The toxicity and pathology of selected dietary herbal medicines

Identification of Potential Plant-Derived Pancreatic Beta-Cell-Directed Agents Using New Custom-Designed Screening Method: Gymnema sylvestre as an Example

BACKGROUND

Folk medicines are attractive therapeutic agents for treating type 2 diabetes mellitus (T2DM). Most plant extracts that have been suggested to restore β-cells function were tested in vivo. Some only have been tested in vitro to determine whether they have a direct effect on β-cells islets of Langerhans. Currently, there are no defined criteria for screening of β-cell-directed plant-based remedies as potential antidiabetic agents.

SUMMARY

In this review, we have identified certain criteria/characteristics that can be used to generate a "screening portfolio" to identify plant extracts as potential β-cell-directed agents for the treatment of T2DM. To validate our screening method, we studied the potential therapeutic efficacy of a Gymnema sylvestre (GS) extract using the screening criteria detailed in the review. Six criteria have been identified and validated using OSA®, a GS extract. By using this screening method, we show that OSA® fulfilled most of the criteria identified for an effective β-cell-directed antidiabetic therapy, being an effective insulin-releasing agent at nontoxic concentrations; maintaining β-cell insulin content by stimulating a concomitant increase in insulin gene transcription; maintaining β-cell mass by protecting against apoptosis; and being effective at maintaining normoglycemia in vivo in a mouse model and a human cohort with T2DM.

KEY MESSAGES

The present review has highlighted the importance of having a screening portfolio for plant extracts that have potential antidiabetic effects in the treatment of T2DM. We propose that this screening method should be adopted for future studies to identify new β-cell-directed antidiabetic plant derived agents.

Phytochemicals targeting lncRNAs: A novel direction for neuroprotection in neurological disorders

Neurological disorders with various etiologies impacting the nervous system are prevalent in clinical practice. Long non-coding RNA (lncRNA) molecules are functional RNA molecules exceeding 200 nucleotides in length that do not encode proteins, but participate in essential activities. Research indicates that lncRNAs may contribute to the pathogenesis of neurological disorders, and may be potential targets for their treatment. Phytochemicals in traditional Chinese herbal medicine (CHM) have been found to exert neuroprotective effects by targeting lncRNAs and regulating gene expression and various signaling pathways. We aim to establish the development status and neuroprotective mechanism of phytochemicals that target lncRNAs through a thorough literature review. A total of 369 articles were retrieved through manual and electronic searches of PubMed, Web of Science, Scopus and CNKI databases from inception to September 2022. The search utilized combinations of natural products, lncRNAs, neurological disorders, and neuroprotective effects as keywords. The included studies, a total of 31 preclinical trials, were critically reviewed to present the current situation and the progress in phytochemical-targeted lncRNAs in neuroprotection. Phytochemicals have demonstrated neuroprotective effects in preclinical studies of various neurological disorders by regulating lncRNAs. These disorders include arteriosclerotic ischemia-reperfusion injury, ischemic/hemorrhagic stroke, Alzheimer's disease, Parkinson's disease, glioma, peripheral nerve injury, post-stroke depression, and depression. Several phytochemicals exert neuroprotective roles through mechanisms such as anti-inflammatory, antioxidant, anti-apoptosis, autophagy regulation, and antagonism of Aβ-induced neurotoxicity. Some phytochemicals targeted lncRNAs and served a neuroprotective role by regulating microRNA and mRNA expression. The emergence of lncRNAs as pathological regulators provides a novel direction for the study of phytochemicals in CHM. Elucidating the mechanism of phytochemicals regulating lncRNAs will help to identify new therapeutic targets and promote their application in precision medicine.

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.

