Important Medicinal Plant Families in Thailand

Antiplasmodial potential of isolated xanthones from Mesua ferrea Linn. roots: an in vitro and in silico molecular docking and pharmacokinetics study

BACKGROUND

Malaria is a major global health concern, particularly in tropical and subtropical countries. With growing resistance to first-line treatment with artemisinin, there is an urgent need to discover novel antimalarial drugs. Mesua ferrea Linn., a plant used in traditional medicine for various purposes, has previously been investigated by our research group for its cytotoxic properties. The objective of this study was to explore the compounds isolated from M. ferrea with regards to their potential antiplasmodial activity, their interaction with Plasmodium falciparum lactate dehydrogenase (PfLDH), a crucial enzyme for parasite survival, and their pharmacokinetic and toxicity profiles.

METHODS

The isolated compounds were assessed for in vitro antiplasmodial activity against a multidrug-resistant strain of P. falciparum K1 using a parasite lactate dehydrogenase (pLDH) assay. In vitro cytotoxicity against Vero cells was determined using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The interactions between the isolated compounds and the target enzyme PfLDH were investigated using molecular docking. Additionally, pharmacokinetic and toxicity properties were estimated using online web tools SwissADME and ProTox-II, respectively.

RESULTS

Among the seven compounds isolated from M. ferrea roots, rheediachromenoxanthone (5), which belongs to the pyranoxanthone class, demonstrated good in vitro antiplasmodial activity, with the IC50 being 19.93 µM. Additionally, there was no toxicity towards Vero cells (CC50 = 112.34 µM) and a selectivity index (SI) of 5.64. Molecular docking analysis revealed that compound (5) exhibited a strong binding affinity of - 8.6 kcal/mol towards PfLDH and was stabilized by forming hydrogen bonds with key amino acid residues, including ASP53, TYR85, and GLU122. Pharmacokinetic predictions indicated that compound (5) possessed favorable drug-like properties and desired pharmacokinetic characteristics. These include high absorption in the gastrointestinal tract, classification as a non-substrate of permeability glycoprotein (P-gp), non-inhibition of CYP2C19, ease of synthesis, a high predicted LD50 value of 4,000 mg/kg, and importantly, non-hepatotoxic, non-carcinogenic, and non-cytotoxic effects.

CONCLUSIONS

This study demonstrated that compounds isolated from M. ferrea exhibit activity against P. falciparum. Rheediachromenoxanthone has significant potential as a scaffold for the development of potent antimalarial drugs.

Impact of Ethanolic Thai Indigenous Leaf Extracts on Melanosis Prevention and Shelf-Life Extension of Refrigerated Pacific White Shrimp

Shrimp has been known for its delicacy, but it undergoes rapid deterioration induced by biochemical and microbiological reactions. Melanosis is a major cause of discoloration associated with consumer rejection. All ethanolic extracts from different leaves including soursop, noni, and Jik leaves were dechlorophyllized via the "Green" sedimentation method before being used. The inhibitory activity against polyphenoloxidase (PPO) from Pacific white shrimp (Litopeneous vannamei) and the copper-chelating properties of varying extracts were compared. Soursop leaf extract (SLE) showed higher PPO inhibitory activity and copper-chelating ability than others (p < 0.05). Based on LC-MS, aempferol-3-O-rutinoside was identified as the most abundant compound, followed by catechin and neocholorigenic acid. The efficacy of SLE at different levels (0.25-1%) for inhibiting melanosis and preserving the quality of Pacific white shrimp was evaluated during refrigerated storage at 4 °C for 12 days in comparison with that of a 1.25% sodium metabisulfite (SMS)-treated sample. SLE at a level of 1% effectively retarded melanosis and bacterial growth, in which the total viable count did not exceed the microbial limit within 12 days. In addition, 1% SLE treatment impeded autolysis, reduced protein degradation and decomposition, and minimized lipid oxidation, as witnessed by the lower increases in pH, TVB-N, and TBARS values. Sensory evaluation indicated higher likeness scores and overall acceptability for SLE-1% and SMS-1.25% shrimps than those of the control and other samples. Therefore, SLE could be used as a natural alternative that effectively lowered the melanosis and quality loss of shrimp during refrigerated storage.

