Botanical drugs: challenges and opportunities: contribution to Linnaeus Memorial Symposium 2007

The Role of Wheatgrass in Colorectal Cancer: A Review of the Current Evidence

The etiology of colon cancer is either genetic in nature or results from inflammatory bowel diseases such as ulcerative colitis and Crohn's disease; nevertheless, dietary habits play a crucial role in the disease. Wheatgrass is a dietary supplement that is rich in vitamins, minerals, and antioxidants which contribute to health promotion in cardiovascular diseases, liver disease, blood diseases, diabetes, and inflammatory bowel diseases, as well as in several types of cancers, such as oral squamous cell cancer, cervical cancer, and breast cancer. In colorectal cancer (CRC), the prospect that wheatgrass possesses anti-inflammatory, antioxidant, and anticancer properties, and its use as an adjunctive therapy, have been minimally investigated and evidence is still limited. In this review, we compiled the available evidence pertaining to wheatgrass and its likely impact on CRC, described the pathways of inflammation in which wheatgrass could possibly play a role, and identified future research needs on the subject.

The gut microbiota and endometriosis: From pathogenesis to diagnosis and treatment

Endometriosis is a common gynecological disease, that often leads to pain and infertility. At present, the specific pathogenesis of endometriosis has not been clarified, but it may be closely related to an imbalance of sex hormones in the body, ectopic hyperplasia stimulated by immune inflammation, and invasion and escape based on tumor characteristics. Gut microbiota is associated with many inflammatory diseases. With the further study of the gut microbiota, people are paying increasing attention to its relationship with endometriosis. Studies have shown that there is an association between the gut microbiota and endometriosis. The specific ways and mechanisms by which the gut microbiota participates in endometriosis may involve estrogen, immune inflammation, and tumor characteristics, among others. Therefore, in the future, regulating gut microbiota disorders in various ways can help in the treatment of endometriosis patients. This study reviewed the research on the gut microbiota and endometriosis in order to provide ideas for clinical diagnosis and treatment.

Immunomodulatory Effects of Diterpene Quinone Derivatives from the Roots of Horminum pyrenaicum in Human PBMC

Several phytochemicals were shown to interfere with redox biology in the human system. Moreover, redox biochemistry is crucially involved in the orchestration of immunological cascades. When screening for immunomodulatory compounds, the two interferon gamma- (IFN-γ-) dependent immunometabolic pathways of tryptophan breakdown via indoleamine 2,3-dioxygenase-1 (IDO-1) and neopterin formation by GTP-cyclohydrolase 1 (GTP-CH-I) represent prominent targets, as IFN-γ-related signaling is strongly sensitive to oxidative triggers. Herein, the analysis of these pathway activities in human peripheral mononuclear cells was successfully applied in a bioactivity-guided fractionation strategy to screen for anti-inflammatory substances contained in the root of Horminum (H.) pyrenaicum L. (syn. Dragon's mouth), the only representative of the monophyletic genus Horminum. Four abietane diterpene quinone derivatives (horminone, 7-O-acetylhorminone, inuroyleanol and its 15,16-dehydro-derivative, a novel natural product), two nor-abietane diterpene quinones (agastaquinone and 3-deoxyagastaquinone) and two abeo 18 (4 → 3) abietane diterpene quinones (agastol and its 15,16-dehydro-derivative) could be identified. These compounds were able to dose-dependently suppress the above mentioned pathways with different potency. Beside the description of new active compounds, this study demonstrates the feasibility of integrating IDO-1 and GTP-CH-I activity in the search for novel anti-inflammatory compounds, which can then be directed towards a more detailed mode of action analysis.

