LC–MS/MS-based metabolites of Eurycoma longifolia (Tongkat Ali) in Malaysia (Perak and Pahang)

Bio-fabricated zinc oxide nanoparticles mediated by endophytic fungus Aspergillus sp. SA17 with antimicrobial and anticancer activities: in vitro supported by in silico studies

Introduction

In recent years, the world's attention has been drawn to antimicrobial resistance (AMR) because to the frightening prospect of growing death rates. Nanomaterials are being investigated due to their potential in a wide range of technical and biological applications.

Methods

The purpose of this study was to biosynthesis zinc oxide nanoparticles (ZnONPs) using Aspergillus sp. SA17 fungal extract, followed by characterization of the produced nanoparticles (NP) using electron microscopy (TEM and SEM), UV-analysis, X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FT-IR).

Results and Discussion

The HR-TEM revealed spherical nanoparticles with an average size of 7.2 nm, and XRD validated the crystalline nature and crystal structure features of the generated ZnONPs, while the zeta potential was 18.16 mV, indicating that the particles' surfaces are positively charged. The FT-IR was also used to identify the biomolecules involved in the synthesis of ZnONPs. The antibacterial and anticancer properties of both the crude fungal extract and its nano-form against several microbial strains and cancer cell lines were also investigated. Inhibition zone diameters against pathogenic bacteria ranged from 3 to 13 mm, while IC50 values against cancer cell lines ranged from 17.65 to 84.55 M. Additionally, 33 compounds, including flavonoids, phenolic acids, coumarins, organic acids, anthraquinones, and lignans, were discovered through chemical profiling of the extract using UPLC-QTOF-MS/MS. Some molecules, such pomiferin and glabrol, may be useful for antibacterial purposes, according to in silico study, while daidzein 4'-sulfate showed promise as an anti-cancer metabolite.

Characterisation of saponins from Hedera nepalensis in Vietnam northwest mountainous areas with the aid of high-resolution mass spectrometry

This research aims to explore the saponins composition of H. nepalensis in four northwest mountainous areas of Vietnam including Ha Giang, Lai Chau, Lao Cai, and Lang Son with the aid of high-resolution mass spectrometry. As a result, 42 saponins are successfully identified in H. nepalensis leaves by UHPLC-Q-TOF-MS/MS analyses, in which two 30-noroleanane and four oleanane triterpene saponins structures have been reported for the first time. Two structures of compound 20 were discovered in four samples. Two structures of compound 8 were found in H. nepalensis from Ha Giang and Lao Cai, while two structures of compound 28 were not observed in Lang Son. Different environmental and climatic circumstances in various places may have an impact on chemical constituents of H. nepalensis. By providing the phytochemicals profile of H. nepalensis leaves, our study supports the orientation for future research on this medicinal plant as well as other Hedera species.

Eurycoma longifolia alkaloid components ameliorate hyperuricemic nephropathy via regulating serum uric acid level and relieving inflammatory reaction

Hyperuricemia is an independent risk factor for chronic kidney disease. We have previously showed the uric-acid-lowering effect of Eurycoma longifolia Jack, yet the renal protective effect and mechanism of E. longifolia remain obscure. The mouse model of hyperuricemic nephropathy was induced by adenine combined with potassium oxonate in male C57BL/6 J mice. E. Longifolia alkaloid components could reduce the level of serum uric acid by regulating the expression of hepatic phosphoribosyl pyrophosphate synthase (PRPS), hypoxanthine-guanine phosphoribosyl transferase (HPRT), and renal urate transporter organic anion transporter 1 (OAT1) and ATP-binding box subfamily G member 2 (ABCG2) in HN mice. Additionally, E. Longifolia alkaloid components alleviated renal injury and function caused by hyperuricemia, which was characterized by improving renal histopathology, reducing urea nitrogen and creatinine levels. E. Longifolia alkaloid components treatment could reduce the secretion of pro-inflammatory factors by inhibiting the activation of NF-κB and NLRP3 inflammatory signaling pathways, including tumor necrosis factor α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), interleukin-1 β (IL-1β), and regulated activated normal T cell expression and secretion proteins (RANTES). Meanwhile, E. longifolia alkaloid components improved renal fibrosis, inhibited the transformation of calcium-dependent cell adhesion molecule E (E-cadherin) to α-smooth muscle actin (α-SMA) transformation, and decreased collagen 1 expression in HN mice.