Important Medicinal and Food Taxa (Orders and Families) in Kenya, Based on Three Quantitative Approaches

Globally, food and medicinal plants have been documented, but their use patterns are poorly understood. Useful plants are non-random subsets of flora, prioritizing certain taxa. This study evaluates orders and families prioritized for medicine and food in Kenya, using three statistical models: Regression, Binomial, and Bayesian approaches. An extensive literature search was conducted to gather information on indigenous flora, medicinal and food plants. Regression residuals, obtained using LlNEST linear regression function, were used to quantify if taxa had unexpectedly high number of useful species relative to the overall proportion in the flora. Bayesian analysis, performed using BETA.INV function, was used to obtain superior and inferior 95% probability credible intervals for the whole flora and for all taxa. To test for the significance of individual taxa departure from the expected number, binomial analysis using BINOMDIST function was performed to obtain p-values for all taxa. The three models identified 14 positive outlier medicinal orders, all with significant values (p < 0.05). Fabales had the highest (66.16) regression residuals, while Sapindales had the highest (1.1605) R-value. Thirty-eight positive outlier medicinal families were identified; 34 were significant outliers (p < 0.05). Rutaceae (1.6808) had the highest R-value, while Fabaceae had the highest regression residuals (63.2). Sixteen positive outlier food orders were recovered; 13 were significant outliers (p < 0.05). Gentianales (45.27) had the highest regression residuals, while Sapindales (2.3654) had the highest R-value. Forty-two positive outlier food families were recovered by the three models; 30 were significant outliers (p < 0.05). Anacardiaceae (5.163) had the highest R-value, while Fabaceae had the highest (28.72) regression residuals. This study presents important medicinal and food taxa in Kenya, and adds useful data for global comparisons.

Very High Food Plant Diversity among Ethnic Groups in Northern Thailand

The combination of the high biodiversity and many ethnicities in Thailand results in extensive ethnobotanical studies, especially in the northern part of the country. Here we have assembled 7620 records from 60 references regarding how plants are used for food among 14 ethnicities in northern Thailand. The uses are based on 1182 different plant species. Vegetables are the most common food category, which contributed more than 60% of all use-reports and involved nearly 900 species. This was followed by the dessert fruit category, which included about 350 species and over 1800 use-reports. The similarity among the different ethnicities was low and the number of uses and species recorded among different ethnicities were significantly related to the number of studies that had been conducted for each group. This implies that additional ethnobotanical studies are still needed in order to conserve and compile the valuable traditional knowledge related to food plants. Many exotic species are now an important part of traditional knowledge, whereas rare endemic species are uncommon among wild food plants. This situation leads to a loss of traditional knowledge about food plants and reduced awareness of their importance. As a key to using this great reservoir of food for local people, traditional knowledge related to local wild food plants can contribute to the zero-hunger goal of the Sustainable Development Goal (SDG). More studies on the nutrient content and health properties of these plants could lead to the development of new crops to meet present consumer demands.

Appraising the therapeutical potentials of Alchornea laxiflora (Benth.) Pax & K. Hoffm., an underexplored medicinal herb: A systematic review

Ethnopharmacological relevance: Alchornea laxiflora (Benth.) Pax & K. Hoffm. (Euphorbiaceae) is an important traditional medicinal plant grown in tropical Africa. The stem, leaves, and root have been widely used in the folk medicine systems in Nigeria, Cameroon, South Africa, and Ghana to treat various ailments, including inflammatory, infectious, and central nervous system disorders, such as anxiety and epilepsy. Material and methods: The scientific name of the plant was validated using the "The Plant List," "Kew Royal Botanic Gardens," and Tropicos Nomenclatural databases. The literature search on A. laxiflora was performed using electronic search engines and databases such as Google scholar, ScienceDirect, PubMed, AJOL, Scopus, and Mendeley. Results: To the best of our knowledge, no specific and detailed review has been reported on A. laxiflora. Consequently, this review provides an up-to-date systematic presentation on ethnobotany, phytoconstituents, pharmacological activities, and toxicity profiles of A. laxiflora. Phytochemical investigations disclosed the presence of important compounds, such as alkaloids, flavonoids, phenolics, terpenoids, and fatty acids. Furthermore, various pharmacological activities and traditional uses reported for this botanical drug were discussed comprehensively. Conclusion: This systemic review presents the current status and perspectives of A. laxiflora as a potential therapeutic modality that would assist future researchers in exploring this African botanical drug as a source of novel drug candidates for varied diseases.

