In vitro anti-tumor promoting and anti-parasitic activities of the quassinoids from Eurycoma longifolia, a medicinal plant in Southeast Asia

A Multifaceted Review of Eurycoma longifolia Nutraceutical Bioactives: Production, Extraction, and Analysis in Drugs and Biofluids

Eurycoma longifolia Jack (known as Tongkat Ali) is a popular traditional herbal medicine, native to southeast Asia, that is well-known for its aphrodisiac as well as several other effects. Mostly, the root extract of E. longifolia is used as a folk medicine for sexual dysfunction, aging, anxiety, exercise recovery, fever, increased energy, and osteoporosis. These health effects led to the inclusion of E. longifolia in dietary supplements, particularly for bodybuilding purposes. These effects are mediated by a myriad of bioactive compounds belonging to quassinoids, canthin-6-one alkaloids, tirucallane triterpenes, squalene derivatives, and bioactive steroids. Among these phytoconstituents, quassinoids account for a large portion of E. longifolia root phytochemicals. Of these ingredients, eurycomanone, the major quassinoid in E. longifolia extract, accounts to a large extent for its health effects. This review capitalizes on the novel trends toward the production of E. longifolia bioactives using biotechnology and extraction optimization for best yields and recovery. Alongside, novel extraction methods, i.e., green techniques, of E. longifolia bioactives are described. Further, an overview of the different analytical approaches for the quality control assessment of E. longifolia plant material and nutraceuticals is presented alongside studies in body fluids to determine its pharmacokinetics and efficacy level. Such a compilation of analytical methods will help ensure safety and efficacy of that major drug.

A Systematic Review on Antimicrobial and Antiparasitic Activity of Eurycoma longifolia Jack (Tongkat Ali)

Eurycoma longifolia or Tongkat Ali (family: Simaroubaceae) has the potential to be utilised as an antimicrobial and antiparasitic agent that correlated with its traditional use to treat jaundice, malaria, antiseptic agent, and many more. This review is aimed at systematically sieving through articles regarding the antimicrobial and antiparasitic activity of E. longifolia. A total of 123 studies have been found using suitable keywords and manually searched from previous studies through the four databases. After title screening and abstract examination, 56 articles were excluded due to duplication and not meeting the acceptance criteria. 67 articles were assessed on full-text accessibility, 31 studies remained, and this number decreased to 20 articles after a careful examination of the full-text articles. Among the 20 articles selected, 17 articles proved the potential of E. longifolia as an antimicrobial and antiparasitic agent efficiently. 2 selected articles showed partial positive results, which specified specific microorganisms tested. In contrast, another 1 article gave a completely negative result. As for the conclusion, current studies highlighted by this review may shed light on the future direction of studies concerning E. longifolia as a novel antimicrobial and antiparasitic agent. However, more research should be done in the future focusing on the efficiency of E. longifolia for veterinary medicine utilisation.

Bioassay-Guided Discovery of Potential Partial Extracts with Cytotoxic Effects on Liver Cancer Cells from Vietnamese Medicinal Herbs

Hepatocellular carcinoma (HCC) is the most frequent type of primary liver cancer and is the leading cause of cancer mortality in Vietnam. Our study aims to discover the partial extracts with the potential cytotoxic effects on HCC cells from the different parts of 24 Vietnamese medicinal plants traditionally used in liver cancer treatment. Out of 52 crude methanol extracts, we found that Luvunga scandens leaves, Hyptis suaveolens roots, and Solanum torvum leaves showed the notable cytotoxic effects against HCC cells. After that, we carried out partial extract of the three methanol extracts with ethyl acetate, water, n-hexane, and 90% methanol. The cytotoxic activity on Huh-7 HCC cells, antioxidant capacity, and total flavonoids content (TFC) of each partial extraction were determined. Methanol, ethyl acetate, and 90% methanol extracts showed moderate to strong cytotoxicity activity against Huh-7 HCC cells. Notably, the ethyl acetate and 90% methanol extract from H. suaveolens roots with high TFC values and strong antioxidant capacity could be promising sources of novel therapeutic modalities for HCC treatment. For the leaves of L. scandens and S. torvum, the ethyl acetate extract showed high TFC value and promising anti-HCC activity, therefore recommended further studies.

Comparison of apoptotic responses in Blastocystis sp. upon treatment with Tongkat Ali and Metronidazole

Blastocystis sp. infection, although many remain asymptomatic, there is growing data in recent studies that suggests it is a frequent cause of gastrointestinal symptoms in children and adults. This proposes that treatment against this infection is necessary however metronidazole (MTZ), which is the current choice of treatment, has expressed non-uniformity in its efficacy in combating this infection which has led to the study of alternative treatment. In our previous study, it was established that Tongkat Ali fractions exhibited promising anti-protozoal properties which leads to the current aim of the study, to further narrow down the purification process in order to identify the specific active compound promoting the anti-protozoal effect through HPLC analysis. Based on the data analysis and in-vitro susceptibility assay, the collected Tongkat Ali fraction that demonstrated anti-blastocystis property was shown to contain eurycomanone. Previous studies have suggested that there is a mechanism in Blastocystis sp. that regulates the apoptotic process to produce higher number of viable cells when treated. In reference to this, our current study also aims to investigate the apoptotic response of Tongkat Ali extract and eurycomanone across different subtype groups with comparison to MTZ. Based on our investigation, both Tongkat Ali extract and eurycomanone induced the high apoptotic rate however exhibited a reduction in viable cell count (p < 0.05) when compared to MTZ. This study suggests that there is potential in developing a standardized treatment regardless of subtype variations which makes Tongkat Ali extract a promising anti-protozoal treatment against all Blastocystis sp. subtype groups.

A review on extraction techniques and therapeutic value of polar bioactives from Asian medicinal herbs: Case study on Orthosiphon aristatus, Eurycoma longifolia and Andrographis paniculata

Medicinal plants have gained much interest in the prevention and treatment of common human disease such as cold and fever, hypertension and postpartum. Bioactive compounds from medicinal plants were synthesised using effective extraction methods which have important roles in the pharmaceutical product development. Orthosiphon aristatus (OA), Eurycoma longifolia (EL) and Andrographis paniculata (AP) are among popular medicinal herbs in Southeast Asia. The major compounds for these medicinal plants are polar bioactive compounds (rosmarinic acid, eurycomanone and andrographolide) which have multiple benefits to human health. The bioactive compounds are used as a drug to function against a variety of diseases with the support of scientific evidence. This paper was intended to prepare a complete review about the extraction techniques (e.g. OA, EL and AP) of these medicinal plants based on existing studies and scientific works. Suitable solvents and techniques to obtain their major bioactive compounds and their therapeutic potentials were discussed.