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.

UHPLC-Q-TOF-MS/MS Dereplication to Identify Chemical Constituents of Hedera helix Leaves in Vietnam

Hedera helix has been reported to contain a wide range of metabolites and produce many pharmacological effects. This research demonstrates the determination and evaluation of the phytochemical profiling of H. helix grown in central Vietnam. Methanolic extract of ivy had been analyzed by ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS/MS). MS, and MS/MS experiments were manipulated using both negative and positive ionization modes to provide molecular mass information and production spectra for the structural elucidation of compounds. A total of 46 compounds including 24 triterpene saponins and other compounds were successfully identified of which four established saponin structures have been reported for the first time. This study has provided a base for building a quality control of the raw materials according to the profile of triterpene saponins and assessment of pharmaceutical ingredients of H. helix planted in Vietnam.

A Quassinoid Diterpenoid Eurycomanone from Eurycoma longifolia Jack Exerts Anti-Cancer Effect through Autophagy Inhibition

Eurycomanone (EN) is one of the representative quassinoid diterpenoids from roots of Eurycoma longifolia Jack, a natural medicine that is widely distributed in Southeast Asia. Previous studies showed that EN induces cancer cell apoptosis and exhibits anti-cancer activity, but the molecular mechanism of EN against cancer has still not been elucidated. In this study, we examined the regulatory effect of EN on autophagy to reveal the mechanism of EN-mediated colon cancer growth inhibition. First, we found that EN is able to inhibit colon cancer cell proliferation and colony formation. The angiogenesis level in cancer cells was inhibited as well. Next, the treatment of EN led to the suppression of autophagy, which was characterized by the downregulation of the LC3-II level and the formation of GFP-LC3 puncta under EN treatment in colon cancer. Moreover, we revealed that the mTOR signaling pathway was activated by EN in a time- and concentration-dependent manner. Finally, autophagy induction protected colon cancer cells from EN treatment, suggesting that autophagy improves cell survival. Taken together, our findings revealed the mechanism of EN against colon cancer through inhibiting autophagy and angiogenesis in colon cancer, supporting that the autophagy inhibitor EN could be developed to be a novel anti-cancer agent.

Antiplasmodial and cytotoxic effects of the methanol extract, canthinone alkaloids, squalene- and protolimonoid-type triterpenes from Homalolepis suffruticosa roots

ETHNOPHARMACOLOGICAL RELEVANCE

Different species of the Simaroubaceae family are used in traditional medicine to treat malaria. Among these is Homalolepis suffruticosa (syn. Simaba suffruticosa and Quassia suffruticosa), which is native to Central Brazil and popularly known as calunga. However, there is a lack of investigation concerning its antimalarial effects.

AIM OF THE STUDY

To investigate the antiplasmodial and cytotoxic effects of the isolated metabolites and methanol extract from H. suffruticosa roots as well as to conduct the dereplication of this extract aiming to characterize its metabolic profile by UPLC-DAD-ESI-MS/MS.

MATERIALS AND METHODS

Methanol extract of the H. suffruticosa roots and six isolated compounds were evaluated against chloroquine-resistant Plasmodium falciparum W2 strain by the PfLDH method and cytotoxicity in HepG2 cells by the MTT assay. Dereplication of the extract was performed by UPLC-DAD-ESI-MS/MS.

