Herbal toxicity

Sida cordifolia L.: Ethnobotany, Phytochemistry, Phytonanotechnology, and Commercial Application

BACKGROUND

After a period of prolonged indifference, where synthetic drugs were preferred, interest in the biological aspects and bioactive ingredients of plants accountable for therapeutic potential has been explored eminently. Sida cordifolia L. is a perennial herb that has been widely utilized in Indian (Ayurveda, Unani, and Siddha), American, and Chinese folk medicine and herbalism practice for curing a wide range of ailments in human beings.

OBJECTIVES

The goal of this review is to elucidate indigenous knowledge parallelly with the pharmacotherapeutics potential of Sida cordifolia L. against various diseases. It is also intended to display pertinent information related to nanoparticle profiling.

METHODS

In the current comprehensive study, web-based searches were performed by using several databases, such as Google Scholar, PubMed, ResearchGate, Science Direct, and Scopus, to figure out relevant research work and data published in academic journals from 1930 to July, 2023 using single or combination of keywords listed herewith.

RESULTS

More than 50 chemical constituents, including quinazoline and phenethylamine alkaloids, flavones, flavonol, phytosterol, fatty acids, etc., were reported to be found in different parts of healthy plants. Apart from traditional claims and pharmacological aspects, several marketed herbal formulations and granted patents were also described.

CONCLUSION

Several in-vitro and in-vivo studies validated the usage of S. cordifolia as antiinflammatory, antibacterial, antifungal, antiprotozoal, anthelmintic, anticancer, antiulcer, cardioprotective, hypoglycemic, etc. agent. Few patents are also related to S. cordifolia, and more research work needs to be carried out for its potential granted to use as an antiviral agent and other new drug discovery molecules.

Safety profile of herbal medicines submitted for marketing authorization in Tanzania: a cross-sectional retrospective study

BACKGROUND

The popular use of herbal medicines necessitates national regulatory authorities to have efficient mechanisms for the control of these products including marketing authorization (MA) and safety follow-up. Herbal medicines like conventional medicines require assessment of efficacy, safety and quality information before MA can be granted. However, the complete proof of safety is mainly based on the history of the long-term traditional use. Herbal medicines can cause adverse reactions due to various factors and thus require clinical trials to ensure their safety. Herbal medicines treatment practices involve combinations of different plants to achieve the desired effect while multiple herbal components have been known to cause herbal-herbal toxicity and interactions due to variety of complex active ingredients in plants. Compliance with regulatory requirements on herbal medicines has been shown to be difficult for manufacturers since different countries have different regulatory requirements with wide variations which results in the MA of very few herbal medicines. Limited studies on dossiers of marketing authorization of herbal medicines have been performed in other countries, with no studies in African regulatory system settings. The aim of this study is to determine the type of safety documentation that is submitted on herbal medicines application dossiers to support MA in Tanzania.

METHODS

A cross-sectional retrospective study of herbal medicines dossiers submitted at the Tanzania Medicines and Medical Devices Authority from 2009 to 2020 was conducted.

RESULTS

As many as 75% of the herbal products applications were combination products made by more than one herbal substance or plant. Out of 84 dossiers subjected to analysis the majority did not provide evidence of preclinical (55%) and clinical safety data (68%). Evidence of safety data in humans was mostly from the literature (70%) and not manufacturers' clinical studies. Quality parameters with safety implications were not included in 48% and 23% of the active herbal substance and finished product specifications, respectively.

CONCLUSION

Analysis of the herbal medicine dossiers submitted showed major deficiencies of safety data to support MA. Manufactures need to provide evidence to support the safety of their products for evidence-based regulatory decisions and to avoid multiple reviews of the applications.