Modulation of Cytoskeleton, Protein Trafficking, and Signaling Pathways by Metabolites from Cucurbitaceae, Ericaceae, and Rosaceae Plant Families

One promising frontier within the field of Medical Botany is the study of the bioactivity of plant metabolites on human health. Although plant metabolites are metabolic byproducts that commonly regulate ecological interactions and biochemical processes in plant species, such metabolites also elicit profound effects on the cellular processes of human and other mammalian cells. In this regard, due to their potential as therapeutic agents for a variety of human diseases and induction of toxic cellular responses, further research advances are direly needed to fully understand the molecular mechanisms induced by these agents. Herein, we focus our investigation on metabolites from the Cucurbitaceae, Ericaceae, and Rosaceae plant families, for which several plant species are found within the state of Florida in Hillsborough County. Specifically, we compare the molecular mechanisms by which metabolites and/or plant extracts from these plant families modulate the cytoskeleton, protein trafficking, and cell signaling to mediate functional outcomes, as well as a discussion of current gaps in knowledge. Our efforts to lay the molecular groundwork in this broad manner hold promise in supporting future research efforts in pharmacology and drug discovery.

GC-MS Analysis, Antibacterial and Antioxidant Potential of Ethyl Acetate Leaf Extract of Senna singueana (Delile) Grown in Kenya

Bacterial diseases are a leading cause of mortality and morbidity globally. During bacterial diseases, an elevation of host immune response occurs, which involves the production of free radicals in response to the bacterial infection. The overproduction of free radicals in excess of the antioxidants leads to oxidative stress. Conventional antibiotics are linked to side effects such as hypersensitivity reactions in addition to bacterial pathogens developing resistance against them. Artificial antioxidants are said to be carcinogenic. This study sought to confirm folklore use and validate the antibacterial and antioxidant potential of Senna singueana which has been widely used in the Mbeere community. The in vitro antibacterial potentials of the plant extract were investigated on Bacillus subtilis ATCC 21332, Escherichia coli ATCC 25922, Salmonella typhi ATCC 1408, and Staphylococcus aureus ATCC 25923. Ciprofloxacin (100 µg/ml) drug was used as a standard reference, whereas 5% DMSO was used as a negative reference. The antibacterial tests included disc diffusion and minimum inhibitory and bactericidal concentrations. S. singueana ethyl acetate extract showed broad-spectrum potential against tested bacterial microbes producing mean zones of inhibition (MZI) from 07.67 ± 0.33 to 17.67 ± 0.33 mm. The extract demonstrated a greater effect on Gram-positive than Gram-negative bacterial pathogens. Antibacterial properties of ciprofloxacin were significantly greater in comparison to plant extract in all the dilutions ( $p<0.05$ ), while 5% DMSO was inactive against all the tested bacteria. MBC values were greater than MIC values. Antioxidant properties of the extract were determined through scavenging effects of DPPH and hydroxyl radicals (•OH) as well as ferric reducing antioxidant potential (FRAP) assay. S. singueana demonstrated effects against all radicals formed. Additionally, the extract exhibited ferric reducing abilities. The extract also contained various phytocompounds with known antibacterial and antioxidant properties. This study recommends the therapeutic use of S. singueana as an antibacterial as well as an antioxidant agent.

Medicinal Plants Used for Treating Mild Covid-19 Symptoms Among Thai Karen and Hmong

Background: The COVID-19 pandemic is causing many severe problems globally, and it is not known for how long it will last. The only hope we have for dealing with the problem is to produce sufficient vaccines and administer them efficiently. However, the current demand for vaccines greatly exceeds the supply, and many people will suffer from the disease for still some time. Moreover, the period for immunity obtained by the vaccines remains unknown, and we cannot predict how long the world will suffer the COVID-19 infections. Therefore, there will be a continued demand for treatments of its symptoms. An alternative solution for providing such treatment is the use of traditional medicinal plants.

Aims: To document medicinal plants used by Hmong and Karen in Thailand to treat mild symptoms of COVID-19.

Methods: Traditional knowledge about ethnomedicinal plants used by Hmong and Karen in Thailand for treating mild symptoms listed by WHO as associated with COVID 19, was collected in field interviews and extracted from the literature.

