Evaluation of an ethnopharmacologically selected Bhutanese medicinal plants for their major classes of phytochemicals and biological activities

Identification of novel AKT1 inhibitors from Sapria himalayana bioactive compounds using structure-based virtual screening and molecular dynamics simulations

Through the experimental and computational analyses, the present study sought to elucidate the chemical composition and anticancer potential of Sapria himalayana plant extract (SHPE). An in vitro analysis of the plant extract was carried out to determine the anticancer potential. Further, network pharmacology, molecular docking, and molecular dynamic simulation were employed to evaluate the potential phytochemical compounds for cervical cancer (CC) drug formulations. The SHPE exhibited anti-cancerous potential through inhibition properties against cancer cell lines. The LC-MS profiling showed the presence of 14 compounds in SHPE. Using network pharmacology analysis, AKT1 (AKT serine/threonine kinase 1) is identified as the possible potential target, and EGFR (Epidermal Growth Factor Receptor) is identified as the possible key signal pathway. The major targets were determined to be AKT1, EGFR by topological analysis and molecular docking. An in silico interaction of phytoconstituents employing molecular docking demonstrated a high binding inclination of ergoloid mesylate and Ergosta-5,7,9(11),22-tetraen-3-ol, (3.beta.,22E)- with binding affinities of -15.5 kcal/mol, and -11.3 kcal/mol respectively. Further, MD simulation and PCA analyses showed that the phytochemicals possessed significant binding efficacy with CC protein. These results point the way for more investigation into SHPE compound's potential as CC treatment.

The Antimicrobial Potential of the Hop (Humulus lupulus L.) Extract against Staphylococcus aureus and Oral Streptococci

Plant extracts are in the focus of the pharmaceutical industry as potential antimicrobials for oral care due to their high antimicrobial activity coupled with low production costs and safety for eukaryotic cells. Here, we show that the extract from Hop (Humulus lupulus L.) exhibits antimicrobial activity against Staphylococcus aureus and Streptococci in both planktonic and biofilm-embedded forms. An extract was prepared by acetone extraction from hop infructescences, followed by purification and solubilization of the remaining fraction in ethanol. The effect of the extract on S. aureus (MSSA and MRSA) was comparable with the reference antibiotics (amikacin, ciprofloxacin, and ceftriaxone) and did not depend on the bacterial resistance to methicillin. The extract also demonstrated synergy with amikacin on six S. aureus clinical isolates, on four of six isolates with ciprofloxacin, and on three of six isolates with ceftriaxone. On various Streptococci, while demonstrating lower antimicrobial activity, an extract exhibited a considerable synergistic effect in combination with two of three of these antibiotics, decreasing their MIC up to 512-fold. Moreover, the extract was able to penetrate S. aureus and S. mutans biofilms, leading to almost complete bacterial death within them. The thin-layer chromatography and LC-MS of the extract revealed the presence of prenylated flavonoids (2',4',6',4-tetrahydroxy-3'-geranylchalcone) and acylphloroglucides (cohumulone, colupulone, humulone, and lupulone), apparently responsible for the observed antimicrobial activity and ability to increase the efficiency of antibiotics. Taken together, these data suggest an extract from H. lupulus as a promising antimicrobial agent for use both as a solely antiseptic and to potentiate conventional antimicrobials.

Aculebiphenyl A-B, new biphenyl derivatives from Ruscus aculeatus

The investigation of chemical constituents from the rhizomes of Ruscus aculeatus resulted in the isolation of two new biphenyl derivatives, aculebiphenyls A and B (1-2), together with two known analogs (3-4). Their chemical structures were elucidated based on extensive spectroscopic interpretation and HR-ESI-MS analysis. Compounds 3-4 were isolated from the Ruscus genus for the first time. The isolated compounds were tested for anti-inflammatory activities and antibacterial activities. Compound 1 exhibited significant inhibitory effects on LPS-induced NO production and COX-2 with IC50 values of 10.8 µM and 0.4 µM. Compound 1 also significantly down-regulated the levels of inflammatory cytokines IL-1β, IL-6, and TNF-α. Compound 1 showed moderate antibacterial activities.

N-Containing α-Mangostin Analogs via Smiles Rearrangement as the Promising Cytotoxic, Antitrypanosomal, and SARS-CoV-2 Main Protease Inhibitory Agents

New N-containing xanthone analogs of α-mangostin were synthesized via one-pot Smiles rearrangement. Using cesium carbonate in the presence of 2-chloroacetamide and catalytic potassium iodide, α-mangostin (1) was subsequently transformed in three steps to provide ether 2, amide 3, and amine 4 in good yields at an optimum ratio of 1:3:3, respectively. The evaluation of the biological activities of α-mangostin and analogs 2-4 was described. Amine 4 showed promising cytotoxicity against the non-small-cell lung cancer H460 cell line fourfold more potent than that of cisplatin. Both compounds 3 and 4 possessed antitrypanosomal properties against Trypanosoma brucei rhodesiense at a potency threefold stronger than that of α-mangostin. Furthermore, ether 2 gave potent SARS-CoV-2 main protease inhibition by suppressing 3-chymotrypsinlike protease (3CL^pro) activity approximately threefold better than that of 1. Fragment molecular orbital method (FMO-RIMP2/PCM) indicated the improved binding interaction of 2 in the 3CL^pro active site regarding an additional ether moiety. Thus, the series of N-containing α-mangostin analogs prospectively enhance druglike properties based on isosteric replacement and would be further studied as potential biotically active chemical entries, particularly for anti-lung-cancer, antitrypanosomal, and anti-SARS-CoV-2 main protease applications.

Antioxidant and Anti-Inflammatory Activities of Endemic Plants of the Australian Wet Tropics

Plants have been a vital source of natural antioxidants since ancient times. Plants growing under various abiotic stress conditions often produce more defensive secondary metabolites such as phenolics, flavonoids, and terpenoids during adaptation to the environment. Many of these secondary metabolites are known to possess antioxidant and anti-inflammatory properties. This study tested seven plants sourced from the mountaintop areas (above 1000 m elevation) of Mount Lewis National Park (falls under the Wet Tropics of Queensland), Australia, for their antioxidant and anti-inflammatory activities. Of the seven studied plants, hydroethanolic extracts of six plants (Leptospermum wooroonooran, Ceratopetalum hylandii, Linospadix apetiolatus, Garcinia brassii, Litsea granitica, and Polyscias willmottii) showed high 2,2-diphenyl-1-picrylhydrazyl (DPPH)-free radical scavenging activity in a dose-dependent (25–1000 μg/mL) manner. At the highest concentration of 1 mg/mL, the DPPH free radical scavenged percentage varied between 75.4% and 92.3%. Only the species Alyxia orophila was inactive in the DPPH free radical scavenging assay. Pseudo-IC₅₀ values of the extracts’ ferric reducing antioxidant power (FRAP) based on dose-response curves showed a significant positive correlation with total phenolic content. Five out of the seven plants, namely G. brassii, C. hylandii, L. apetiolatus, L. wooroonooran, and A. orophila, showed inhibitory effects on the secretion of proinflammatory cytokines, tumour necrosis factor (TNF), and interleukins (IL)-23 in a lipopolysaccharide (LPS)-stimulated human peripheral blood mononuclear cells (PBMCs) assay. The results of this study demonstrate the value of tropical mountaintop plants in the biodiscovery of antioxidant and anti-inflammatory lead compounds.

