天然产物抗氧化活性成分研究进展

天然产物抗氧化剂在自然界有广泛的分布,研究表明多糖、黄酮、多酚、生物碱、皂苷、维生素等天然产物均能有效清除自由基以保护机体健康。随着人们回归自然思潮的兴起及安全意识的提高,天然抗氧化剂因其高效、低毒更是倍受关注。从天然产物中寻找新的清除体内自由基的抗氧化剂已成为现代医药、保健行业发展的必然趋势。综述了天然产物抗氧化活性成分的研究进展,以期为天然产物抗氧化活性的研究和发展提供参考。     

The ethics of dietary supplements and natural health products in pharmacy practice: A systematic documentary analysis

Objectives Many natural health products and dietary supplements are purchased in pharmacies and it has been argued that pharmacists are in the best position to provide patients with evidence‐based information about them. This study was designed to identify how the pharmacist's role with respect to natural health products and dietary supplements is portrayed in the literature. Method A systematic search was conducted in a variety of health databases to identify all literature that pertained to both pharmacy and natural health products and dietary supplements. Of the 786 articles identified, 665 were broad‐coded and 259 were subjected to in‐depth qualitative content analysis for emergent themes. Key findings Overwhelmingly, support for the sale of natural health products and dietary supplements in pharmacies is strong. Additionally, a role for pharmacist counselling is underscored. But another recurrent theme is that pharmacists are ill‐equipped to counsel patients about these products that are available on their shelves. This situation has led some to question the ethics of pharmacists selling natural health products and dietary supplements and to highlight the existence of an ethical conflict stemming from the profit‐motive associated with sales of natural health products and dietary supplements. Conclusions This analysis raises concerns about the ethics of natural health products and dietary supplements being sold in pharmacies, and about pharmacists being expected to provide counselling about products of which they have little knowledge.     

Regulation of Natural Health Products in Canada

Abstract

The Natural Health Products Directorate of Health Canada has developed a new regulatory framework for natural health products including herbs, vitamins, minerals and other dietary supplements. The new regulations are the result of a consultative process that included Canadian consumers, health care providers and manufacturers of natural health products. This article summarizes the current (2002) regulatory status of natural health products, reviews the process by which the new regulations were developed, and describes the proposed new regulatory framework. The paper concludes with an exploration of the strengths and weaknesses of the new regulations.     

Liver toxicity mechanisms of herbs commonly used in Latin America

Mexico owns approximately 4500 medicinal plants species, a great diversity that position it at the second place after China. According to the Mexican health department, 90% of common population consumes them to treat various diseases. Additionally, herbal remedies in Latin America (LA) are considered a common practice, but the frequency of use and the liver damage related to its consumption is still unknown. Despite the high prevalence and indiscriminate herbal consumption, the exact mechanism of hepatotoxicity and adverse effects is not fully clarified and is still questioned. Some herb products associated with herb induced liver injury (HILI) are characterized by presenting a different chemical composition that may vary from batch to batch, also the biological activity of many medicinal plants and other natural products are directly related to their most active component and its concentration. There are two main biological components that are associated with liver damage, alkaloids, and flavonoids, which are frequent constituents of commonly used herbs. The interaction with the different cytochrome P-450 isoforms, inflammatory, and oxidative activities seem to be the main damage pathway involved in the liver. It is important to know the herbal adverse effects and mechanisms involved; therefore, this article is focused on the beneficial and deleterious effects as well as the possible toxicity mechanisms and interactions of the herbs that are frequently used in LA, since the herb–host interaction may not always be the expected or desired depending on the clinical context in which it is administered.     

The Role of Titanium Dioxide (E171) and the Requirements for Replacement Materials in Oral Solid Dosage Forms: An IQ Consortium Working Group Review

Titanium dioxide (in the form of E171) is a ubiquitous excipient in tablets and capsules for oral use. In the coating of a tablet or in the shell of a capsule the material disperses visible and UV light so that the contents are protected from the effects of light, and the patient or caregiver cannot see the contents within. It facilitates elegant methods of identification for oral solid dosage forms, thus aiding in the battle against counterfeit products. Titanium dioxide ensures homogeneity of appearance from batch to batch fostering patient confidence. The ability of commercial titanium dioxide to disperse light is a function of the natural properties of the anatase polymorph of titanium dioxide, and the manufacturing processes used to produce the material utilized in pharmaceuticals. In some jurisdictions E171 is being considered for removal from pharmaceutical products, as a consequence of it being delisted as an approved colorant for foods. At the time of writing, in the view of the authors, no system or material which could address both current and future toxicological concerns of Regulators and the functional needs of the pharmaceutical industry and patients has been identified. This takes into account the assessment of materials such as calcium carbonate, talc, isomalt, starch and calcium phosphates. In this paper an IQ Consortium team outlines the properties of titanium dioxide and criteria to which new replacement materials should be held.     

