Bassia longifolia (= Madhuca longifolia): Isolation of flavan-3-ols and their contribution to the antibacterial and antidiabetic activity in vitro

Bassia longifoliaKOENIG (= Madhuca longifolia (L.) is an evergreen tree that is widely distributed throughout Nepal, India, and Sri Lanka. The bark has various traditional uses: as a paste in the treatment of cuts and wounds or internally as a decoction that is given to diabetic patients. Chemical-analytical and pharmacological investigations regarding the bark are not sufficiently available. We focused on the isolation of flavan-3-ols from the methanolic extract and their contribution to the described traditional uses in wound healing and diabetes treatment. Therefore, an antibacterial assay and an α-glucosidase assay were performed. The isolation process was performed by a combination of Sephadex®-, MCI®-Gel-, and RP-18 chromatography. The structures of the isolated compounds were elucidated by 1H- and 13C-NMR-spectroscopy including COSY, ROESY, HSQC, and HMBC methods. Optical characterization was performed by polarimetry and circular dichroism. Two monomeric, seven dimeric, six trimeric, and one tetrameric flavan-3-ols were found including one dimer and three trimers with rare epiafzelechin units. Two compounds were isolated for the first time. A fraction containing higher oligomeric and polymeric proanthocyanidins (PAs) was examined by 13C NMR spectroscopy and revealed an average degree of polymerization of 8-9. PA with cis-configurated subunits predominated at 90 % and the presence of further monohydroxylated flavan-3-ols was revealed. Minimal inhibitory concentrations (MICs) were investigated by the serial microdilution broth assay with Staphylococcus aureus. The bacterial suspension was inoculated on agar plates for determining the MICs. The α-glucosidase assay was performed in 96 well plates with α-glucosidase from Bacillus stearothermophilus. For the detection of enzyme inhibition, p-nitrophenyl-α-d-glucopyranoside was used as a substrate and after incubation absorbance was measured at 405 nm. Antibacterial effects were only found for fractions enriched with PAs or containing higher oligomeric and polymeric flavan-3-ols. All tested substances showed high α-glucosidase inhibition. Whereby 4β→8 conjugated dimers and the monomers showed the lowest inhibition, procyanidin (PC) B5 as 4β→6 conjugated and cinnamtannin A2 as tetrameric flavan-3-ol showed the highest. PAs with epiafzelechin units are rarely found in nature but their reoccurring appearance in B. longifolia could be characteristic of this plant. For its traditional uses, the antibacterial activity of the PA-enriched fractions could contribute to the wound healing process when applied to the injured skin. Moreover, all tested substances and fractions showed α-glucosidase inhibition, which could also explain the use of a decoction in the treatment of diabetes. In conclusion, pharmacological investigations could provide scientific evidence for traditional uses of B. longifolia.

Taxus wallichiana Zucc. (Himalayan Yew): A Medicinal Plant Exhibiting Antibacterial Properties

Taxus wallichiana Zucc. or the Himalayan yew is a gymnosperm growing along the Himalayan region of India and adjacent countries. Traditionally, this plant was extensively used by indigenous people for folk medicines for treating various diseases such as fever, headache, diarrhoea, fractures, problems of the nervous system etc. It is also practiced in the Unani system of medicine. The plant is rich in various bio-organic compounds and natural products, such as hydrocarbons, glycosides, flavonoids, phenol, tannins, terpenoids etc. In this research work, an effort has been made to highlight the valuable properties of T. wallichiana. The present study was undertaken to evaluate the secondary metabolites (flavonoids, glycosides, phenols, saponins, tannins, terpenoids) and antibacterial potential of methanol extracts and the subsequent fractions of the leaves and fruit of Taxus wallichiana Zucc. In order to rationalise traditional use, methanol extracts from the leaves and fruit of Taxus wallichiana Zucc. were tested against five bacteria using the agar well diffusion method. Ciprofloxacin was used as a standard. All extracts and fractions displayed significant anti-microbial effects. Taxus wallichiana leaves and fruit methanolic extracts showed a maximum zone of inhibition with Bacillus subtilis, which is 18 ± 0.0 mm, and Staphylococcus aureus, 19 ± 0.2 mm. The methanolic extracts of the leaves of Taxus wallichiana tested positive for glycosides, flavonoids, phenol, tannins and terpenoids, whereas the T. wallichiana fruit tested positive for flavonoids, saponins and terpenoids. According to the research findings, it was identified that the methanol extract of Taxus wallichiana exhibited quite high anti-microbial activity as well as secondary metabolites, and with this quality, together with lots of its other values, this plant can very well become a source of medicine for the better management of a large number of diseases, including cancer, and value-added products.