Semi-Synthesis of N-Aryl Amide Analogs of Piperine from Piper nigrum and Evaluation of Their Antitrypanosomal, Antimalarial, and Anti-SARS-CoV-2 Main Protease Activities

Piper nigrum, or black pepper, produces piperine, an alkaloid that has diverse pharmacological activities. In this study, N-aryl amide piperine analogs were prepared by semi-synthesis involving the saponification of piperine (1) to yield piperic acid (2) followed by esterification to obtain compounds 3, 4, and 5. The compounds were examined for their antitrypanosomal, antimalarial, and anti-SARS-CoV-2 main protease activities. The new 2,5-dimethoxy-substituted phenyl piperamide 5 exhibited the most robust biological activities with no cytotoxicity against mammalian cell lines, Vero and Vero E6, as compared to the other compounds in this series. Its half-maximal inhibitory concentration (IC₅₀) for antitrypanosomal activity against Trypanosoma brucei rhodesiense was 15.46 ± 3.09 μM, and its antimalarial activity against the 3D7 strain of Plasmodium falciparum was 24.55 ± 1.91 μM, which were fourfold and fivefold more potent, respectively, than the activities of piperine. Interestingly, compound 5 inhibited the activity of 3C-like main protease (3CL^Pro) toward anti-SARS-CoV-2 activity at the IC₅₀ of 106.9 ± 1.2 μM, which was threefold more potent than the activity of rutin. Docking and molecular dynamic simulation indicated that the potential binding of 5 in the 3CL^pro active site had the improved binding interaction and stability. Therefore, new aryl amide analogs of piperine 5 should be investigated further as a promising anti-infective agent against human African trypanosomiasis, malaria, and COVID-19.

Towards Advances in Medicinal Plant Antimicrobial Activity: A Review Study on Challenges and Future Perspectives

The increasing incidence of drug- resistant pathogens raises an urgent need to identify and isolate new bioactive compounds from medicinal plants using standardized modern analytical procedures. Medicinal plant-derived compounds could provide novel straightforward approaches against pathogenic bacteria. This review explores the antimicrobial activity of plant-derived components, their possible mechanisms of action, as well as their chemical potential. The focus is put on the current challenges and future perspectives surrounding medicinal plants antimicrobial activity. There are some inherent challenges regarding medicinal plant extracts and their antimicrobial efficacy. Appropriate and optimized extraction methodology plant species dependent leads to upgraded and selective extracted compounds. Antimicrobial susceptibility tests for the determination of the antimicrobial activity of plant extracts may show variations in obtained results. Moreover, there are several difficulties and problems that need to be overcome for the development of new antimicrobials from plant extracts, while efforts have been made to enhance the antimicrobial activity of chemical compounds. Research on the mechanisms of action, interplay with other substances, and the pharmacokinetic and/or pharmacodynamic profile of the medicinal plant extracts should be given high priority to characterize them as potential antimicrobial agents.

Isolation of bioactive compounds from medicinal plants used in traditional medicine: Rautandiol B, a potential lead compound against Plasmodium falciparum

Background

Neorautanenia mitis, Hydnora abyssinica, and Senna surattensis are medicinal plants with a variety of traditional uses. In this study, we sought to isolate the bioactive compounds responsible for some of these activities, and to uncover their other potential medicinal properties.

Methods

The DCM and ethanol extracts of the roots of N. mitis and H. abyssinica, and the leaves of S. surattensis were prepared and their phytochemical components were isolated and purified using chromatographic methods. These extracts and their pure phytochemical components were evaluated in in-vitro models for their inhibitory activities against Plasmodium falciparum, Trypanosoma brucei rhodesiense, Mycobacterium tuberculosis, α-amylase (AA), and α-glucosidase (AG).

Results

Rautandiol B had significant inhibitory activities against two strains of Plasmodium falciparum showing a high safety ratio (SR) and IC₅₀ values of 0.40 ± 0.07 μM (SR - 108) and 0.74 ± 0.29 μM (SR - 133) against TM4/8.2 and K1CB1, respectively. While (−)-2-isopentenyl-3-hydroxy-8-9-methylenedioxypterocarpan showed the highest inhibitory activity against T. brucei rhodesiense with an IC₅₀ value of 4.87 ± 0.49 μM (SR > 5.83). All crude extracts showed inhibitory activities against AA and AG, with three of the most active phytochemical components; rautandiol A, catechin, and dolineon, having only modest activities against AG with IC₅₀ values of 0.28 mM, 0.36 mM and 0.66 mM, respectively.

Conclusion

These studies have led to the identification of lead compounds with potential for future drug development, including Rautandiol B, as a potential lead compound against Plasmodium falciparum. The relatively higher inhibitory activities of the crude extracts against AG and AA over their isolated components could be due to the synergistic effects between their phytochemical components. These crude extracts could potentially serve as alternative inhibitors of AG and AA and as therapeutics for diabetes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03406-y.

Medicinal plants from the Himalayan region for potential novel antimicrobial and anti-inflammatory skin treatments

BACKGROUND AND OBJECTIVES

Adequate treatment of wounds remains one of the major medical needs globally, most notably in the regions with poor or limited access to health care. In many local and traditional systems of medicine, plants are often widely used for treating infected wounds.

AIM AND OBJECTIVES

The overarching aim of this project was selection of potential species for use in a future treatment by combining with plant resources with aspects of antimicrobial photodynamic therapy (aPDT). Specifically, we focussed on species used locally in the Himalayan region for the treatment of skin disorders and then assessed the existing pharmacological evidence for key species based on the published evidence available.

METHODS

Database searches were performed to identify relevant publications describing local and traditional uses of plants in the Himalayan region of Bhutan, PR China, India, Nepal and Pakistan. Using the Global Biodiversity Information Facility (GBIF), species were researched in terms of their distribution including in different climatic regions, focussing on species mostly found in higher climatic zones (based on the Köppen-Geiger climate classification). For species used in three or more countries and restricted to the higher altitudes, data on safety, pharmacology, as it relates to dermatological conditions, and phytochemistry were retrieved.

KEY FINDINGS

The study identified a total of 606 species that are used in the treatment of various skin conditions often associated with infections reported in 84 articles. Common weeds like Ageratum conyzoides and Bidens pilosa, widely used and cultivated species like Centealla asiatiaca and Prunus armenica were excluded. This ultimately led to the identification of a core group of five widely used species restricted to the Himalayan region (Cedrus deodara, Nardostachys jatamansi, Pinus wallichiana, Pinus roxburghii and Valeriana jatamansi).