RESULTS

The six isolated compounds disclosed high to moderate antiplasmodial activity (IC₅₀ 0.0548 ± 0.0083 μg/mL to 26.65 ± 2.40 μg/mL) and cytotoxicity was in the range of CC₅₀ 0.62 ± 0.33 μg/mL to 56.43 ± 2.54 μg/mL, while 5-metoxycantin-6-one proved to be the most potent constituent of the six assayed ones. The methanol extract of the roots showed high in vitro antiplasmodial activity (IC₅₀ 1.88 ± 0.56 μg/mL), moderate cytotoxicity (CC₅₀ 41.93 ± 2.30 μg/mL), and good selectivity index (SI = 22.30). Finally, C₂₀ quassinoids and canthin-6-one alkaloids were putatively identified in the H. suffruticosa methanol extract by LC-MS.

CONCLUSIONS

Taken together, the isolated compounds, mainly the 5-metoxycantin-6-one and the methanol extract from H. suffruticosa roots, disclose good antiplasmodial activity, supporting the ethnopharmacological history of the Simaroubaceae species as traditional antimalarial drugs.

Safety of Eurycoma longifolia (Tongkat Ali) root extract as a novel food pursuant to Regulation (EU) 2015/2283

Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on Eurycoma longifolia (Tongkat Ali) root extract as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF is standardised water extract prepared from the dried ground root chips of Tongkat Ali (Eurycoma longifolia Jack) and proposed by the applicant to be used as food supplement in amounts up to 200 mg/day. The target population is the adult population, except pregnant and lactating women. The characteristic components of the NF are glycosaponins (40-65%) and eurycomanone (0.8-1.5%). It can also contain canthin-6-one alkaloids and isoscopoletin (coumarin). The NF has been present in various international markets since 2009. The Panel notes positive results from the submitted in vitro chromosome aberration test, which indicates clastogenic properties of the NF. In the requested follow-up in vivo mammalian alkaline comet assay, the NF induced positive results at the highest dose tested (2,000 mg/kg body weight (bw)) at the tissues of the first site of contact (stomach and duodenum). Histopathological evaluation of the tested tissues indicated that the positive results of the comet assay were rather due to genotoxicity than cytotoxicity. Taken together, the Panel concludes that the NF has the potential to induce DNA damage, which is of concern, particularly locally for tissues that represent first sites of contact. The Panel concludes that the safety of NF has not been established under any condition of use.

An exploratory double-blind, randomized, placebo-controlled study to assess the efficacy of CitruSlim on body composition and lipid parameters in obese individuals

The prevalence of obesity in developing and developed countries has been well recognized, and the worldwide obesity rates have nearly tripled since 1975, according to the World Health Organization. CitruSlim, a standardized product containing a blend of Citrus bergamia and Eurycoma longifolia, can reduce cortisol, cholesterol, triglycerides, and hyperglycemia. These properties can contribute to reduction in body weight or body mass index (BMI) in obese patients. A randomized, double-blind, placebo-controlled clinical study was designed to evaluate the efficacy and tolerability of CitruSlim in body weight management in obese individuals, and the results were compared with that of placebo. A total of 97 participants were allocated, randomized, and treated with CitruSlim high-dose (HD, 400 mg), CitruSlim low-dose (LD, 200 mg), and placebo for 112 days. At the end of the study, CitruSlim HD and CitruSlim LD significantly reduced BMI compared to the placebo group and were well tolerated; however, it did not improve parameters associated with dyslipidemia and metabolic disturbances. The study findings suggested that CitruSlim was effective in reducing body weight in obese patients.

LC-PDA-MS/MS-Based Characterization of Key Phytochemicals in Eurycoma Longifolia Roots

The objective of the study was to fractionate the crude extract of Eurycoma longifolia (E. longifolia) roots and identify the intense peaks using HPLC-PDA-MS/MS, UPLC-MS/MS and H-NMR. Column chromatography was used to fractionate the crude extract into individual fractions using six solvent systems ranged from ethyl acetate, methanol and water in increasing polarity. Two fractions with nearly pure and intense peaks were selected for compound identification. Chromenone (coumarin) and chromone derivatives were putatively identified, besides several previously reported quassinoid glycosides (eurycomanone derived glycoside, 2,3-dehydro-4α-hydroxylongilactone glucoside, eurycomanol glycoside and eurycomanol trimer) in the fraction 11 of 100% methanol. A newly reported compound, namely hydroxyl glyyunanprosapogenin D (838 g/mol) was proposed to be the compound detected in the fraction 11 of 50% ethyl acetate and 50% methanol. This is also the first study to report the identification of chromenones and chromones in E. longifolia extract.