Phytonanotherapy for management of diabetes using green synthesis nanoparticles

The world has a rich diversity of indigenous medicinal plants. The World Health Organization (WHO) gives high priority to eco-friendly, non-hazardous and cost effective healthcare such as the use of medicinal plants to treat various illnesses, including Human immunodeficiency virus (HIV) infection and Acquired immune deficiency syndrome (AIDS), tuberculosis (TB), diabetes mellitus (DM), malaria, and cancer. In developing countries, a high proportion of the population tends to use complementary and alternative medicines (CAM) together with conventional prescription drugs. Globally, CAM has been used in both developed and developing countries. In China, 30-50% of medicinal use is based on traditional alternative medicine. In Africa, it is estimated that 80% of primary health care is CAM, whilst in the USA, about 158 million people us CAM. This increase is due to three main influences: improve their eminence of life, relieve symptoms and preclude long-term complications. Despite the advances and advantages of conventional pharmaceutical medication, these are associated with long-term side effects and pose risks of inefficacy for treatment of chronic diseases such as cancer and DM. The biosynthesis of metal nanoparticles (NPs) using medicinal plants has received considerable attention as a proper alternative to using hazardous chemical and physical synthetic techniques. Plants are being exploited for their unique metal tolerance and effective production of gold metal NPs. A single medicinal plant contains an orchestra of chemical elements (e.g. proteins, vitamins, enzymes, amino acids, polysaccharides and organic compounds) that are "environmentally benign, yet chemically complex" and therefore serve as ideal tools for enhanced medicinal applications. It is reported that phytocompounds such as terpenoids, polysaccharides, polyols and flavones take part in the bio-reduction, stabilization and bio-capping mechanisms to form stable gold and silver NPs. Also the inhibitory potential of plant compounds against diabetic targets followed by a study of enzyme inhibitor kinetics, ligand binding dynamics supported by in silico docking studies that reveal the mode of bioactive compounds and their inhibitory activities. The present review focuses on the potential anticancer, antidiabetic and antimicrobial activity of phyto-synthesized gold and silver NPs. In phytonanotherapy, synergistic features of plant and metal NPs are unique as they offer healing properties that may be the clinical bioequivalent to many synthetic drugs, with minimal side effects. This could provide alternative treatment for chronic diseases that is efficient to overcome the disadvantages of synthetic monotherapy and allows medicinal plant therapy to co-exist with current synthetic treatments. This creates a much needed paradigm shift for further clinical studies in non-communicable and communicable diseases.

Wheatgrass: Green Blood can Help to Fight Cancer

INTRODUCTION

Oral squamous cell carcinoma is the sixth most common cancer worldwide and is one of the leading causes of death especially in developing countries like India. It is usually managed with the help of chemotherapeutic agents that are toxic not only to the tumor cells but also to normal cells in many ways. Whereas the traditional herbal medicines which are used from ancient days in India are generally known to be free of toxic effects and are effective. Wheatgrass is the young grass of the wheat plant 'Tritcumaestivum Linn', family Poaceae (Gramineae). It contains a number of vitamins, mineral, amino acids and vital enzymes, these play an important role in the anticancer approach of this herbal product. It is also called as 'green blood' because of its high content of chlorophyll, which bears a structural similarity to haemoglobin and this result in high oxygen supply to all the body tissues.

AIM

To analyse the effect of the aqueous wheat grass extract on Oral Squamous Cell Carcinoma (OSCC) cell line by MTT assay.

MATERIALS AND METHODS

'KB cell line' (Mouth Epidermal Carcinoma Cells) was used for the present study. Aqueous extract of wheat grass was prepared in the institution. The aim of the study was to assess the effect of the aqueous wheat grass extract on KB cell line(OSCC) by MTT assay.

RESULTS

A 41.4% of OSCC cell inhibition was observed at 1000 µg/ml dilution of aqueous wheatgrass extract in 24 hours.

CONCLUSION

The aqueous extract of wheatgrass has an inhibitory effect on the oral cancer cell line proliferation.

Medicinal Bioprospecting of the Amazon Rainforest: A Modern Eldorado?

Ignorant of the New World, Europeans believed in El Dorado, a hidden city of immense wealth in gold. Many consider the Amazonian forest to be a medicinal treasure chest and potentially the largest drug dispensary in the world. Yet, the quest to obtain drugs from indigenous tropical plants remains elusive. Here, we assess the potential of new technologies to tap into the metabolic diversity of tropical plants. We also consider how regulations affect access to plant resources. We conclude that, although the road to this medicinal El Dorado may be long and arduous, many other smaller but still valuable finds are hidden along the way.