Botanical Products in the Treatment and Control of Schistosomiasis: Recent Studies and Distribution of Active Plant Resources According to Affected Regions

Schistosomiasis, a parasitic disease caused by trematodes of the genus Schistosoma, is the second most prevalent parasitic disease in the world. It affects around 200 million people. Clinical treatment, prophylaxis, and prevention are performed in countries susceptible to schistosomiasis. In the pharmacological treatment for an acute form of schistosomiasis, the use of antiparasitics, mainly praziquantel, is more common. As an alternative way, prevention methods such as reducing the population of intermediate hosts (mollusks) with molluscicides are important in the control of this disease by interrupting the biological cycle of this etiological parasite. Despite the importance of pharmacological agents and molluscicides, they have side effects and environmental toxicity. In addition, they can lead to the development of resistance enhancing of parasites, and lead to the search for new and effective drugs, including resources of vegetal origin, which in turn, are abundant in the affected countries. Thus, the purpose of this review is to summarize recent studies on botanical products with potential for the control of schistosomiasis, including anti-Schistosoma and molluscicide activities. In addition, species and plant derivatives according to their origin or geographical importance indicating a possible utility of local resources for countries most affected by the disease are presented.

14,15β-dihydroxyklaineanone inhibits HepG2 cell proliferation and migration through p38MAPK pathway

OBJECTIVES

Eurycoma longifolia Jack (Simaroubaceae) is commonly distributed in the Southeast Asia and Indo China, which has been shown to possess antianxiety, antibacterial, anticancer, antifungal, anti-inflammatory, antimalarial and antioxidant biological activities. 14,15β-dihydroxyklaineanone is a diterpene isolated from E. longifolia Jack, which is cytotoxic against human lung cancer and human breast cancer cell lines. However, the effects and underlying mechanisms of 14,15β-dihydroxyklaineanone on hepatocellular carcinoma remain unknown.

METHODS

Cell viability assay and colony formation assay were used to measure HepG2 cell proliferation. Flow cytometry was used to analyse cell cycle and apoptosis. Wound-healing assay and transwell assay were used to observe cells migration. RNA sequencing and the enrichment of differentially expressed genes (DEGs) in Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were used to find and determine underlying pathways.

KEY FINDINGS

We found that 14,15β-dihydroxyklaineanone inhibited the growth and migration of HepG2 cells but did not induce cell apoptosis. 14,15β-dihydroxyklaineanone induced S cell cycle arrest by downregulating the expression levels of cyclin A, p-CDK2, cyclin B1, p21, E2F-1 and PCNA. In addition, RNA sequencing showed that 14,15β-dihydroxyklaineanone regulated MAPK pathway by increasing the expression levels of phosphor-p38. Downregulating of p38 via both p38 inhibitor (SB203580) and p38-siRNA could antagonize the inhibition of cell proliferation and migration and reverse the changes in p-p38, E-cadherin, N-cadherin and PCNA expression induced by 14,15β-dihydroxyklaineanone treatment.

CONCLUSIONS

14,15β-dihydroxyklaineanone inhibited cell proliferation and migration through regulating p38 MAPK pathway in HCC cells.

In vivo effect of essential oil of Mentha x villosa and its active compound against Schistosoma mansoni (Sambon, 1907)

Schistosomiasis treatment is dependent on a single drug, praziquantel (PZQ). The development of resistance of PZQ has drawn the attention of many researchers to alternative drugs. One viable and promising treatment is the study of medicinal plants as a new approach to the experimental treatment for Schistosomiasis. The present work aimed to evaluate in vivo antischistosomal activity of effect of Mentha x villosa Oil Essential (Mv-EO) and rotundifolone (ROT) against Schistosoma mansoni. Thirty-day-old female Swiss webster mice (Mus musculus) weighing 50 grams were used. Mice were infected with 80 cercariae of S. mansoni (BH strain) and orally administered Mv-EO (50, 100 and 200 mg/Kg) and ROT (35.9, 70.9 and 141.9 mg/Kg) at 45-days post infection for 5 consecutive days. All mice were euthanized 60 days after infection. Praziquantel was the positive control in the experiment. Doses of 200 mg/kg (Mv-EO) and ROT (141.9 mg/Kg) resulted in a significant reduction in fluke burden (72.44% and 74.48%, respectively). There was also marked reduction in liver, intestinal and faecal and changed oogram pattern, compared to infected untreated mice. Considering the results obtained, further biological studies are required in order to elucidate the mechanism of schistosomicidal action on against adult S. mansoni.

Chemical constituents and synergistic anti-gout studies on Eurycoma longifolia and potential mechanisms evaluation based on systemic analysis approach

37 compounds mainly including triterpenoids with the quassinoid skeleton and β-carboline alkaloids have been isolated from the roots of Eurycoma longifolia Jack (EL), which has been used as traditional medicine for a long history. It has been demonstrated that the total extracts from EL could significantly inhibit the joint swelling in MSU-induced acute gout arthritis rat model at middle and high doses (P < 0.05, P < 0.01), as meanwhile, better performance than that of positive control (P < 0.05, P < 0.01) has been observed at the dose of 10 g/kg. Aiming to search potential compounds and probable mechanisms, network pharmacology, molecular docking and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis were adopted, leading to the hypothesis of 17 targets related to different pathogenesis of gout and 5 potential compounds (C36, C107, C124, C125 and C130) among 156 selected compounds, playing synergetic role with multiple targets. Instead of the guiding ideology of "a gene, a drug, a disease", varieties of compounds but not a single one from EL display holistic performance through multiple pathways with multi-targets. It was noteworthy that Xanthine dehydrogenase/oxidase (XDH), Prostaglandin G/H synthase 2 (PTGS2), Fatty acid-binding protein, liver (FABP1), Purine nucleoside phosphorylase (PNP), and Peroxisome proliferator activated receptor alpha (PPARA) were the key targets with intensely interaction. Furthermore, the functional enrichment analysis indicated that EL probably produced the gout protection effects by synergistic regulation in multiple biological pathways, including Toll-like receptor signaling pathway, MAPK signaling pathway, and NOD-like receptor signaling pathway, etc.