Self-assembled small molecule natural product gel for drug delivery: a breakthrough in new application of small molecule natural products

Natural products, as a gift of nature to humanity, have long been used as drugs or pharmacological actives to help people cure various diseases. Yet we still know comparatively little about their ability to be materials. In recent years, some small molecule natural products isolated from traditional Chinese medicines have been found to have new features, namely, self-assembly to form gels (i.e., natural product gels, NPG). However, the application development of these natural products is seriously lacking, which greatly weakens their practical value and delays the maturity of the field. Here, a series of self-assembled triterpenoid natural products are used as materials (gel scaffolds) to construct drug delivery systems. Surprisingly, these NPG not only exhibit the excellent self-healing, controlled gelation, good safety and sustained release, but also achieve synergistic treatment of tumors through bioactive natural products. Compared with non-bioactive gel scaffolds, NPG scaffolds show great advantages in tumor therapy, including optimal tumor inhibition, preferable health, better body recovery, stronger immune function, less toxic side effects and longer survival. The successful construction of NPG scaffolds not only takes full advantage of the self-assembled natural products, but also takes an important step in the development of new applications for natural products.     

Triterpene derivatives as inhibitors of protein involved in the inflammatory process: molecules interfering with phospholipase A2, cycloxygenase, and lipoxygenase

Over the past years, there was an explosion in the knowledge of the protein target and molecular mechanism associated with various disease types and in the new research of drugs of natural origin. The key idea is to evaluate bioactive natural products interacting with protein domains of different genetic origin but structurally preserved to develop libraries of compounds biologically validated and selected from an evolutionistic point of view. Compared with synthetic compounds, natural products have a major number of unused scaffolds and not comparable to the libraries of synthetic compounds, and could represent a promising starting points for the discovery of new bioactive compounds. Many natural products are reported to interact with proteins involved in serious diseases, such as inflammation and cancer. Recently various chemical classes of plant secondary metabolites have emerged as potential therapeutic compounds in several inflammatory diseases. Owing to the findings that triterpenoids, a common class of plant secondary metabolites, have anti-inflammatory and anti-cancer effects on humans, the interest in their potential application in human health and disease is increasing. The present review describes anti-inflammatory triterpenes derivatives from plant and fungi reported during the last two decades in order to provide an account of this field of investigation, sorting compounds according to their targets, phospholipase A(2) (PLA(2)), cycloxygenase (COX), and lipoxygenase (LOX). The attempt is also being made to enumerate the possible leads for further synthetic and drug discovery program development.     

Surveillance of suspected adverse reactions to natural health products: the case of propolis.

Natural health products are promoted to the public as equally or more effective and less toxic than conventional drugs. However, some 'natural' medicines are known to have adverse effects. From April 2002 to August 2007, 18 suspected adverse reactions associated with propolis-containing products were reported to the national surveillance system of natural health products, coordinated by the Italian National Health Institute. Sixteen reports concerned allergic reactions (with dermatological or respiratory symptoms), while two concerned the digestive tract. Some of the reactions were serious: six patients were admitted to hospital or visited an emergency department and in two of these a life-threatening event was reported. In seven patients (four of whom were children), an allergic predisposition was indicated. Propolis, a resinous substance collected by honeybees from the buds of living plants, has been used for several purposes (dermatitis, laryngitis, oral ulcers) because of its wide range of suggested activities (antibacterial, antiviral, antifungal, anti-inflammatory, antioxidant and chemopreventive actions). However, propolis is also a potent sensitizer and should not be used in patients with an allergic predisposition, in particular an allergy to pollen. In Italy, products containing bee derivatives (bee pollen, royal jelly or propolis) are available to the public as food supplements. No label warning of possible adverse reactions is found on the packaging, although it is well known that atopic and asthmatic individuals may be at an increased risk of allergic reactions after using these products. The public and healthcare practitioners should be aware of the risk of allergic reactions to products derived from bees and a warning should be added to the packaging of these products.     

Potential interactions between pharmaceuticals and natural health products in Canada

This study sought to measure the extent to which potentially interacting combinations of natural health products (NHPs) and drugs are used in the Canadian adult population. Data were obtained from the Statistics Canada 2000-2001 National Population Health Survey. A total of 11 424 adults completed the survey. Of the survey participants, 9.3% reported the use of at least 1 natural health product in the prior 2 days. Among natural health product users, 57% also used a conventional medicine with systemic exposure in the same time period. A minimum of 1 potential drug-NHP interaction was identified in 28.4% of such combination users. Most interactions (90%) were of unknown clinical significance. Female gender, older age, lower education, and the presence of diabetes and high blood pressure were associated with a higher risk of having at least 1 potential interaction. Health professionals need to maintain a working knowledge of common potential drug-NHP interactions, to dialogue with all patients regarding the use of natural health products, and to remain vigilant in reporting all suspected interactions and adverse events involving natural health products. Regulatory agencies should also capture and assess reports of drug-NHP interactions more effectively.     