Biochemical and antioxidant activity of wild edible fruits of the eastern Himalaya, India

The eastern Himalayas, one of the important hotspots of global biodiversity, have a rich diversity of wild edible fruit trees. The fruits of these tree species have been consumed by the tribal people since time immemorial. However, there is limited information available on the biochemical and antioxidant properties of the fruits. Therefore, the present investigation was undertaken to study the physico-chemical and antioxidant properties of the nine most important wild fruit trees. Among the species, Pyrus pashia had the maximum fruit weight (37.83 g), while the highest juice (43.72%) and pulp content (84.67%) were noted in Haematocarpus validus and Myrica esculenta, respectively. Maximum total soluble solids (18.27%), total sugar (11.27%), moisture content (88.39%), ascorbic acid content (63.82 mg/100 g), total carotenoids (18.47 mg/100 g), and total monomeric anthocyanin (354.04 mg/100 g) were recorded in H. validus. Docynia indica had the highest total phenolic content (19.37 mg GAE/g), while H. validus recorded the highest total flavonoids and flavanol content. The antioxidant activities of the different fruits ranged from 0.17 to 0.67 IC50 for DPPH activity and 3.59-13.82 mg AAE/g for FRAP. These fruits had attractive pigmentation of both pulp and juice and were a good potential source for the extraction of natural edible color in the food industry. The fruits also possess high market prices; Prunus nepalensis fetched $ 34.10-$ 141.5 per tree. Therefore, these fruits are rich sources of antioxidants, pigments and have a high market value for livelihood and nutritional security.

Pharmacological and phytochemical potential of Rubus ellipticus: a wild edible with multiple health benefits

OBJECTIVES

Rubus ellipticus (family Rosaceae) is used for its delicious edible fruits in the Himalayan region and other parts of the globe. However, the full potential of the species is yet to be harnessed. The current review focuses on the phytochemical, traditional uses, morphological, molecular and pharmacological potential of R. ellipticus.

KEY FINDINGS

The review of the literature reveals that many health-promoting compounds of R. ellipticus have been reported from the species along with the different biological properties, such as nephroprotective, anti-inflammatory, analgesic, anti-pyretic, anti-proliferative, cytotoxicity, anti-cancer, wound healing, anti-fertility, anti-plasmodial, anti-microbial and antioxidant. Traditionally, it is used in many formulations, which are validated through primary pharmacological assays. However, several medicinal properties are still need to be validated through detailed pharmacological and clinical studies.

SUMMARY

All the information is available in a scanty form, and the complete information is missing on a single platform. Such type of information will help researchers to better utilize the available data for initiating future research on the species as it has the potential to contribute to the food and pharmaceutical industry. The review highlights the need for further studies on the species to harness its potential in nutraceutical, functional food, energy supplement, and beneficial therapeutic drug development program.

Transcriptome repository of North-Western Himalayan endangered medicinal herbs: a paramount approach illuminating molecular perspective of phytoactive molecules and secondary metabolism

Medicinal plants of the North-Western Himalayan region are known for their unprecedented biodiversity and valuable secondary metabolites that are unique to this dynamic geo-climatic region. From ancient times these medicinal herbs have been used traditionally for their therapeutic potentials. But from the last 2 decades increasing pharmaceutical demand, illegal and unorganized trade of these medicinal plants have accelerated the rate of over-exploitation in a non-scientific manner. In addition, climate change and anthropogenic activities also affected their natural habitat and driving most of these endemic plant species to critically endangered that foresee peril of mass extinction from this eco-region. Hence there is an urgent need for developing alternative sustainable approaches and policies to utilize this natural bioresource ensuring simultaneous conservation. Hither, arise the advent of sequencing-based transcriptomic studies significantly contributes to better understand the background of important metabolic pathways and related genes/enzymes of high-value medicinal herbs, in the absence of genomic information. The use of comparative transcriptomics in conjunction with biochemical techniques in North-Western Himalayan medicinal plants has resulted in significant advances in the identification of the molecular players involved in the production of secondary metabolic pathways over the last decade. This information could be used to further engineer metabolic pathways and breeding programs, ultimately leading to the development of in vitro systems dedicated to the production of pharmaceutically important secondary metabolites at the industrial level. Collectively, successful adoption of these approaches can certainly ensure the sustainable utilization of Himalayan bioresource by reducing the pressure on the wild population of these critically endangered medicinal herbs. This review provides novel insight as a transcriptome-based bioresource repository for the understanding of important secondary metabolic pathways genes/enzymes and metabolism of endangered high-value North-Western Himalayan medicinal herbs, so that researchers across the globe can effectively utilize this information for devising effective strategies for the production of pharmaceutically important compounds and their scale-up for sustainable usage and take a step forward in omics-based conservation genetics.

Nitric Oxide as a Target for Phytochemicals in Anti-Neuroinflammatory Prevention Therapy

Nitric oxide (NO) is a neurotransmitter that mediates the activation and inhibition of inflammatory cascades. Even though physiological NO is required for defense against various pathogens, excessive NO can trigger inflammatory signaling and cell death through reactive nitrogen species-induced oxidative stress. Excessive NO production by activated microglial cells is specifically associated with neuroinflammatory and neurodegenerative conditions, such as Alzheimer’s and Parkinson’s disease, amyotrophic lateral sclerosis, ischemia, hypoxia, multiple sclerosis, and other afflictions of the central nervous system (CNS). Therefore, controlling excessive NO production is a desirable therapeutic strategy for managing various neuroinflammatory disorders. Recently, phytochemicals have attracted considerable attention because of their potential to counteract excessive NO production in CNS disorders. Moreover, phytochemicals and nutraceuticals are typically safe and effective. In this review, we discuss the mechanisms of NO production and its involvement in various neurological disorders, and we revisit a number of recently identified phytochemicals which may act as NO inhibitors. This review may help identify novel potent anti-inflammatory agents that can downregulate NO, specifically during neuroinflammation and neurodegeneration.