Effects of Eurycoma Longifolia Jack Supplementation Combined with Resistance Training on Isokinetic Muscular Strength and Power, Anaerobic Power, and Urinary Testosterone: Epitestosterone Ratio in Young Males

Introduction

This study investigated the effects of resistance training and Eurycoma longifolia Jack supplementation on isokinetic muscular strength and power, Wingate anaerobic power, and testosterone: epitestosterone (T/E) ratio in young males.

Methods

Forty young males were weight-matched and assigned into four groups: control (C), Eurycoma longifolia jack (ElJ), resistance training (RT), and Eurycoma longifolia Jack plus resistance training group (ElJ & RT). Participants in ElJ and ElJ & RT groups consumed 200 mg Eurycoma longifolia Jack daily, whereas participants in the C and RT groups consumed placebo capsules daily for 8 weeks. Resistance training program which consisted of 10 different exercises was conducted three times per week for 8 weeks. Participants' isokinetic muscular strength and power, anaerobic power, and urinary TE ratio were measured before and after the intervention period. This is a randomized placebo-controlled intervention study. Paired t-test and one-way analysis of variance were used for statistical analysis.

Results

The mean average power of knee flexion at 300°/s in the RT and ElJ & RT groups was significantly (P < 0.05) higher in the posttest compared with pretest. Wingate relative peak power in the RT group increased significantly (P < 0.05) compared with respective pretest value, whereas peak power in the combined ElJ & RT group was significantly (P < 0.05) higher in posttest compared with pretest. There was no significant difference in T/E ratio between pre- and posttests in all the groups.

Conclusions

The prescribed resistance training program, either with or without ElJ supplementation, improved isokinetic power of the lower limb. Resistance training alone improved relative anaerobic power, whereas combined Eurycoma longifolia Jack and resistance training improved peak power output. ElJ consumption of 200 mg daily for 8 weeks did not affect the urinary T/E ratio.

Biomimetic synthesis and anticancer activity of Eurycoma longifolia branch extract‐mediated silver nanoparticles

In the present study, silver nanoparticles (AgNPs) were synthesised by adding 1 mM Ag nitrate solution to different concentrations (1%, 2.5%, 5%) of branch extracts of Eurycoma longifolia, a well known medicinal plant in South–East Asian countries. Characterisation of AgNPs was carried out using techniques such as ultraviolet–visible spectrophotometry, X‐ray diffractrometry, Fourier transform infrared–attenuated total reflection spectroscopy (FTIR–ATR), scanning electron microscopy. XRD analysis revealed face centre cubic structure of AgNPs and FTIR–ATR showed that primary and secondary amide groups in combination with the protein molecules present in the branch extract were responsible for the reduction and stabilisation of AgNPs. Furthermore, antioxidant [2,2‐diphenyl‐1‐picrylhydrazyl and 2,2′‐Azino‐bis(3‐ethylbenzthiazoline‐6‐sulphonic acid)], antimicrobial and anticancer activities of AgNPs were investigated. The highest bactericidal activity of these biogenic AgNPs was found against Escherichia coli with zone inhibition of 11 mm. AgNPs exhibited significant anticancer activity against human glioma cells (DBTRG and U87) and human breast adenocarcinoma cells (MCF‐7 and MDA‐MB‐231) with IC50 values of 33, 42, 60 and 38 µg/ml.

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).

Ethnobotany, phytochemistry, and pharmacology of the genus Litsea: An update

ETHNOPHARMACOLOGICAL RELEVANCE

The genus Litsea is one of the most diverse genera of evergreen trees or shrubs belong to Lauraceae, and comprises roughly 400 species of tree that are distributed abundantly throughout tropical and subtropical Asia, North and South America. Litsea species have been used globally in traditional medicine for the treatment of various diseases including influenza, stomach aches, diarrhea, diabetes, vomiting, bone pain, inflammation, illness related to the central nervous system and other ailments. The purpose of this review is to provide updated, comprehensive and categorized information on the ethnobotany, phytochemistry and pharmacological research of Litsea species in order to explore their therapeutic potential and evaluate future research opportunities.

MATERIALS AND METHODS

All the available information on Litsea species was actualised by systematically searching the scientific literatures including Chinese, Korean, Japanese, Indian, and South American herbal classics, library catalogs and scientific databases (PubMed, SciFinder, Web of Science, Google Scholar, VIP and Wanfang). The Plant List, International Plant Name index and Scientific Database of China Plant Species were used to validate scientific names.

RESULTS

407 secondary metabolites have been reported from Litsea species. Litsea Species are sources of secondary metabolites with interesting chemical structures (alkaloids, lactones, sesquiterpenes, flavonoids, lignans, and essential oils) and significant bioactivities. Crude extracts, fractions and phytochemical constituents isolated from Litsea show a wide spectrum of in vitro and in vivo pharmacological activities including anticancer, anti-inflammatory, antimicrobial, antioxidant, antidiabetic, anti-HIV, insecticidal, etc.

CONCLUSIONS

From data collected in this review, the genus Litsea comprises a wide range of therapeutically promising and valuable plants, and has attracted much attention owing to its multiple functions. Many traditional uses of Litsea species have now been validated by modern pharmacology research. Deep and systematic phytochemical investigation of the genus Litsea and the pharmacological properties, especially its mechanism of action and toxicology, to illustrate its ethnomedicinal use, explore the therapeutic potential and support further health-care product development will undoubtedly be the focus of further research. Therefore, detailed and extensive studies and clinical evaluation of Litsea species should be carried out in future for the safety approval of therapeutic applications.

