Background: Dioscorea bulbiferaL. (Dioscoreaceae) has been traditionally used in Thai folk medicine as a diuretic and anthelmintic, for longevity preparations, and for wound and inflammation treatment. This plant is also commonly used in traditional Indian and Chinese medicines in the treatment of sore throat, gastric cancer, rectal carcinoma and goiters. However, the wound healing effects of the active compounds in this plant have not been investigated.Objective: This study aimed to identify compounds responsible for the wound healing activity ofD.bulbiferaand determine their potential anti-inflammatory and antioxidant activities.Methods: Crude extracts ofD.bulbiferabulbils, their derived fractions and eleven purified compounds were tested for anti-inflammatory activity against LPS-induced NO production in RAW264.7 macrophages. The wound healing effects were evaluated via cell proliferation and migration assays using human dermal fibroblasts (HDFs), and the antioxidant effects were determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radical (^•OH) scavenging activity assays.Results: 15,16-Epoxy-6α-O-acetyl-8β-hydroxy-19-nor-clero-13(16),14-diene-17,12;18,2-diolide (2), (+)-catechin (5), quercetin (6) and myricetin (11) exhibited significantly potent wound healing effects and promoted marked cell proliferation, resulting in % viabilities of 107.4–137.6, 121.1–151.9, 98.0–131.9, 90.9–115.9, respectively. Among them, (+)-catechin produced the highest % cell migration, resulting in 100.0% wound closure sooner (at day 2) than the other compounds. In addition, 1 μg/ml (+)-catechin significantly increased fibroblast migration by 2.4-fold compared to that in the control after 24 h. Regarding anti-inflammatory properties, kaempferol (7) and quercetin (6) decreased (p< 0.005) NO production, with IC₅₀values of 46.6 and 56.2 μM, respectively. In addition, the crude extracts, solvent fractions and flavonoid compounds were also found to possess marked antioxidant activity in both DPPH and^•OH radical scavenging assays.Conclusions: These findings provide more evidence to support the traditional use ofD.bulbiferafor the treatment of wounds and inflammation.

The resistance of malaria parasites to the current antimalarial drugs has led to the search for novel effective drugs. Betula alnoides has been traditionally used for the treatment of malaria, but the scientific evidence to substantiate this claim is still lacking. Therefore, the present study aimed at evaluating the antimalarial activity and toxicity of an aqueous stem extract of B. alnoides in a mouse model. The in vivo antimalarial activity of an aqueous stem extract of B. alnoides was determined by a 4-day suppressive test in mice infected with chloroquine-sensitive Plasmodium berghei ANKA. The B. alnoides extract was administered orally at different doses of 200, 400, and 600 mg/kg body weight. The levels of parasitaemia, survival time, body weight change, and food and water consumption of the mice were determined. The acute toxicity of the extract was assessed in the mice for 14 days after the administration of a single oral dose of 5000 mg/kg. An aqueous stem extract of B. alnoides exhibited a significant dose-dependent reduction of parasitaemia in P. berghei-infected mice at all dose levels compared to the reduction in the negative control. Extract doses of 200, 400, and 600 mg/kg body weight suppressed the levels of parasitaemia by 46.90, 58.39, and 71.26%, respectively. The extract also significantly prolonged the survival times of the P. berghei-infected mice compared to the survival times of the negative control mice. In addition, at all dose levels, the extract prevented body weight loss in P. berghei-infected mice. For the acute toxicity, there were no significant alterations in the biochemical parameters and in the histopathology. In conclusion, the aqueous stem extract of B. alnoides possesses antimalarial properties. A single oral dose of 5000 mg/kg body weight had no significant toxic effects on the function and structure of the kidneys and liver. These results support its use in traditional medicine for the treatment of malaria.

Background: The emergence of antimalarial drug resistance encourages the search for new antimalarial agents.Mammea siamensisbelongs to the Calophyllaceae family, which is a medicinal plant that is used in traditional Thai preparations. The hexane and dichloromethane extracts of this plant were found to have potent antimalarial activity. Therefore, this study aimed to isolate active compounds fromM. siamensisflowers and evaluate their antimalarial potential and their interactions withPlasmodium falciparumlactate dehydrogenase (PfLDH).Methods: The compounds fromM. siamensisflowers were isolated by chromatographic techniques and evaluated for their antimalarial activity against chloroquine (CQ)-resistantP. falciparum(K1) strains using a parasite lactate dehydrogenase (pLDH) assay. Interactions between the isolated compounds and thePfLDH enzyme were investigated using a molecular docking method.Results: The isolation produced the following thirteen compounds: two terpenoids, lupeol (1) and a mixture of β-sitosterol and stigmasterol (5); two mammea coumarins, mammea A/AA cyclo D (6) and mammea A/AA cyclo F (7); and nine xanthones, 4,5-dihydroxy-3-methoxyxanthone (2), 4-hydroxyxanthone (3), 1,7-dihydroxyxanthone (4), 1,6-dihydroxyxanthone (8), 1-hydroxy-5,6,7-trimethoxyxanthone (9), 3,4,5-trihydroxyxanthone (10), 5-hydroxy-1-methoxyxanthone (11), 2-hydroxyxanthone (12), and 1,5-dihydroxy-6-methoxyxanthone (13). Compound9exhibited the most potent antimalarial activity with an IC₅₀value of 9.57 µM, followed by10,1,2and13with IC₅₀values of 15.48, 18.78, 20.96 and 22.27 µM, respectively. The molecular docking results indicated that9, which exhibited the most potent activity, also had the best binding affinity to thePfLDH enzyme in terms of its low binding energy (-7.35 kcal/mol) and formed interactions with ARG109, ASN140, and ARG171.Conclusion: These findings revealed that isolated compounds fromM. siamensisflowers exhibited antimalarial activity. The result suggests that 1-hydroxy-5,6,7-trimethoxyxanthone is a possible lead structure as a potent inhibitor of thePfLDH enzyme.