Phytochemical investigation and potential pharmacologically active compounds of Rumex nepalensis: an appraisal

Background

Rumex nepalensis, a widely known traditional medicinal plant and is used as the source of medicines and human diet in various communities. Currently, the phytochemical investigation and pharmacological studies of R. nepalensis are of significant research interest. Therefore, the current review is mainly focused on the phytochemical investigation and pharmacological applications of R. nepalensis

Main body

Various secondary metabolites like emodin, endocrocin, chrysophanol, neopodin, physcion, torachrysone, aloesin, catechin, quercetin, resveratrol, and their derivatives were isolated from root and aerial parts of the plant. Both isolated compounds and extracts from R. nepalensis are reported to have pharmacological activities such as anti-inflammatory, antioxidant, antimicrobial, wound healing, and anti-plasmodial activities

Conclusions

Different parts of R. nepalensis have ethnomedicinal importance. R. nepalensis is one of the potential sources of pharmacologically active extracts and isolated compounds. In future R. nepalensis can play a vital role for the preparation of modern drugs.

Graphical abstract

Characterization of defensive cadinenes and a novel sesquiterpene synthase responsible for their biosynthesis from the invasive Eupatorium adenophorum

Eupatorium adenophorum is a malignant invasive plant possessing extraordinary defense potency, but its chemical weaponry and formation mechanism have not yet been extensively investigated. We identified six cadinene sesquiterpenes, including two volatiles (amorpha-4,7(11)-diene and (-)-amorph-4-en-7-ol) and four nonvolatiles (9-oxo-10,11-dehydroageraphorone, muurol-4-en-3,8-dione, 9-oxo-ageraphorone and 9β-hydroxy-ageraphorone), as the major constitutive and inducible chemicals of E. adenophorum. All cadinenes showed potent antifeedant activity against a generalist insect Spodoptera exigua, indicating that they have significant defensive roles. We cloned and functionally characterized a sesquiterpene synthase from E. adenophorum (EaTPS1), catalyzing the conversion of farnesyl diphosphate to amorpha-4,7(11)-diene and (-)-amorph-4-en-7-ol, which were purified from engineered Escherichia coli and identified by extensive nuclear magnetic resonance (NMR) spectroscopy. EaTPS1 was highly expressed in the aboveground organs, which was congruent with the dominant distribution of cadinenes, suggesting that EaTPS1 is likely involved in cadinene biosynthesis. Mechanical wounding and methyl jasmonate negatively regulated EaTPS1 expression but caused the release of amorpha-4,7(11)-diene and (-)-amorph-4-en-7-ol. Nicotiana benthamiana transiently expressing EaTPS1 also produced amorpha-4,7(11)-diene and (-)-amorph-4-en-7-ol, and showed enhanced defense function. The findings presented here uncover the role and formation of the chemical defense mechanism of E. adenophorum - which probably contributes to the invasive success of this plant - and provide a tool for manipulating the biosynthesis of biologically active cadinene natural products.

Neuroprotective potential of Myrica esulenta in Haloperidol induced Parkinson's disease

BACKGROUND

Myrica esculenta is a notable therapeutic plant widely utilized in Indian system of medicine. Ayurvedic literature reported fruit and bark of this plant is used in gulma, jvara, arsa, grahani, pandu roga, hrillasa, mukha roga, kasa, svasa, agnimandhya, aruchi, meha, and kantharoga.

OBJECTIVE

The present study aimed to investigate the neuroprotective potential of "Himalayan Bayberry" (Myrica esculenta Buch.-Ham. ex D. Don) leaves methanol extract in Parkinson's disease induced by haloperidol.

MATERIALS AND METHODS

The present investigation was completed in wistar rats, in which Parkinson's disease (PD) was induced with haloperidol 1 mg/kg, intraperitoneally. The rats were randomly divided into six gatherings and the test animals received the methanolic extract of M. esculenta (MEME) at a dose of 50, 100 and 200 mg/kg, orally for one week. Various behavioural, biochemical and histopathological parameters were estimated in haloperidol exposed rats.

RESULTS

MEME demonstrated significant and dose-dependent increment in behavioural activity and improved muscle coordination. The significant diminution in malonaldehyde level while improved the level of antioxidant enzymes like catalase, superoxide dismutase and reduced glutathione in extract treated group were observed as compared to the control group. Histopathological changes revealed MEME significantly reduced haloperidol-induced damage in the substantia nigra and there was very little neuronal atrophy.

CONCLUSION

The outcomes showed the defensive role of M. esculenta against PD. The mechanism of protection may be due to an escalation of cellular antioxidants.

Evaluation of Abortifacient Effect of Rumex nepalensis Spreng Among Pregnant Swiss Albino Rats: Laboratory-Based Study

Background

Rumex nepalensis Spreng (Amharic: Yewsha Tult) belongs to the Polygonaceae (buckwheat) family. In Ethiopia, the plant is traditionally used for the treatment of stomach ache, tonsillitis, ascariasis, uterine bleeding, etc. An ethnobotanical study from Mizan–Tepi University also reported the use of the plant by “Shekicho” people as an abortifacient. As a result, this study aimed at the assessment of the outcome of hydro-ethanolic leaves extract of R. nepalensis on Swiss albino pregnant rats and confirm its abortifacient activity.