Review on a Traditional Herbal Medicine, Eurycoma longifolia Jack (Tongkat Ali): Its Traditional Uses, Chemistry, Evidence-Based Pharmacology and Toxicology

Eurycoma longifolia Jack (known as tongkat ali), a popular traditional herbal medicine, is a flowering plant of the family Simaroubaceae, native to Indonesia, Malaysia, Vietnam and also Cambodia, Myanmar, Laos and Thailand. E. longifolia, is one of the well-known folk medicines for aphrodisiac effects as well as intermittent fever (malaria) in Asia. Decoctions of E. longifolia leaves are used for washing itches, while its fruits are used in curing dysentery. Its bark is mostly used as a vermifuge, while the taproots are used to treat high blood pressure, and the root bark is used for the treatment of diarrhea and fever. Mostly, the roots extract of E. longifolia are used as folk medicine for sexual dysfunction, aging, malaria, cancer, diabetes, anxiety, aches, constipation, exercise recovery, fever, increased energy, increased strength, leukemia, osteoporosis, stress, syphilis and glandular swelling. The roots are also used as an aphrodisiac, antibiotic, appetite stimulant and health supplement. The plant is reported to be rich in various classes of bioactive compounds such as quassinoids, canthin-6-one alkaloids, β-carboline alkaloids, triterpene tirucallane type, squalene derivatives and biphenyl neolignan, eurycolactone, laurycolactone, and eurycomalactone, and bioactive steroids. Among these phytoconstituents, quassinoids account for a major portion of the E. longifolia root phytochemicals. An acute toxicity study has found that the oral Lethal Dose 50 (LD50) of the alcoholic extract of E. longifolia in mice is between 1500-2000 mg/kg, while the oral LD50 of the aqueous extract form is more than 3000 mg/kg. Liver and renal function tests showed no adverse changes at normal daily dose and chronic use of E. longifolia. Based on established literature on health benefits of E. longifolia, it is important to focus attention on its more active constituents and the constituents' identification, determination, further development and most importantly, the standardization. Besides the available data, more evidence is required regarding its therapeutic efficacy and safety, so it can be considered a rich herbal source of new drug candidates. It is very important to conserve this valuable medicinal plant for the health benefit of future generations.

Review Ergogenic Effect of Long Jack, Eurycoma Longifolia

Eurycoma longifolia (family: Simaroubaceae) is commonly distributed in the Southeast Asia and Indo-China. In particular, the aqueous extract and decoction of its root are a well-known folk medicine which enhances sexuality, fertility, and antiaging. Furthermore, it has been shown to possess anti-inflammatory, antimalarial, antimicrobial, and antioxidant properties. Its common phytochemical components include alkaloids, flavonoids, phenolics, saponins, tannins, and triterpenes. This plant is rich in various quassinoids including eurycolactone, eurycomalactone, eurycomanol, eurycomanone, and eurycomaoside all of which has been reported to contribute to its remedial properties including increased muscle strength, endurance in cycling time, and reduced anxiety and stress. Based on established literature on the health benefits of E. longifolia, this review article has attempted to compile E. longifolia to be one of the choices of ergogenic plants.

Uncovering potential of Indonesian medicinal plants on glucose uptake enhancement and lipid suppression in 3T3-L1 adipocytes

ETHNOPHARMACOLOGICAL RELEVANCE

As obesity is a key factor in the development of type 2 diabetes, lowering lipid accumulation in adipose tissues is as important as increasing insulin sensitivity in diabetic patients. The selected plant extracts used in this screen have been traditionally used in Indonesian medicine for the treatment of diabetes and its complications.

AIM OF THE STUDY

To investigate the ability of the selected plants to both increase insulin sensitivity through the enhancement of glucose uptake after insulin induction in adipocytes and suppress lipid production in the same target cells.

MATERIALS AND METHODS

Dried Indonesian medicinal plants were extracted with 50% (v/v) aq. methanol. The extracts were dissolved in 50% DMSO when tested in 3T3-L1 adipocytes. The screening platform consists of insulin-induced glucose uptake, lipid accumulation, and cell viability. Initially, an enzymatic fluorescence assay was designed to demonstrate the enhancement of 2-deoxyglucose (2-DG) uptake after insulin induction. Different concentrations of the extracts that enhanced glucose uptake were subjected to lipid accumulation assay using Oil Red O staining. Potential extracts based on lipid suppression were subsequently assessed by CCK-8 cell viability assay to distinguish lipid reduction activity from cytotoxicity.

RESULTS

Out of 59 plants, 13 plants demonstrated their ability to increase glucose uptake in 3T3-L1 adipocytes after insulin induction, and 4 of these plants' extracts suppressed lipid production of the cells. The CCK-8 assay results of those 4 plant extracts suggest that the lipid inhibition activity of Eurycoma longifolia Jack (root) and Piper nigrum L. (fruits) extracts is not attributed to their cytotoxicity in the adipose cells. Both of the plant extracts increased glucose uptake by more than 200% at 50 μg/mL and suppressed lipid accumulation in a concentration-dependent manner.

CONCLUSIONS

Screening of selected Indonesian medicinal plants has uncovered the potentials of E. longifolia Jack (root) and P. nigrum L. (fruits) with dual active functions, increasing insulin sensitivity through the enhancement of glucose uptake and reducing lipid accumulation in adipose cells. These findings suggest that the ability of both plants to suppress lipid production would provide additional benefits in the treatment of diabetes.

Tongkat Ali (Eurycoma longifolia): a possible therapeutic candidate against Blastocystis sp

BACKGROUND

In the local Malaysian context, herbal plants such as Eurycoma longifolia (Tongkat Ali), Orthosiphon stamineus (MisaiKucing), Ficus deltoidea (Mas Cotek), Zingiber officinale (Halia Bara) and Barringtonia racemosa (Putat) are known and widely used for its therapeutic properties. The first part of this study aims to screen for the anti-protozoal activity of these herbal plant extracts against Blastocystis sp. isolate subtype (ST) 3. Herbal extract with the highest efficacy was further fractionized into water and ethyl acetate fractions and tested against ST1, ST3 and ST5 Blastocystis sp. isolates. These isolates were also exposed to allopathic drugs, Metronidazole (MTZ), Tinidazole, Trimethoprim-sulfamethoxazole(TMP-SMX), Ketoconazole and Nitazoxanide for comparison purpose.

METHODS

Blastocystis sp. isolates from human-derived stool samples were exposed to herbal extracts and allopathic drugs at a concentration of 0.1 mg/ml and 1.0 mg/ml and were incubated at 37 °C. Growth profile studies were carried out. After 72 h of treatment, the viability of Blastocystis sp. as a result of the effects of the drugs and herbal extracts were assessed.

RESULTS

Based on the screening process, amongst all the extracts, Tongkat Ali exhibited the highest anti-protozoal activity at 1.0 mg/ml. Between the water and ethyl acetate fractions of Tongkat Ali, the ethyl acetate fraction exhibited a slightly higher percentage of anti-protozoal activity at 1.0 mg/ml across subtypes, ST1 (94.9%), ST3 (95.1%) and ST5 (94.3%). When tested with allopathic drugs, at the same concentration, MTZ exhibited the highest anti-protozoal activity across subtypes, ST1 (95.8%), ST3 (93.4%) and ST5 (90.8%).