Discovery and resupply of pharmacologically active plant-derived natural products: A review

Medicinal plants have historically proven their value as a source of molecules with therapeutic potential, and nowadays still represent an important pool for the identification of novel drug leads. In the past decades, pharmaceutical industry focused mainly on libraries of synthetic compounds as drug discovery source. They are comparably easy to produce and resupply, and demonstrate good compatibility with established high throughput screening (HTS) platforms. However, at the same time there has been a declining trend in the number of new drugs reaching the market, raising renewed scientific interest in drug discovery from natural sources, despite of its known challenges. In this survey, a brief outline of historical development is provided together with a comprehensive overview of used approaches and recent developments relevant to plant-derived natural product drug discovery. Associated challenges and major strengths of natural product-based drug discovery are critically discussed. A snapshot of the advanced plant-derived natural products that are currently in actively recruiting clinical trials is also presented. Importantly, the transition of a natural compound from a "screening hit" through a "drug lead" to a "marketed drug" is associated with increasingly challenging demands for compound amount, which often cannot be met by re-isolation from the respective plant sources. In this regard, existing alternatives for resupply are also discussed, including different biotechnology approaches and total organic synthesis. While the intrinsic complexity of natural product-based drug discovery necessitates highly integrated interdisciplinary approaches, the reviewed scientific developments, recent technological advances, and research trends clearly indicate that natural products will be among the most important sources of new drugs also in the future.

Topical treatment in pain medicine: from ancient remedies to modern usage

Over several millennia, substances have been applied to the skin for treatment of pain. Some ingredients are in current use; others have been discontinued. Mechanisms of action include interactions with nociceptive neural networks and inflammatory processes. Substances must penetrate the stratum corneum barrier and vehicles that enhance penetration have been developed. Topical drugs with links to the past include menthol, capsaicin, some opioids, local anesthetic agents and NSAIDs. Mandragora is also described as an example of a herbal remedy that has been discontinued due to its toxicity. The future for topical drugs is promising, with the advent of new drugs tailored for specific pain mechanisms and the development of both penetration enhancers and sterile preparation methods.

Plant derived substances with anti-cancer activity: from folklore to practice

Plants have had an essential role in the folklore of ancient cultures. In addition to the use as food and spices, plants have also been utilized as medicines for over 5000 years. It is estimated that 70-95% of the population in developing countries continues to use traditional medicines even today. A new trend, that involved the isolation of plant active compounds begun during the early nineteenth century. This trend led to the discovery of different active compounds that are derived from plants. In the last decades, more and more new materials derived from plants have been authorized and subscribed as medicines, including those with anti-cancer activity. Cancer is among the leading causes of morbidity and mortality worldwide. The number of new cases is expected to rise by about 70% over the next two decades. Thus, there is a real need for new efficient anti-cancer drugs with reduced side effects, and plants are a promising source for such entities. Here we focus on some plant-derived substances exhibiting anti-cancer and chemoprevention activity, their mode of action and bioavailability. These include paclitaxel, curcumin, and cannabinoids. In addition, development and use of their synthetic analogs, and those of strigolactones, are discussed. Also discussed are commercial considerations and future prospects for development of plant derived substances with anti-cancer activity.

Microbial biosynthesis of medicinally important plant secondary metabolites

Secondary metabolites derived from plants are a valuable source of pharmaceuticals, nutraceuticals, and cosmetics. To harness the potential of these natural products, reliable methods must be developed for their rapid and sustainable resupply. Microbial production of plant secondary metabolites through the heterologous expression of plant biosynthetic genes represents one such solution. This highlight focuses on recent advances in the microbial biosynthesis of plant secondary metabolites including terpenoids, flavonoids, and alkaloids as well as providing a brief insight into the current limitations and future prospects.