CONCLUSIONS

Here we apply a novel approach comprising an assessment of the published information on the use of medicinal plants (i.e. local and traditional knowledge) in the context of their potential to be used in a biomedical form of clinical treatment - aPDT. Then, once sustainable sourcing based on access and benefit-sharing arrangements is in place, these species are investigated for their potential in wound treatment. Ultimately, the goal is to develop a new baseline for primary health care in some of the regions of the world with poor or limited access to health care.

Unique polyacetylenic ester-neolignan derivatives from Mitrephora tomentosa and their antimalarial activities

The phytochemical investigation of the methanol extracts of the leaves and twigs of Mitrephora tomentosa Hook. f. & Thomson resulted in the isolation and identification of undescribed polyacetylenic ester-neolignan derivatives, along with six known compounds. These six undescribed natural products were named as mitrephentosins A-F. The structures of these compounds were determined by spectroscopic techniques including UV, IR, NMR, and mass spectrometric analyses. The absolute configurations of mitrephentosins A-F were determined based on specific rotations values and ECD spectral data by comparisons made with the known parent neoligan compound mitredrusin. Mitrephentosins C, E, and F showed moderate antimalarial activities (IC₅₀ values of 13.3-24.6 μM) against the Plasmodium falciparum strains TM4/8.2 and K1CB1 and were not toxic to Vero cells, while the other isolated compounds were not active against these P. falciparum strains.

Dataset of materia medica in Sowa Rigpa: Tibetan medicine botanicals and Gawé Dorjé's classification system

This article provides the most updated dataset of Latin botanical identifications for the materia medica in Tibetan medicine, known as Bö Luk Sowa Rigpa (Tib. Bod lugs gso ba rig pa), or the “Tibetan knowledge field of healing,” often denoted in English simply as Sowa Rigpa. As one of the major scholarly Asian traditional medical systems, Sowa Rigpa is the principal health resource for populations across Tibetan regions of China, Mongolia, Bhutan, Nepal, India, and culturally-related areas of Russia. The geography represented by this medicinal plant dataset extends across the entire Tibetan plateau, its adjacent ranges, the wider transregional Himalayas, central Asia and much of the Indian subcontinent. Data collection drew from textual analysis of the seminal works of the Tibetan medical canon, including the Four Medical Treatises, Crystal Orb and Rosary among others; as well as the contemporary definitive work Stainless Crystal Mirror of Materia Medica by Gawé Dorjé. Study authors applied the same classification system as Gawé Dorjé, yet reanalyzed specimens according to a database cataloging research on regional herbarium botanical specimens, geographic distributions and regional plant chemistry studies, and confirming proper identification with the most current modern botanical taxonomies. Subsequently, almost 700 of the most commonly used materia medica were selected for compilation. Thus, this dataset represents updated botanical identifications and confirmations from both early and contemporary sources. Botanical specimen names were entered into spreadsheet format with Gawé Dorjé’s categories listed alongside Deumar Tendzin Püntsok's early standard. Enclosed raw data are written in Unicode Tibetan font to retain fidelity to entries in the classical texts, with parallel columns in standard Wylie Tibetan transliteration and phonetic transcription. Latin botanical names are updated for each materia medica specimen using Kew's Medicinal Plant Names Services (Kew-MPNS) with missing entries supplied by World Flora Online (WFO) and Flora of China (FoC). This dataset is the first publicly available comprehensive ethnobotanical identification of Sowa Rigpa materia medica with Latin binomial nomenclature. This dataset was developed to inform botanical and pharmacological analysis of the Tibetan medical materia medica repertoire as well as make comparative analyses of related materia medica in other Asian medical systems.

Isolation of CFTR and TMEM16A inhibitors from Neorautanenia mitis (A. Rich) Verdcourt: Potential lead compounds for treatment of secretory diarrhea

A phytochemical study on the root extracts of Neorautanenia mitis, a Nigerian medicinal plant used in the management of diarrhea, led to the isolation of one new and 19 known natural products. These compounds and crude extracts were evaluated for Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Cl^- channel and calcium-activated Cl^- channel (TMEM16A) inhibitory activities in T84 and Calu-3 cells, respectively. Four compounds namely dolineon, neodulin, pachyrrhizine, and neotenone inhibited cAMP-induced Cl- secretion across T84 cell monolayers with IC₅₀ values of ~0.81 μM, ~2.42 μM, ~2.87 μM, and ~4.66 μM, respectively. Dolineon having the highest inhibitory activity also inhibited a Ca + activated Cl^- channel (TMEM16A) with an IC₅₀ value of ~4.38 μM. The in vitro antidiarrheal activity of dolineon was evaluated on cholera toxin (CT) induced chloride secretion in T84 cells, where it inhibited CT-induced chloride secretion by >70% at 100 μM. Dolineon also inhibited CT-induced fluid secretion by ~70% in an in vivo mouse closed loop model at a dose of 16.9 μg/loop. The cytotoxicity of the extracts and compounds was evaluated on KB, Vero and BHK21 cells, dolineon showed low cytotoxicity of >29.6 μM and 57.30 + 6.77 μM against Vero and BHK21 cells, respectively. Our study revealed that several compounds isolated from N. mitis showed antidiarrheal activity. The most active compound dolineon can potentially serve as a lead compound towards the development of CFTR and TMEM16A inhibitors as future therapeutics for secretory diarrhea.

Chemical profile and therapeutic potentials of Xylocarpus moluccensis (Lam.) M. Roem.: A literature-based review

ETHNOPHARMACOLOGICAL RELEVANCE

Historically, mangrove plants are among the potential sources of foods and remedies for humans living in the forests and nearby communities. Xylocarpus moluccensis (Lam.) M. Roem., an important mangrove medicinal plant, has been traditionally used for many purposes such as treatment of fever, dysentery, diarrhea, swelling, and abdominal disorders. The aim of the present work was to summarize the chemical reports and biological activities of the mangrove medicinal plant X. moluccensis based on information collected from different databases.

MATERIALS AND METHODS

An up-to-date search (till Aug 2019) was carried out in databases such as PubMed, Science Direct, Google Scholar, and various patient offices (e.g., WIPO, CIPO, USPTO) using the keywords: 'Xylocarpus moluccensis', and/or paired with 'ethnobotanical use', and 'phytochemical'. In vitro, ex vivo, or in vivo studies were included.

RESULTS

Findings suggest that X. moluccensis contains various important minerals and phytochemicals, where flavonoids, terpenes and terpenoids are the most prominent isolated phyto-constituents of X. moluccensis. Extracts/fractions or isolated compounds from this plant possess diverse biological activities, including anti-inflammatory, anti-microbial, antineoplastic, anti-diarrheal, insecticidal, anti-feedant, neuropharmacological (e.g., central nervous system depressant), anti-atherosclerotic, and lipid-lowering activity. Only one report suggests that the methanol and aqueous extracts of this plant did not exert cytotoxic effects on normal mouse fibroblast cells. However, no clinical studies were reported.

CONCLUSIONS

Taken all together, X. moluccensis may be one of the best sources of pharmacologically active lead compounds. More research, however, is necessary to establish the safety and efficacy, and its toxicogenetic effects in animal models.