CONCLUSION

This study is the first to describe the anti-protozoal properties of Tongkat Ali against Blastocystis sp. isolates. Ethyl acetate fraction of Tongkat Ali demonstrated the highest anti-protozoal activity against Blastocystis sp. isolates and showed a sizeable reduction in the cell count which was comparable with MTZ. Tongkat Ali also demonstrated a more uniformed sensitivity across subtypes in comparison to the allopathic drugs.

Simultaneous quantitation of six major quassinoids in Tongkat Ali dietary supplements by liquid chromatography with tandem mass spectrometry

Tongkat Ali (Eurycoma longifolia) is one of the most popular traditional herbs in Southeast Asia and generally consumed as forms of dietary supplements, tea, or drink additives for coffee or energy beverages. In this study, the liquid chromatography with tandem mass spectrometry method for the simultaneous quantitation of six major quassinoids of Tongkat Ali (eurycomanone, 13,21-dihydroeurycomanone, 13α(21)-epoxyeurycomanone, 14,15β-dihydroxyklaineanone, eurycomalactone, and longilactone) was developed and validated. Using the developed method, the content of the six quassinoids was measured in Tongkat Ali containing dietary supplement tablets or capsules, and the resulting data were used to confirm the presence of Tongkat Ali in those products. Among the six quassinoids, eurycomanone was the most abundant quassinoid in all samples tested. The developed method would be useful for the quality assessment of Tongkat Ali containing dietary supplements.

Ethnomedicinal plants used by traditional healers in Phatthalung Province, Peninsular Thailand

BACKGROUND

In rural communities of Thailand, traditional healers still play an important role in local health care systems even though modern medicine is easily accessible. Meanwhile, natural forests in Thailand which are important sources of materia medica are being greatly destroyed. This has led to an erosion of traditional Thai medicine. Furthermore, the concept of medicinal plant selection as medicine based on their tastes is still an important component of traditional Thai medicine, but no or little publications have been reported. Thus the aim of the present study is to collect ethnomedicinal data, medicinal plant tastes and relevant information from experienced traditional healers before they are lost.

METHODS

An ethnobotanical survey was carried out to collect information from nine experienced traditional healers on the utilization of medicinal plants in Phatthalung Province, Peninsular Thailand. Data were obtained using semi-structured interviews and participant observations. Plant specimens were also collected and identified according to the plant taxonomic method.

RESULTS

A total of 151 medicinal plants were documented and 98 of these are reported in the study. Local names, medicinal uses, parts used, modes of preparation, and the relationship between ailments and tastes of medicinal plant species are presented.

CONCLUSIONS

This research suggests that traditional healers are still considered important for public health among Thai communities and that many people trust the healing properties of medicinal plants. In the future, it is hoped that traditional Thai medicine will be promoted and therefore will help reduce national public health expense.

A penta-substituted pyridine alkaloid from the rhizome of Jatropha elliptica (Pohl) Muell. Arg. is active against Schistosoma mansoni and Biomphalaria glabrata

Jatropha elliptica is a shrub distributed throughout the north and west of Brazil and reputedly possesses a wide range of therapeutical properties. The roots of this plant possess molluscicidal activity and contain terpenoids, coumarin, lignoid, steroids and alkaloid. In the present study, we assessed the schistosomicidal, miracicidal and cercaricidal activities (against Schistosoma mansoni) and molluscicidal activities (against adults and egg masses of Biomphalaria glabrata) of the alkaloid diethyl 4-phenyl-2,6-dimethyl-3,5-pyridinedicarboxylate, isolated from the ethanol extract of the rhizome of J. elliptica, have been determined. The alkaloid was 100 % lethal to adult schistosomes within 4 days at a concentration of 50 μg/mL. Alterations were observed in the schistosome tegument occasioned by treatment with the alkaloid, such as formation of vesicles and vacuolisation. The extent of tegumental damage of the worm was proportional to the time of incubation and to the concentration of compound. The alkaloid also exhibited a potent cercaricidal activity (LC₁₀₀ = 2 μg/mL); it was totally ineffective against miracicidal forms of the parasite. Moreover, the alkaloid presented strong activity against adult snails (LC₉₀ = 36.43 μg/mL) but was inactive against their egg masses. It is observed then the potential of this compound for the development of new therapies for the treatment of schistosomiasis.

Anti-tumor activity of Eurycoma longifolia root extracts against K-562 cell line: in vitro and in vivo study

Eurycoma longifolia Jack has been widely used in traditional medicine for its antimalarial, aphrodisiac, anti-diabetic, antimicrobial and anti-pyretic activities. Its anticancer activity has also been recently reported on different solid tumors, however no anti-leukemic activity of this plant has been reported. Thus the present study assesses the in vitro and in vivo anti-proliferative and apoptotic potentials of E. longifolia on K-562 leukemic cell line. The K-562 cells (purchased from ATCC) were isolated from patients with chronic myelocytic leukemia (CML) were treated with the various fractions (TAF273, F3 and F4) of E. longifolia root methanolic extract at various concentrations and time intervals and the anti-proliferative activity assessed by MTS assay. Flow cytometry was used to assess the apoptosis and cell cycle arrest. Nude mice injected subcutaneously with 10⁷ K-562 cells were used to study the anti-leukemic activity of TAF273 in vivo. TAF273, F3 and F4 showed various degrees of growth inhibition with IC50 values of 19, 55 and 62 µg/ml, respectively. TAF273 induced apoptosis in a dose and time dependent manner. TAF273 arrested cell cycle at G1and S phases. Intraperitoneal administration of TAF273 (50 mg/kg) resulted in a significant growth inhibition of subcutaneous tumor in TAF273-treated mice compared with the control mice (P = 0.024). TAF273 shows potent anti-proliferative activity in vitro and in vivo models of CML and therefore, justifies further efforts to define more clearly the potential benefits of using TAF273 as a novel therapeutic strategy for CML management.