Malaria remains a life-threatening health problem and encounters with the increasing of antimalarial drug resistance. Medicinal plants play a critical role in synthesizing novel and potent antimalarial agents. This study aimed to investigate the phytochemical constituents, antiplasmodial activity, and evaluate the toxicity of crude ethanolic extracts of Myristica fragrans, Atractylodes lancea, and Prabchompoothaweep remedy in a mouse model. The phytochemical constituents were characterized by liquid chromatography-mass spectrometry (LC-MS). Antimalarial efficacy against Plasmodium berghei was assessed using 4-day suppressive tests at doses of 200, 400, and 600 mg/kg body weight. Acute toxicity was assessed at a dose of 2000 mg/kg body weight of crude extracts. The 4-day suppression test showed that all crude extracts significantly suppressed parasitemia (p < 0.05) compared to the control group. Higher parasitemia suppression was observed both in Prabchompoothaweep remedy at a dose of 600 mg/kg (60.1%), and A. lancea at a dose of 400 mg/kg (60.1%). The acute oral toxicity test indicated that the LD₅₀ values of all extracts were greater than 2000 mg/kg and that these extracts were not toxic in the mouse model. LC-MS analysis revealed several compounds in M. fragrans, A. lancea, and Prabchompoothaweep remedy. For quantitative analysis, 1,2,6,8-tetrahydroxy-3-methylanthraquinone 2-O-b-D-glucoside, chlorogenic acid, and 3-O-(beta-D-glucopyranosyl-(1->6)-beta-D-glucopyranosyl) ethyl 3-hydroxyoctanoate were found in A. lancea, while (7′x,8′x)-4,7′-epoxy-3,8′-bilign-7-ene-3,5′-dimethoxy-4′,9,9′-triol, edulisin III, and tetra-hydrosappanone A trimethyl ether are found in M. fragrans. 6′-O-Formylmarmin was present in the Prabchompoothaweep remedy, followed by pterostilbene glycinate and amlaic acid. This study showed that the ethanolic extracts of A. lancea and Prabchompoothaweep remedy possess antimalarial activity against Plasmodium berghei. None of the extracts had toxic effects on liver and kidney function. Therefore, the ethanolic extract of A. lancea rhizome and Prabchompoothaweep remedy could be used as an alternative source of new antimalarial agents. Further studies are needed to determine the active compounds in both extracts.

The Kheaw Hom remedy is a traditional Thai medicine widely used to treat fevers. Some plant ingredients in this remedy have been investigated for their antimicrobial, antiviral, anti-inflammatory, and antioxidant activities. However, there have been no reports on the antimalarial activities of the medicinal plants in this remedy. Therefore, this study focuses on identifying potential antimalarial drug candidates from the medicinal plant ingredients of the Kheaw Hom remedy. Eighteen plants from the Kheaw Hom remedy were extracted using distilled water and ethanol. All extracts were investigated for their in vitro antimalarial activity and cytotoxicity. An extract that exhibited good in vitro antimalarial activity and low toxicity was selected for further investigation by using Peter’s 4-day suppressive test and an acute oral toxicity evaluation in mice. Based on the in vitro antimalarial activity and cytotoxicity studies, the ethanolic extract of Globba malaccensis rhizomes showed promising antimalarial activity against the Plasmodium falciparum K1 strain (IC₅₀ = 1.50 µg/mL) with less toxicity to Vero cells (CC₅₀ of >80 µg/mL). This extract exhibited a significant dose-dependent reduction in parasitemia in P. berghei-infected mice. The maximum suppressive effect of this extract (60.53%) was observed at the highest dose administered (600 mg/kg). In a single-dose acute toxicity test, the animals treated at 2000 mg/kg died within 48 h after extract administration. In conclusion, our study indicates that the ethanolic extract of G. malaccensis rhizomes exhibited in vitro and in vivo antimalarial activities, which could serve as a promising starting point for antimalarial drug.

This study evaluated the in vitro and in vivo antiplasmodial efficacy and toxicity of aqueous and ethanolic extracts from traditional recipes used in Thailand. The aqueous and ethanolic extracts of ten traditional recipes were tested for in vitro antiplasmodial activity (parasite lactate dehydrogenase assay), cytotoxicity (MTT assay), and hemolysis). Oxidant levels were measured using cell-permeable probe 5-(and-6)-chloromethyl-2′,7′-dichlorodihydrofluorescein diacetate fluorescent dye-based assays. The best candidate was chosen for testing in mouse models using 4-day suppressive and acute toxicity assays. An in vitro study showed that ethanolic extracts and three aqueous extracts exhibited antiplasmodial activity, with an IC₅₀ in the range of 2.8–15.5 µg/mL. All extracts showed high CC₅₀ values, except for ethanolic extracts from Benjakul, Benjalotiga, and Trikatuk in HepG2 and Benjalotiga and aqueous extract from Chan-tang-ha in a Vero cell. Based on the results of the in vitro antiplasmodial activity, an aqueous extract of Triphala was chosen for testing in mouse models. The aqueous extract of Triphala exhibited good antiplasmodial activity, was safe at an oral dose of 2 g/kg, and is a potential candidate as a new source for the development of antimalarial drugs.