Japanese Mucuna pruriens (Hasshou Beans) Showed Fast-acting and Long-lasting Effects in Parkinson's Disease.

Objective Mucuna pruriens (MP) is a legume whose seeds contain levodopa (LD), which has potential therapeutic effects against Parkinson's disease (PD). However, further research is needed to thoroughly evaluate its efficacy and safety for treating this condition. In this study, we analyzed the pharmacokinetics of MP grown in Japan and investigated its mechanism of action in PD. Methods MP seeds ground after roasting (containing 4.02% LD per MP powder) were used as the reagent and compared with an equivalent LD/carbidopa (CD) preparation. This clinical trial was conducted using a crossover design among PD patients attending our institution. Each patient received a single dose of 100/10 mg LD/CD tablets and 11 g of MP reagent. Results Among the seven patients with PD, MP prolonged the ON time 2-fold compared to LD/CD. The LD concentrations after MP intake were higher than those after LD/CD intake, whereas dyskinesia did not increase. An analysis of the LD metabolites showed that the 3-O-methyl-dopa/LD metabolic ratio was significantly lower after MP ingestion than after LD/CD ingestion, indicating that MP has a catechol-O-methyl transferase inhibitory effect. Conclusions This is the first report of a pharmacokinetic analysis conducted on actual patients with PD showing that MP significantly prolongs the ON time. The advantages of MP as a treatment for PD have been confirmed: it is inexpensive, as effective as LD, works faster and longer than LD, and does not increase dyskinesia.

Research Progress in the Pharmacological Activities, Toxicities, and Pharmacokinetics of Sophoridine and Its Derivatives.

Sophoridine is a natural quinolizidine alkaloid and a bioactive ingredient that can be isolated and identified from certain herbs, including Sophora flavescens Alt, Sophora alopecuroides L, and Sophora viciifolia Hance. In recent years, this quinolizidine alkaloid has gained widespread attention because of its unique structure and minimal side effects. Modern pharmacological investigations have uncovered sophoridine's multiple wide range biological activities, such as anti-cancer, anti-inflammatory, anti-viral, anti-arrhythmia, and analgesic functions, among others. These pharmacological activities and beneficial effects point to sophoridine as a strong potential therapeutic candidate for the treatment of various diseases, including several cancer types, hepatitis B virus, enterovirus 71, coxsackievirus B3, cerebral edema, cancer pain, heart failure, acute myocardial ischemia, arrhythmia, inflammation, acute lung injury, and osteoporosis. The data showed that sophoridine had adverse reactions, including hepatotoxicity and neurotoxicity. Additionally, analyses of sophoridine's safety, bioavailability, and pharmacokinetic parameters in animal models of research have been limited, especially in the clinic, as have been investigations on its structure-activity relationship. In this article, we comprehensively summarize the biological activities, toxicity, and pharmacokinetic characteristics of sophoridine and its derivatives, as currently reported in publications, as we attempt to provide an overall perspective on sophoridine analogs and the prospects of its application clinically.

Unpredictable adverse effects of herbal products.

Herbal products are being increasingly used all over the world for preventive and therapeutic purposes because of the belief of their safety. They have become an important part of health care system in many countries since they can easily be purchased in the health food stores or online. However, the lack of sufficient study on their efficacy and toxicity, inadequate controls of their availability, reduce their safety. Unlike conventional drugs, herbal products are not regulated for purity and potency. Herbal products contain substances which can induce or inhibit enzymes that take part in drug metabolism. Therefore the concurrent use of drugs with some medicinal plants can cause serious adverse effects and can also decrease the efficacy of the therapy. Particularly, drugs with narrow therapeutic index and plants which can affect drug metabolizing enzymes when used together, may lead to unpredictable adverse reactions. Impurities, contaminants and adulterants found in the herbal products, are the most common malpractises in herbal raw-material trade. In this review the unpredictable adverse effects of herbal products due to their possible interactions with drugs and also due to the adulteration and contamination with prohibited chemicals will be discussed in detail.