Attenuation of obesity related inflammation in RAW 264.7 macrophages and 3T3-L1 adipocytes by varanadi kashayam and identification of potential bioactive molecules by UHPLC-Q-Orbitrap HRMS

Obesity is associated with chronic low-grade inflammation, characterised by the up-regulation of pro-inflammatory cytokines in obese adipose tissue. In this study, 3T3-L1 CM enhanced TNF-α and IL-1β in RAW 264.7 cells compared with LPS treated cells. However, treatment with Varanadi kashayam suppressed the inflammatory changes associated with RAW 264.7 cells. Subsequently, RAW CM used to stimulate adipocytes, resulting in decreased intracellular lipid content and reduced adipogenic markers after Varanadi kashayam treatment. The chemical profiling of Varanadi kashayam using UHPLC-Q-Orbitrap-HRMS identified 194 compounds by comparing their retention time, the experimentally measured exact mass of precursor, and fragmented ions, and fragmentation pattern with spectral library and reported literature. Collectively, Varanadi kashayam act as a potent anti-inflammatory and anti-adipogenic agent that could disrupt the crosstalk between adipocytes and macrophages. Hence it could be a better candidate for reducing inflammation associated with obese adipose tissue.

Brain Cortical and Hippocampal Dopamine: A New Mechanistic Approach for Eurycoma longifolia Well-Known Aphrodisiac Activity and Its Chemical Characterization

Eurycoma longifolia Jack (Fam.: Simaroubaceae), known as Tongkat Ali (TA), has been known as a symbol of virility and sexual power for men. Metabolic profiling of the aqueous extract of E. longifolia (AEEL) using UPLC-MS/MS in both positive and negative modes allowed the identification of seventeen metabolites. The identified compounds were classified into four groups: quassinoids, alkaloids, triterpenes, and biphenylneolignans. AEEL is considered safe with oral LD₅₀ cut-off >5000 mg/kg. Oral administration of 50, 100, 200, 400, or 800 mg/kg of AEEL for 10 consecutive days to Sprague-Dawley male rats caused significant reductions in mounting, intromission, and ejaculation latencies and increased penile erection index. AEEL increased total body weight and relative weights of seminal vesicles and prostate. Total and free serum testosterone and brain cortical and hippocampal dopamine content was significantly elevated in treated groups with no significant effects on serotonin or noradrenaline content.

Solvent Fractionation and Acetone Precipitation for Crude Saponins from Eurycoma longifolia Extract

Eurycoma longifolia is a popular folk medicine in South East Asia. This study was focused on saccharide-containing compounds including saponins, mainly because of their medical potentials. Different organic solvents such as ethyl acetate, butanol, and chloroform were used to fractionate the phytochemical groups, which were consequently precipitated in cold acetone. Solvent fractionation was found to increase the total saponin content based on colorimetric assay using vanillin and sulfuric acid. Ethyl acetate fraction and its precipitate were showed to have the highest crude saponins after acetone precipitation. The samples were shown to have anti-proliferative activity comparable with tamoxifen (IC50 = 110.6 µg/mL) against human breast cancer cells. The anti-proliferative activities of the samples were significantly improved from crude extract (IC50 = 616.3 µg/mL) to ethyl acetate fraction (IC50 = 185.4 µg/mL) and its precipitate (IC50 = 153.4 µg/mL). LC-DAD-MS/MS analysis revealed that the saccharide-containing compounds such as m/z 497, 610, 723, 836, and 949 were abundant in the samples, and they could be ionized in negative ion mode. The compounds consisted of 226 amu monomers with UV-absorbing property at 254 nm, and were tentatively identified as formylated hexoses. To conclude, solvent fractionation and acetone precipitation could produce saccharide-containing compounds including saponins with higher anti-proliferative activity than crude extract against MCF-7 cells. This is the first study to use non-toxic solvents for fractionation of bioactive compounds from highly complex plant extract of E. longifolia.