Antiplasmodial natural products: an update

Background

Malaria remains a significant public health challenge in regions of the world where it is endemic. An unprecedented decline in malaria incidences was recorded during the last decade due to the availability of effective control interventions, such as the deployment of artemisinin-based combination therapy and insecticide-treated nets. However, according to the World Health Organization, malaria is staging a comeback, in part due to the development of drug resistance. Therefore, there is an urgent need to discover new anti-malarial drugs. This article reviews the literature on natural products with antiplasmodial activity that was reported between 2010 and 2017.

Methods

Relevant literature was sourced by searching the major scientific databases, including Web of Science, ScienceDirect, Scopus, SciFinder, Pubmed, and Google Scholar, using appropriate keyword combinations.

Results and Discussion

A total of 1524 compounds from 397 relevant references, assayed against at least one strain of Plasmodium, were reported in the period under review. Out of these, 39% were described as new natural products, and 29% of the compounds had IC₅₀ ≤ 3.0 µM against at least one strain of Plasmodium. Several of these compounds have the potential to be developed into viable anti-malarial drugs. Also, some of these compounds could play a role in malaria eradication by targeting gametocytes. However, the research into natural products with potential for blocking the transmission of malaria is still in its infancy stage and needs to be vigorously pursued.

Asian Medicinal Plants’ Production and Utilization Potentials: A Review

Medicinal plants research in Asia continues to receive significant national and international attention, particularly concerning its multiple roles in poverty alleviation and health care support. However, scientific information on the institutional arrangements, the potentials of different medicinal plants production systems, and the utilization methods, remain highly fragmented. This incomprehensive information base shades the development of a comprehensive research agenda to improve the current body of knowledge, at least in the context of Asia. To address this impasse and propose future research perspectives, we systematically reviewed 247 journal articles, 15 institutional reports, and 28 book chapters. From the reviews, five key lessons are drawn: (i) Asian medicinal plant production systems demonstrate some dynamics, characterized by a gradual but continuous shift from wild gathering to cultivation, (ii) sub-regional variations exist with regards to the appreciation of medicinal plants potentials for traditional healing, modern healthcare and livelihoods support, (iii) knowledge on the effect of multi-scale institutional arrangements (formal and informal) on medicinal plant management practices is fragmented, (iv) very few studies dwell on the challenges of medicinal plants commercialization, particularly with regards to the role of middlemen, boom–bust cycle, raw material readiness, and product quality, and (v) law enforcement, benefit and knowledge sharing, and research and development should be prioritized to serve the interest of medicinal plants production actors. To further extend the body of knowledge on medicinal plants in Asia, we advance the need for empirical investigations on the performance of medicinal plants production systems and their contribution to livelihoods in diverse institutional contexts.

Pedicularis L. Genus: Systematics, Botany, Phytochemistry, Chemotaxonomy, Ethnopharmacology, and Other

In this review, the relevance of the plant species belonging to the Pedicularis L. genus has been considered from different points of view. Particular emphasis was given to phytochemistry and ethnopharmacology, since several classes of natural compounds have been reported within this genus and many of its species are well known to be employed in the traditional medicines of many Asian countries. Some important conclusions on the chemotaxonomic and chemosystematic aspects of the genus have also been provided for the first time. Actually, this work represents the first total comprehensive review on this genus.

Polyoxygenated Cyclohexenes and Their Chlorinated Derivatives from the Leaves of Uvaria cherrevensis

The chemical study of leaf extracts from Uvaria cherrevensis resulted in the identification of 11 new polyoxygenated cyclohexenes, cherrevenols A-K (1-11), and a new seco-cyclohexene derivative, cherrevenol L (12). Nine known compounds (13-21) were also isolated. Three of the isolated compounds are chlorinated polyoxygenated cyclohexenes. The structures of these compounds were determined using spectroscopic methods and, in some cases (compounds 2, 6, 8, and 10), single-crystal X-ray crystallographic structural analysis or chemical correlation (compounds 6 and 7). Compounds 6 and 7 were both isolated as scalemic mixtures (ee 23-24%).

Defined Small Molecules Produced by Himalayan Medicinal Plants Display Immunomodulatory Properties

Plant-derived compounds that modulate the immune responses are emerging as frontline treatment agents for cancer, infectious diseases and autoimmunity. Herein we have isolated 40 phytochemicals from five Bhutanese Sowa Rigpa medicinal plants-Aconitum laciniatum, Ajania nubegina, Corydalis crispa, Corydalis dubia and Pleurospermum amabile-and tested 14 purified compounds for their immunomodulatory properties using a murine dendritic cell (DC) line, and cytotoxicity against a human cholangiocyte cell line using xCELLigence real time cell monitoring. These compounds were: pseudaconitine, 14-veratryolpseudaconitine, 14-O-acetylneoline, linalool oxide acetate, (E)-spiroether, luteolin, luteolin-7-O-β-d-glucopyranoside, protopine, ochrobirine, scoulerine, capnoidine, isomyristicin, bergapten, and isoimperatorin. Of the 14 compounds tested here, scoulerine had adjuvant-like properties and strongly upregulated MHC-I gene and protein expression whereas bergapten displayed immunosuppressive properties and strongly down-regulated gene and protein expression of MHC-I and other co-stimulatory molecules. Both scoulerine and bergapten showed low cytotoxicity against normal healthy cells that were consistent with their immunoregulatory properties. These findings highlight the breadth of immunomodulatory properties of defined compounds from Bhutanese medicinal plants and show that some of these compounds exert their mechanisms of action by modulating DC activity.

Wound healing and anti-inflammatory activities induced by a Plantago australis hydroethanolic extract standardized in verbascoside

ETHNOPHARMACOLOGICAL RELEVANCE

Plantago australis is a popular plant found to be widely spread in Latin America. In folk medicine, the seeds and leaves are used mainly for anti-inflammatory, wound healing, among others. The verbascoside, a phenolic glycoside, is an active chemical component described in this species of plant, which has antioxidant, anti-inflammatory and healing effects.

PURPOSE

The aim of the present study was to evaluate whether P. australis hydroethanolic extract (PAHE) standardized in verbascoside could promote wound healing associated with anti-inflammatory action within both in vitro and in vivo models.

METHODS

For the wound healing activity, we used a Scratch Test, an assay capable of evaluating the migratory ability of keratinocyte cells (HaCat) in vitro and thereby confirming the activity in rats. For the anti-inflammatory activity, the inflammation was induced with LPS in microglial murine cells (N9). Inflammatory mediators (IL-6, IL-10, IL-12p70, INFγ, MCP-1 and TNFα) were measured and the activity of superoxide dismutase (SOD), catalase (CAT), and mitochondrial membrane potential were evaluated. In addition, using paw edema induced by carrageenan in rats, the anti-inflammatory activity in vivo was analyzed.