Jordanian Use of and Beliefs Concerning the Efficacy of Medicinal Plants: A Cross-Sectional Study

Background: Medicinal herbs are incorrectly believed to be free of risks and are commonly used for self-medication without medical supervision. Jordan does not currently have a national policy on traditional medicine (TM) and/or complementary/alternative medicine (CAM). The present study aims to explore the use of and beliefs about the efficacy of medicinal plants among the Jordanian population. Method: A cross-sectional study was conducted using a self-administrated questionnaire for the duration between April and June 2019. Multiple linear regression analysis was used to identify predictors of positive attitudes towards the use of medicinal plants. Results: A total of 1,057 individuals participated in the study. The participants in our study showed a positive attitude towards the use of medicinal plants and herbs (median score of 33.0 (interquartile range (IQR): 26.0-37.0; equals 68.8% of the maximum total score), and believed in alternative therapies other than chemical drugs for disease treatment, mainly using medicinal herbs and plants. The majority of the participants (77.8% (n = 822)) believe in the efficacy of the use of medicinal herbs and plants and are aware (64.6 % (n = 683)) of the correct and proper way of using these plants and herbs. Pharmacists and herbalist are the main sources of information for the proper use of medicinal herbs and plants. Age was the main predictor of positive attitudes towards the use of medicinal plants and herbs (P<0.001). Conclusion: Efforts must be made to regulate the dispensing of these products, to educate health service providers and to raise consumer awareness.

Intestinal epithelial damage due to herbal compounds - an in vitro study

Intestinal epithelial injury from herbal products has rarely been reported, despite the gut being the first point of contact for oral preparations. These products often consist of multiple herbs, thereby potentially exposing consumers to higher levels of reactive phytochemicals than predicted due to pharmacokinetic interactions. The phytochemical coumarin, found in many herbal products, may be taken in combination with herbal medicines containing astragalosides and atractylenolides, purported cytochrome P450 (CYP) modulators. As herbal use increases, the need to predict interactions in multiple at-risk organ systems is becoming critical. Hence, to determine whether certain herbal preparations containing coumarin may cause damage to the intestinal epithelium, Caco2 cells were exposed to common phytochemicals. Coumarin, astragaloside IV (AST-IV) or atractylenolide I (ATR-I) solutions were exposed to Caco2 cultures in increasing concentrations, individually or combined. Coumarin produced a significant concentration-dependant fall in cell viability that was potentiated when CYP enzymes were induced with rifampicin and incubated with CYP3A4 inhibitor econazole, suggesting a role for other CYP enzymes generating toxic metabolites. ATR-I alone produced no toxicity in uninduced cells but showed significant toxicity in rifampicin-induced cells. ATR-I had no effect on coumarin-induced toxicity. AST-IV was nontoxic alone but produced significant toxicity when combined with nontoxic concentrations of coumarin. The combination of coumarin, ATR-I and AST-IV was significantly toxic, but no synergistic interaction was seen. This investigation was conducted to determine the likelihood for intestinal-based interactions, with the results demonstrating coumarin is potentially toxic to intestinal epithelium, and combinations with other phytochemicals can potentiate this toxicity.

Assessment of toxicity and anti-plasmodial activities of chloroform fractions of Carapa procera and Alchornea cordifolia in murine models

Background: Plant as a source of medicine has gained international popularity in recent times because of its natural origin, availability in local communities, cheaper to purchase, ease of administration, and its usefulness as an alternative treatment in case of numerous side effects and drug resistance. However, the use of herbal formulations can also result in short-term and long-term organ damage or dysfunction to the host. In this study, chloroform fractions of the leaves of two medicinal plants, Alchornea cordifolia (ACL) and Carapa procera (CPL), were investigated for their toxicological and anti-malarial effects in murine models. Method: Acute (14-day) and sub-acute (28-day) studies were conducted based on the Organization for Economic Cooperation and Development (OECD) Guidelines in Institute for Cancer Research (ICR) mice and Sprague Dawley (SD) rats respectively. A dosage of 2000 mg/kg body weight was administered orally to each ICR mouse during the acute study and 100, 300, and 1000 mg/kg body weight to each SD rat during the sub-acute study. A 5-day curative anti-plasmodial activity was assessed in ICR mouse model. Results: The assessment of toxicity revealed that all three fractions did not influence mortality, clinical appearance, body weight gain, or necropsy at the various doses. Hematological and serum biochemical analysis indicated no significant elevations in liver and renal function parameters. Histopathological examinations of the liver indicated reversible liver degeneration with the chloroform fraction of the 100% ethanol extract of Carapa procera leaves (CPL100%) at 1000 mg/kg. Anti-plasmodial assessments showed CPL100% exhibiting dose-dependent anti-plasmodial activity from 16% to 26.67%. On the other hand, chloroform fraction of the 100% ethanol extract of Alchornea cordifolia leaves (ACL100%) showed declining anti-plasmodial activity from 21.1% to 15.1%. Conclusion: These preliminary findings demonstrate that chloroform fractions of the leaves of Carapa procera and Alchornea cordifolia may be safe agents for treating malaria hence further development for drug discovery must be pursued.