Pharmacokinetics and brain distribution studies of 6-hydroxykynurenic acid and its structural modified compounds.

OBJECTIVES: 6-Hydroxykynurenic acid (6-HKA) is an organic acid component in extracts of Ginkgo biloba leaves and acts as a major contributor to neurorestorative effects, while its oral bioavailability was low. Therefore, using prodrug method to improve the bioavailability and brain content of 6-HKA is significant. METHODS: Three structural modified compounds of 6-HKA were synthesized, and ultra performance liquid chromatography-tandem mass spectrometry methods for quantification of these structural modified compounds in rat plasma and rat brain homogenate were established and comprehensively validated. The methods were effectively applied to investigate the effects of structural modification on apparent permeability coefficients in cells, the pharmacokinetics and the brain distribution in rats. KEY FINDINGS: The results illustrated that esterification can greatly improve the apparent permeability coefficient and bioavailability of 6-HKA. Comparing with direct oral administration of 6-HKA, the bioavailability of isopropyl ester was greatly improved (from 3.96 ± 1.45% to 41.8 ± 15.3%), and the contents of 6-HKA in rat brains (49.7 ± 9.2 ng/g brain) were significantly higher after oral administration. CONCLUSIONS: The bioavailability and the brain content of 6-HKA can be improved by the prodrug method. Among three structural modified compounds, isopropyl-esterified 6-HKA was the most promising treatment.

Overview of Current Herb-Drug Interaction Databases.

An HERB-Drug Interaction (HDI) database is a structured data collection method for HDI information extracted from scattered literatures for quick retrieval. Our review summarized the ten currently available HDI databases, including those databases comprising HDI on the market. A detailed comparison on the scope of monographs, including the nature of content extracted from the original literature and user interfaces of these databases, was performed, and the number of references of fifty popular herbs in each HDI database was counted and presented in a heatmap to give users an intuitive understanding of the focuses of different HDI databases. Since it is well known that the development and maintenance of databases need continuous investment of capital and manpower, the sustainability of these databases was also reviewed and compared. Recently, artificial intelligence (AI) technologies, especially Natural Language Processing (NLP), have been applied to screen specific topics from massive articles and automatically identify the names of drugs and herbs in the literature. However, its application on the labor-intensive extraction and evaluation of HDI-related experimental conditions and results from literature remains limited due to the scarcity of these HDI data and the lack of well-established annotated datasets for these specific NLP recognition tasks. In view of the difficulties faced by current HDI databases and potential expansion of AI application in HDI database development, we propose a standardized format for data reporting and use of Concept Unique Identifier (CUI) for medical terms in the literature to accelerate the structured data collection. SIGNIFICANCE STATEMENT: The worldwide popularity of botanical and/or traditional medicine products has raised safety concerns due to potential HDI. However, the publicly available HDI databases are mostly outdated or incomplete. Through our review of the currently available HDI databases, a clear understanding of the key issues could be obtained and possible solutions to overcome the labour-intensive extraction as well as professional evaluation of information in HDI database development are proposed.

Lamiophlomis herba: A comprehensive overview of its chemical constituents, pharmacology, clinical applications, and quality control.

Lamiophlomis rotata (Benth.) Kudo (LR) is an extensively used Chinese herbal medicine. It contains a variety of chemical constituents with significant biological activities that were first recorded in the classical masterpiece of Tibetan Medicine, Somaratsa. In this review, we summarize the information regarding the traditional uses, chemical constituents, pharmacological effects, clinical applications, quality control, toxicology, and pharmacokinetics of LR. At least 223 chemical constituents have been isolated from LR, including phenylethanoid glycosides, flavonoids, iridoids, volatile oils, et al. Their various physiological activities have been demonstrated as analgesic, hemostatic, anti-inflammatory, anti-tumor, marrow-supplementing, anti-bacterial, and immunity-strengthening. The clinical applications of LR and quality control are also discussed, as well as some existing problems. This article aims to provide more comprehensive information on the chemical composition, pharmacological activity, and clinical application of LR, so as to provide a theoretical basis for the further reasonable development of LR in clinical practice and of new drugs.

