Health Impacts of Traditional Medicines and Bio-prospecting: A World Scenario Accentuating Bhutan's Perspective

Life without natural products is unimaginable. It has provided mankind with oxygen, water, fire, food, clothing, shelter and medicine. Its public health impact is considerably high, especially of traditional medicines and nature-based modern drugs. The traditional medicines, despite its limitations, are addressing the health needs of millions of people worldwide. It is estimated that about 65-85% of the world population uses traditional medicines for their primary health cares. It is also estimated that about 39% of all 520 new approved drugs in 1983-1994 were natural products and out of that 74% were discovered as a result of bio-prospecting from plants used in traditional medicines. Traditional medicines are increasingly getting more popular mainly because: a) it is holistic system with less side effects; b) it is evolving as an evidence-based medicine; c) its ethno-medical knowledge is applicable to modern drug discovery programs. As there are many diseases that cannot be cured by the existing drugs and as there are increasing cases of drug resistance, there is urgent need for drugs that are effective against these pathogens. Probably, traditional medicines could provide a solution in fighting them both as a health care delivery mechanism and as a means of chemotherapeutic pool. Bhutan is fortunate to be gifted with rich natural bio-diversity and rich traditional medical knowledge. The positive health impacts of the Bhutanese traditional medicines are resoundingly felt by Bhutanese. Besides, there is huge potential for bio-prospecting in Bhutan. This paper highlights world scenario on the health impacts of the: 1) natural product-based traditional medicines, 2) the natural product-based drug discoveries, and 3) Bhutanese traditional medicine and potential of bio-prospecting in Bhutan

Historical Roots, Spiritual Significance and the Health Benefits of mKhempa-lJong gNyes Tshachu (hot spring) in Lhuntshe

Bhutan is a country blessed with many rich natural medicinal resources such as minerals, animals, plants, sman-chu (medicinal waters) and tshachu (hot springs). While minerals, animal parts and medicinal plants are used by the Institute of Traditional Medicine Services (ITMS) for compounding herbal medicines to provide health care services in Bhutan, tshachu are popularly used by the public as an alternative curative therapy for treating various diseases. Given such inherent health benefits that the tshachu reportedly have, the ITMS has carried out research on seven popular tshachu in Bhutan with a view to document, identify, validate and classify them according to the therapeutic properties described in the gSo-ba Rig-pa texts. Amongst all the seven tshachu studied, Kurtoe mKhem-pa lJong gNyes tshachu (in Lhuntshe-located in the north-east of Bhutan) was found to have profound religious, spiritual and historical significance, supported in many texts going back as far as the 8th century. It was reported that this tshachu was blessed by Guru Rimpoche and for the benefit of all sentient beings his manifestation Terton Pema Lingpa revealed it in the year 1475. Mainly for these reasons, it is considered the most sacred tshachu in Bhutan and people believe that it also cleanses one's defilements and sins. The literature reports the presence of nine related pools in the mKhem-pa lJong gNyes areas. However, only three pools in close proximity, called Guru tshachu, Tshe-dpag-med-tshachu and mKha'-'gro'i tshachu exist today. The users of this tshachu are mainly the people of Kurtoe, Kurman, Mongar, Tashigang, Tashi Yangtse and Bumthang. It is estimated that every year about twenty groups of at least 10 people each, visit this sacred tshachu. The study carried out by ITMS in 23rd January 2001 identified and established the main medicinal substances as well as the therapeutic properties of these three pools. The identification was based on their organoleptic properties

