-oxidative properties and as a source of flavonoids, including rutin and quercetin. This review focused on the safety of S. japonicum flower and flower bud as dietary supplement ingredients. No serious adverse events or toxicity were reported in the clinical or experimental animal studies we reviewed. Although some studies indicated that rutin or quercetin may have potential for drug interactions, none were identified for S. japonicum flower or flower bud. S. japonicum flower and flower bud are not known to have been associated with serious health risks when appropriately consumed in dietary supplements and have been admitted to the U.S. Pharmacopeial Convention monograph development process. However, pregnant and breastfeeding women should seek the advice of a healthcare professional because no data are available on their use by these special populations.

Increase in dietary supplement use in the United States suggests a great need for clinicians to be aware of the range of supplements' quality parameters. Regulatory requirements exist, but specific quality parameters for each ingredient are not set by regulators. This article considers how clinicians can evaluate dietary supplement product quality, assess manufacturers' adherence to public quality standards, and encourage use of verification and certification programs.

Gamma-amino butyric acid (GABA) is marketed in the U.S. as a dietary supplement. USP conducted a comprehensive safety evaluation of GABA by assessing clinical studies, adverse event information, and toxicology data. Clinical studies investigated the effect of pure GABA as a dietary supplement or as a natural constituent of fermented milk or soy matrices. Data showed no serious adverse events associated with GABA at intakes up to 18 g/d for 4 days and in longer studies at intakes of 120 mg/d for 12 weeks. Some studies showed that GABA was associated with a transient and moderate drop in blood pressure (<10% change). No studies were available on effects of GABA during pregnancy and lactation, and no case reports or spontaneous adverse events associated with GABA were found. Chronic administration of GABA to rats and dogs at doses up to 1 g/kg/day showed no signs of toxicity. Because some studies showed that GABA was associated with decreases in blood pressure, it is conceivable that concurrent use of GABA with anti-hypertensive medications could increase risk of hypotension. Caution is advised for pregnant and lactating women since GABA can affect neurotransmitters and the endocrine system, i.e., increases in growth hormone and prolactin levels.

Cranberry is a popular ingredient in dietary supplements in the U.S. and is commonly used for preventing urinary tract infections. Because of its popularity in dietary supplements, the U.S. Pharmacopeial Convention has developed quality standards for cranberry ingredients. The purpose of this review was to determine if there are safety issues that should preclude the admission of cranberry ingredients from the development of U.S. Pharmacopeial Convention quality standards. Based on the totality of the data, the U.S. Pharmacopeial Convention concluded that cranberry ingredients are not known to be associated with serious risks to human health when consumed properly in dietary supplements and therefore were admitted for standard development. Although published clinical and animal data indicated that cranberry is not associated with serious adverse effects, interactions with warfarin and kidney stone formation were identified as potential risks. Studies have reported contradictory data regarding the role of cranberry in kidney stone formation, with some reports suggesting cranberry is associated with a reduced risk of kidney stones. Interactions with warfarin were not associated with moderate intakes of cranberry juice (240-480mL). Some reports suggested that the potential for warfarin interactions requires excessive intakes of cranberry juice (1-2L/day) or cranberry extracts (3000mg/day). Cases of warfarin interactions with cranberry have mostly involved patients with serious illnesses and/or individuals taking concomitant medications. Based on these findings, the U.S. Pharmacopeial Convention concluded that the use of cautionary labeling statements regarding interactions with warfarin or kidney stone formation is not necessary in the development of quality standards for cranberry ingredients.

Military personnel use dietary supplements (DS) for performance enhancement, bodybuilding, weight loss, and to maintain health. Adverse events, including cardiovascular (CV) effects, have been reported in military personnel taking supplements. Previous research determined that ingestion of multi-ingredient dietary supplements (MIDS), can lead to signals of safety concerns. Therefore, to assess the safety of MIDS, the Department of Defense via a contractor explored the development of a model-based risk assessment tool. We present a strategy and preliminary novel multi-criteria decision analysis (MCDA)-based tool for assessing the risk of adverse CV effects from MIDS. The tool integrates toxicology and other relevant data available on MIDS; likelihood of exposure, and biologic plausibility that could contribute to specific aspects of risk. Inputs for the model are values of four measures assigned based on the available evidence supplemented with the opinion of experts in toxicology, modeling, risk assessment etc. Measures were weighted based on the experts' assessment of measures' relative importance. Finally, all data for the four measures were integrated to provide a risk potential of 0 (low risk) to 100 (high risk) that defines the relative risk of a MIDS to cause adverse reactions. We conclude that the best available evidence must be supplemented with the opinion of experts in medicine, toxicology and pharmacology. Model-based approaches are useful to inform risk assessment in the absence of data. This MCDA model provides a foundation for refinement and validation of accuracy of the model predictions as new evidence becomes available.

As part of the United States Pharmacopeia’s ongoing review of dietary supplement safety data, a new comprehensive systematic review on green tea extracts (GTE) has been completed. GTEs may contain hepatotoxic solvent residues, pesticide residues, pyrrolizidine alkaloids and elemental impurities, but no evidence of their involvement in GTE-induced liver injury was found during this review. GTE catechin profiles vary significantly with manufacturing processes. Animal and human data indicate that repeated oral administration of bolus doses of GTE during fasting significantly increases bioavailability of catechins, specifically EGCG, possibly involving saturation of first-pass elimination mechanisms. Toxicological studies show a hepatocellular pattern of liver injury. Published adverse event case reports associate hepatotoxicity with EGCG intake amounts from 140 mg to ∼1000 mg/day and substantial inter-individual variability in susceptibility, possibly due to genetic factors. Based on these findings, USP included a cautionary labeling requirement in its Powdered Decaffeinated Green Tea Extract monograph that reads as follows: “Do not take on an empty stomach. Take with food. Do not use if you have a liver problem and discontinue use and consult a healthcare practitioner if you develop symptoms of liver trouble, such as abdominal pain, dark urine, or jaundice (yellowing of the skin or eyes).”