Methods

The hydro-alcoholic leaves extract of Rumex nepalensis Spreng was evaluated for its abortifacient activity in Swiss albino rats. The mature female rats were mated overnight to male rats in mating cages. Two different dosage regimens (300 mg/kg, 600 mg/kg) of the extract were administered. Laparotomy was performed on the rats to assess the uterus and ovary, the viable, non-viable, adsorbing sites, and corpora lutea. Differences between the experimental and control groups were compared using one-way analysis of variance (ANOVA), followed by Dunnett’s T-test to determine their level of significance.

Results and Discussion

This study revealed that Rumex nepalensis Spreng had anti-implantation and abortifacient activities at both 300 and 600 mg/kg doses, which was statistically significant as compared with the controls. It was relatively safe up to the dose of 5000 mg/kg, where no mortality and organ toxicity were manifested. Phytochemicals identified were alkaloids, flavonoids, saponins, tannins, steroids, and anthraquinones.

Conclusion

In general, our study showed that R. nepalensis had a significant abortifacient activity that testifies its traditional dibs. Therefore, the use of this plant should be avoided in pregnant women to minimize unintended abortion and further studies are needed to know its mechanism of activity and to identify the phytochemicals corresponding to this activity. Checking its efficacy on other species is also needed.

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Traditional Uses of Medicinal Plants by Ethnic People in the Kavrepalanchok District, Central Nepal

In rural areas of Nepal, where it is difficult to get access to Government health care facilities, people depend on medicinal plants and local healers for health problems. This study concerns an ethnobotanical survey of the Kavrepalanchok District, reporting some unusual uses of medicinal plants and original recipes. A total of 32 informants were interviewed, 24 of them being key informants. Ethnobotanical uses concerned 116 taxa, of which 101 were medicinal plants, with the most representative species belonging to Asteraceae, Fabaceae, Lamiaceae, and Zingiberaceae. Ethnobotanical indexes were used to evaluate the ethnopharmacological importance of each plant species and the degree of agreement among the informants’ knowledge. Informant consensus factor (Fic) showed that the fever category had the greatest agreement. Highest fidelity level (FL) values were found for Calotropis gigantea used for dermatological diseases, Drymaria cordata for fever, Mangifera indica and Wrightia arborea for gastrointestinal disorders. Data document the richness of the local flora and the traditional knowledge on medicinal plant species used by ethnic communities in rural areas. The active involvement of local populations in the conservation and management of medicinal plant species will encourage future projects for the sustainable development of the biological and cultural diversity of these rural areas of Nepal.

Physical and chemical characteristics of soils in Ephedra gerardiana and E. pachyclada habitats of Kali Gandaki Valley in Central Nepal

In the Kali Gandaki Valley in Central Nepal, Ephedra gerardiana and E. pachyclada show species specificity for physical and chemical characteristics of soils. Here, the relationship between soil characteristics and ephedrine and pseudoephedrine contents was examined. E. gerardiana grew in moist alpine scrub and upper alpine meadow from 3735 to 4156 m a.s.l., while E. pachyclada grew in the lower Caragana steppe and dry alpine scrub from 2629 to 3671 m a.s.l. The soil texture of E. gerardiana and E. pachyclada collection sites were classified as loam or sandy loam mainly composed of sand and silt. Loss on ignition (%) of soil in E. gerardiana habitats (28.4-35.0%) was markedly higher than for that in E. pachyclada habitats (14.2-17.2%). E. pachyclada soil (pH 8.4-9.2) was more alkaline than that for E. gerardiana (pH 8.5). The five ions (Cl^-, SO₄^2-, Ca²⁺, Mg²⁺, and Na⁺) in soil of E. pachyclada (Cl^-, 0.01-18.97 mmol/100 g dry soil weight; SO₄^2-, 1.95-83.33; Ca²⁺, 3.79-77.91; Mg²⁺, 1.28-27.9; Na⁺, 0.94-34.49) were markedly higher than those of E. gerardiana (Cl^-, 0.18-0.29; SO₄^2-, 0.07-0.08; Ca²⁺, 4.19-4.59; Mg²⁺, 0.22-0.58; Na⁺, 0.93-1.40). The main factor contributing to strongly alkali soils for each species was different between E. gerardiana and E. pachyclada: CaCO₃ for E. gerardiana and CaSO₄, MgSO₄, NaCl, or a combination of these for E. pachyclada. The total ephedrine and pseudoephedrine content in E. gerardiana and E. pachyclada ranged from 1.67-1.88%DW and 1.95-4.80%DW, respectively. Both E. gerardiana and E. pachyclada were amenable for use a raw material source for extraction of ephedrine and pseudoephedrine, and the ephedrine content of both species showed a statistically significantly positive correlation with Mg²⁺ and Na⁺ contents of the soil.

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.

Review on antibacterial activity of Himalayan medicinal plants traditionally used to treat pneumonia and tuberculosis

Objectives

The main objective of this review was to collect scattered literature on ethnomedicinal plants used to treat pneumonia and tuberculosis in the Himalayan region and their in-vitro validation against bacterial pathogens.