Anti-angiogenic quassinoid-rich fraction from Eurycoma longifolia modulates endothelial cell function

Targeting angiogenesis could be an excellent strategy to combat angiogenesis-dependent pathophysiological conditions such as cancer, rheumatoid arthritis, obesity, systemic lupus erythematosus, psoriasis, proliferative retinopathy and atherosclerosis. Recently a number of clinical investigations are being undertaken to assess the potential therapeutic application of various anti-angiogenic agents. Many of these angiogenesis inhibitors are directed against the functions of endothelial cells, which are considered as the building blocks of blood vessels. Similarly, roots of a traditional medicinal plant, Eurycoma longifolia, can be used as an alternative treatment to prevent and treat the angiogenesis-related diseases. In the present study, antiangiogenic potential of partially purified quassinoid-rich fraction (TAF273) of E. longifolia root extract was evaluated using ex vivo and in vivo angiogenesis models and the anti-angiogenic efficacy of TAF273 was investigated in human umbilical vein endothelial cells (HUVEC). TAF273 caused significant suppression in sprouting of microvessels in rat aorta with IC50 11.5μg/ml. TAF273 (50μg/ml) showed remarkable inhibition (63.13%) of neovascularization in chorioallantoic membrane of chick embryo. Tumor histology also revealed marked reduction in extent of vascularization. In vitro, TAF273 significantly inhibited the major angiogenesis steps such as proliferation, migration and differentiation of HUVECs. Phytochemical analysis revealed high content of quassinoids in TAF273. Specially, HPLC characterization showed that TAF273 is enriched with eurycomanone, 13α(21)-epoxyeurycomanone and eurycomanol. These results demonstrated that the antiangiogenic activity of TAF273 may be due to its inhibitory effect on endothelial cell proliferation, differentiation and migration which could be attributed to the high content of quassinoids in E. longifolia.

Acute and subacute oral toxicity of Litsea elliptica Blume essential oil in rats

Litsea elliptica Blume has been traditionally used to treat headache, fever, and stomach ulcer, and has also been used as an insect repellent. The acute and subacute toxicities of L. elliptica essential oil were evaluated orally by gavage in female Sprague-Dawley rats. For the acute toxicity study, L. elliptica essential oil was administered in doses from 500 to 4000 mg/kg (single dose), and in the subacute toxicity test, the following doses were used: 125, 250, and 500 mg/kg, for 28 consecutive days. In the acute toxicity study, L. elliptica essential oil caused dose-dependent adverse behaviours and mortality. The median lethal dose value was 3488.86 mg/kg and the acute non-observed-adversed-effect level value was found to be 500 mg/kg. The subacute toxicity study of L. elliptica essential oil did not reveal alterations in body weight, and food and water consumptions. The haematological and biochemical analyses did not show significant differences between control and treated groups in most of the parameters examined, except for the hemoglobin, mean cell hemoglobin concentration, mean cell volume, mean cell hemoglobin, serum albumin, and serum sodium. However, these differences were still within the normal range. No abnormalities or histopathological changes were observed in the liver, pancreatic islet of Langerhans, and renal glomerulous and tubular cells of all treated groups. In conclusion, L. elliptica essential oil can be classified in the U group, which is defined as a group unlikely to present an acute hazard according to World Health Organization (WHO) classification.

Involvement of intrinsic mitochondrial pathway in neosergeolide-induced apoptosis of human HL-60 leukemia cells: the role of mitochondrial permeability transition pore and DNA damage

CONTEXT

Quassinoids are biologically active secondary metabolites found exclusively in the Simaroubaceae family of plants. These compounds generally present important biological properties, including cytotoxic and antitumor properties.

OBJECTIVE

In the present study, the cytotoxic effects of neosergeolide, a quassinoid isolated from Picrolemma sprucei Hook. f., were evaluated in human promyelocytic leukemia cells (HL-60).

MATERIALS AND METHODS

Cytotoxicity and antiproliferative effects were evaluated by the MTT assay, May-Grünwald-Giemsa's staining, BrdU incorporation test, and flow cytometry procedures. The comet assay and micronuclei analysis were applied to determine the genotoxic and mutagenic potential of neosergeolide.

RESULTS

After 24 h exposure, neosergeolide strongly inhibited cancer cell proliferation (IC₅₀ 0.1 µM), and its activity seemed to be selective to tumor cells because it had no antiproliferative effect on human peripheral blood mononuclear cells (PBMC) at tested concentrations. Apoptosis was induced at submicromolar concentrations (0.05, 0.1, and 0.2 µM) as evidenced by morphological changes, mitochondrial depolarization, phosphatidylserine externalization, caspases activation, and internucleosomal DNA fragmentation. Additionally, neosergeolide effects were prevented by cyclosporine A (CsA), an inhibitor of the mitochondrial permeability transition (MPT) pore, which reinforced the participation of intrinsic pathways in the apoptotic process induced by this natural quassinoid. Direct DNA damage was further confirmed by comet assay and cytokinesis-block micronucleus test.

DISCUSSION AND CONCLUSION

The present study provided experimental evidence to support the underlying mechanism of action involved in the neosergeolide-mediated apoptosis. In addition, no antiproliferative effect or DNA damage effect of neosergeolide was evident in PBMC, highlighting its therapeutic potential.

Eurycoma longifolia : Medicinal Plant in the Prevention and Treatment of Male Osteoporosis due to Androgen Deficiency

Osteoporosis in elderly men is now becoming an alarming health issue due to its relation with a higher mortality rate compared to osteoporosis in women. Androgen deficiency (hypogonadism) is one of the major factors of male osteoporosis and it can be treated with testosterone replacement therapy (TRT). However, one medicinal plant, Eurycoma longifolia Jack (EL), can be used as an alternative treatment to prevent and treat male osteoporosis without causing the side effects associated with TRT. EL exerts proandrogenic effects that enhance testosterone level, as well as stimulate osteoblast proliferation and osteoclast apoptosis. This will maintain bone remodelling activity and reduce bone loss. Phytochemical components of EL may also prevent osteoporosis via its antioxidative property. Hence, EL has the potential as a complementary treatment for male osteoporosis.

Chemical composition and in vitro schistosomicidal activity of the essential oil of Plectranthus neochilus grown in Southeast Brazil

The chemical composition and the in vitro schistosomicidal effects of the essential oil of Plectranthus neochilus (PN-EO) grown in Southeast Brazil was studied. β-Caryophyllene (1; 28.23%), α-thujene (2; 12.22%), α-pinene (3; 12.63%), β-pinene (4; 6.19%), germacrene D (5; 5.36%), and caryophyllene oxide (6; 5.37%) were the major essential oil constituents. This chemical composition differed from that previously reported for specimens harvested in Africa. Concerning the in vitro schistosomicidal activity against adult Schistosoma mansoni worms, PN-EO was considered to be active, but less effective than the positive control praziquantel (PZQ) in terms of separation of coupled pairs, mortality, decrease in the motor activity, and tegumental alterations. However, PN-EO caused an interesting dose-dependent reduction in the number and the percentage of developed S. mansoni eggs. These results suggest that PN-EO might be very promising for the development of new schistosomicidal agents.