Current Trends in Toxicity Assessment of Herbal Medicines: A Narrative Review

Even in modern times, the popularity level of medicinal plants and herbal medicines in therapy is still high. The World Health Organization estimates that 80% of the population in developing countries uses these types of remedies. Even though herbal medicine products are usually perceived as low risk, their potential health risks should be carefully assessed. Several factors can cause the toxicity of herbal medicine products: plant components or metabolites with a toxic potential, adulteration, environmental pollutants (heavy metals, pesticides), or contamination of microorganisms (toxigenic fungi). Their correct evaluation is essential for the patient’s safety. The toxicity assessment of herbal medicine combines in vitro and in vivo methods, but in the past decades, several new techniques emerged besides conventional methods. The use of omics has become a valuable research tool for prediction and toxicity evaluation, while DNA sequencing can be used successfully to detect contaminants and adulteration. The use of invertebrate models (Danio renio or Galleria mellonella) became popular due to the ethical issues associated with vertebrate models. The aim of the present article is to provide an overview of the current trends and methods used to investigate the toxic potential of herbal medicinal products and the challenges in this research field.

Evaluation of the toxic potential of the aqueous extract from Mangifera indica Linn. (Anacardiaceae) in rats submitted to experimental models of acute and subacute oral toxicity

ETHNOPHARMACOLOGICAL RELEVANCE

The population has traditionally used the Mangifera indica plant leaves to treat diseases such as Diabetes Mellitus and alleviate signs and symptoms such as inflammation, diarrhea, and dysentery. In a previous study, we demonstrated that the flavonoids present in the aqueous extract from M. indica leaves (EAMI) exhibited a potent hypoglycemic effect in diabetic rats, promoting the widespread use of the plant by the population and highlighting the importance of investigating its oral toxicity.

AIM OF THE STUDY

The present study aimed to assess the toxic potential of EAMI in rats submitted to experimental models of acute and subacute (short-term) oral toxicity.

MATERIAL AND METHODS

For the acute toxicity test, female Wistar rats received a single oral dose of 2000 mg/kg body weight of EAMI and were observed for 14 days. In the short-term toxicity test, male and female Wistar rats received repeated oral EAMI doses of 125, 250, 500 or 1000 mg/kg body weight and observed for 28 days.

RESULTS

The phytochemical analysis of EAMI demonstrated that the extract has high levels of flavonoids. No animals died in the acute toxicity test, and no clinical changes were observed that show signs of toxicity in the animals. There was no significant change in the weight of the organs of the animals submitted to tests with the EAMI, suggesting that LD50 is greater than 2000 mg/kg. In the conditions and doses tested in the short-term toxicity experiments, the treatment did not produce significant changes in the physiological, biochemical, hematological, and histopathological parameters in the animals evaluated.

CONCLUSIONS

Our study demonstrated that high doses of EAMI administered acutely, as well as all doses evaluated in the short-term oral toxicity model, should be considered safe during traditional therapeutic use.

Natural product remedies for COVID-19: A focus on safety

Infection by the novel coronavirus SARS-CoV-2 causing the coronavirus disease (COVID-19), is currently a global pandemic with more than two million deaths to date. Though a number of vaccines have recently been approved against the virus, availability remains a big challenge, and also acceptance by most people has become a big debate. This review discusses possible/proposed natural product remedies and some major conventional treatment options used to manage the infection and, safety concerns on the use of unproven or unapproved health products against COVID-19. An extensive literature review indicated that the influx of unproven and unapproved health products in the global market are on the rise, leading to various forms of self- medication. To this effect, there have been warnings by the United States Food and Drug Administration and the World Health Organisation against the use of such products. Conventional drugs such as remdesivir, chloroquine/hydroxychloroquine and dexamethasone are the major proposed drugs that are currently undergoing clinical trials for the management of this disease. Efforts are being made globally in the search for possible therapeutics which may be the best way to eradicating this disease. Some countries have approved the use of natural products in the management of COVID-19, despite little or no clinical evidence on their efficacy and safety. Natural products may hold a great potential in the fight against COVID-19 but without detailed clinical trials, their potency against the virus and their safe use cannot be established. To attain this goal, extensive research followed by clinical studies are needed. Collaborative efforts between researchers, clinicians, governments and traditional medicinal practitioners in the search and development of safe and effective therapeutics from natural products for the treatment of COVID-19 could be a potential option.