Bioactive alkaloids from medicinal plants of Bhutan

Natural products had been indispensably used by many cultures and traditions in folklore medicines for thousands of years. These traditional medicines cater to about 85% of the world population for their primary health care needs. Natural products have been intensively explored also for their bioactive pharmacophores by modern pharmaceutical companies. In fact they are the skeletal framework of about 60% of the modern drugs that are available today. Of these, about 80% of antibacterial drugs and 90% of antimalarial drugs are natural derivatives. One of the interesting secondary metabolite groups which provides these potent drug leads are the alkaloids. Owing to their broad range of bioactivities, bioprospecting for these natural products are undertaken in many countries. In this study, on the molecular basis of traditional medicine of Bhutan, particularly those with potential antimicrobial components, four alkaloid positive medicinal plants, i.e. Aconitum orochryseum Stapf, Corydalis gerdae Fedde, Rununculus brotherusi Freyn and an Australian naturalized plant Tribulus terrestris Linn, but also used in Bhutan, were selected for phytochemical analysis. Bhutanese traditional medicines use Aconitum orochryseum (whole parts) for the treatment of bilious fever or high fever related to bile disorders including cold and flu, fever of bile (liver), fever caused by malaria, snake bites and for treating blood infections. Corydalis gerdae (whole parts) is used for the treatment of malaria and infections. Ranunculus brotherusi (aerial parts) is used for treating wounds, pus, infections and as antipyretics. Tribulus terrestris (fruit) is used for the treatment of arthritis, kidney diseases and as a diuretic. Though Tribulus terrestris and Ranunculus brotherusi failed to give any alkaloids, a number of new as well as known alkaloids were isolated from Aconitum orochryseum and Corydalis gerdae. Three new hetisane type diterpenoid alkaloids named orochrine, 2-O-acetylorochrine, and lingshinaline, together with two known alkaloids atisinium chloride and virescenine and six other unidentified alkaloids, were isolated from Aconitum orochryseum. The structures of the new alkaloids were elucidated by (superscript 1)H-NMR, gCOSY, gNOESY, TOCSY, (superscript 13)C-NMR, DEPT, gHSQC and gHMBC spectral data analysis. Atisinium chloride, a major alkaloid of the plant, was identified by single crystal X-ray crystallography. Four known protopine type and protoberberine type isoquinoline alkaloids (protopine, scoulerine, cheilanthifoline, and stylopine) along with one unidentified alkaloid were isolated from Corydalis gerdae. The protopine was the major alkaloid of this plant. The alkaloids were identified by MS and (superscript 1)H-NMR spectral data comparison. The antibacterial testing of crude methanol extracts, crude alkaloids and the major alkaloids (atisinium chloride, orochrine and protopine) of these two plants were found inactive against the bacterium Staphylococcus aureus (MIC = greater than 125 ?g/ml) and Vancomycin resistant Enterococcus faecium (MIC = greater than 125 ?g/ml). But the in vitro antimalarial assay of crude methanol extracts, crude alkaloids, atisinium chloride, protopine, and cheilanthifoline gave very significant activity against Plasmodium falciparum, TM4 and K1 strains. Crude methanol extract (AO-ME) of Aconitum orochryseum was not that active (IC(subscript 50) of greater than10 ?g/ml for both the strains). Increased activity was observed for its crude alkaloid (AO-CEA) with IC(subscript 50) values of 20.40 ?g/ml against TM4 and 19.20 ?g/ml against K1 strains. The activity was further increased for atisinium chloride with IC(subscript 50) values of 4.02 ?M against TM4/8.2 and 3.59 ?M against K1CB1 strains. The antimalarial activity was better for the extracts and alkaloids of Corydalis gerdae. Its crude methanol extract (CG-ME) had the IC(subscript 50) values of 1.00 ?g/ml against TM4 strain and 2.56 ?g/ml against K1 strain. The activity of crude alkaloid of this plant was far better with IC(subscript 50) values of 0.33 ?g/ml against TM4 strain and 0.63 ?g/ml against K1 strain. Protopine had IC(subscript 50) values of 4.25 ?M against TM4/8.2 and 4.29 ?M against K1CB1 strains. Cheilanthifoline had the IC(subscript 50) values of 3.76 ?M against K1 and 2.78 ?M against TM4 strains. These alkaloids have the potential to become candidates for antimalarial leads. Similar activities may be expected from other alkaloids including new ones isolated from these two plants. Therefore, the combination of these two plant extracts would make the best antimalarial herbal mixture for Bhutanese traditional medicines. The results proved that ethno-directed biorational approach, combined with an alkaloid focus, is an efficient strategy for drug lead discovery. The results also proved for the first time at the molecular level that Bhutanese traditional medicines have clinical efficacy. The medicinal plants of Bhutan thus have potential to provide important new drug leads. Bioprospecting them would benefit local people, pharmaceutical industries and the patients at large. [Note: this abstract contained scientific formulae that would not come across on this form. Please see the 01Front files abstract for the full details.