RESULTS

The PAHE and verbascoside, induced a significant increase in migration of keratinocytes, at all concentrations tested when compared to the negative control. The wound healing activity in vivo showed that the PAHE accelerated the process. The treatments with PAHE and verbascoside induce increases in the antioxidants enzymes, suggesting a possible activation of these enzymes. However, this did not result in an increase in the expression of inflammatory mediators in microglial cells. In LPS activated cells the verbascoside displayed a significant reduction of TNFα, IL-6, IL-12p70, MCP-1 and INFγ, while the PAHE only displayed statistically significant reduction in TNFα. Interestingly, both the compounds could reduce the oxidative parameters in N9 cells activated by LPS. Additionally, pretreatment with PAHE inhibited the paw edema in rats.

CONCLUSION

The results suggest that PAHE has wound healing activity, improving cells migration and, as well as was able to reverse the oxidation effect in LPS-activated N9 cells. The wound-healing and anti-inflammatory activities of PAHE were confirmed in vivo. In addition, the presence of verbascoside can be related to PAHE effects, since this compound was capable of increase keratinocytes migration and inhibiting inflammation mediators.

Geopharmaceuticals of Himalayan Sowa Rigpa medicine: Ethnopharmacological uses, mineral diversity, chemical identification and current utilization in Bhutan

ETHNOPHARMACOLOGICAL RELEVANCE

Geological materials, such as minerals, have a long history of usage as ingredients in multicompound formulations of Himalayan Sowa Rigpa medicine - as well as in its localized form of Bhutanese traditional medicine (BTM) - for treating various disorders for over thousand years. Yet, hardly any scientific research has been done on their ethnopharmacological efficacy and chemistry.

AIM OF THE STUDY

This study documents and correlates the rarely explored ethnopharmacological and chemical identification of various minerals and their ethnomedicinal uses in BTM formulations for the first time.

MATERIAL AND METHODS

A five stage cross-disciplinary process was conducted as follows: (1) a review of classical literature of Sowa Rigpa texts (Tibetan medical texts, pharmacopoeias and formularies) that are still in use today; (2) listing of mineral ingredients according to Sowa Rigpa names, followed by identification with common English and chemical names, as well as re-translating their ethnomedical uses; (3) cross-checking the chemical names and chemical composition of identified Sowa Rigpa minerals with various geological mineral databases and mineral handbooks; (4) authentication and standardization of Sowa Rigpa names through open forum discussion with diverse BTM practitioners; (5) further confirmation of the chemical names of identified minerals by consulting different experts and pharmacognosists.

RESULTS

Our current study lists 120 minerals as described in Sowa Rigpa medical textbooks most of which we were able to chemically identify, and of which 28 are currently used in BTM herbo-mineral formulations. Out of these 28 mineral ingredients, 5 originate from precious metal and stone, 10 stem from earth, mud and rocks, 8 are salts, and 5 concern 'essences' and exudates.

CONCLUSIONS

Our study identified 120 mineral ingredients described in Sowa Rigpa medical textbooks, out of which 28 are currently used. They are crucial in formulating 108 multicompound prescription medicines in BTM presently in use for treating more than 135 biomedically defined ailments.

A medicinal plant compound, capnoidine, prevents the onset of inflammation in a mouse model of colitis

ETHNOPHARMACOLOGICAL RELEVANCE

The traditional uses of Corydalis dubia, Ajania nubigena and Pleurospermum amabile in the Bhutanese traditional medicine for treating disorders related to inflammatory conditions and the in vitro anti-inflammatory activity of their crude extracts inspired the isolation and the investigation of anticolitic properties of four pure compounds.

MATERIALS AND METHODS

Three medicinal plants were collected from Himalayan Mountains of Bhutan. Capnoidine and scoulerine were isolated from C. dubia, linalool oxide acetate from A. nubigena and isomyristicin from P. amabile using natural product isolation protocols. Four compounds were investigated for their anti-inflammatory activities against IBD-colitis using chemically induced (TNBS) mice model of colitis. Capnoidine conferred the best preliminary protection against TNBS-induced colitis in mice and we have conducted in-depth pharmacological investigation of this compound including clinical symptoms, pathological signs, cytokine profiles, histological structure and inflammasomes using relevant bioassay protocols.

RESULTS

Capnoidine-treated mice had significantly: a) improved clinical symptoms (body weight loss, mobility, piloerection and faecal consistency); b) reduced colon pathology (adhesion, oedema, ulceration, and colon length); c) altered inflammatory cytokines profiles within the colons; d) reduced levels of p-IκB-α (Ser32) and p-NF-κB p65 (Ser536) and e) reduced histological inflammation in the colon when compared with mice administered TNBS only.

CONCLUSION

Capnoidine presents as a potential new anti-inflammatory drug lead candidate for diseases where current standard-of-care often fails and is associated with major side effects. It also validates the traditional uses of C. dubia against inflammatory conditions and underlines the value of pursuing bioactive compounds derived from traditionally used ethnobotanical medicines.

Medicinal plants for in vitro antiplasmodial activities: A systematic review of literature

The increasing resistance of malaria to drugs raise the need to new antimalarial agents. Antiplasmodial herbs and their active compounds are the most promising source the new antimalarial agents. This study aimed to identify the medicinal plants with very good in vitro antiplasmodial activities, with half-maximal inhibitory concentration (IC₅₀)≤1μg/ml, and to determine trends in the process of screening their antiplasmodial activities. A total of 58 reports published in the English language were retrieved from the bibliographical databases. Screening and data extraction were performed by two independent reviewers. The herbs were categorized as very good, good, moderate and inactive if the IC₅₀ values were <0.1μg/ml, 0.1-1μg/ml, >1-5μg/ml and >5μg/ml respectively. We documented 752 medicinal plants belonging to 254 genera. The majority of the plants were reported from Africa followed by Asia. The traditional use for malaria treatment was the most common reason for the selection of the plants for investigation. About 80% of the plants experimented were reported to be inactive. Among plants identified as having very good to good antiplasmodial crude extracts are Harungana madagascariensis, Quassia africana, and Brucea javanica, while Picrolemma spruce, Aspidosperma vargasi, Aspidosperma desmanthum, and Artemisia annua were reported to have individual compound isolates with very good antiplasmodial activities. In conclusion, the number of plant species assessed so far is still small compared with the stock in nature's plant library. A mechanism of systematically approaching and exploring the untouched plant genera needs to be designed.

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.

Antimalarial and cytotoxic quassinoids from the roots of Brucea javanica

Two new quassinoids, brujavanol A (1) and brujavanol B (2), along with five known quassinoids (3-7), were isolated from the roots of Brucea javanica. Their structures were elucidated by spectroscopic methods. The antimalarial and cytotoxic activities of the isolated compounds were also assessed. Compounds 1 and 2 exhibited significant in vitro cytotoxicity against human oral cavity cancer (KB) cells with IC₅₀ values of 1.30 and 2.36 μg/ml, respectively, whereas compound 3 showed excellent antiplasmodial activity against the Plasmodium falciparum strains, K1 (IC₅₀ = 0.58 μg/ml).