Key findings

Current review contains information on ethnomedicines of total 137 plants from Himalaya region. Out of these, 59 plants have been studied in vitro against bacteria while seven plants extracts have been checked for their toxicological effects. The most commonly used plant families for pneumonia and tuberculosis therapy in the study region were Asteraceae, Bignoniaceae and Fabaceae (seven plants in each); of these, Curcuma longa L., Punica granatum L. and Justicia adhatoda L. carried the most inhibiting potential against Staphylococcus aureus and Streptococcus pneumoniae while that of Acalypha indica L. against Mycobacterium tuberculosis. Different compounds such as ascorbic acid, curcumin, vasicine, piperine, quercetin, myricetin and gallic acid being reportedly isolated from these plants possess antibacterial potential.

Summary

Himalayan region has variety of ethnomedicinal plants used against pneumonia and tuberculosis; however, studies on in-vivo activity, toxicology and mechanism of action are very limited. Hence, detailed investigation on these aspects needs to be carried out for the development of novel antibacterial drugs from the studied plant species.

Ethnomedicinal Uses of Plant Resources in the Machhapuchchhre Rural Municipality of Kaski District, Nepal

Background: Medicinal plants are being used by the majority of the population throughout the world for their primary health care needs. The reliance is also prevalent in Nepal, aided by its ethnic and biological diversity. This study aimed to catalogue the ethnomedicinal knowledge of plants used by local people of Machhapuchchhre Rural Municipality of Kaski district. Methods: Data were collected between February 2017 and April 2018 from eight different villages of the Kaski district by using semi-structured interviews, guided field works, focus group discussions, and in-depth interviews. The reported traditional uses were supported by local assistants, cataloguing vernacular names and crosschecking with the earlier published and gray literature. Results: A total of 105 medicinal plants, belonging to 58 families and 99 genera were documented to treat 70 different diseases and ailments. The highest numbers of plants (37) were used for gastrointestinal disorders and the lowest (4) were used for female genital disorders. Commonly used parts were underground portions (28 species) followed by fruits and seeds (25 species each). The most preferred dosage form was juice, used for 50 ailments, and the oral route was the most favored route of administration (77 species). The medicinal properties of 22 plant species were found hitherto unreported in the district. Conclusions: The study area was found to be rich in plant resources and the people have ample knowledge on the use of medicinal plants. Due to a lack of proper documentation, conservation, and cultivation practices, valuable plant species are at risk of extinction. Thus, appropriate conservation measures and scientific assessment of plant-lore in the district is immediately required.

Myrica esculenta Buch.-Ham. ex D. Don: A Natural Source for Health Promotion and Disease Prevention

Myrica esculenta (Myricaceae) is a popular medicinal plant most commonly found in the sub-tropical Himalayas. It is widely used in folk medicine to treat several ailments such as asthma, cough, chronic bronchitis, ulcers, inflammation, anemia, fever, diarrhea, and ear, nose, and throat disorders. Due to its multidimensional pharmacological and therapeutic effects, it is well recognized in the ayurvedic pharmacopeia. However, the recent upsurge in M. esculenta use and demand has led to illicit harvesting by the horticultural trade and habitat loss, pushing the plant to the brink of extinction. Thus, the present review aims to provide updated information on M. esculenta botany, ethnomedicinal uses, phytochemistry, pharmacological effects, toxicity, and conservation methods, as well as also highlight prospective for future research. Particular emphasis is also given to its antioxidant potential in health promotion. In-depth literature was probed by searching several sources via online databases, texts, websites, and thesis. About 57 compounds were isolated and identified from M. esculenta, and the available reports on physicochemical parameters, nutritional and high-performance thin-layer chromatography analysis of bioactive plant parts are portrayed in a comparative manner. Friendly holistic conservation approaches offered by plant biotechnology applications, such as micropropagation, germplasm preservation, synthetic seed production, and hairy root technologies are also discussed. Nonetheless, further studies are needed to propose the mechanistic role of crude extracts and other bioactives, and even to explore the structure–function relationship of active components.

Medicinal plants brought by Indian indentured immigrants: A comparative review of ethnopharmacological uses between Mauritius and India

ETHNOPHARMACOLOGICAL RELEVANCE

Mauritius is famous for its floricultural diversity and traditions practiced across the island by various ethnic groups. During the British rule in the 1835s, Indian indentured labourers migrated to Mauritius and played a very important role in shaping the Mauritian culture. They brought along their high heritage of traditional knowledge of certain medicinal herbs and spices. Nonetheless, there has been no comparative study to investigate whether these past traditional knowledge are still preserved in Mauritius and India.

AIM OF THE STUDY

To document and compare the traditional uses of medicinal herbs and spices brought by Indian indentured labourers with their current uses in Mauritius and India, and to review pharmacological studies of such plants.

MATERIALS AND METHODS

Locally published textbooks, research dissertations, and relevant records from the 'Mauritiana' section of the University of Mauritius library were scrutinised for possible early records of such herbs and spices brought by Indian indentured immigrants. Field trips and site visits to Mauritius Herbarium and The National Folk Museum were conducted to gather data on their traditional uses as practiced by the Indian indentured immigrants. A literature search was performed to gather the current ethnomedicinal uses of these plants in Mauritius and India using key databases such as ScienceDirect and PubMed, as well as thesis from local university website. Pharmacological studies on these plants were also reviewed in an attempt to compare the ethnomedicinal uses against reported ailments.