Sub-chronic toxicity evaluation of top three commercial herbal antimalarial preparations in the Kumasi metropolis, Ghana

PURPOSE

Safety data on commonly used herbal medicinal (HM) products (HMPs) and marketed in Ghana are scarce. We assessed the sub-chronic toxicity of three most-patronised commercial antimalarial HMPs in Kumasi, Ghana.

METHOD

Top three HMPs (designated as herbal products 'A' (HPA), 'B' (HPB) and 'C' (HPC)) were selected after a mini-survey and sub-chronic toxicity evaluation conducted in accordance with Organisation for Economic Co-operation and Development (OECD) 407 guidelines. Control rats received clean water while test groups received daily adult human dose (DAHD), 5× DAHD or 10× DAHD of either HPA, HPB or HPC for 30 days. Rats were killed on day 31 to obtain biochemical, haematology and histology samples for analysis. Data were analysed by one-way analysis of variance (ANOVA) and post hoc Tukey's test.

RESULTS

The three HMPs produced alterations in liver morphology predominantly characterised by prominent foci of fatty change with scattered hepatocytes containing intracytoplasmic fat globules and congested central veins and sinusoids. The lungs showed alveolar with evidence of inflammation and foci of epithelial sloughing. Alveolar spaces were also obscured by debris and inflammatory cells. HPA and HPC produced scattered intensely congested heart vessels while HPB(10) produced haemorrhage and amorphous exudates within the heart. All HMPs produced neither treatment-related deaths nor significant change in haematological and biochemical parameters, except for HPA and HPB which decreased (P<0.05) aspartate aminotransferase (AST) and HPB, which elevated (P<0.05) fasting blood glucose (FBG).

CONCLUSION

Data from the present study suggest the potential of the herbal products (HPs), HPA, HPB and HPC, to cause major organ-system dysfunction or damage. We advise cautious use of these products and recommend further safety evaluation in chronic toxicity models.

The toxicologic pathology aspects of selected natural herbal products and related compounds

Herbal products have been in use for many years, but they are becoming more and more popular in recent years, and they are currently in widespread use throughout the world. In this review article we describe the histopathologic findings found after exposure to 12 dietary herbals in studies conducted in rodent model systems. Clear or some evidence for carcinogenic activity was seen with 6 herbals, with the liver being the most common organ affected. The intestine was affected by two herbals (aloe vera nondecolorized extract and senna), three had no clear evidence for carcinogenic activity and one was cardiotoxic (Ephedrine and Ephedra in combination with caffeine). Information from these studies can help to better understand potential target organs for further evaluation from exposure to various herbal products.

Chemical-Induced Oral Squamous Cell Neoplasms in Rodents: An Overview of NTP 2-Year Cancer Studies

Oral cancer is the seventh most common malignancy worldwide, and lifestyle factors participate in its development. Rodent studies can help identify substances that contribute to its development and provide information on the early stages of carcinogenicity. The National Toxicology Program (NTP) has conducted more than 500 short-term and 2-year toxicology and carcinogenicity studies in rodents, and some of the tested compounds resulted in oral cancer. Our goal was to review the NTP carcinogenic studies to describe those chemicals that have oral carcinogenic outcome in rodents. For this project, we reviewed the results from all NTP carcinogenicity studies and a board-certified veterinary pathologist reviewed the slides from all neoplasms in the oral cavity that were considered treatment related. We have identified 26 chemicals with an adverse effect in the oral cavity. Fourteen chemicals demonstrated clear evidence of carcinogenicity in the oral cavity. We provide information on the carcinogenic findings in rodents together with a detailed description of the morphologic aspects of the oral cancers and speculate that the carcinogenic effects can be induced by different pathological modes of action. The findings reviewed here provide indicators for potential oral carcinogenesis processes in rodent models, which can be further investigated in future mechanistic studies.