Bioavailability of Eurycomanone in Its Pure Form and in a Standardised Eurycoma longifolia Water Extract

Eurycoma longifolia is one of the commonly consumed herbal preparations and its major chemical compound, eurycomanone, has been described to have antimalarial, antipyretic, aphrodisiac, and cytotoxic activities. Today, the consumption of E. longifolia is popular through the incorporation of its extract in food items, most frequently in drinks such as tea and coffee. In the current study, the characterisation of the physicochemical and pharmacokinetic (PK) attributes of eurycomanone were conducted via a series of in vitro and in vivo studies in rats and mice. The solubility and chemical stability of eurycomanone under the conditions of the gastrointestinal tract environment were determined. The permeability of eurycomanone was investigated by determining its distribution coefficient in aqueous and organic environments and its permeability using the parallel artificial membrane permeability assay system and Caco-2 cultured cells. Eurycomanone’s stability in plasma and its protein-binding ability were measured by using an equilibrium dialysis method. Its stability in liver microsomes across species (mice, rat, dog, monkey, and human) and rat liver hepatocytes was also investigated. Along with the PK evaluations of eurycomanone in mice and rats, the PK parameters for the Malaysian Standard (MS: 2409:201) standardised water extract of E. longifolia were also evaluated in rats. Both rodent models showed that eurycomanone in both the compound form and extract form had a half-life of 0.30 h. The differences in the bioavailability of eurycomanone in the compound form between the rats (11.8%) and mice (54.9%) suggests that the PK parameters cannot be directly extrapolated to humans. The results also suggest that eurycomanone is not readily absorbed across biological membranes. However, once absorbed, the compound is not easily metabolised (is stable), hence retaining its bioactive properties, which may be responsible for the various reported biological activities.

A self-feedback network based on liquid chromatography-quadrupole-time of flight mass spectrometry for system identification of β-carboline alkaloids in Picrasma quassioides

Profiling chemical components in herbs by mass spectrometry is a challenging work because of the lack of standard compounds, especially for position isomers. This paper provides a strategy based on a self-feedback network of mass spectra (MS) data to identify chemical constituents in herbs by liquid chromatography-quadrupole-time of flight mass spectrometry without compound standards. Components sharing same skeleton were screened and all ions were classified into a database. All candidates were connected by the selected bridging ions to establish a primary MS network. Benefited from such a network, it is feasible to characterize sequentially the structures of all diagnostic ions and candidates once single component has been de novo identified. Taking Picrasma quassioides as an example, the primary network of β-carbolines was established with 65 ions (selected from 76 β-carbolines), each of which appeared at least in four compounds. Once an alkaloid has been identified, its logical ions could feedback into primary network to build pathways with other unknown compounds. Moreover, the position of the substituent groups could be deduced through the secondary metabolic pathways of alkaloids (plant secondary metabolism). The network therefore can be utilized for identification of unknown compounds and even their position isomers.

A tricyclic pyrrolobenzodiazepine produced by Klebsiella oxytoca is associated with cytotoxicity in antibiotic-associated hemorrhagic colitis