The Ethnopharmacology, Phytochemistry and Bioactivities of the Corymbia Genus (Myrtaceae)

Plants have been vital to human survival for aeons, especially for their unique medicinal properties. Trees of the Eucalyptus genus are well known for their medicinal properties; however, little is known of the ethnopharmacology and bioactivities of their close relatives in the Corymbia genus. Given the current lack of widespread knowledge of the Corymbia genus, this review aims to provide the first summary of the ethnopharmacology, phytochemistry and bioactivities of this genus. The Scopus, Web of Science, PubMed and Google Scholar databases were searched to identify research articles on the biological activities, phytochemistry and ethnomedical uses of Corymbia species. Of the 115 Corymbia species known, 14 species were found to have ethnomedical uses for the leaves, kino and/or bark. Analysis of the references obtained for these 14 Corymbia spp. revealed that the essential oils, crude extracts and compounds isolated from these species possess an array of biological activities including anti-bacterial, anti-fungal, anti-protozoal, anti-viral, larvicidal, insecticidal, acaricidal, anti-inflammatory, anti-oxidant, anti-cancer and anti-diabetic activities, highlighting the potential for this under-studied genus to provide lead compounds and treatments for a host of medical conditions

Metabolomics and lipidomics studies of parasitic helminths: molecular diversity and identification levels achieved by using different characterisation tools

Introduction: Helminths are parasitic worms that infect millions of people worldwide and secrete a variety of excretory-secretory products (ESPs), including proteins, peptides, and small molecules. Despite this, there is currently no comprehensive review article on cataloging small molecules from helminths, particularly focusing on the different classes of metabolites (polar and lipid molecules) identified from the ESP and somatic tissue extracts of helminths that were studied in isolation from their hosts. Objective: This review aims to provide a comprehensive assessment of the metabolomics and lipidomics studies of parasitic helminths using all available analytical platforms. Method: To achieve this objective, we conducted a meta-analysis of the identification and characterization tools, metabolomics approaches, metabolomics standard initiative (MSI) levels, software, and databases commonly applied in helminth metabolomics studies published until November 2021. Result: This review analyzed 29 studies reporting the metabolomic assessment of ESPs and somatic tissue extracts of 17 helminth species grown under ex vivo/in vitro culture conditions. Of these 29 studies, 19 achieved the highest level of metabolite identification (MSI level-1), while the remaining studies reported MSI level-2 identification. Only 155 small molecule metabolites, including polar and lipids, were identified using MSI level-1 characterization protocols from various helminth species. Despite the significant advances made possible by the ‘omics’ technology, standardized software and helminth-specific metabolomics databases remain significant challenges in this field. Overall, this review highlights the potential for future studies to better understand the diverse range of small molecules that helminths produce and leverage their unique metabolomic features to develop novel treatment options

Pharmacological, ethnopharmacological, and botanical evaluation of subtropical medicinal plants of Lower Kheng region in Bhutan