Teucrium polium Alters the Vascular Branching Pattern and VEGF-A Expression in the Chick Extra-Embryonic Membrane Model

Background: The Teucrium polium is used in traditional medicine for the treatment of various diseases, including inflammations, rheumatism, diabetes, and ulcers. While this herb and its aqueous extract have been consumed in Iran for hypoglycemia treatment, medicine has proved several side effects such as hepatitis, vomiting, changes in the kidney functions, and allergic responses. Also, using this herb is not safe during pregnancy or lactation. The chick embryo is a live animal model applicable for assessing the pathological property of herbs. In this regard, some details of the embryonic vascular toxicity of the Teucrium polium were evaluated via a chick embryo model. Objectives: The current study assessed vessels' alteration in the chick's extra embryonic membrane following Teucrium polium treatment. Change in molecular cues involved in early embryonic angiogenesis has also been investigated. Methods: The eggs of the chicken were divided into three equal treatment groups; as follow: first group one: considered as a sham, next groups: herbal extract that eggs injected with T. polium extract of 3 (150 µg/50 µL) or 6 (300 µg/50 µL) mg/kg, respectively. Results: The anti-angiogenic effect of the herb extract in which vessel area, total vessel length, and vascular branching decreased, whereas lacunarity increased in a dose-dependent manner. VEGF-A expression was also down-regulated in herb-exposed extra-embryonic membranes. Concerns regarding the side effects of T. polium during pregnancy were confirmed. Conclusions: We conclude that changes in early vascular expansion and gene expression might finally lead to developmental defects in embryos following consumption of T. polium. Thus, this herb's consumption should be decreased during embryonic development, and clinicians should limit the herb prescription in pregnant women, particularly at dosages > 3 mg/kg.

Bioprospecting for Antibacterial Drugs: a Multidisciplinary Perspective on Natural Product Source Material, Bioassay Selection and Avoidable Pitfalls

Bioprospecting is the exploration, extraction and screening of biological material and sometimes indigenous knowledge to discover and develop new drugs and other products. Most antibiotics in current clinical use (eg. β-lactams, aminoglycosides, tetracyclines, macrolides) were discovered using this approach, and there are strong arguments to reprioritize bioprospecting over other strategies in the search for new antibacterial drugs. Academic institutions should be well positioned to lead the early stages of these efforts given their many thousands of locations globally and because they are not constrained by the same commercial considerations as industry. University groups can lack the full complement of knowledge and skills needed though (eg. how to tailor screening strategy to biological source material). In this article, we review three key aspects of the bioprospecting literature (source material and in vitro antibacterial and toxicity testing) and present an integrated multidisciplinary perspective on (a) source material selection, (b) legal, taxonomic and other issues related to source material, (c) cultivation methods, (d) bioassay selection, (e) technical standards available, (f) extract/compound dissolution, (g) use of minimum inhibitory concentration and selectivity index values to identify progressible extracts and compounds, and (h) avoidable pitfalls. The review closes with recommendations for future study design and information on subsequent steps in the bioprospecting process.

A Behavioral Confirmation and Reduction of the Natural versus Synthetic Drug Bias

Research reveals a biased preference for natural v. synthetic drugs; however, this research is based on self-report and has not examined ways to reduce the bias. We examined these issues in 5 studies involving 1125 participants. In a pilot study (N = 110), participants rated the term natural to be more positive than the term synthetic, which reveals a default natural-is-better belief. In studies 1 (N = 109) and 2 (N = 100), after a supposed personality study, participants were offered a thank you "gift" of a natural or synthetic pain reliever. Approximately 86% (study 1) and 93% (study 2) of participants chose the natural v. synthetic pain reliever, which provides a behavioral choice confirmation of the natural drug bias. In studies 3 (N = 350) and 4 (N = 356), participants were randomly assigned to a control or experimental condition and were asked to consider a scenario in which they had a medical issue requiring a natural v. synthetic drug. The experimental condition included a stronger (study 3) or weaker (study 4) rational appeal about the natural drug bias and a statement suggesting that natural and synthetic drugs can be good or bad depending on the context. In both studies, the natural bias was reduced in the experimental condition, and perceived safety and effectiveness mediated this effect. Overall, these data indicate a bias for natural over synthetic drugs in preferences and behavioral choices, which might be reduced with a rational appeal.