Anti-inflammatory, Anti-bacterial and Anti-acetylcholinesterase Activities of two Isoquinoline Alkaloids–Scoulerine and Cheilanthifoline

Corydalis plants containing isoquinoline alkaloids are reported to possess promising pharmacological properties for the treatment of important diseases including cancer, inflammation, Alzheimer's disease and microbial infections. As part of a wider program investigating Bhutanese medicinal plants, we have previously identified eight isoquinoline alkaloids from C. dubia. Out of these, we report here on two of the major alkaloids, scoulerine (1) and cheilanthifoline (2) and their inhibitory activities against acetylcholinesterase (anti-AChE), tumor necrosis factor alpha (anti TNF-α) and a bacterial strain, Helicobacter pylori. Both alkaloids showed weak anti TNF-α and antibacterial activities. However, the anti-AChE activity of scoulerine (1) was promising as it significantly inhibited AChE with a minimum inhibitory requirement (MIR) value of 0.0015 nmol, which was two-fold better than the reference drug, galanthamine (MIR value of 0.003 nmol). As there are limited anti-Alzheimer's chemotherapeutics, scoulerine (1) is worthy of further exploration, including lead optimization, structure-activity-relationship studies, analog development, pharmacodynamics and in vivo animal studies

New Phytochemical Constituent and Bioactivities of Horwoodia dicksoniae and Rumex cyprius

BACKGROUND

Many plants growing in Saudi Arabia are used in folk medicine for treatment of several diseases.

OBJECTIVE

Information of the chemical constituents and biological activities of plants is desirable for the discovery of therapeutic agents and discovering the actual value of folkloric remedies.

MATERIALS AND METHODS

The compounds were isolated and purified using silica gel column chromatography and preparative high-performance liquid chromatography-diode array detector (HPLC-DAD) Method. The alcoholic extracts of these plants were evaluated for biological activities.

RESULTS

Isolation and characterization of 1-feruloyl-β-D-glucopyranoside (1) as well as new secondary metabolite tryptophan methyl ester (2) were isolated for the 1(st) time from the Horwoodia dicksoniae. The three flavones were isolated from Rumex cyprius identified as isoorientin (3), vitexin (4), and Cynarosid (5). The structures of these compounds were characterized by nuclear magnetic resonance and mass spectrometry analysis and comparing with literature. The compounds were isolated and purified using silica gel column chromatography and preparative HPLC-DAD Method. The alcoholic extracts of these plants were evaluated for antimicrobial activities against two Gram-positive bacteria, two Gram-negative bacteria, and four pathogenic fungi. Both plants showed good activities against Syncephalastrum racemosum and Streptococcus pneumoniae with minimal inhibitory concentrations (MICs) 0.98 and 1.95 μg/mL, respectively. H. dicksoniae showed good activity against Aspergillus fumigates with an MIC 1.95 μg/mL. The two extracts showed also effective free radical scavenging activities in the 1,1-diphenyl-2-picrylhydrazyl assay. H. dicksoniae exhibited remarkable cytotoxic activity against Human breast cancer mammary cancer cells-7, Human liver cancer human hepatoma carcinoma cells-2, and human lung carcinoma (A-549) cell lines.

CONCLUSIONS

It was suggested that further work should be carried out to isolate, purify, and characterize the active constituents responsible for the activity of these plants.

SUMMARY

New secondary metabolite Tryptophane methyl ester as well as 1-feruloyl-β-D-glucopyranoside were isolated for the first time from the HD.Isoorientin, vitexin and Cynarosid were isolated from RC.HD exhibited good activity against Aspergillus fumigates with an MIC 1.95 µg mL(-1).HD showed significant cytotoxic activity against Human breast cancer (MCF-7), Human liver cancer (HepG-2) and Human lung carcinoma (A-549) cell lines.

Identification of lead chemotherapeutic agents from medicinal plants against blood flukes and whipworms

Schistosomiasis and trichuriasis are two of the most common neglected tropical diseases (NTD) that affect almost a billion people worldwide. There is only a limited number of effective drugs to combat these NTD. Medicinal plants are a viable source of parasiticides. In this study, we have investigated six of the 19 phytochemicals isolated from two Bhutanese medicinal plants, Corydalis crispa and Pleurospermum amabile, for their anthelmintic properties. We used the xWORM technique and Scanning Electron Microscope-based imaging to determine the activity of the compounds. Of the six compounds tested, isomyristicin and bergapten showed significant anthelmintic activity against Schistosoma mansoni and Trichuris muris with bergapten being the most efficacious compound one against both parasites (S. mansoni IC₅₀ = 8.6 μg/mL and T. muris IC₅₀ = 10.6 μg/mL) and also against the schistosomulum stage of S. mansoni. These two compounds induced tegumental damage to S. mansoni and affected the cuticle, bacillary bands and bacillary glands of T. muris. The efficacy against multiple phylogenetically distinct parasites and different life stages, especially the schistosomulum where praziquantel is ineffective, makes isomyristicin and bergapten novel scaffolds for broad-spectrum anthelmintic drug development that could be used for the control of helminths infecting humans and animals.

Quality assurance of the university medical education, hospital services and traditional pharmaceutical products of the Bhutanese So-wa-rig-pa health care system

BACKGROUND

The Bhutanese So-wa-rig-pa medicine (BSM) was integrated with the allopathic (modern) health care system in 1967. Ever since the health care integration policy was implemented, the BSM has gone through many phases of quality improvement and changes including the establishment of one university-based institute, 58 hospitals and Basic Health Units (BHU)-based health care services, and one traditional medicine factory. The BSM provides primary health care services to more than 20-30 % of patients who visit hospitals and BHU on a daily basis. However, there has been no study covering the quality assurance system of BSM. Our paper addresses this information gap.

METHODS

This study was an observational ethnographic study supported by phenomenological understanding and content analysis of the data. The information was triangulated through consultation with the BSM practitioners (discussion (N = 8)) and personalized in-depth question-answer sessions using electronic protocols (N = 5). These participants comprised BSM educationists, clinical physicians, researchers, production and the quality assurance staff who were selected using convenience and purposive sampling method. The relevant So-wa-rig-pa information and literature were obtained from the government policy documents, official websites, scientific papers and the traditional medical texts. This study is enhanced by our practical observations and first-hand experience with BSM while working as the researchers at the Ministry of Health in Bhutan. In addition, the information in this paper is crosschecked and authenticated by five So-wa-rig-pa practitioners of Bhutan.

RESULTS

The study highlights the following: a) The BSM receives both the government and people's support, b) The quality assurance system have been developed by integrating the traditional empirical knowledge and modern scientific protocols, c) There exist three administrative and functional organizations responsible for providing the quality BSM health care services in Bhutan, d) Extensive standard treatment guidelines and Quality documentation system exist for BSM as required by the regulatory bodies in Bhutan. The paper also recommends appropriate future directions for BSM.

CONCLUSIONS

The BSM plays significant role in the primary health care system of the country. Consequently, the quality, safety and efficacy of BSM has been given priority by the Bhutan government. Many scientific protocols were integrated with the traditional quality approaches and further scientific studies are still required to improve its quality.