Plants with anti-Leishmania activity: Integrative review from 2000 to 2011

The search for more effective new drugs to treat Leishmaniasis is undoubtedly relevant. Our objective in this study was to investigate research publications addressing plants with anti-Leishmaniasis activity. An integrative review of the literature from 2000 to 2011 was carried out in the databases such as Latin-American and Caribbean Health Sciences (LILACS), Scientific Electronic Library Online (SciELO), and Medical Literature Analysis and Retrieval System Online (MEDLINE). In the initial search, 150 articles were found, with 25 based in LILACS, 68 in SciELO, and 46 in MEDLINE. From these data, after reading the abstracts that were available online, we excluded 12 from LILACS, 39 from SciELO, and 28 from MEDLINE for presenting article duplications. This left 61 articles to be read; however, only 18 of them answered the research questions and determined the final sample of this review. The results showed that research involving the search for new drugs against Leishmaniasis should be intensified, especially for the amastigote form, and studies with in vivo tests could become a great strategy for successfully finding new treatments for Leishmaniasis. It is believed that it is extremely important and urgent to conduct more trials in search of new effective drugs against Leishmaniasis that possess minimal adverse effects and that are easily accessible to the public.

A review of the chemistry of the genus Crataegus

Since the 1800s, natural health products that contain hawthorn (Crataegus spp.) have been used in North America for the treatment of heart problems such as hypertension, angina, arrhythmia, and congestive heart failure. Traditionally, Native American tribes used hawthorn (Crataegus spp.) to treat gastrointestinal ailments and heart problems, and consumed the fruit as food. Hawthorn also has a long history of use in Europe and China for food, and in traditional medicine. Investigations of Crataegus spp. typically focus on the identification and quantification of flavonoids and anthocyanins, which have been shown to have pharmacological activity. The main flavonoids found in Crataegus spp. are hyperoside, vitexin, and additional glycosylated derivatives of these compounds. Reviewed herein are the botany, ethnobotany, and traditional use of hawthorn while focusing on the phytochemicals that have been reported in Crataegus species, and the variation in the described chemistry between individual species.

Dissolution test of herbal medicines containing Paullinia cupana: validation of methods for quantification and assessment of dissolution

"Guaraná" (Paullinia cupana) is used as a physical activity enhancer and stimulator due to its methylxanthines and condensed tannins. The aim of this work was to evaluate the dissolution behavior of five herbal medicines in the form of capsules and tablets containing guaraná. Assay and dissolution methods were validated and results obtained allowed simultaneous marker quantification with precision, accuracy, selectivity and robustness. Findings showed that 100% of the herbal medicinal products analyzed did not provide satisfactory results concerning the presence of four markers, 60% had three markers (caffeine, catechin and epicatechin), while 40% had only caffeine at tested dosage forms. In addition, after 30 minutes, only capsule A showed at least 80% of the dissolved markers. In other capsules, marker dissolution did not exceed 60% whereas 60% of the samples had some characteristic pharmacotechnical problems. These results evidence the need for rigorous quality control to help ensure the therapeutic action of these drugs. To this end, dissolution studies are an essential tool for quality assurance of herbal medicines.

Hepatic perturbations provoked by azathioprine: a paradigm to rationalize the cytoprotective potential of Ficus hispida Linn

The present study was embarked upon in an endeavor to ascertain whether Ficus hispida leaf extract (FHLE) modulates azathioprine-induced hepatic damage. Azathioprine treated rats displayed a plethora of pathological events, which include loss of hepatocellular membrane integrity, mitochondrial dysfunction, and nuclear damage; whilst FHLE pretreated rats significantly precluded these abnormalities. These data were in harmony with the transmission electron microscopic studies. Observations from this investigation directed us to propose the plausible mechanisms through which FHLE thwarts the repercussions of azathioprine-induced hepatocellular necrosis: upholding of thiol homeostasis, curtailing the membrane effects, and perpetuation of adenine nucleotide status. These data offer credence to the notion that FHLE might be a beneficial intervention in the prevention of hepatotoxicity in azathioprine therapy.

Virtual Screening as a Technique for PPAR Modulator Discovery

Virtual screening (VS) is a discovery technique to identify novel compounds with therapeutic and preventive efficacy against disease. Our current focus is on the in silico screening and discovery of novel peroxisome proliferator-activated receptor-gamma (PPARgamma) agonists. It is well recognized that PPARgamma agonists have therapeutic applications as insulin sensitizers in type 2 diabetes or as anti-inflammatories. VS is a cost- and time-effective means for identifying small molecules that have therapeutic potential. Our long-term goal is to devise computational approaches for testing the PPARgamma-binding activity of extensive naturally occurring compound libraries prior to testing agonist activity using ligand-binding and reporter assays. This review summarizes the high potential for obtaining further fundamental understanding of PPARgamma biology and development of novel therapies for treating chronic inflammatory diseases through evolution and implementation of computational screening processes for immunotherapeutics in conjunction with experimental methods for calibration and validation of results.