Using SSR-HRM to Identify Closely Related Species in Herbal Medicine Products: A Case Study on Licorice

Traditional herbal medicines have played important roles in the ways of life of people around the world since ancient times. Despite the advanced medical technology of the modern world, herbal medicines are still used as popular alternatives to synthetic drugs. Due to the increasing demand for herbal medicines, plant species identification has become an important tool to prevent substitution and adulteration. Here we propose a method for biological assessment of the quality of prescribed species in the Chinese Pharmacopoeia by use of high resolution melting (HRM) analysis of microsatellite loci. We tested this method on licorice, a traditional herbal medicine with a long history. Results showed that nine simple sequence repeat (SSR) markers produced distinct melting curve profiles for the five licorice species investigated using HRM analysis. These results were validated by capillary electrophoresis. We applied this protocol to commercially available licorice products, thus enabling the consistent identification of 11 labels with non-declared Glycyrrhiza species. This novel strategy may thus facilitate DNA barcoding as a method of identification of closely related species in herbal medicine products. Based on this study, a brief operating procedure for using the SSR-HRM protocol for herbal authentication is provided.

Cancer Related to Herbs and Dietary Supplements: Online Table of Case Reports. Part 5 of 5

A current listing of potentially life-threatening, cancer-related dietary supplements (DSs; includes herbs) based on PubMed case reports was summarized in online tables that can now be updated continually to forewarn United States consumers, clinicians, and DS companies. Documented PubMed case reports were used to create a "Toxic Table" related to cancer (1966 to April 2016, and cross-referencing). Keywords included "herb" or "dietary supplement" combined with "cancer" as well as the specific herb "name" combined with "cancer" and sometimes "toxicity." Excluded were herb combinations (some exceptions), Chinese herb mixtures, teas of mixed herb contents, fungi (mycotoxins from molds and mushrooms), poisonous plants, self-harm, excessive doses (except vitamins/minerals), legal or illegal drugs, drug-herb interactions, and confounders of drugs or diseases related to cancer. Also included were a few foods related to cancer. Over the past 50+ years, PubMed case reports revealed an increased risk of cancer related to approximately one herb (guang fang ji), no dietary supplements (except those containing guang fang ji or aristolochic acid), and two foods (bracken fern, which is sometimes sold as an herbal supplement, and hot maté). This online "Toxic Table" can now be continually updated to assist researchers and clinicians in preventing serious adverse events from DSs related to cancer.

The Influence of Safety, Efficacy, and Medical Condition Severity on Natural versus Synthetic Drug Preference

Research indicates that there is a preference for natural v. synthetic products, but the influence of this preference on drug choice in the medical domain is largely unknown. We present 5 studies in which participants were asked to consider a hypothetical situation in which they had a medical issue requiring pharmacological therapy. Participants ( N = 1223) were asked to select a natural, plant-derived, or synthetic drug. In studies 1a and 1b, approximately 79% of participants selected the natural v. synthetic drug, even though the safety and efficacy of the drugs were identical. Furthermore, participants rated the natural drug as safer than the synthetic drug, and as that difference increased, the odds of choosing the natural over synthetic drug increased. In studies 2 and 3, approximately 20% of participants selected the natural drug even when they were informed that it was less safe (study 2) or less effective (study 3) than the synthetic drug. Finally, in study 4, approximately 65% of participants chose a natural over synthetic drug regardless of the severity of a specific medical condition (mild v. severe hypertension), and this choice was predicted by perceived safety and efficacy differences. Overall, these data indicate that there is a bias for natural over synthetic drugs. This bias could have implications for drug choice and usage.