Use of Dietary Supplements in Living Kidney Donors: A Critical Review

Dietary supplement use is high among US adults, with the intention by users to promote overall health and wellness. Kidney donors, who are selected based on their overall good health and wellness, can have high utilization rates of dietary supplements. We provide a framework for the evaluation of living kidney donors and use of dietary supplements. In this review, dietary supplements will include any orally administered dietary or complementary nutritional products, but excluding micronutrients (vitamins and minerals), food, and cannabis. Use of dietary supplements can influence metabolic parameters that mask future risk for chronic illness such as diabetes and hypertension. Dietary supplements can also alter bleeding risk, anesthesia and analgesic efficacy, and safety in a perioperative period. Finally, postdonation monitoring of kidney function and risk for supplement-related nephrotoxicity should be part of a kidney donor educational process. For practitioners evaluating a potential kidney donor, we provide a list of the most commonly used herbal supplements and the effects on evaluation in a predonation, perioperative donation, and postoperative donation phase. Finally, we provide recommendations for best practices for integration into a comprehensive care plan for kidney donors during all stages of evaluation. We recommend avoidance of dietary supplements in a kidney donor population, although there is a paucity of data that identifies true harm. Rather, associations, known mechanisms of action, and common sense suggest that we avoid use in this population.

Herbal fertility treatments used in North America from colonial times to 1900, and their potential for improving the success rate of assisted reproductive technology

This paper serves to fill a gap in the literature regarding evidence for the use of botanical remedies in the promotion of fertility. It examines the botanical remedies that were used in North America (1492-1900) for all stages of reproduction from preconception to birth, and discusses their potential for future use with present-day infertility treatments. Each medicinal plant discussed in this paper is assessed using an ethnomedicinal methodology that entails examining the published ethnobotanical, phytochemical and pharmacological data. A few clinical trials have shown that there is potential for medicinal plants to improve the success rate of assisted reproductive technology (ART) treatment if used in an integrated manner, similar to the integrated use of traditional Chinese medicine with ART treatment. For example, research has shown that older women who become pregnant have a high miscarriage rate, and this is one area that complementary and alternative medicines can address.

Liver enzyme abnormalities in taking traditional herbal medicine in Korea: A retrospective large sample cohort study of musculoskeletal disorder patients

ETHNOPHARMACOLOGICAL RELEVANCE

The objective of this study is to report the incidence of liver injury from herbal medicine in musculoskeletal disease patients as large-scale studies are scarce. Considering that herbal medicine is frequently used in patients irrespective of liver function in Korea, we investigated the prevalence of liver injury by liver function test results in musculoskeletal disease patients.

MATERIALS AND METHODS

Of 32675 inpatients taking herbal medicine at 7 locations of a Korean medicine hospital between 2005 and 2013, we screened for liver injury in 6894 patients with liver function tests (LFTs) at admission and discharge. LFTs included t-bilirubin, AST, ALT, and ALP. Liver injury at discharge was assessed by LFT result classifications at admission (liver injury, liver function abnormality, and normal liver function). In analyses for risk factors of liver injury at discharge, we adjusted for age, sex, length of stay, conventional medicine intake, HBs antigen/antibody, and liver function at admission.