Compounds Derived from the Bhutanese Daisy, Ajania nubigena, Demonstrate Dual Anthelmintic Activity against Schistosoma mansoni and Trichuris muris

Background

Whipworms and blood flukes combined infect almost one billion people in developing countries. Only a handful of anthelmintic drugs are currently available to treat these infections effectively; there is therefore an urgent need for new generations of anthelmintic compounds. Medicinal plants have presented as a viable source of new parasiticides. Ajania nubigena, the Bhutanese daisy, has been used in Bhutanese traditional medicine for treating various diseases and our previous studies revealed that small molecules from this plant have antimalarial properties. Encouraged by these findings, we screened four major compounds isolated from A. nubigena for their anthelmintic properties.

Methodology/Principal Findings

Here we studied four major compounds derived from A. nubigena for their anthelmintic properties against the nematode whipworm Trichuris muris and the platyhelminth blood fluke Schistosoma mansoni using the xWORM assay technique. Of four compounds tested, two compounds—luteolin (3) and (3R,6R)-linalool oxide acetate (1)—showed dual anthelmintic activity against S. mansoni (IC₅₀ range = 5.8–36.9 μg/mL) and T. muris (IC₅₀ range = 9.7–20.4 μg/mL). Using scanning electron microscopy, we determined luteolin as the most efficacious compound against both parasites and additionally was found effective against the schistosomula, the infective stage of S. mansoni (IC₅₀ = 13.3 μg/mL). Luteolin induced tegumental damage to S. mansoni and affected the cuticle, bacillary bands and bacillary glands of T. muris. Our in vivo assessment of luteolin (3) against T. muris infection at a single oral dosing of 100 mg/kg, despite being significantly (27.6%) better than the untreated control group, was markedly weaker than mebendazole (93.1%) in reducing the worm burden in mice.

Conclusions/Significance

Among the four compounds tested, luteolin demonstrated the best broad-spectrum activity against two different helminths—T. muris and S. mansoni—and was effective against juvenile schistosomes, the stage that is refractory to the current gold standard drug, praziquantel. Medicinal chemistry optimisation including cytotoxicity analysis, analogue development and structure-activity relationship studies are warranted and could lead to the identification of more potent chemical entities for the control of parasitic helminths of humans and animals.

Schistosomiasis and trichuriasis affects millions of people worldwide and are caused by blood flukes and whipworms, respectively. Only a handful of anthelmintic drugs exist to treat these infections and the pipeline for the next generation of anthelmintic drugs is sparse, precipitating the need for new drug development. In this context, medicinal plants present a viable source of novel anthelmintic compounds. This inspired us to study the selected naturally occurring compounds derived from a Bhutanese daisy medicinal plant, Ajania nubigena for their anthelmintic activities. Here, using the xWORM motility assay, we demonstrate that two compounds, luteolin (3) and (3R,6R)-linalool oxide acetate (1), display significant broad-spectrum anthelmintic activity against two of the most important genera of human helminth parasites, the nematode whipworm and the platyhelminth blood fluke. Luteolin exhibited the best activities with IC₅₀ values of 5.8 μg/mL against schistosomes and 9.7 μg/mL against whipworms. Using scanning electron microscopy we showed that luteolin damages the tegument of blood flukes and induces abnormalities in the bacillary bands/glands and cuticles of whipworms. Intriguingly, our previous study showed that luteolin (3) was effective against multi-drug resistant Plasmodium falciparum malaria. Due to its broad-spectrum anti-parasitic activities, luteolin (3) is a desirable drug lead scaffold, which could be used for developing effective compounds to control and treat numerous tropical diseases.

A flavonoid compound from Chrysosplenium nudicaule inhibits growth and induces apoptosis of the human stomach cancer cell line SGC-7901

CONTEXT

Gastric cancer remains highly prevalent, but treatment options are limited. Natural products have proved to be a rich source of anticancer drugs. Chrysosplenium nudicaule Ledeb. (Saxifragaceae) is a perennial herb that grows in the highlands of China. It has been used as a traditional Chinese medicine to treat digestive diseases for hundreds of years. Recent studies revealed that this herb had anticancer activity, and the flavonoids were speculated to be the effective components. 6,7,3'-Trimethoxy-3,5,4'-trihydroxy flavone (TTF) and 5,4'-dihydroxy-3,6,3'trimethoxy-flavone-7-O-β-d-glucoside (DTFG) are flavonoid compounds isolated from Chrysosplenium nudicaule.

OBJECTIVE

This study examined the effect of TTF and DTFG on SGC-7901 human stomach cancer cell in vitro to determine the anticancer and induction of apoptosis properties of TTF.

MATERIALS AND METHODS

The proliferation of cells treated with 32, 16, 8, 4, and 2 μg/mL of TTF or DTFG for 24, 48, and 72 h was assessed by the MTT assay. After being treated with TTF, the apoptosis of SGC-7901 cells was assessed by acridine orange staining, ultrastructure, electrophoresis of DNA fragmentation, and flow cytometry.

RESULTS

Results indicated that TTF inhibited the growth of cancer cells with an IC50 value of 8.33 μg/mL after 72 h incubation. However, DTFG showed no inhibitory effect on the growth of the cancer cell. Further studies on TTF also confirmed that it was able to induce apoptosis of SGC-7901 cells at a concentration as low as 4 μg/mL.

DISCUSSION AND CONCLUSION

The apoptotic effect of TTF makes it a promising candidate for future chemotherapeutic application in treating stomach cancer.

Medicinal plants of Dagala region in Bhutan: their diversity, distribution, uses and economic potential

BACKGROUND

The traditional g.so-ba-rig-pa hospitals in Bhutan uses more than 100 polyingredient medicines that are manufactured by the Menjong Sorig Pharmaceuticals (MSP). The MSP has been collecting medicinal plants from Lingzhi region for about 48 years and therefore the ecological pressure on these plants have increased. It is MSP's top priority to identify an alternative collection site to ease the problem. Therefore, this study was carried out to determine whether Dagala region could potentially be an alternative collection site for MSP.

METHODS

First the multidisciplinary research team generated a tentative plant list by reviewing a body of ancient g.so-ba-rig-pa literature, current formulations, and the MSP medicinal plants inventory documents. Second, the research team visited the study areas in Dagala region for spot identification of medicinal plants. Third, we confirmed our traditional and botanical identification by crosschecking the descriptions with the series of books on traditional texts, Flora of Bhutan, scientific papers on medicinal plants, and the plant databases.

RESULTS

We have identified 100 species of high altitude medicinal plants from Dagala region. Of these, 24 species grow abundantly, 29 species grow in moderate numbers and 47 species were scarce. More than 85 species belonged to the herbaceous life form and 51 of them are used as a whole plant. A total of 68 species grow in between 4000 and 4999 meter above sea level. These 100 medicinal plants represented 39 different families and 80 genera and the maximum number of plants belonged to the family Asteraceae. Of 60 species that are currently used for formulating medicines at MSP, 16 species have economic importance with potential for commercial collection. Out of seven areas covered by the survey, Kipchen hosted maximum number of medicinal plants (21 species).