Response of gammadelta T Cells to plant-derived tannins

Many pharmaceutical drugs arc isolated from plants used in traditional medicines, and new plant-derived pharmaceutical drugs continue to be identified. Relevant to this review, different plant-derived agonists for gammadelta T cells are described that impart effector functions upon distinct subsets of these cells. Recently, plant tannins have been defined as one class of gammadelta T cell agonist and appear to preferentially activate the mucosal population. Mucosal gammadelta T cells function to modulate tissue immune responses and induce epithelium repair. Select tannins, isolated from apple peel, rapidly induce immune gene transcription in gammadelta T cells, leading to cytokinc production and increased responsiveness to secondary signals. Activity of these tannin preparations tracks to the procyanidin fraction, with the procyanidin trimer (C1) having the most robust activity defined to date. The response to the procyanidins is evolutionarily conserved in that responses are seen with human, bovine, and murine gammadelta T cells, although human cells show less selectivity. Procyanidin-induced responses described in this review likely account for the expansion of mucosal gammadelta T cells seen in mice and rats fed soluble extracts of tannins. Use of procyanidins to activate gammadelta T cells may represent a novel approach for the treatment of tissue damage and autoimmune diseases.

Detailed studies on Quercus infectoria Olivier (nutgalls) as an alternative treatment for methicillin-resistant Staphylococcus aureus infections

AIMS

To investigate the antimethicillin-resistant Staphylococcus aureus (MRSA) mechanism of Quercus infectoria (nutgalls) extract and its components.

METHODS AND RESULTS

Ethanol extract, an ethyl acetate fraction I, gallic acid and tannic acid could inhibit the growth of clinically isolated MRSA strains with minimum inhibitory concentration values between 63 and 250 microg ml(-1). Clumps of partly divided cocci with thickened cell wall were observed by transmission electron microscopy in the cultures of MRSA incubated in the presence of the ethanol extract, the ethyl acetate fraction I and tannic acid. Because cell wall structure of the organism structures seemed to be a possible site for antibacterial mechanisms, their effect with representative beta-lactam antibiotics were determined. Synergistic effects with fractional inhibitory concentration index ranged from 0.24 to 0.37 were observed with 76% and 53% of the tested strains for the combination of the ethanol extract with amoxicillin and penicillin G, respectively.

CONCLUSIONS

The appearance of pseudomulticellular bacteria in the treated cells and the synergistic effect of the plant extract with beta-lactamase-susceptible penicillins suggest that the extract may interfere with staphylococcal enzymes including autolysins and beta-lactamase.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our results provide scientific data on the use of the nutgalls, which contain mainly tannin contents up to 70% for the treatment of staphylococcal infections.

Current perspectives on an emerging formal natural products sector in South Africa

Indigenous medical plants contribute significantly to a large South African population as part of a long-standing healthcare system intimately linked to folklore and for livelihood security. For the economically marginalized, access to such plants is largely through herbal markets which are part of an informal economy. Otherwise the formal natural products economy services those with a better socio-economic standing. Recently, the latter has experienced tremendous growth which largely mirrors the global cultural trend for organic naturopathies. Commercialisation of traditional plants and their contribution to the cosmeceutical, nutraceutical and pharmaceutical industries locally and abroad is reviewed. Traditional plant knowledge of southern African people is a source of inspiration for new product development. Concomitantly, an upsurge in research activities emanating from South Africa which confirms the pharmacological efficacy of these plants is fuelling a greater trust in indigenous flora. The escalating consumption of ethnomedicinals as highly valued commodities not only presents South Africa with socio-economic opportunities but also with challenges. Sustainable utilization benefiting the commodification of ethnoherbals, plus meeting aims of poverty alleviation and people empowerment, is a new paradigm in South Africa. The future sustainability of local ecosystems depends upon scientific conservation management practices that recognize the importance of involving local communities. Conservationists should remain aware and sensitive of socio-cultural dynamics within communities in order to manage natural resources.