Cytotoxin-producing Klebsiella oxytoca is the causative agent of antibiotic-associated hemorrhagic colitis (AAHC). Recently, the cytotoxin associated with AAHC was identified as tilivalline, a known pentacyclic pyrrolobenzodiazepine (PBD) metabolite produced by K. oxytoca Although this assertion of tilivalline's role in AAHC is supported by evidence from animal experiments, some key aspects of this finding appear to be incompatible with toxicity mechanisms of known PBD toxins. We therefore hypothesized that K. oxytoca may produce some other uncharacterized cytotoxins. To address this question, we investigated whether tilivalline alone is indeed necessary and sufficient to induce cytotoxicity or whether K. oxytoca also produces other cytotoxins. LC-MS- and NMR-based metabolomic analyses revealed the presence of an abundant tricyclic PBD, provisionally designated kleboxymycin, in the supernatant of toxigenic K. oxytoca strains. Moreover, by generating multiple mutants with gene deletions affecting tilivalline biosynthesis, we show that a tryptophanase-deficient, tilivalline-negative K. oxytoca mutant induced cytotoxicity in vitro similar to tilivalline-positive K. oxytoca strains. Furthermore, synthetic kleboxymycin exhibited greater than 9-fold higher cytotoxicity than tilivalline in TC₅₀ cell culture assays. We also found that the biosynthetic pathways for kleboxymycin and tilivalline appear to overlap, as tilivalline is an indole derivative of kleboxymycin. In summary, our results indicate that tilivalline is not essential for inducing cytotoxicity observed in K. oxytoca-associated AAHC and that kleboxymycin is a tilivalline-related bacterial metabolite with even higher cytotoxicity.

Determination of eurycomanone in rat plasma using hydrophilic interaction liquid chromatography-tandem mass spectrometry for pharmacokinetic study

In this study, a rapid, sensitive, and reliable hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS) method for the determination of eurycomanone in rat plasma was developed and validated. Plasma samples were pretreated with a protein precipitation method and quercitrin was used as an internal standard (IS). A HILIC silica column (2.1 × 100 mm, 3 μm) was used for hydrophilic-based chromatographic separation, using the mobile phase of 0.1% formic acid with acetonitrile in gradient elution at a flow rate of 0.25 mL/min. Precursor-product ion pairs for multiple-reaction monitoring were m/z 409.1 → 391.0 for eurycomanone and m/z 449.1 → 303.0 for IS. The linear range was 2-120 ng/mL. The intra- and inter-day accuracies were between 95.5 and 103.4% with a precision of <4.2%. The developed method was successfully applied to the pharmacokinetic analysis of eurycomanone in rat plasma after oral dosing with pure compound and E. longifolia extract. The C_max and AUC_0-t , respectively, were 40.43 ± 16.08 ng/mL and 161.09 ± 37.63 ng h/mL for 10 mg/kg eurycomanone, and 9.90 ± 3.97 ng/mL and 37.15 ± 6.80 ng h/mL for E. longifolia extract (2 mg/kg as eurycomanone). The pharmacokinetic results were comparable with each other, based on the dose as eurycomanone.

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.

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.

Development and validation of liquid chromatography combined with tandem mass spectrometry methods for the quantitation of simalikalactone E in extracts of Quassia amara L. and in mouse blood

INTRODUCTION

Simalikalactone E (SkE) from Quassia amara, has been proved to be a valuable anti-malarial and anti-cancer compound. As SkE is very scarce, methods of quantitation are needed in order to optimise its isolation process and to determine pharmacokinetic data.

OBJECTIVE

To validate methods using liquid chromatography coupled to mass spectrometry for the quantitation of SkE in plant extracts and in biological fluids.

METHODS

High- and ultrahigh-performance liquid chromatography (UHPLC) coupled to ion trap mass spectrometry (MS) with single ion monitoring detection and to triple quadrupole-linear ion trap tandem mass spectrometry with multiple reaction monitoring detection methods were developed. Validation procedure was realised according to the International Conference on Harmonisation guideline. Methanol extracts of dried Quassia amara leaves, and mouse-blood samples obtained after various routes of administration, were analysed for SkE.

RESULTS

Methods were validated and gave similar results regarding the content of SkE expressed per kilogram of dry leaves in the traditional decoction (160 ± 12 mg/kg) and in the methanol extract (93 ± 2 mg/kg). The recovery of the analyte from mouse blood ranged from 80.7 to 119.8%. Simalikalactone E was only detected using UHPLC-MS/MS (0.2 ± 0.03 mg/L) in mouse blood after intravenous injection: none was detected following intraperitoneal or oral gavage administration of SkE.

CONCLUSION

The LC-MS methods were used for the quantitation of SkE in plant extracts and in mouse blood. These methods open the way for further protocol optimisation of SkE extraction and the determination of its pharmacokinetic data.