Screening of natural products for drug discovery

The discovery of new biologically active compounds derived from natural products seems to be the main objective of many scientific researchers and pharmaceutical companies. Screening of natural products for this objective with the greatest possibility of success is always needed. Using plants in this area, especially, has a huge advantage owing to their long-term use in health care. In this review, the place of natural products in the therapeutic arsenal is rigorously analysed. The authors also describe and discuss several approaches (essentially biological approaches, including pharmacological and clinical) in selecting and screening natural products as candidates for drug discovery and for drug development. Furthermore, the steps leading from plants to drug discovery are given. In addition, approaches to select plants for biological and/or phytochemical investigation in the laboratory are discussed. Finally, the authors list some of the known drugs and their plant sources.     

The 1st Euro-Mediterranean Workshop: Natural Products in Health and Diseases: Cairo,Egypt, March 2, 2015

Natural plant products have been used for centuries for health maintenance and treatment of a variety of diseases in various traditional systems of medicine in Egypt and other African countries, India, China, and other countries around the world. Over the past several decades, the popularity of herbal and other natural products has gradually increased in many western countries. Despite the increasing popularity of natural products, both the public and the professionals are skeptical about the use of these products. Reasons for this skepticism include, but are not limited to, the lack of proper documentation about the source and formulations used; standardization of the composition, batch-to-batch consistency, documented safety of herbal products; and information about the mechanisms of action of these products. The 1st Euro-Mediterranean Workshop: Natural Products in Health and Diseases was organized by the Euro-Mediterranean Association of Life Sciences (EMALS) and various other local organizations to review and discuss the above-mentioned strengths and limitations of the use of natural products. The aim of this workshop was to share best practices and expertise about natural products, and to identify opportunities for collaboration among researchers, health professionals, and business personnel in a productive atmosphere.     

Risk assessment to humans of mycotoxins in animal-derived food products

This paper addresses approaches for assessing potential human health hazards from the presence of natural toxicants, such as mycotoxins, in animal food products. At high levels in feed these mycotoxins may cause loss or illness of farm animals, through development of animal toxicoses, such as aflatoxicosis. At lower levels in feed these mycotoxins may have no apparent effect on livestock production, but their residues and related substances may move up the food chain. This indirect intake of mycotoxins and related substances from the consumption of animal food products may pose a health hazard to humans. These health hazards are compared to the possible health hazards from the direct intake by humans of cereal and other food crops that may contain mycotoxins.     

加拿大天然健康产品质量、监管要求及胆宁片注册、认证、出口实践

加拿大作为药品监管水平和国际影响力较高的国家,已明确承认中成药的药品身份。中成药在加拿大申请产品许可证,需要提交产品的安全性、有效性和高质量的支持性证据。本文通过介绍加拿大天然健康产品的质量、监管要求,为中成药在加拿大注册、认证和上市应用提供参考;同时介绍胆宁片在加拿大成功注册、认证和出口实践,为中药国际化提供借鉴和启示。     

Activation of antioxidant activity in natural medicinal products by heating, brewing and lipophilization. A new drug delivery system

On the basis of the authors' previous hypothesis (1) that treatment of natural plant products with heating and gastric juice results in liberation of low molecular weight compounds with antioxidant activity that exist in the native products as repeating subunits of high molecular weight polymers, they have developed specially treated natural health or medicinal products in which several identifiable low molecular weight compounds with antioxidant activity are liberated and activated. The principal features of the treatment protocol included heating at 80-95 degrees C with continuous manual stirring in an oriental pottery vessel over a Japanese traditional oven, subsequent brewing with Koji (Aspergillus oryzae), and final emulsification in sesame oil. These products were named AOA (antioxidant analogues) or B-H (Bio-harmony). AOA and B-H were markedly effective both in scavenging the reactive oxygen species (ROS) generated and in inhibiting lipid peroxidation; they also significantly reduced both adjuvant- and adriamycin-induced paw oedema in rats. These agents were strikingly effective in ameliorating a variety of inflammatory diseases in patients and caused a fall in their serum lipid peroxide levels. Significant levels of several low molecular weight antioxidant compounds such as flavoprotein and carotene were directly detected by analysis of the treated products. The authors conclude that the procedures are useful and effective for potentiating the bioavailability of pharmacologically active natural products.     