Improving oral bioavailability of medicinal herbal compounds through lipid-based formulations - A Scoping Review.

BACKGROUND: Although numerous medicinal herbal compounds demonstrate promising therapeutic potential, their clinical application is often limited by their poor oral bioavailability. To circumvent this barrier, various lipid-based herbal formulations have been developed and trialled with promising experimental results. PURPOSE: This scoping review aims to describe the effect of lipid-based formulations on the oral bioavailability of herbal compounds. METHODS: A systematic search was conducted across three electronic databases (Medline, Embase and Cochrane Library) between January 2010 and January 2021 to identify relevant studies. The articles were rigorously screened for eligibility. Data from eligible studies were then extracted and collated for synthesis and descriptive analysis using Covidence. RESULTS: A total of 109 studies were included in the present review: 105 animal studies and four clinical trials. Among the formulations investigated, 50% were emulsions, 34% lipid particulate systems, 12% vesicular systems, and 4% were other types of lipid-based formulations. Within the emulsion system classification, self-emulsifying drug delivery systems were observed to produce the best improvements in oral bioavailability, followed by mixed micellar formulations. The introduction of composite lipid-based formulations and the use of uncommon surfactants such as sodium oleate in emulsion preparation was shown to consistently enhance the bioavailability of herbal compounds with poor oral absorption. Interestingly, the lipid-based formulations of magnesium lithospermate B and Pulsatilla chinensis produced an absolute bioavailability greater than 100% indicating the possibility of prolonged systemic circulation. With respect to chemical conjugation, D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) was the most frequently used and significantly improved the bioavailability of its phytoconstituents. CONCLUSION: Our findings suggest that there is no distinct lipid-based formulation superior to the other. Bioavailability improvements were largely dependent on the nature of the phytoconstituents. This scoping review, however, provided a detailed summary of the most up-to-date evidence on phytoconstituents formulated into lipid preparations and their oral bioavailability. We conclude that a systematic review and meta-analysis between bioavailability improvements of individual phytoconstituents (such as kaempferol, morin and myricetin) in various lipid-based formulations will provide a more detailed association. Such a review will be highly beneficial for both researchers and herbal manufacturers.

Evaluation of Microwave-Assisted Extraction Method for Preparation and Assessment of Thai Herbal Medicine Oral Tablets With Enriched Phytochemical Compounds.

In developing countries, populations have employed herbal medicines for primary health care because they are believed to be more appropriate to the human body and have less side effects than chemically synthesized drugs. The present study aimed to develop and evaluate herbal tablets incorporated with a Thai traditional medicinal extract, U-pa-ri-waat (URW), using microwave-assisted extraction (MAE). The extraction efficiency for URW using MAE and traditional solvent extraction was compared based on the percent yield after spray drying. URW tablets were prepared using the dry granulation method. The optimized products were assessed using standard characterization methods based on the United States and British Pharmacopeias. DPPH and ABTS radical scavenging assays were performed to analyze the antioxidant capacity of the microwave-assisted extracts. The results revealed that the flowability of the dry granule with added maltodextrin was improved compared to a granule without additives, as indicated by an angle of repose of 33.69 ± 2.0°, a compressibility index of 15.38 ± 0.66, and a Hausner's ratio of 1.18 ± 0.06. The resulting formulation produced flat tablets with uniform weight variation, hardness, thickness, friability, and optimum disintegration time. The URW extracts showed antioxidant activity and MAE with maltodextrin carrier displayed the strongest DPPH and ABTS radical activities with IC50 values of 1.60 ± 0.02 µg/mL and 4.02 ± 0.24 µg/mL, respectively. The URW tablet formulation passed the quality control tests. Storage of the formulation tablets for 90 days under accelerated conditions had minimal effects on tablet characteristics.