Quercetin-induced apoptosis of HL-60 cells by reducing PI3K/Akt

To explore the effect and mechanism of quercetin on proliferation and apoptosis of leukemia cells, and provide a theoretical basis for its clinical application. HL-60 leukemia cell lines was treated with different dose quercetin, the proliferation activity of leukemia cells was assessed by MTT method; the morphological changes of apoptosis of HL-60 cells, including nuclear condensation and DNA fragmentation, were observed by Hoechst 33258 fluorescence staining, the apoptosis rate and caspase 2,3 activation were assessed by flow cytometry, and the cell signal pathway including phosphatidylinositol 3-kinase (PI3K), phosphorylated protein kinase B (pAkt), Bcl-2, Bax were detected by western blotting. Quercetin could significantly decrease the proliferation activity of HL-60 cells through the blockade of G(0)/G(1) phase, and induce the apoptosis of HL-60 cells in a time- and dose-dependent manner. Quercetin caused leukemia cells apoptosis by decreasing the protein expression of PI3K and Bax, the inhibitory phosphorylation of Akt, the decreased levels of Bcl-2 protein and increased activations of caspase-2 and -3, and increased poly(ADP-ribose) polymerase cleavage. Our results indicate that the apoptotic processes caused by quercetin are mediated by the decrease of pAkt and Bcl-2 levels, the increase of Bax level, and the activation of caspase families in HL-60 cells.

Schistosomicidal activity of the essential oil of Ageratum conyzoides L. (Asteraceae) against adult Schistosoma mansoni worms

The in vitro schistosomicidal effects of the essential oil of Ageratum conyzoides L. (Ac-EO) against adult worms of Schistosoma mansoni is reported in this paper. Concerning this activity, Ac-EO was considered to be active, but less effective than the positive control (praziquantel, PZQ) in terms of separation of coupled pairs, mortality, decrease in motor activity, and tegumental alterations. However, Ac-EO caused an interesting dose-dependent reduction in the number of eggs of S. mansoni. Precocene I (74.30%) and (E)-caryophyllene (14.23%) were identified as the two major constituents of Ac-EO. These compounds were tested individually and were found to be much less effective than Ac-EO and PZQ. A mixture of the two major compounds in a ratio similar to that found in the Ac-EO was also less effective than Ac-EO, thus revealing that there are no synergistic effects between these components. These results suggest that the essential oil of A. conyzoides is very promising for the development of new schistosomicidal agents.

Tongkat Ali (Eurycoma longifolia Jack): a review on its ethnobotany and pharmacological importance

Eurycoma longifolia Jack is an herbal medicinal plant of South-East Asian origin, popularly recognized as 'Tongkat Ali.' The plant parts have been traditionally used for its antimalarial, aphrodisiac, anti-diabetic, antimicrobial and anti-pyretic activities, which have also been proved scientifically. The plant parts are rich in various bioactive compounds (like eurycomaoside, eurycolactone, eurycomalactone, eurycomanone, and pasakbumin-B) among which the alkaloids and quassinoids form a major portion. Even though toxicity and safety evaluation studies have been pursued, still a major gap exists in providing scientific base for commercial utilization and clearance of the Tongkat Ali products with regard to consumer's safety. The present review aims at reviewing the research works undertaken till date, on this plant in order to provide sufficient baseline information for future works and for commercial exploitation.

Eurycoma longifolia Jack in managing idiopathic male infertility

This study investigated the effect of treatment with the proprietary standardized, water-soluble extract of the root of the Malaysian plant, Eurycoma longifolia Jack, which is thought to enhance male fertility with regard to higher semen volumes, sperm concentrations, the percentage of normal sperm morphology and sperm motility in male partners of sub-fertile couples with idiopathic infertility. A total of 350 patients were given 200 mg of the extract daily and follow-up semen analyses were performed every 3 months for 9 months. Of these 350 patients, 75 patients completed one full cycle of 3 months. Follow-up semen analyses in these patients showed significant improvement in all semen parameters. The proprietary extract of Eurycoma longifolia Jack significantly improved the sperm quality in these patients, allowing for 11 (14.7%) spontaneous pregnancies.

Toxic effects of Litsea elliptica Blume essential oil on red blood cells of Sprague-Dawley rats

Litsea elliptica Blume leaves have been traditionally used as medicinal herbs because of its antimutagenicity, chemopreventative and insecticidal properties. In this study, the toxic effects of L. elliptica essential oil against Sprague-Dawley rat's red blood cells (RBCs) were evaluated. L. elliptica essential oil was given by oral gavage 5 times per week for 3 treated groups in the doses of 125, 250, and 500 mg/(kg body weight), respectively, and the control group received distilled water. Full blood count, RBC osmotic fragility, RBC morphological changes, and RBC membrane lipid were analyzed 28 d after the treatment. Although L. elliptica essential oil administration had significantly different effects on hemoglobin (Hb), mean cell hemoglobin concentration (MCHC), mean cell volume (MCV), and mean cell hemoglobin (MCH) in the experimental groups as compared to the control group (P<0.05), the values were still within the normal range. L. elliptica induced morphological changes of RBC into the form of echinocyte. The percentage of echinocyte increased significantly among the treated groups in a dose-response manner (P<0.001). The concentrations of RBC membrane phospholipids and cholesterol of all treated groups were significantly lower than those of control group (P<0.001). However, the RBC membrane osmotic fragility and total proteins of RBC membrane findings did not differ significantly between control and treated groups (P>0.05). It is concluded that structural changes in the RBC membrane due to L. elliptica essential oil administration did not cause severe membrane damage.

Eurycomanone induce apoptosis in HepG2 cells via up-regulation of p53

Background

Eurycomanone is a cytotoxic compound found in Eurycoma longifolia Jack. Previous studies had noted the cytotoxic effect against various cancer cell lines. The aim of this study is to investigate the cytotoxicity against human hepato carcinoma cell in vitro and the mode of action. The cytotoxicity of eurycomanone was evaluated using MTT assay and the mode of cell death was detected by Hoechst 33258 nuclear staining and flow cytometry with Annexin-V/propidium iodide double staining. The protein expression Bax, Bcl-2, p53 and cytochrome C were studied by flow cytometry using a spesific antibody conjugated fluorescent dye to confirm the up-regulation of p53 and Bax in cancer cells.