Background: The Bhutanese Sowa Rigpa medicine (BSM) uses medicinal plants as the bulk ingredients. Our study was to botanically identify subtropical medicinal plants from the Lower Kheng region in Bhutan, transcribe ethnopharmacological uses, and highlight reported pharmacological activities of each plant. Methods: We freely listed the medicinal plants used in the BSM literature, current formulations, and the medicinal plants inventory documents. This was followed by a survey and the identification of medicinal plants in the Lower Kheng region. The botanical identification of each medicinal plant was confirmed using The Plant List, eFloras, and TROPICOS. Data mining for reported pharmacological activities was performed using Google Scholar, Scopus, PubMed, and SciFinder Scholar. Results: We identified 61 subtropical plants as the medicinal plants used in BSM. Of these, 17 plants were cultivated as edible plant species, 30 species grow abundantly, 24 species grow in moderate numbers, and only seven species were scarce to find. All these species grow within the altitude range of 100-1800 m above sea level. A total of 19 species were trees, and 13 of them were shrubs. Seeds ranked first in the parts usage category. Goshing Gewog (Block) hosted maximum number of medicinal plants. About 52 species have been pharmacologically studied and only nine species remain unstudied. Conclusion: Lower Kheng region is rich in subtropical medicinal plants and 30 species present immediate economic potential that could benefit BSM, Lower Kheng communities and other Sowa Rigpa practicing organizations

Indigenous Uses, Phytochemical Analysis, and Anti-Inflammatory Properties of Australian Tropical Medicinal Plants

Australian tropical plants have been a rich source of food (bush food) and medicine to the first Australians (Aboriginal people), who are believed to have lived for more than 50,000 years. Plants such as spreading sneezeweed (Centipeda minima), goat’s foot (Ipomoea pes-caprae), and hop bush (Dodonaea viscosa and D. polyandra) are a few popular Aboriginal medicinal plants. Thus far, more than 900 medicinal plants have been recorded in the tropical region alone, and many of them are associated with diverse ethnomedicinal uses that belong to the traditional owners of Aboriginal people. In our effort to find anti-inflammatory lead compounds in collaboration with Aboriginal communities from their medicinal plants, we reviewed 78 medicinal plants used against various inflammation and inflammatory-related conditions by Aboriginal people. Out of those 78 species, we have included only 45 species whose crude extracts or isolated pure compounds showed anti-inflammatory properties. Upon investigating compounds isolated from 40 species (for five species, only crude extracts were studied), 83 compounds were associated with various anti-inflammatory properties. Alphitolic acid, Betulinic acid, Malabaric acid, and Hispidulin reduced proinflammatory cytokines and cyclooxygenase enzymes (COX-1 and 2) with IC50 values ranging from 11.5 to 46.9 uM. Other promising anti-inflammatory compounds are Brevilin A (from Centipeda minima), Eupalestin, and 5′-methoxy nobiletin (from Ageratum conyzoides), Calophyllolide (from Calophyllum inophyllum), and Brusatol (from Brucea javanica). D. polyandra is one example of an Aboriginal medicinal plant from which a novel anti-inflammatory benzoyl ester clerodane diterpenoid compound was obtained (compound name not disclosed), and it is in the development of topical medicines for inflammatory skin diseases. Medicinal plants in the tropics and those associated with indigenous knowledge of Aboriginal people could be a potential alternative source of novel anti-inflammatory therapeutics

Excretory/secretory metabolome of the zoonotic roundworm parasite Toxocara canis

Toxocariasis is a zoonotic disease affecting humans that is predominantly caused by Toxocara canis and T. cati, primarily parasites of dogs and cats, respectively. Toxocara generally establishes long-term infections by co-opting its host’s physiological processes, while at the same time exploiting the nutritional environment. Adult stage T. canis reside in the gut of the definitive canine host where they employ a suite of strategies to combat intestinal immune responses by actively producing and releasing excretory-secretory products (ESPs). The protein component of T. canis ESPs has been widely studied, but characterisation of the non-protein ESP complement remains neglected. To characterize the secreted metabolome of Toxocara ESPs and to shed light on the parasite’s metabolic processes, we profiled the ESPs of T. canis using both gas chromatography (GC) and liquid chromatography (LC) mass spectrometry approaches. We successfully identified 61 small molecules, including 41 polar metabolites, 14 medium-long chain fatty acids (MLCFAs) and six short chain fatty acids (SCFAs). We identified talose, stearic acid and isovalerate as the major compounds belonging to the polar, MLCFA and SCFA chemical classes, respectively. Most of the 61 identified metabolites appear to have been produced by T. canis via three distinct metabolic pathways - fatty acid, amino acid and carbohydrate metabolism. The majority of the identified ESPs have known biological properties, especially as immunomodulators. However, there is limited/no information on the biological roles or applications of 31 ESP biomolecules, suggesting that these may have novel activities that merit further investigation