Black Cumin (Nigella sativa L.): A Comprehensive Review on Phytochemistry, Health Benefits, Molecular Pharmacology, and Safety.

Mounting evidence support the potential benefits of functional foods or nutraceuticals for human health and diseases. Black cumin (Nigella sativa L.), a highly valued nutraceutical herb with a wide array of health benefits, has attracted growing interest from health-conscious individuals, the scientific community, and pharmaceutical industries. The pleiotropic pharmacological effects of black cumin, and its main bioactive component thymoquinone (TQ), have been manifested by their ability to attenuate oxidative stress and inflammation, and to promote immunity, cell survival, and energy metabolism, which underlie diverse health benefits, including protection against metabolic, cardiovascular, digestive, hepatic, renal, respiratory, reproductive, and neurological disorders, cancer, and so on. Furthermore, black cumin acts as an antidote, mitigating various toxicities and drug-induced side effects. Despite significant advances in pharmacological benefits, this miracle herb and its active components are still far from their clinical application. This review begins with highlighting the research trends in black cumin and revisiting phytochemical profiles. Subsequently, pharmacological attributes and health benefits of black cumin and TQ are critically reviewed. We overview molecular pharmacology to gain insight into the underlying mechanism of health benefits. Issues related to pharmacokinetic herb-drug interactions, drug delivery, and safety are also addressed. Identifying knowledge gaps, our current effort will direct future research to advance potential applications of black cumin and TQ in health and diseases.

Insights into oral bioavailability enhancement of therapeutic herbal constituents by cytochrome P450 3A inhibition.

Herbal plants typically have complex compositions and diverse mechanisms. Among them, bioactive constituents with relatively high exposure in vivo are likely to exhibit therapeutic efficacy. On the other hand, their bioavailability may be influenced by the synergistic effects of different bioactive components. Cytochrome P450 3A (CYP3A) is one of the most abundant CYP enzymes, responsible for the metabolism of 50% of approved drugs. In recent years, many therapeutic herbal constituents have been identified as CYP3A substrates. It is more evident that CYP3A inhibition derived from the herbal formula plays a critical role in improving the oral bioavailability of therapeutic constituents. CYP3A inhibition may be the mechanism of the synergism of herbal formula. In this review, we explored the multiplicity of CYP3A, summarized herbal monomers with CYP3A inhibitory effects, and evaluated herb-mediated CYP3A inhibition, thereby providing new insights into the mechanisms of CYP3A inhibition-mediated oral herb bioavailability.

Pharmacokinetics of Eleven Kratom Alkaloids Following an Oral Dose of Either Traditional or Commercial Kratom Products in Rats.

Kratom, Mitragyna speciosa Korth., is being widely consumed in the United States for pain management and the reduction of opioid withdrawal symptoms. The central nervous system (CNS) active alkaloids of kratom, including mitragynine, 7-hydroxymitragynine, and numerous additional compounds, are believed to derive their effects through opioid receptor activity. There is no literature describing the systemic exposure of many of these alkaloids after the consumption of kratom. Therefore, we have developed and validated a bioanalytical method for the simultaneous quantitation of 11 kratom alkaloids (mitragynine, 7-hydroxymitragynine, corynantheidine, speciogynine, speciociliatine, paynantheine, corynoxine, corynoxine-B, mitraphylline, ajmalicine, and isospeciofoline) in rat plasma. The validated method was used to analyze oral pharmacokinetic study samples of lyophilized kratom tea (LKT) and a marketed product, OPMS liquid shot, in rats. Among the 11 alkaloids, only mitragynine, 7-hydroxymitragynine, speciociliatine, and corynantheidine showed systemic exposure 8 h postdose, and the dose-normalized systemic exposure of these four alkaloids was higher (1.6-2.4-fold) following the administration of the commercial OPMS liquid. Paynantheine and speciogynine levels were quantifiable up to 1 h postdose, whereas none of the other alkaloids were detected. In summary, the method was successfully applied to quantify the exposure of individual kratom alkaloids after an oral dose of traditional or commercial products. This information will contribute to understanding the role of each alkaloid in the overall pharmacology of kratom and elucidating the pharmacokinetic differences between traditional and commercial kratom products.