Results: We identified 491 plant species used medicinally by both ethnic groups to treat fever, cough, diarrhea, muscle pain and ache, rash, headache, sore throat, and conjunctivitis. Of the 491 species 60 were mentioned at least five times in the literature or in our field data. Of these 60 species, we propose the most commonly used ones for treatments of mild COVID-19 symptoms. Ten of these most commonly mentioned species were used for treatments of fever, nine for treatment of cough, four for treatment of diarrhea, two for treatment of rash, and a single species was used to treat muscle pain and headache.

Conclusion: This study suggests alternative treatments for mild symptoms of COVID-19 with medicinal plants that are traditionally used by the ethnic minority groups of the Hmong and Karen in Thailand. Although COVID-19 is a new disease, its mild symptoms are shared with many other diseases. Traditional knowledge on medicinal plants used by the Thai Karen and Hmong could help in the treatments of these symptoms associated with COVID-19. Many of the proposed plants were used abundantly by both ethnic groups, and other studies on biological activities support their efficacy in such treatments.

Ethnobotanical study on herbal market at the Dragon Boat Festival of Chuanqing people in China

BACKGROUND

The Chuanqing people () are a linguistic group native to the Guizhou Province of China, with unique culture and rich knowledge of traditional medicinal plants. Herbal market at Dragon Boat Festival (DBF) plays an important role in the inheritance of traditional medicinal knowledge among the Chuanqing people. This study aims to record the profile of medicinal plants of the Chuanqing people, discuss the dilemmas faced by their inheritance, and propose some strategies for passing down information, which is critical for the inheritance and protection of the Chuanqing people's traditional medical knowledge.

METHODS

Data were collected through key informants and semi-structured interviews and free listing. Collected voucher specimens were identified using by botanical taxonomy method and deposited in the herbarium. Data were analyzed through use-value (UV) and cultural importance index (CI) values. Medicinal plants were compared with the Information System of Chinese Rare and Endangered Plants of the Chinese Academy of Sciences. Results were compared with the Pharmacopoeia of the People's Republic of China (ChP), the Quality Standard of Traditional Chinese Medicine and National Medicine in Guizhou Province (QSG), and traditional medicines of Southeast Asian countries.

RESULTS

A total of 102 species from 53 families and 92 genera were recorded, with Orchidaceae and Asparagaceae (six species each), and Berberidaceae and Asteraceae (five species each) as the predominant families. The whole plant (36%) was the most common medicinal part. Decoction (44%) was the most common preparation method. Seventy-one investigated human ailments were grouped into 12 categories. Diseases of the musculoskeletal system (34 mentions) were most frequently mentioned in this study. Moreover, the most frequently used taxon was Hedera sinensis (Tobler ) Hand.-Mazz. (UV and CI = 0.29). The Chuanqing people's medicine was highly similar to ChP and QSG. In comparison with Southeast Asian countries' traditional medicines, except for the same preparation methods, the similarities in terms of medicinal ingredients, plants, and disease treatment were very low.

CONCLUSIONS

The herbal market at the DBF is an important platform for exchanging knowledge about the Chuanqing people's traditional medicinal plants. The Chuanqing people's traditional medicine is facing many challenges to its inheritance and development. To solve these problems, this study highlights the traditional medicinal knowledge of the Chuanqing people, providing basic data for further research and protection of minority medicine.

Using ICPC-2 Standard to Identify Thai Zingiberaceae of Pharmacological Interest

The Economic Botany Data Collection Standard (EBDCS) is a widely used standard among ethnobotanists. However, this standard classifies ethnomedicinal uses into categories based on local peoples’ perception. It is difficult to apply in pharmacological research. The International Classification of Primary Care (ICPC), now updated to ICPC-2, is more related to medical terms, but is rarely used among ethnobotanists. This study aims to apply the ICPC-2 to classify metadata of the ethnomedicinal uses of Zingiberaceae plants in Thailand, in order to identify important medicinal taxa for future research. Data on the ethnomedicinal uses of Thai gingers were collected from 62 theses, journal articles, scientific reports and a book, published between 1990 and 2019. Scientific plant names were updated using The World Checklist of Vascular Plants (WCVP) website. Informant Consensus Factor (ICF) was used to identify the medicinal issues commonly treated with gingers, and the Cultural Importance Index (CI) was used to identify species that might have pharmacological potential. We found records of 76 ginger species with ethnomedicinal uses, and together they had 771 use reports. The gingers were commonly used for treatments related to digestive system conditions, particularly abdominal pain and flatulence. Gingers remain exceedingly important in Thai ethnomedicine, with a high number of useful species. They are used to treat a variety of health conditions, but most commonly such ones that are related to the digestive system. Apart from the popular studied ginger, Curcuma longa, we identified a number of other useful gingers in Thailand.