RESULTS

A total 354 patients (prevalence 5.1%) had liver injury at admission, and 217 (3.1%) at discharge. Of the 354 patients with liver injury at admission, only 9 showed a clinically significant increase after herbal medicine intake, and 225 returned to within normal range or showed significant liver function recovery. Out of 4769 patients with normal liver function at admission, 27 (0.6%) had liver injury at discharge. In multivariate analyses for risk factors, younger age, liver function abnormality at admission, and HBs antigen positive were associated with injury at discharge.

CONCLUSIONS

The prevalence of liver injury in patients with normal liver function taking herbal medicine for musculoskeletal disease was low, and herbal medicine did not exacerbate liver injury in most patients with injury prior to intake.

A case of life-threatening acute kidney injury with toxic encephalopathy caused by Dioscorea quinqueloba

Some herbal medications induce acute kidney injury. The acute kidney injuries caused by herbal medications are mild and commonly treated by palliative care. A 51-years-old man who drank the juice squeezed from the raw tubers of Dioscorea quinqueloba (D. quinqueloba) was admitted with nausea, vomiting and chilling. He developed a seizure with decreased level of consciousness. He was diagnosed with acute kidney injury, which was cured by continuous venovenous hemodialfiltration. Non-detoxified D. quinqueloba can cause severe acute kidney injury with toxic encephalopathy. It is critical to inform possible adverse effects of the medicinal herbs and to implement more strict regulation of these products.

Internet claims on dietary and herbal supplements in advanced nephropathy: truth or myth

BACKGROUND

The use of complementary/alternative medicine has garnered rising interest in recent years. Natural products including herbs, vitamins, and minerals are the most popularly consumed. The Internet is a ubiquitous source of information/market for these supplements.

AIM

To systematically evaluate the dietary and herbal supplement recommended for patients with CKD and ESRD on the Internet, and try to distinguish between the claim of the manufacturer and proven scientific data.

METHODS

A questionnaire assessing each website was formulated. Each product ingredient was recorded in the questionnaire by two independent reviewers and statistically analyzed.

RESULTS

Of the 184 websites, 28% claimed to decrease CKD progression, 60% did not advise to consult a doctor before taking the supplement, and >90% did not mention any potential drug interaction, disease interaction, or caution in use during pregnancy or in children. The ten common plant ingredients claiming to be beneficial in kidney diseases were uva ursi, dandelion, parsley, corn silk, juniper, celery, buchu, horsetail, marshmallow, and stinging nettle. In contrast to their claims, these substances were not adequately studied in humans. The available animal studies showed detrimental effects and potential drug interactions with commonly used medications in the CKD/ESRD population.

CONCLUSIONS

Nephrologists need to be cognizant of the lack of substantiated proven benefits of these substances and of the potential adverse effects in the animal models that can translate to the patients. Most importantly, the policy needs to change regarding the regulation of these products to prevent patient harm and misinformation.

Underestimating the toxicological challenges associated with the use of herbal medicinal products in developing countries

Various reports suggest a high contemporaneous prevalence of herb-drug use in both developed and developing countries. The World Health Organisation indicates that 80% of the Asian and African populations rely on traditional medicine as the primary method for their health care needs. Since time immemorial and despite the beneficial and traditional roles of herbs in different communities, the toxicity and herb-drug interactions that emanate from this practice have led to severe adverse effects and fatalities. As a result of the perception that herbal medicinal products have low risk, consumers usually disregard any association between their use and any adverse reactions hence leading to underreporting of adverse reactions. This is particularly common in developing countries and has led to a paucity of scientific data regarding the toxicity and interactions of locally used traditional herbal medicine. Other factors like general lack of compositional and toxicological information of herbs and poor quality of adverse reaction case reports present hurdles which are highly underestimated by the population in the developing world. This review paper addresses these toxicological challenges and calls for natural health product regulations as well as for protocols and guidance documents on safety and toxicity testing of herbal medicinal products.