Validation of a HPLC method for quantification of midazolam in rat plasma: Application during a Maytenus ilicifolia-drug interaction study.

Midazolam (MDZ) is routinely employed as a marker compound of cytochrome P450 3A (CYP3A) activity. Despite the many HPLC-UV methods described to quantify MDZ in plasma, all of them use acetonitrile (ACN) or a mixture of methanol-isopropanol as organic solvent of the mobile phase. Since the ACN shortage in 2008, efforts have been made to replace this solvent during HPLC analysis. A simple, sensitive, accurate and repeatable HPLC-UV method (220 nm) was developed and validated to quantify MDZ in rat plasma using methanol instead. The method was applied during a herb-drug interaction study involving Maytenus ilicifolia, a Brazilian folk medicine used to treat gastric disorders. Plasma samples were alkalinized and MDZ plus alprazolam (internal standard) were extracted with diethyl ether. After solvent removal, the residue was reconstituted with methanol-water (1:1). The analyte was eluted throughout a C18 column using sodium acetate buffer (10 mm, pH 7.4)-methanol (40:60, v/v). The precision at the lower limit of quantification never exceeded 19.40%, and 13.86% at the higher levels of quality control standards, whereas the accuracy ranged from -19.81 to 14.33%. The analytical curve was linear from 50 to 2,000 ng/ml. The activity of the hepatic CYP3A enzymes was not affected by the extract.

Ginger (Zingiber officinale Rosc.) and its bioactive components are potential resources for health beneficial agents.

Zingiber officinale Rosc. (Zingiberacae), commonly known as ginger, is a perennial and herbaceous plant with long cultivation history. Ginger rhizome is one of the most popular food spices with unique pungent flavor and is prescribed as a well-known traditional Chinese herbal medicine. To date, over 160 constituents, including volatile oil, gingerol analogues, diarylheptanoids, phenylalkanoids, sulfonates, steroids, and monoterpenoid glycosides compounds, have been isolated and identified from ginger. Increasing evidence has revealed that ginger possesses a broad range of biological activities, especially gastrointestinal-protective, anti-cancer, and obesity-preventive effects. In addition, gingerol analogues such as 6-gingerol and 6-shogaol can be rapidly eliminated in the serum and detected as glucuronide and sulfate conjugates. Structural variation would be useful to improve the metabolic characteristics and bioactivities of lead compounds derived from ginger. Furthermore, some clinical trials have indicated that ginger can be consumed for attenuating nausea and vomiting during early pregnancy; however, there is not sufficient data available to rule out its potential toxicity, which should be monitored especially over longer periods. This review provides an up-to-date understanding of the scientific evidence on the development of ginger and its active compounds as health beneficial agents in future clinical trials.

Overview of Pharmacokinetics and Liver Toxicities of Radix Polygoni Multiflori.

Radix Polygoni Multiflori (RPM), a traditional Chinese medicine, has been used as a tonic and an anti-aging remedy for centuries. However, its safe and effective application in clinical practice could be hindered by its liver injury potential and lack of investigations on its hepatotoxicity mechanism. Our current review aims to provide a comprehensive overview and a critical assessment of the absorption, distribution, metabolism, excretion of RPM, and their relationships with its induced liver injury. Based on the well-reported intrinsic liver toxicity of emodin, one of the major components in RPM, it is concluded that its plasma and liver concentrations could attribute to RPM induced liver injury via metabolic enzymes alteration, hepatocyte apoptosis, bile acids homeostasis disruption, and inflammatory damage. Co-administered 2,3,5,4'-tetrahydroxystilbene-2-O-ß-D-glucopyranoside in RPM and other drugs/herbs could further aggravate the hepatotoxicity of emodin via enhancing its absorption and inhibiting its metabolism. To ensure the safe clinical use of RPM, a better understanding of the toxicokinetics and effect of its co-occurring components or other co-administered drugs/herbs on the pharmacokinetics of emodin is warranted.