Results

The findings suggested that eurycomanone was cytotoxic on cancerous liver cell, HepG2 and less toxic on normal cells Chang's liver and WLR-68. Furthermore, various methods proved that apoptosis was the mode of death in eurycomanone-treated HepG2 cells. The characteristics of apoptosis including chromatin condensation, DNA fragmentation and apoptotic bodies were found following eurycomanone treatment. This study also found that apoptotic process triggered by eurycomanone involved the up-regulation of p53 tumor suppressor protein. The up-regulation of p53 was followed by the increasing of pro-apoptotic Bax and decreasing of anti-apoptotic Bcl-2. The increased of cytochrome C levels in cytosol also results in induction of apoptosis.

Conclusion

The data suggest that eurycomanone was cytotoxic on HepG2 cells by inducing apoptosis through the up-regulation of p53 and Bax, and down-regulation of Bcl-2.

The Production of 9-methoxycanthin-6-one from Callus Cultures of (Eurycoma longifolia Jack) Tongkat Ali

Plant cell culture technology is potentially useful in producing high-valued secondary metabolites. Eurycoma longifolia root extracts are consumed as a health tonic but more popularly used as an aphrodisiac. Studies on the aphrodisiac properties and the possible compounds involved have been widely studied. There are many potentially useful compounds reported from the root extracts of E. longifolia. However, studies on the in vitro production of useful compounds from this plant have not been reported. This chapter will describe methods of callus induction and extraction of 9-methoxycanthin-6-one from E. longifolia Jack explants with emphasis on the tap and fibrous roots. This compound, known to have anti-tumour activity, is present in intact plant parts and in callus tissues of different explants.

Promoting potential of a Jamaica quassia extract in a rat medium-term hepatocarcinogenesis bioassay

Jamaica quassia extract (JQE), a natural bittering agent, was investigated for hepatocarcinogenesis-promoting potential using a medium-term liver bioassay system. F344 male rats were given a single intraperitoneal injection of diethylnitrosamine (200mg/kg body weight) and then starting 2 weeks later, received JQE in the diet at concentrations of 500, 5000 or 30,000 ppm for 6 weeks. Animals for tumor promotion (+) and (-) controls were fed 500 ppm sodium phenobarbital (PB) and basal diet, respectively during the promotion phase in this model. All animals were subjected to two-thirds partial hepatectomy at week 3 and killed at week 8. As with the PB-promoted case, both numbers and areas of glutathione S-transferase placental form-positive liver cell foci were significantly increased by JQE at 30,000 ppm, with non-significant increases evident at 5000 ppm. The results thus indicate that JQE at high dose has promoting potential for rat hepatocarcinogenesis.

Antimalarial and cytotoxic activities of ethnopharmacologically selected medicinal plants from South Vietnam

Malaria is a major global public health problem and the alarming spread of drug resistance and limited number of effective drugs now available underline how important it is to discover new antimalarial compounds. An ethnopharmacological investigation was undertaken of medicinal plants traditionally used to treat malaria in the South Vietnam. Forty-nine plants were identified, 228 extracts were prepared and tested for their in vitro activity against Plasmodium falciparum, and assessed for any cytotoxicity against the human cancer cell line HeLa and the embryonic lung MRC5 cell line. In a first screening at a concentration of 10 microg/ml, 92 extracts from 46 plants showed antiplasmodial activity (parasite growth inhibition >30%). The IC(50) values of the most active extracts were determined as well as their selectivity towards Plasmodium falciparum in comparison to their cytotoxic effects against the human cell lines. Six plants showed interesting antiplasmodial activity (IC(50) ranging from 0.4 to 8.6 microg/ml) with a good selectivity: two Menispermaceae, Arcangelisia flava (L.) Merr. and Fibraurea tinctoria Lour., and also Harrisonia perforata (Blanco) Merr. (Simaroubaceae), Irvingia malayana Oliv. ex Benn. (Irvingiaceae), Elaeocarpus kontumensis Gagn. (Elaeocarpaceae) and Anneslea fragrans Wall. (Theaceae).

Screening of selected indigenous plants of Cambodia for antiplasmodial activity

The in vitro antiplasmodial activity of 117 aqueous, methanol and dichloromethane extracts derived from different parts of 28 indigenous wild plant species was studied. These plants are commonly used in Cambodian traditional medicine. The plant extracts were tested for in vitro activity against a chloroquine resistant Plasmodium falciparum strain (W2). Nine extracts were moderately active with IC(50) values ranging between 5 and 10 microg/ml, 17 extracts were active with IC(50) values ranging between 1 and 5 microg/ml. These 26 extracts derived from eight plants belong to six families. The most active extracts were dichloromethane and came from Stephania rotunda and Brucea javanica with IC(50) values of 1 microg/ml and a selectivity index > or = 25. It is interesting to note that some aqueous extracts were as active as dichloromethane extracts especially aqueous extracts of Stephania rotunda, Brucea javanica, Phyllanthus urinaria and Eurycoma longifolia with IC(50) values of < or = 4 microg/ml. These results are in agreement with statements of healers on traditional uses of these plants for the treatment of malaria and/or fever. In this study, we report the antiplasmodial potential activity of eight plant species from Cambodia. Among them four are tested for the first time.

Antiplasmodial studies of Eurycoma longifolia Jack using the lactate dehydrogenase assay of Plasmodium falciparum

The roots of Eurycoma longifolia Jack have been used as traditional medicine to treat malaria. A systematic bioactivity-guided fractionation of this plant was conducted involving the determination of the effect of its various extracts and their chemical constituents on the lactate dehydrogenase activity of in vitro chloroquine-resistant Gombak A isolate and chloroquine-sensitive D10 strain of Plasmodium falciparum parasites. Their antiplasmodial activity was also compared with their known in vitro cytotoxicity against KB cells. Four quassinoids, eurycomanone (1), 13,21-dihydroeurycomanone (3), 13 alpha(21)-epoxyeurycomanone (4), eurycomalactone (6) and an alkaloid, 9-methoxycanthin-6-one (7), displayed higher antiplasmodial activity against Gombak A isolate but were less active against the D10 strain when compared with chloroquine. Amongst the compounds tested, 1 and 3 showed higher selectivity indices obtained for the cytotoxicity to antiplasmodial activity ratio than 14,15 beta-dihydroxyklaineanone (2), eurycomanol (5), 6 and 7.