Ban Tu Wan hepatotoxicity

Medications are thought to contribute to approximately 50% of the cases of acute liver failure in the USA. This number includes some herbal medications and supplements. However, little regulatory oversight of these later substances occurs. This report describes a case of fulminant hepatic failure secondary to Ban Tu Wan (a Chinese herb). We discuss the use of this herbal supplement and the relationship to drug-induced hepatitis.

Herbal bioactivation, molecular targets and the toxicity relevance

There have been increasing reports on the adverse reactions associated with herbal consumption. For many of these adverse reactions, the underlying biochemical mechanisms are unknown, but bioactivation of herbal compounds to generate reactive intermediates have been implicated. This minireview updates our knowledge on metabolic activation of herbal compounds, molecular targets and the toxicity relevance. A number of studies have documented that some herbal compounds can be converted to toxic or even carcinogenic metabolites by Phase I [e.g. cytochrome P450s (CYPs)] and less frequently by Phase II enzymes. For example, aristolochic acids (AAs) in Aristolochia spp, which undergo reduction of the nitro group by hepatic CYP1A1/2 or peroxidases in extrahepatic tissues to generate highly reactive cyclic nitrenium ions. The latter can react with macromolecules (DNA and protein), resulting in activation of H-ras and myc oncogenes and gene mutation in renal cells and finally carcinogenesis of the kidneys. Teucrin A and teuchamaedryn A, two diterpenoids found in germander (Teuchrium chamaedrys) used as an adjuvant to slimming herbal supplements that caused severe hepatotoxicity, are converted by CYP3A4 to reactive epoxide which reacts with proteins such as CYP3A and epoxide hydrolase and inactivate them. Some naturally occurring alkenylbenzenes (e.g. safrole, methyleugenol and estragole) and flavonoids (e.g. quercetin) can undergo bioactivation by sequential 1-hydroxylation and sulfation, resulting in reactive intermediates capable of forming DNA adducts. Extensive pulegone metabolism generated p-cresol that is a glutathione depletory. The hepatotoxicity of kava is possibly due to intracellular glutathione depletion and/or quinone formation. Moreover, several herbal compounds including capsaicin from chili peppers, dially sulfone in garlic, methysticin and dihydromethysticin in kava, oleuropein in olive oil, and resveratrol found in grape seeds are mechanism-based (suicide) inhibitors of various CYPs. Together with advances of proteomics, metabolomics and toxicogenomics, an integrated systems toxicological approach may provide deep insights into mechanistic aspects of herb-induced toxicities, and contribute to bridging the relationships between herbal bioactivation, protein/DNA adduct formation and the toxicological consequences.

Effects of Flos carthami on CYP2D6 and on the Pharmacokinetics of Metoprolol in Rats

Flos carthami is a traditional Chinese herbal medicine. Clinically, the Flos carthami Injection has been used concomitantly with other Western drugs and may be used concomitantly with β-blockers, such as metoprolol, to treat cerebrovascular and coronary heart diseases, in China. Metoprolol is a CYP2D6 substrate and is predominantly metabolized by this isozyme. However, we do not know whether there is an effect of Flos carthami on CYP2D6 and the consequences of such an effect. Concern is raised regarding the possible herb-drug interaction. In this report, the effects of Flos carthami on the activity of CYP2D6 in vivo and in vitro and on the pharmacokinetics of metoprolol, in rats, are investigated. To assess the inhibitory potency of Flos carthami, the concentration associated with 50% inhibition (IC₅₀) of dextromethorphan metabolism was determined based on the concentration-inhibition curves. The inhibitory effect of Flos carthami on CYP2D6 was also compared with cimetidine in vitro. Flos carthami could significantly inhibit CYP2D6 in rats both in vitro and in vivo (P < .05) and could slow down the metabolic rate of metoprolol as suggested by prolonged t_1/2 (67.45%), by increased C_max (74.51%) and AUC_0−∞ (76.89%). These results suggest that CYP2D6 is a risk factor when Flos carthami is administered concomitantly with metoprolol or other CYP2D6 substrates.