Research Progress of Herbal Medicines on Drug Metabolizing Enzymes: Consideration Based on Toxicology.

The clinical application of herbal medicines is increasing, but there is still a lack of comprehensive safety data and in-depth research into mechanisms of action. The composition of herbal medicines is complex, with each herb containing a variety of chemical components. Each of these components may affect the activity of metabolizing enzymes, which may lead to herb-drug interactions. It has been reported that the combined use of herbs and drugs can produce some unexpected interactions. Therefore, this study reviews the progress of research on safety issues caused by the effects of herbs on metabolizing enzymes with reference to six categories of drugs, including antithrombotic drugs, non-steroidal anti-inflammatory drugs, anti-diabetic drugs, statins lipid-lowering drugs, immunosuppressants, and antineoplastic drugs. Understanding the effects of herbs on the activity of metabolizing enzymes could help avoid the toxicity and adverse drug reactions resulting from the co-administration of herbs and drugs, and help doctors to reduce the risk of prescription incompatibility.

Application of an in vitro digestion model to study the metabolic profile changes of an herbal extract combination by UHPLC-HRMS.

BACKGROUND: STW 5 is a fixed herbal combination containing extracts from nine medicinal plants: bitter candytuft, greater celandine, garden angelica roots, lemon balm leaves, peppermint leaves, caraway fruits, licorice roots, chamomile flowers, and milk thistle fruit. STW 5 is a clinically proven treatment for functional dyspepsia and irritable bowel syndrome. PURPOSE: Using a static in vitro method, we simulated oral, gastric, and small intestinal digestion and analyzed the metabolic profile changes by UHPLC-HRMS to determine the impact of oro-gastro-intestinal digestion on STW 5 constituents. STUDY DESIGN AND METHODS: STW 5 was incubated according to the InfoGest consensus method. Samples of each digestive phase were analyzed by UHPLC-HRMS in ESI positive and negative modes. After data processing, background subtraction, and normalization, the peak areas of detectable compounds were compared to untreated reference samples and recovery ratios were calculated to monitor the metabolic profile of STW 5 during simulated digestion. RESULTS: Although the levels of some constituents were reduced, we did not observe complete degradation of any of the constituents of STW 5 upon in vitro digestion. We did not detect any new metabolites beyond increased levels of caffeic acid and liquiritigenin due to degradation of progenitor compounds. Changes observed in intestinal bioaccessibility ratios were mainly a result of isomerization, hydrolysis, protein binding, and low water solubility. CONCLUSION: The majority of STW 5 constituents are stable towards simulated in vitro digestion and can reach the colon to interact with gut microbiota if they remain unabsorbed in the upper intestinal tract.

Fast Dissolving/Disintegrating Dosage Forms of Natural Active Compounds and Alternative Medicines.

Fast Dissolving/Disintegrating Dosage Forms (FDDFs) are a group of dosage forms which dissolve or disintegrate quickly, leading to fast distribution of active ingredients at the site of administration; thereby providing ease of oral ingestion of solid unit dosage forms and have the potential to enhance transmucosal absorption. With time, the use of FDDFs in alternative systems has significantly increased. Homeopathic systems and traditional Chinese medicine have embraced FDDFs for the delivery of active compounds. Most of the patents in this area are from China or by the Chinese innovators. In Europe and US, FDDFs have been extensively studied for the delivery of natural active compounds. It was fascinating to know that some new dosage forms and new routes of delivering active compounds are also making their way to the family of FDDFs. The dose of active compound, size of dosage forms, standardization of extracts, polyherbal mixtures, stability of active compounds, safety, efficacy and pharmacokinetics are challenging issues for developing FDDF herbal formulations or phytopharmaceuticals.