The seeds of the guarana plant (Paullinia cupana Kunth, family Sapindaceae) are well-known to many cultures as a stimulant, aphrodisiac, and astringent. Its rhizome was traditionally boiled into a tea by Amazonian cultures. Today, guarana seeds are ground to a fine powder and sold as powder, tablets, and capsules. This review focuses on the traditional uses, phytochemistry, and biological activities of the guarana seed to evaluate its safety as a dietary ingredient. A comprehensive review of published literature was conducted to identify articles that focused on the phytochemistry, pharmacology, and safety of guarana. On the basis of this review, guarana is not currently known to be associated causally with any serious health risks when consumed properly. Overall, guarana is generally recognized as safe as a dietary ingredient marketed for its flavor and caffeine content. If guidelines for caffeine intake are respected, guarana consumption is not likely to be associated with any serious health risks.

Willow bark (Salix spp.) is an ingredient in some dietary supplements. No serious adverse effects were reported from trials of willow bark extracts delivering 120 - 240 mg salicin (the purported active constituent) daily for up to 8 weeks. All studies involved adults only; none involved special subpopulations such as pregnant or breastfeeding women, or children. The most common adverse effects associated with willow bark are gastrointestinal; a few allergic reactions were also reported. Some publications advise caution when taking willow bark. There is a risk of increased bleeding in vulnerable individuals, salicylates cross the placenta and are eliminated slowly in newborns, some persons are sensitive or allergic to aspirin, and children are at risk of Reye syndrome. Concurrent use with other salicylate-containing medicines increases these risks. Metabolism of 240 mg salicin from willow bark could yield 113 mg of salicylic acid, yet dietary supplement products are not required to be labeled with warnings. In contrast, over-the-counter low-dose aspirin (81 mg strength), which delivers 62 mg salicylic acid, is required by law to include cautions, warnings, and contraindications related to its use in pregnant and nursing women, children, and other vulnerable subpopulations, e.g., those using anticoagulants. In the interest of protecting public health, the United States Pharmacopeia has included a cautionary labeling statement in the United States Pharmacopeia Salix Species monograph as follows: "Dosage forms prepared with this article should bear the following statement: 'Not for use in children, women who are pregnant or nursing, or by persons with known sensitivity to aspirin.'".

BACKGROUND:In order to define appropriate quality of botanical dietary supplements, botanical drugs, and herbal medicines, the United States Pharmacopeia (USP) and the Herbal Medicines Compendium (HMC) contain science-based quality standards that include multiple interrelated tests to provide a full quality characterization for each article in terms of its identity, purity, and content.PURPOSE:To provide a comprehensive description of the pharmacopeial tests and requirements for articles of botanical origin in the aforementioned compendia. Selective chromatographic procedures, such as high-performance liquid chromatography (HPLC) and high-performance thin-layer chromatography (HPTLC), are used as Identification tests in pharmacopeial monographs to detect species substitution or other confounders. HPLC quantitative tests are typically used to determine the content of key constituents, i.e., the total or individual amount of plant secondary metabolites that are considered bioactive constituents or analytical marker compounds. Purity specifications are typically set to limit the content of contaminants such as toxic elements, pesticides, and fungal toxins. Additional requirements highlight the importance of naming, definition, use of reference materials, and packaging/storage conditions.METHODS:Technical requirements for each section of the monographs were illustrated with specific examples. Tests were performed on authentic samples using pharmacopeial reference standards. The chromatographic analytical procedures were validated to provide characteristic profiles for the identity and/or accurate determination of the content of quality markers.RESULTS:The multiple tests included in each monograph complement each other to provide an appropriate pharmacopeial quality characterization for the botanicals used as herbal medicines and dietary supplements. The monographs provide detailed specifications for identity, content of bioactive constituents or quality markers, and limits of contaminants, adulterants, and potentially toxic substances. Additional requirements such as labeling and packaging further contribute to preserve the quality of these products.CONCLUSION:Compliance with pharmacopeial specifications should be required to ensure the reliability of botanical articles used for health care purposes.

The United States Pharmacopeia (USP) is an independent, nonprofit, science-based organization whose mission is to improve global health through public quality standards for dietary supplements, medicines, and food ingredients.1 Before developing standards for dietary supplement ingredients, the USP performs an "Admission Evaluation" (Figure 1), which includes an assessment to ascertain that an ingredient does not present a serious health risk.2 This article discusses the challenges encountered during the evaluation of botanicals and proposes possible solutions.

Due to the extensive use of botanical dietary supplements by consumers in the United States, there is a need for appropriate research and data to support safety assessments. Complexity and variability, both natural and introduced, of botanical dietary supplements make research on these products difficult. Botanical dietary supplements are regulated by the Food and Drug Administration (FDA) under the Federal Food, Drug, and Cosmetic Act (FD&C Act), as amended by the 1994 Dietary Supplement Health and Education Act (DSHEA). They are regulated as a category of food, which differs from the regulation of pharmaceutical products. Both manufacturers and the FDA are faced with the challenge of determining the best approaches for evaluating and monitoring the safety of botanical products. High quality botanicals research requires accurate identification and characterization of the material being studied. Inconsistent results in efficacy studies of botanical dietary supplements have led to efforts to improve the rigor and reproducibility of research in the field. Addressing the challenges associated with botanical dietary supplement safety is a global effort requiring coordination between numerous stakeholders, including researchers, suppliers, manufacturers, and regulators, all of whom play a role in ensuring that high quality products are available on the market.