Ethnomedicinal Plant Knowledge of the Karen in Thailand

The Thai Karen, the largest hill-tribe in Thailand, guard substantial ethnomedicinal plant knowledge, as documented in several studies that targeted single villages. Here, we have compiled information from all the reliable and published sources to present a comprehensive overview of the Karen ethnomedicinal plant knowledge. Our dataset covers 31 Karen villages distributed over eight provinces in Thailand. We used the Cultural Importance Index (CI) to determine which species were the most valuable to the Karen and the Informant Consensus Factor (ICF) to evaluate how well distributed the knowledge of ethnomedicinal plants was in various medicinal use categories. In the 31 Karen villages, we found 3188 reports of ethnomedicinal plant uses of 732 species in 150 plant families. Chromolaena odorata, Biancaea sappan, and Tinospora crispa were the most important medicinal plants, with the highest CI values. The Leguminosae, Asteraceae, Zingiberaceae, Euphorbiaceae, Lamiaceae, Acanthaceae, Apocynaceae, and Menispermaceae were the families with the highest CI values in the mentioned order. A high proportion of all the 3188 Karen use reports were used to treat digestive, general and unspecified, musculoskeletal, and skin disorders.

Anti-Infectious Plants of The Thai Karen: A Meta-Analysis

Pharmacology has developed many drugs to treat infections, but many people, especially in developing countries, cannot afford to purchase them, and still depend on traditional knowledge and local medicinal plants to fight off infections. In addition, numerous microbes have developed resistance to the pharmaceutical drugs developed to fight them, and for many, such as Covid-19, effective drugs remain to be found. Ethnomedicinal knowledge is useful, not only for local people as a source of medicine for primary health care, but also for new pharmacological discoveries. This study aimed to identify the plants that the Karen, the largest hill-tribe ethnic minority in northern and western Thailand, use for treatments of infectious diseases. We present a meta-analysis of data from 16 ethnobotanical studies of 25 Karen villages with the aim of understanding traditional knowledge and treatments and point to potential plants for further pharmacological development. The Karen used 127 plant species from 59 plant families to treat infections and infectious diseases. The Cultural Important Index (CI) showed that the Leguminosae, Euphorbiaceae, Asteraceae, Lauraceae, Apocynaceae, Menispermaceae, and Lamiaceae were the most commonly used families. As for species, Cleidion javanicum, Tinospora crispa, Litsea cubeba, Aesculus assamica, Tadehagi triquetrum, Senna alata, Tithonia diversifolia, Embelia sessiliflora, and Combretum indicum were the most commonly used in treatments of infectious diseases. We suggest that these plant species should be the first to be pharmacologically tested for possible development of medicines, and the remaining species registered should subsequently undergo testing.

High-Value Plant Species Used for the Treatment of "Fever" by the Karen Hill Tribe People

The symptom “fever” is generally not itself a terminal condition. However, it does occur with common mild to severe ailments afflicting the world population. Several allopathic medicines are available to attenuate fever by targeting the pathogen or the symptom itself. However, many people in marginal civilizations are obligated to use locally grown medicinal plants due to limited access to common pharmaceuticals. The Karen ethnic group is the biggest ethnic minority group in the hill-tribes of Thailand. They utilise a vast repertoire of medicinal plant species. Since many modern drugs were discovered out of traditional therapies, it is possible to discover new allopathic drugs in the treatment of fever and associated pathogens from the Karen people. Thus, this study aims to identify and record the ethnomedicinal plants they used for the treatment of “fever”. The names of plants used by the Thai Karen people for the treatment of fever were mined from publications on ethnomedicinal uses. Useful plant species and families were identified using the Cultural Importance Index (CI). With the mined data, 125 plant species from 52 families were identified, distributed across 25 Karen villages. A chemical cross-examination of these species provided valuable insights into chemical classes worthy of further investigation in the context of fever and associated pathogens.