RESULTS

Indian labourers brought 18 medicinal plants for medicinal purposes as documented at the folk museum of Indian Immigration. Piper betle L., Azadirachta indica A. Juss., and Curcuma longa L. were common plants used by Indian indentured immigrants against a wide range of ailments. Data obtained from recent ethnomedicinal surveys revealed that A. indica and C. longa were the most traditionally used plants in India, while in Mauritius, C. longa was the most popular plant followed by Allium sativum L. and Ocimum tenuiflorum L. It was also found that all these plants are currently being used against a wide range of diseases in both countries. In addition, several studies have highlighted the pharmacological properties such as analgesic, anti-inflammatory, anti-microbial, anti-pyretic, and anti-diabetic for some plants.

CONCLUSION

This investigation can be considered as a first attempt to document and compare traditional knowledge of medicinal plants brought by Indian immigrants. We observed that some of these knowledge are preserved and still practiced in Mauritius. It is anticipated that this study will revive the interest in safeguarding and promoting the ancestral knowledge on the uses of such plants.

High altitude species, high profits: Can the trade in wild harvested Fritillaria cirrhosa (Liliaceae) be sustained?

ETHNOPHARMACOLOGICAL RELEVANCE

Fritillaria cirrhosa D. Don bulbs contain alkaloids and are one of the most intensively exploited alpine Himalayan medicinal species. In terms of proprietary medicines, our study shows that 210 F. cirrhosa products are offered by 46 suppliers, most of which (44) are situated in China and two in Nepal. A widespread commercial use is as one of the main ingredients in cough syrups. A well known example is "Nin Jiom Pei Pa Koa Herbal Cough & Throat Syrup", which typically contains more F. cirrhosa than any other herbal ingredient in the formulation. The biggest market for F. cirrhosa bulbs is China, where demand exceeds supply of this wild harvested species for use in traditional Chinese medicine (TCM). Cross-border trade from Nepal to China occurs in significant quantities. Bhutan also imports F. cirrhosa bulbs from Nepal. In addition, F. cirrhosa is registered as an active ingredient in traditional herbal medicinal preparations in Australia, Canada, Hong Kong SAR, Malaysia, Republic of Korea, Singapore and Taiwan. There is also an export trade in F. cirrhosa to Europe. Assessing how much F. cirrhosa is traded is complex, however, due to a "look-alike" challenge, as nine Chinese Fritillaria species are traded in Europe (Fritillaria cirrhosa, F. delavayi, F. hupehensis, F. pallidiflora, F. przewalskii, F. thunbergii, F. unibracteata, F. ussuriensis and F. walujewii).

AIMS OF THE STUDY

The aims of this review were to assess the scale of the global trade in F. cirrhosa, and to synthesise studies of the impacts of wild harvest on F. cirrhosa populations and on the extent of emerging cultivation initiatives as an alternative to wild harvest.

METHODS

Firstly, we reviewed published information on studies on impacts of wild F. cirrhosa harvest from across the geographic range of this species. Secondly, global trade data for F. cirrhosa were analysed.

RESULTS

The principal demand for F. cirrhosa bulbs is in China, where hundreds of different companies produce Fritillaria preparations. Trade data also show that in 2013, China exported over 44 tonnes of F. cirrhosa bulbs to Taiwan and 26.7 tonnes to the Republic of Korea. Extensive commercial use and limited wild stocks result in a high price (2000 - 3800 CNY per kg (around US$ 303 -560 per kg in 2017)) for F. cirrhosa bulbs. Prices of cultivated Fritillaria bulbs are much lower (600-680 CNY per kg in 2017) than wild harvested bulbs. But due to very specific growth requirements of F. cirrhosa, cultivation is not yet able to meet total demand. The consequence is continued exploitation of wild stocks. At the same time, however, an increasing proportion of the demand is met by cultivation of alternative Fritillaria species that are easier to grow than F. cirrhosa. The air-dry mass of F. cirrhosa bulbs varies between 0.0917 and 0.1116 g per bulb. This represents 8960 - 10,900 bulbs/kg or 8.9 - 10.9 million bulbs per tonne. Current demand therefore represents billions of bulbs per year.

CONCLUSIONS

Demand for F. cirrhosa bulbs, particularly from China, makes this species one of the most intensively harvested alpine Himalayan medicinal bulbs. Although F. cirrhosa is listed as a Class III protected species in China, billions of these tiny, wild harvested bulbs are sold per year. Due to demand exceeding supply, the price of F. cirrhosa bulbs has increased dramatically. Between 2002 and 2017, for example, the price of wild harvested F. cirrhosa bulbs increased over nine-fold, from the equivalent of US$60 in 2002 to US$560 per kg in 2017. To date, cultivation has been unable to meet the entire market demand for F. cirrhosa bulbs, although other Fritillaria species are successfully cultivated on a larger scale.