Plants Consumption and Liver Health

The liver is a very important organ with a lot of functions for the host to survive. Dietary components are essential for and can be beneficial or detrimental to the healthy or diseased liver. Plants food is an essential part of the human diet and comprises various compounds which are closely related to liver health. Selected food plants can provide nutritional and medicinal support for liver disease. At the present, the knowledge of the effects of plants on the liver is still incomplete. The most urgent task at the present time is to find the best dietary and medicinal plants for liver health in an endless list of candidates. This review article updates the knowledge about the effects of plants consumption on the health of the liver, putting particular emphasis on the potential beneficial and harmful impact of dietary and medicinal plants on liver function.

Schisandrin B inhibits cell growth and induces cellular apoptosis and autophagy in mouse hepatocytes and macrophages: implications for its hepatotoxicity

A number of drugs and herbal compounds have been documented to cause hepatoxicity. Schisandrin B (Sch B) is an active dibenzocyclooctadiene isolated from Schisandrae fructus, with a wide array of pharmacological activities. However, the potential hepatotoxicity of Sch B is a major safety concern, and the underlying mechanism for Sch B-induced liver toxic effects is not fully elucidated. In the present study, we aimed to investigate the liver toxic effects and the molecular mechanisms of Sch B in mouse liver and macrophage cells. The results have shown that Sch B exhibits potent grow inhibitory, proapoptotic, and proautophagic effects in AML-12 and RAW 264.7 cells. Sch B markedly arrested cells in G₁ phase in both cell lines, accompanied by the down-regulation of cyclin dependent kinase 2 (CDK2) and cyclin D1 and up-regulation of p27 Kip1 and checkpoint kinase 1. Furthermore, Sch B markedly increased the apoptosis of AML-12 and RAW 264.7 cells with a decrease in the expression of B-cell lymphoma-extra-large and (Bcl-xl) B-cell lymphoma 2 (Bcl-2), but an increase in the expression of B-cell lymphoma 2-associated X protein (Bax). Sch B promoted the cleavage of caspase 3 and poly-adenosine diphosphate-ribose polymerase (PARP) in both cell lines. Additionally, Sch B significantly induced autophagy of AML-12 and RAW 264.7 cells. Sch B inhibited the activation of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway, as indicated by their altered phosphorylation, contributing to the proautophagic effect of Sch B. Taken together, our findings show that the inducing effects of Sch B on cell cycle arrest, apoptosis, and autophagy may contribute to its liver toxic effects, which might provide a clue for the investigation of the molecular toxic targets and underlying mechanisms for Sch B-induced hepatotoxicity in herbal consumers. More studies are warranted to fully delineate the underlying mechanisms, efficacy, and safety of Sch B for clinical use.

Data mining in the U.S. National Toxicology Program (NTP) database reveals a potential bias regarding liver tumors in rodents irrespective of the test agent

Long-term studies in rodents are the benchmark method to assess carcinogenicity of single substances, mixtures, and multi-compounds. In such a study, mice and rats are exposed to a test agent at different dose levels for a period of two years and the incidence of neoplastic lesions is observed. However, this two-year study is also expensive, time-consuming, and burdensome to the experimental animals. Consequently, various alternatives have been proposed in the literature to assess carcinogenicity on basis of short-term studies. In this paper, we investigated if effects on the rodents' liver weight in short-term studies can be exploited to predict the incidence of liver tumors in long-term studies. A set of 138 paired short- and long-term studies was compiled from the database of the U.S. National Toxicology Program (NTP), more precisely, from (long-term) two-year carcinogenicity studies and their preceding (short-term) dose finding studies. In this set, data mining methods revealed patterns that can predict the incidence of liver tumors with accuracies of over 80%. However, the results simultaneously indicated a potential bias regarding liver tumors in two-year NTP studies. The incidence of liver tumors does not only depend on the test agent but also on other confounding factors in the study design, e.g., species, sex, type of substance. We recommend considering this bias if the hazard or risk of a test agent is assessed on basis of a NTP carcinogenicity study.