Evaluation of the Robustness of A Novel NIR-based Technique to Measure the Residual Moisture In Freeze-dried Products

(Bio)pharmaceutical products freeze-dried in vials must meet stringent quality specifications: among these, the residual moisture (RM) is crucial. The most common techniques adopted for measuring the RM are destructive, e.g. Karl Fisher titration, thus few samples from each batch are tested. Being a high intra-batch variability an intrinsic feature of batch freeze-drying, a high number of samples needs to be tested to get a representative measurement. Near-Infrared (NIR) spectroscopy was extensively applied in the past as a non-invasive method to quantify the RM. In this paper, an accurate Partial Least Square (PLS) model was developed and calibrated with a single product, focusing on a small but significative wavelength range of NIR spectra (model SR), characteristic of the water and not of the product. The salient feature of this approach is that the model SR appears to provide fairly accurate estimates with the same product but at a higher concentration, with other excipients and in presence of an amino acid at high concentration, without requiring any additional calibration with KF analysis, as in previous techniques; the irrelevance of the vial shape was also shown. This approach was compared to a simpler one, based on a single-variable linear regression, and to more complex one, using a wider wavelength range or calibrating the PLS model with several products. Model SR definitely ended up as the most accurate, and it appeared to have a great potential as a robust model, suitable also for products that were not involved in the calibration step.     

The paradox of natural products as pharmaceuticals. Experimental evidences of a mango stem bark extract.

Recent findings regarding basic, pre-clinical and clinical studies on a mango stem bark extract (MSBE) developed in Cuba (Vimang) on an industrial scale are summarized. Ethnomedical studies, extract reproducibility, biological effects and clinical evaluations in terms of patient quality of life are described as experimental evidences to support the statement that natural products, even being a mixture of compounds, could be as effective as "monoceuticals" for medical uses. Discussion about the use of "monoceuticals" versus "natureceuticals" in health care and medicine is based on effectiveness and availability, taking Vimang as an example of a natural product with supported scientific evidence to be used as antioxidant, analgesic, anti-inflammatory and immunomodulator.     

Natural products chemistry: The emerging trends and prospective goals

The role and contributions of natural products chemistry in advancements of the physical and biological sciences, its interdisciplinary domains, and emerging of new avenues by providing novel applications, constructive inputs, thrust, comprehensive understanding, broad perspective, and a new vision for future is outlined. The developmental prospects in bio-medical, health, nutrition, and other interrelated sciences along with some of the emerging trends in the subject area are also discussed as part of the current review of the basic and core developments, innovation in techniques, advances in methodology, and possible applications with their effects on the sciences in general and natural products chemistry in particular. The overview of the progress and ongoing developments in broader areas of the natural products chemistry discipline, its role and concurrent economic and scientific implications, contemporary objectives, future prospects as well as impending goals are also outlined. A look at the natural products chemistry in providing scientific progress in various disciplines is deliberated upon.     

来源于天然产物的抗肿瘤先导结构研究进展

肿瘤严重威胁人类生命健康,因此发现新结构类型、新作用机制、更有效的抗肿瘤药成为当务之急。天然产物在抗肿瘤药物发现过程中有着重要的作用和意义。综述几种具有抗肿瘤活性的天然产物,重点阐述其作用机制、抗肿瘤活性及构效关系的研究进展。     

海洋卤化天然产物研究进展

卤化天然产物是一类常见的次级代谢产物,在医药研发领域占有重要地位。卤素的存在通常可以增强化合物的生物活性。海洋是卤化天然产物的主要来源。这些卤化物由海绵、海藻、珊瑚、真菌和细菌等生物产生。文章按照化合物中卤素原子的不同综述了近十年（2012年-2022年3月）181个海洋来源卤化天然产物及其抗菌、抗抗肿瘤和抗污等生物活性的研究进展。     

海洋微生物次级代谢产物抗炎作用研究进展

炎症作为机体抵抗有害刺激修复损伤组织的防御反应，参与多种疾病的发展进程，严重危害人类生命健康。而临床常用的抗炎药物有一定的不良反应，寻找一些高效、低毒的抗炎先导化合物仍是一个重要方向。海洋作为各类生物资源的宝库，由于海洋生态环境的特殊性(高压、高盐，低氧等)，使得许多海洋生物在生命过程中产生大量具有特殊结构和抗炎活性的天然产物，成为炎症新药物研发的重要来源。本文总结了2016-2021年从放线菌、真菌、细菌三类海洋微生物中分离出的约73种天然产物，并对其在抑制炎症活性方面进行综述，以期望为今后的研究提供借鉴和启发。