Correlation study between the pharmacokinetics of seven main active ingredients of Mahuang decoction and its pharmacodynamics in asthmatic rats.

The aim of this study was to investigate the pharmacokinetics and pharmacodynamics of seven main active components of Mahuang decoction (MHD) and its time-concentration-effect relationship. The asthmatic rat model was established by the method of ovalbumin (OVA) sensttization. The plasma concentrations of ephedrine, pseudoephedrine, methylephedrine, amygdalin, liquiritin, cinnamic acid, glycyrrhizic acid in asthmatic model rat were investigated by a selective and rapid HPLC/MS-MS method. Simultaneously, the asthma-involved cytokines including leukotrienes B4 (LTB4), thromboxane B2 (TXB2), 6-Keto-Prostaglandin F1α (6-K-PGF1α) and histamine (HIS) levels in rat plasma were determined by using ELISA. A mathematics method was applied to assess the trend of percentage rate of change among different time intervals of the seven components. The sigmoid E max function was used to establish the PK-PD modeling of MHD. The results indicated that MHD could control or ameliorate asthma. There was a hysteresis between the peaked drug concentration and maximum therapeutic effect of MHD. The PK-PD curves of MHD showed clockwise or counter-clockwise hysteresis loop. In addition, amygdalin might exert a more significant influence on regulating cytokines levels in asthmatic rats among the seven components of MHD.

The dose-response effect on polyphenol bioavailability after intake of white and red wine pomace products by Wistar rats.

Wine pomace by-products are an important source of phenolic acids with significant health benefits. However, phenolic acid bioavailability in vivo has been little studied and there are few comparative studies on bioavailability between red and white wine pomace and the effect of intake of different doses. The qualitative and quantitative profile of phenolic acid metabolites in plasma and urine samples from Wistar rats was obtained by gas chromatography/mass detection, after oral administration of four doses (50, 100, 150, and 300 mg) of both the red and the white wine pomace products (rWPP and wWPP, respectively). The antioxidant capacity of the plasma samples assessed by both the ABTS and the FRAP levels was also evaluated. The results showed that neither the bioavailability nor the antioxidant capacity in vivo of the rWPP increased at high doses. However, both parameters were dependent on the intake of the wWPP.

The safety and tolerability of Annona muricata leaf extract: a systematic review.

OBJECTIVES: Annona muricata, also known as graviola, soursop and guanabana, has been widely utilised for the treatment of a range of cancers. The mechanism of action and the efficacy of A. muricata and its constituents in the treatment of cancer have been comprehensively reviewed. The aim of this systematic review was to summarise the available literature that reports on factors related to the safety and tolerability of A. muricata leaf extract and its acetogenins. METHODS: In-vitro, preclinical animal studies and human studies of any design written in any language were included. Studies that evaluated A. muricata leaf extract and its constituents were searched through the databases Pubmed, Medline and Embase from inception to April 2019. The elaborated item 4 of Consolidated Standards of Reporting Trials statement and Animals in Research: Reporting In vivo Experiments guidelines were used to evaluate the quality of the studies. KEY FINDINGS: The results suggest that A. muricata and its constituents have hepatoprotective, neurotoxic, antinociceptive, anti-ulcerative and chemopreventive effects. The dose and duration used in animal studies demonstrating toxicity may not directly translate into the effects in humans. Studies included in this review were judged to be of medium to high quality. CONCLUSIONS: The overall outcome of the current review suggests that A. muricata has a favourable safety and tolerability profile. Future studies investigating its use in people diagnosed with a range of cancers are warranted.