Safety surveillance of traditional Chinese medicine: current and future

Herbal medicine, including traditional Chinese medicine, has been used for the prevention, treatment, and cure of disorders or diseases for centuries. In addition to being used directly as therapeutic agents, medicinal plants are also important sources for pharmacological drug research and development. With the increasing consumption of herbal products intended to promote better health, it is extremely important to assure the safety and quality of herbal preparations. However, under current regulation surveillance, herbal preparations may not meet expectations in safety, quality, and efficacy. The challenge is how to assure the safety and quality of herbal products for consumers. It is the responsibility of producers to minimize hazardous contamination and additives during cultivation, harvesting, handling, processing, storage, and distribution. This article reviews the current safety obstacles that have been involved in traditional Chinese herbal medicine preparations with examples of popular herbs. Approaches to improve the safety of traditional Chinese medicine are proposed.

Herbal medicine for hospitalized patients with severe depressive episode: a retrospective controlled study

Herbal medicine is increasingly used in depressed patients. The purpose of this retrospective controlled study was to evaluate the efficacy and safety of herbal medicine treatment of severe depressive episode. A total of 146 severely depressed subjects were selected from patients who were admitted to the Department of Psychosomatics of Tongde Hospital at Hangzhou, China between 1st September 2009 and 30th November 2013. While all were medicated with psychotropic drugs, 78 received additional individualized herbal medicine. The severity of depressive symptoms was measured using 24-item Hamilton Rating Scale for Depression (HAMD-24) at admission and thereafter once weekly during hospital stay. The proportion of patients achieving clinical response and remission and incidence of adverse events were compared. The two groups had similar average length of hospital stay for approximately 28 days and were not different in the use of psychotropic medications. Survival analysis revealed that patients with herbal medicine had significantly higher chance of achieving clinical response [relative risk (RR)=2.179, P<0.001] and remission (RR=5.866, P<0.001) compared to those without herbal medicine. Patients with herbal medicine experienced remarkably fewer incidences of physical tiredness, headache, palpitation, dry mouth and constipation, but had a significantly higher incidence of digestive discomfort compared to patients without herbal medicine. These results indicate that additional treatment with individualized herbal medicine enhances antidepressant response and reduces certain side effects associated with psychotropic medications. Herbal medicine is an effective and relatively safe therapy for severe depressive episode (Trial Registration: ChiCTR-OCH-13003864).

Curcumin a potent cancer preventive agent: Mechanisms of cancer cell killing

There is no doubt that diet could effectively improve health and halt cancers. Dietary phytochemical compounds and their derivatives represent a cornucopia of effectively anticancer compounds. This review discusses existing data on the anticancer activities of curcumin, and then offers possible explanations for and mechanisms of its cancer-preventive action. This review also offers insights into the molecular mechanism and targets through which curcumin modulates cell cycle, apoptotic signals, anti-apoptotic proteins, miRNAs, Wnt/beta-catenin signaling, protein kinases, nuclear factor-κB, proteasome activation, epigenetic regulation including DNA methylation and histone modification. Finally, this review provides explanations for how curcumin reverses the multi-drug resistance (MDR) of cancer cells.

The growing use of herbal medicines: issues relating to adverse reactions and challenges in monitoring safety

The use of herbal medicinal products and supplements has increased tremendously over the past three decades with not less than 80% of people worldwide relying on them for some part of primary healthcare. Although therapies involving these agents have shown promising potential with the efficacy of a good number of herbal products clearly established, many of them remain untested and their use are either poorly monitored or not even monitored at all. The consequence of this is an inadequate knowledge of their mode of action, potential adverse reactions, contraindications, and interactions with existing orthodox pharmaceuticals and functional foods to promote both safe and rational use of these agents. Since safety continues to be a major issue with the use of herbal remedies, it becomes imperative, therefore, that relevant regulatory authorities put in place appropriate measures to protect public health by ensuring that all herbal medicines are safe and of suitable quality. This review discusses toxicity-related issues and major safety concerns arising from the use of herbal medicinal products and also highlights some important challenges associated with effective monitoring of their safety.