Plant secondary metabolites produced in response to abiotic stresses has potential application in pharmaceutical product development

Plant secondary metabolites (PSMs) are vital for human health and constitute the skeletal framework of many pharmaceutical drugs. Indeed, more than 25% of the existing drugs belong to PSMs. One of the continuing challenges for drug discovery and pharmaceutical industries is gaining access to natural products, including medicinal plants. This bottleneck is heightened for endangered species prohibited for large sample collection, even if they show biological hits. While cultivating the pharmaceutically interesting plant species may be a solution, it is not always possible to grow the organism outside its natural habitat. Plants affected by abiotic stress present a potential alternative source for drug discovery. In order to overcome abiotic environmental stressors, plants may mount a defense response by producing a diversity of PSMs to avoid cells and tissue damage. Plants either synthesize new chemicals or increase the concentration (in most instances) of existing chemicals, including the prominent bioactive lead compounds morphine, camptothecin, catharanthine, epicatechin-3-gallate (EGCG), quercetin, resveratrol, and kaempferol. Most PSMs produced under various abiotic stress conditions are plant defense chemicals and are functionally anti-inflammatory and antioxidative. The major PSM groups are terpenoids, followed by alkaloids and phenolic compounds. We have searched the literature on plants affected by abiotic stress (primarily studied in the simulated growth conditions) and their PSMs (including pharmacological activities) from PubMed, Scopus, MEDLINE Ovid, Google Scholar, Databases, and journal websites. We used search keywords: “stress-affected plants,” “plant secondary metabolites, “abiotic stress,” “climatic influence,” “pharmacological activities,” “bioactive compounds,” “drug discovery,” and “medicinal plants” and retrieved published literature between 1973 to 2021. This review provides an overview of variation in bioactive phytochemical production in plants under various abiotic stress and their potential in the biodiscovery of therapeutic drugs. We excluded studies on the effects of biotic stress on PSMs

Immunomodulatory and biological properties of helminth-derived small molecules: Potential applications in diagnostics and therapeutics

Parasitic helminths secrete and excrete a vast array of molecules known to help skew or suppress the host’s immune response, thereby establishing a niche for sustained parasite maintenance. Indeed, the immunomodulatory potency of helminths is attributed mainly to excretory/secretory products (ESPs). The ESPs of helminths and the identified small molecules (SM) are reported to have diverse biological and pharmacological properties. The available literature reports only limited metabolites, and the identity of many metabolites remains unknown due to limitations in the identification protocols and helminth-specific compound libraries. Many metabolites are known to be involved in host-parasite interactions and pathogenicity. For example, fatty acids (e.g., stearic acid) detected in the infective stages of helminths are known to have a role in host interaction through facilitating successful penetration and migration inside the host. Moreover, excreted/secreted SM detected in helminth species are found to possess various biological properties, including anti-inflammatory activities, suggesting their potential in developing immunomodulatory drugs. For example, helminths-derived somatic tissue extracts and whole crude ESPs showed anti-inflammatory properties by inhibiting the secretion of proinflammatory cytokines from human peripheral blood mononuclear cells and suppressing the pathology in chemically-induced experimental mice model of colitis. Unlike bigger molecules like proteins, SM are ideal candidates for drug development since they are small structures, malleable, and lack immunogenicity. Future studies should strive toward identifying unknown SM and isolating the under-explored niche of helminth metabolites using the latest metabolomics technologies and associated software, which hold potential keys for finding new diagnostics and novel therapeutics