Herbal Medicine in Ischemic Stroke: Challenges and Prospective

Herbal medicines, mainly of plant source, are invaluable source for the discovery of new therapeutic agents for all sorts of human ailments. The complex pathogenesis of stroke and multifactorial effect of herbal medicine and their active constituents may suggest the promising future of natural medicine for stroke treatment. Anti-oxidant, anti-inflammatory, anti-apoptotic, neuroprotective and vascular protective effect of herbal medicines are believed to be efficacious in stroke treatment. Herbs typically have fewer reported side effects than allopathic medicine, and may be safer to use over longer period of time. Herbal medicines are believed to be more effective for the longstanding health complaints, such as stroke. Several medicinal plants and their active constituents show the promising results in laboratory research. However failure in transformation of laboratory animal research to the clinical trials has created huge challenge for the use of herbal medicine in stroke. Until and unless scientifically comprehensive evidence of the efficacy and safety of herbal medicine in ischemic stroke patients is available, efforts should be made to continue implementing treatment strategies of proven effectiveness. More consideration should be paid to natural compounds that can have extensive therapeutic time windows, perfect pharmacological targets with few side effects. Herbal medicine has excellent prospective for the treatment of ischemic stroke, but a lot of effort should be invested to transform the success of animal research to human use.

Biofilm reduction, cell proliferation, anthelmintic and cytotoxicity effect of green synthesised silver nanoparticle using Artemisia vulgaris extract

Infectious diseases are caused by etiological agents. Nanotechnology has been used to minimise the effect of clinical pathogens which have resistance to antibiotics. In current research synthesis, characterisation and biological activities of green synthesised nanoparticles using Artemisia vulgaris extract have been done. The characterisation of AgNPs was carried out using Fourier transform infrared spectroscopy, UV‐Vis spectrophotometry, and scanning electron microscopy. Anti‐biofilm, cell viability, antibacterial, brine shrimp lethality, and deoxyribonucleic acid protection effects have been screened. UV‐Vis spectra showed the absorption peak of synthesised nanoparticles at 400 nm. FT‐IR indicated the involvement of the functional group in the preparation of AgNPs. SEM showed the spherical shape of AgNPs with 30 nm diameter. Biological screening results revealed the antibacterial effect against clinical bacterial pathogens. Biofilm reduction and cell viability assay also supported the antibacterial effect. Cytotoxicity effect was recorded as 100% at 200 μg/ml through brine shrimp lethality assay. Protein kinase inhibition zones recorded for AgNPs (16 mm bald) compared with A. vulgaris extract (11 mm bald). It has been concluded that green synthesised AgNPs are more effective against infectious pathogens and could be used as a potential source for therapeutic drugs.

Anti-neuroinflammatory and neuroprotective effects of the Lindera neesiana fruit in vitro

BACKGROUND

Lindera neesiana Kurz (Lauraceae), popularly known as Siltimur in Nepal, is an aromatic and spicy plant with edible fruits. It is a traditional herbal medicine widely used for the treatment of diarrhea, tooth pain, headache, and gastric disorders and is also used as a stimulant.

PURPOSE

The aim of the present study was to examine in vitro cytoprotective, anti-neuroinflammatory and neuroprotective potential of an aqueous extract of L. neesiana (LNE) fruit using different central nervous system (CNS) cell lines.

METHODS

In order to study the neuroprotective potential of LNE, we used three different types of CNS cell lines: murine microglia (BV2), rat glioma (C6), and mouse neuroblastoma (N2a). Cell viability was assessed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reagent, and prostaglandin E2 (PGE2), tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, and nerve growth factor (NGF) release in the culture media was determined using enzyme linked immunosorbent assay (ELISA) kits. Western blot analysis was performed to determine the protein expression of inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX2), mitogen activated protein kinase (MAPK) family proteins, Bax, B cell lymphoma (BCL)-2, and cleaved caspase 3. Neurite outgrowth was determined using the IncuCyte imaging system.

RESULTS

LNE treatment not only reduced nitric oxide (NO) production in a dose-dependent manner, but also significantly reduced proinflammatory cytokines, iNOS and COX-2 production by lipopolysaccharide (LPS) stimulated BV-2 cells. LNE increased the expression of phosphorylated (p)-extracellular signal-regulated kinase (ERK), whereas p-p38 and p- janus kinase (JNK) expression was significantly decreased in activated microglia. Furthermore, LNE increased cell viability of N2a cells, which was accompanied by decreased caspase-3 expression and the ratio of Bax/Bcl2 protein expression as well as increased NGF and neurite outgrowth, suggesting its neuroprotective potential against LPS-induced effects. Additionally, LNE substantially increased nuclear factor erythroid 2-related factor 2 (Nrf2) secretion in N2a cells and inhibited lipid dehydrogenase (LDH) release in H2O2-stimulated BV2 cells demonstrating the strong anti-inflammatory and antioxidant effects of LNE in CNS cell lines.

CONCLUSION

Here we found that water the soluble extract of LNE has promising anti-neuroinflammation and anti-apoptotic properties and identify LNE as a potential natural candidate for neuroprotection.

Himalayan Aromatic Medicinal Plants: A Review of their Ethnopharmacology, Volatile Phytochemistry, and Biological Activities

Aromatic plants have played key roles in the lives of tribal peoples living in the Himalaya by providing products for both food and medicine. This review presents a summary of aromatic medicinal plants from the Indian Himalaya, Nepal, and Bhutan, focusing on plant species for which volatile compositions have been described. The review summarizes 116 aromatic plant species distributed over 26 families.