CONCLUSIONS

Our survey identified 100 medicinal plants from Dagala region and of these, 16 species has economic potential that could benefit both MSP and Dagala communities. It is feasible to establish an alternative medicinal plants collection center in Dagala Gewog.

An Ethnopharmacological, Phytochemical and Pharmacological Review of the Genus Meconopsis

The Meconopsis plants (Chinese: 绿绒篙), belonging to the family Papaveraceae, have been used as traditional Tibetan medicine (TTM) for thousands of years. Meconopsis has the effects of clearing heat, reducing swelling, and easing pain, and is mainly prescribed for heat syndromes, hepatitis, pneumonia, and pain in joints. Phytochemical studies have revealed the presence of major isoquinoline alkaloids and flavonoids. Modern pharmacological research has demonstrated its antitumor, hepatoprotective, analgestic, antimicrobial, anti-oxidant, antitussive, and anti-inflammatory activities. However, resource availability, in-depth in vivo pharmacological study and qualitative and quantitative analysis are still insufficient and deserve further efforts. This paper provides a comprehensive advance on the ethnopharmacological, phytochemical, and pharmacological studies of the genus, in hopes of promoting a better understanding of their medicinal values.

Antimalarial Oxoprotoberberine Alkaloids from the Leaves of Miliusa cuneata

Five new oxoprotoberberine alkaloids, miliusacunines A-E (1-5), along with nine known compounds, 6-14, were isolated from an acetone extract of the leaves and twigs of Miliusa cuneata. Their structures were elucidated by spectroscopic analysis. All isolated compounds were evaluated for their cytotoxicities against the KB and Vero cell lines and for antimalarial activities against the Plasmodium falciparum strains TM4 and K1 (a sensitive and a multi-drug-resistant strain, respectively). Compound 1 showed in vitro antimalarial activity against the TM4 strain, with an IC50 value of 19.3 ± 3.4 μM, and compound 2 demonstrated significant activity against the K1 strain, with an IC50 value of 10.8 ± 4.1 μM. Both compounds showed no discernible cytotoxicity to the Vero cell line at the concentration levels evaluated.

Effectiveness of Stevia Rebaudiana Whole Leaf Extract Against the Various Morphological Forms of Borrelia Burgdorferi in Vitro

Lyme disease is a tick-borne multisystemic disease caused by Borrelia burgdorferi. Administering antibiotics is the primary treatment for this disease; however, relapse often occurs when antibiotic treatment is discontinued. The reason for relapse remains unknown, but recent studies suggested the possibilities of the presence of antibiotic resistant Borrelia persister cells and biofilms.

In this study, we evaluated the effectiveness of whole leaf Stevia extract against B. burgdorferi spirochetes, persisters, and biofilm forms in vitro. The susceptibility of the different forms was evaluated by various quantitative techniques in addition to different microscopy methods. The effectiveness of Stevia was compared to doxycycline, cefoperazone, daptomycin, and their combinations. Our results demonstrated that Stevia had significant effect in eliminating B. burgdorferi spirochetes and persisters. Subculture experiments with Stevia and antibiotics treated cells were established for 7 and 14 days yielding, no and 10% viable cells, respectively compared to the above-mentioned antibiotics and antibiotic combination. When Stevia and the three antibiotics were tested against attached biofilms, Stevia significantly reduced B. burgdorferi forms. Results from this study suggest that a natural product such as Stevia leaf extract could be considered as an effective agent against B. burgdorferi.

Diterpenoid alkaloids of Aconitum laciniatum and mitigation of inflammation by 14-O-acetylneoline in a murine model of ulcerative colitis

Aconitum laciniatum is used in Bhutanese traditional medicine for treating various chronic infections and inflammatory conditions. We carried out in-depth isolation and characterization of the phytochemicals from the root component and determined the anti-inflammatory effects of the isolated compounds against chemically-induced colitis in mice. Five diterpenoid alkaloids - pseudaconitine, 14-veratroylpseudaconine, 14-O-acetylneoline, neoline, and senbusine A - were isolated from A. laciniatum for the first time. Two of the alkaloids were tested for anti-inflammatory properties in the TNBS-induced colitis model in mice. Various parameters were measured to assess pathology including weight loss, clinical and macroscopic scores, histological structure and IFN-γ production in the gut. Of the two alkaloids tested, 14-O-acetylneoline showed significant protection against different parameters of colitic inflammation. Compared to control mice that received TNBS alone, mice treated with 14-O-acetylneoline experienced significantly less weight loss and had significantly lower clinical scores, macroscopic pathology and grades of histological inflammation. Moreover, colonic IFN-γ mRNA levels were significantly reduced in mice that received 14-O-acetylneoline compared to control mice that received TNBS alone. This alkaloid is now considered a novel anti-colitis drug lead compound.

Cytotoxic and Antimalarial Alkaloids from the Twigs of Dasymaschalon obtusipetalum

One new p-quinonoid aporphine alkaloid, obtusipetadione (1), and eleven known compounds (2–12) were isolated from the acetone extract of the twigs of Dasymaschalon obtusipetalum. Their structures were elucidated by spectroscopic methods. The cytotoxic and antimalarial activities of the isolated compounds were evaluated. Compound 1 showed significant in vitro antiplasmodial activity against the P. falciparum strains TM4 and K1 (multidrug resistant strain) with IC50 values of 2.46±0.12 and 1.38±0.99 μg/mL, respectively with no cytotoxicity. Compound 9 had more modest antiplasmodial activity, but significant cytotoxicity.

Contributions of medicinal plants to the Gross National Happiness and Biodiscovery in Bhutan

BACKGROUND

The medicinal plants and the associated Bhutanese traditional medicine (BTM) are protected by the country's constitution and receive both government support and acceptance by the wider public. More than 1000 medicinal plants are described in the BTM but currently collects only 300 species for daily formulations of BTM. These medicinal plants have been one of the drivers of the 'Gross National Happiness (GNH)' and biodiscovery projects in Bhutan. However, no review covering the systematic evaluations of the contributions of medicinal plants and the BTM to the GNH and biodiscovery exist till date.

METHODS

This paper, therefore addresses this information gap. It is based on the review of the existing traditional and scientific literature, government websites and policy documents. The descriptions and discussions of the paper is straightened, authenticated and enhanced by the data collected through the informal discussions with the BTM practitioners and also through the authors' many years of practical observations of the impact of the medicinal plants programs and the BTM practices in Bhutan.

RESULTS

This paper found the following: a) the medicinal plants generates income to the farmers elevating their living standard and the economic status, b) it serves as the bulk ingredients of the BTM facilitating the provision of free traditional health care services to the patients, c) helps the conservation of medicinal plants and their pristine environment through recognition of their spiritual, social and economic values, d) preserves the rich BTM cultural heritage, and e) guides the biodiscovery projects based on their ethnobotanical information. The paper also identified the challenges and research gaps, and recommends appropriate strategies that can help secure the sustainable future of the medicinal plants, the BTM and the biodiscovery projects.

CONCLUSIONS

The medicinal plants play significant role in the country's biodiscovery projects and the internationally renowned development policy of 'Gross National Happiness'.