Review on ethnomedicinal, phytochemical and pharmacological evidence of Himalayan anticancer plants

ETHNOPHARMACOLOGICAL RELEVANCE

Himalayan plants have 6500 years old history of being using as traditional medicines. Inhabitants of the region use indigenous knowledge for the preparation of various herbal recipes in order to treat different kinds of cancer. The aim of this review is to provide ethnopharmacological, phytochemical and toxicological overview of Himalayan medicinal plants having anticancer potential. This will provide a baseline for the discovery of new anticancer drugs.

MATERIAL AND METHODS

In total, 155 articles (mostly published) were reviewed by using online search engines like PubMed, Scopus, Google Scholar, Web of Science, and floras of different Himalayan countries.

RESULTS

Sixty four anticancer medicinal plants were documented belonging to 59 genera and 37 families. Majority of 42 plants were reported from India followed by 17 from Pakistan. Traditional healers in the region mostly prepare ethnomedicinal recipes from leaves (32% plants) and roots (30% plants) in the form of decoction. Thirty plants had reported anticancer related pharmacological and phytochemical activities. Of these, 27 plants were tested in-vitro on cellular models while 16 plants for in-vivo activities. Methanolic, ethanolic and ethylacetate extracts of plants have shown excellent cytotoxic activities against breast, stomach and blood cancers' cell lines. Total 14 active secondary metabolites including phenolic compounds, glycosides, terpenoids, lignans and alkynes from the studied plants were reported active against different cancer cell lines. Plants such as Bergenia ciliata, Argemone mexicana, Capsella bursa-pastoris and Centella asiatica had toxic effects on the living systems at higher doses when studied in-vivo.

CONCLUSIONS

Certain Himalayan medicinal plants present therapeutic properties against different types of cancer. However, not all of the plants have been fully analysed for in vitro, in vivo and toxicological activities, and isolation of secondary metabolites. Further ethnomedicinal studies would help in identifying potential medicinal plant species in the region to be analysed for detailed anticancer activities.

Traditional uses of medicinal plants in gastrointestinal disorders in Nepal

ETHNOPHARMACOLOGICAL RELEVANCE

Gastrointestinal disorders cause morbidity and can lead to mortality, especially in the developing world where sanitation is deficient. A large part of the human population relies on medicinal plants for treating various diseases, including gastrointestinal disorders. The present review summarizes the traditional uses of medicinal plants of Nepal used to treat gastrointestinal disorders, and evaluates their bio-efficacy based on a review of the available phytochemical and pharmacological literature.

MATERIAL AND METHODS

We searched different electronic databases and libraries for the literature on medicinal plants used in Nepal to treat gastrointestinal disorders. For each species, we also searched the literature for information on conservation status, as well as for phytochemical and pharmacological studies in support of the ethnobotanical information. We used principal component analysis to explore the relation among disorders and plant families, plant life forms, plant parts and preparation modes. We also performed permutation tests to determine if botanical families were used more often than expected considering their availability in the Nepali flora.

RESULTS

We documented a total of 947 species belonging to 158 families and 586 genera used to treat gastrointestinal disorders in Nepal. Diarrhea was the disorder treated by the highest number of species (348), followed by stomachache (340) and dysentery (307). Among the reported species, five were endemic to Nepal, whereas 16 orchid species were protected under CITES Appendices II and III. The randomization test showed that species belonging to 14 families were used less often than expected, whereas plants belonging to 25 families were used more often than expected. The PCA scatter plot showed distinct groups of gastrointestinal disorders treated with similar plant life forms, plant parts, and/or preparation modes. We found 763 phytochemical studies on 324 species and 654 pharmacological studies on 269 species.

CONCLUSION

We showed the diversity and importance of medicinal plants used to treat gastrointestinal disorders in the traditional health care system of Nepal. As such disorders are still causing several deaths each year, it is of the utmost importance to conduct phytochemical and pharmacological studies on the most promising species. It is also crucial to increase access to traditional medicine, especially in rural areas. Threatened species need special attention for traditional herbal medicine to be exploited sustainably.

Medicinal plants used by the Tamang community in the Makawanpur district of central Nepal

BACKGROUND

We can conserve cultural heritage and gain extensive knowledge of plant species with pharmacological potential to cure simple to life-threatening diseases by studying the use of plants in indigenous communities. Therefore, it is important to conduct ethnobotanical studies in indigenous communities and to validate the reported uses of plants by comparing ethnobotanical studies with phytochemical and pharmacological studies.

MATERIALS AND METHODS

This study was conducted in a Tamang community dwelling in the Makawanpur district of central Nepal. We used semi-structured and structured questionnaires during interviews to collect information. We compared use reports with available phytochemical and pharmacological studies for validation.

RESULTS

A total of 161 plant species belonging to 86 families and 144 genera to cure 89 human ailments were documented. Although 68 plant species were cited as medicinal in previous studies, 55 different uses described by the Tamang people were not found in any of the compared studies. Traditional uses for 60 plant species were consistent with pharmacological and phytochemical studies.

CONCLUSIONS

The Tamang people in Makawanpur are rich in ethnopharmacological understanding. The present study highlights important medicinal plant species by validating their traditional uses. Different plant species can improve local economies through proper harvesting, adequate management and development of modern techniques to maximize their use.