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

Eurycomanone from Eurycoma longifolia Jack upregulates neurotrophin-3 gene expression in retinal Müller cells in vitro

Photoreceptor degeneration decreases light sensitivity and leads to vision loss and various retinal diseases. Neurotrophin-3, originating from Müller glial cells in the retina, plays a key role in protecting photoreceptors from damage induced by light or hypoxia. This neuroprotective approach is important because there are no established methods to regenerate lost photoreceptors. Dietary supplements are one of the useful methods for improving eye health. Eurycoma longifolia (E. longifolia) Jack, which is native to the tropical forest of Malaysia and other Southeast Asian countries, exhibits several medicinal properties. In the present study, we demonstrated that the water extract of E. longifolia roots enhanced neurotrophin-3 gene expression in primary rat Müller cells. Using a stepwise bioassay-guided fractionation and purification of E. longifolia root extracts, we isolated the active compound underlying neurotrophin-3 gene-enhancing activities. Mass spectrometry and nuclear magnetic resonance spectral data identified the compound as eurycomanone. This study provides evidence for the efficacy of E. longifolia and eurycomanone in enhancing neurotrophin-3 expression in Müller cells in vitro. Although the biological significance of this effect and its underlying mechanism remain to be elucidated, this study suggests that E. longifolia may be promising for improving eye health and must be further investigated.

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.

Eurycomanol and eurycomanone as potent inducers for cell-cycle arrest and apoptosis in small and large human lung cancer cell lines

Eurycoma longifolia Jack is one of traditional herbal medicines in South-East Asia. This study evaluated the anticancer, cell-cycle arrest, and apoptotic induction potentials of eurycomanone (EONE) and eurycomanol (EOL), highly oxygenated quassinoids previously isolated from its roots, against large (H460) and small (A549) lung cancer cells. EOL and EONE exhibited IC₅₀ of 386 and 424 µg/mL on normal human lung cell line. EONE exhibited higher anticancer activity with an IC₅₀ of 1.78 µg/mL and 20.66 μg/mL than EOL which exhibited an IC₅₀ of 3.22 µg/mL and 38.05 µg/mL against H460 and A549, respectively. Both reduced the viability of H460 and A549 and arrested G0/G1 phase. The increase in the apoptotic rates was mainly in the percentage of late apoptosis. Moreover, they inhibited A549 by inducing the accumulation of S and G2/M phases. This study revealed EOL and EONE potential as novel leads exhibiting cell-cycle arrest and apoptosis induction potentials.

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.

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.

Comparing the pharmacokinetics of 13α,21-dihydroeurycomanone and eurycomanone exclusively enriched in Eurycoma longifolia extracts and their spermatogenesis enhancement in andrographolide-induced oligospermia in rats

OBJECTIVES

The quassinoids eurycomanone (EN) and 13α,21-dihydroeurycomanone (DHY) of Eurycoma longifolia Jack are reported to enhance spermatogenesis. This study aims to profile the pharmacokinetics of DHY, a minor and hitherto unstudied constituent, evaluate its spermatogenesis enhancement property and compare these attributes with that of the predominant EN.

METHODS

Crude Eurycoma longifolia extract was chromatographed into a DHY-enriched extract (DHY-F) and an EN-enriched extract (EN-F). Male Sprague-Dawley rats were administered intravenously and orally with both extracts and their plasma levels of both quassinoids were determined. The extracts were then tested for their spermatogenesis augmentation ability in normal rats and an andrographolide-induced oligospermia model.

KEY FINDINGS

Chromatographic enrichment resulted in a 28-fold increase of DHY in DHY-F and a 5-fold increase of EN in EN-F compared with non-chromatographed crude extracts. DHY showed better oral bioavailability (1.04 ± 0.58%) than EN (0.31 ± 0.19%). At 5 mg/kg, EN exhibited higher efficacy in spermatogenesis enhancement in normal rats and restoration of oligospermia to normal sperm profile versus DHY.

CONCLUSIONS

Despite the better pharmacokinetic profile of DHY, EN remains the main chemical contributor to plant bioactivity. DHY-F and EN-F represent improvements in developing Eurycoma longifolia as a potential phytomedicine for male infertility particularly oligospermia.

Herbal-Based Formulation Containing Eurycoma longifolia and Labisia pumila Aqueous Extracts: Safe for Consumption?

A combined polyherbal formulation containing tongkat ali (Eurycoma longifolia) and kacip fatimah (Labisia pumila) aqueous extracts was evaluated for its safety aspect. A repeated dose 28-day toxicity study using Wistar rats was conducted where the polyherbal formulation was administered at doses 125, 500 and 2000 mg/kg body weight to male and female treatment groups daily via oral gavage, with rats receiving only water as the control group. In-life parameters measured include monitoring of food and water consumption and clinical and functional observations. On day 29, blood was collected for haematological and biochemical analysis. The rats were necropsied and the organs were collected for histopathological examination. This study showed that the combined formulation did not induce any significant toxicity effect at any dose level in terms of morbidity, mortality, behaviour, functional observation, body weight, food and water consumption, whole blood haematology and serum biochemistry. However, there were some microscopic changes in the histopathological examinations of some organs given 2000 mg/kg body weight, which may suggest an early response to the polyherbal formulation. From this study, the no observed adverse effect level is estimated to be more than 500 mg/kg body weight but not exceeding 2000 mg/kg body weight. The observed effects at the highest dose indicate the need for further study of longer dosing duration.

Eurycoma longifolia-Infused Coffee-An Oral Toxicity Study

Coffee infused with the additive Eurycoma longifolia, also known as Tongkat ali (TA), has become widely available in the Malaysian market. Safety evaluations for consumption of the products have been called for due to the herbal addition. This study investigates the acute, subacute and chronic effects of a commercial TA coffee in Sprague Dawley rats when given in a single, repeated and prolonged dosage. The dosages of 0.005, 0.05, 0.30 and 2 g/kg body weight (BW) were used in the acute study and 0.14, 0.29 and 1 g/kg BW were used in the repeated dose studies. The in-life parameters measured were food and water intake, body weight and clinical observations. Blood were collected for hematology and clinical biochemistry analyses. All animals were subjected to full necropsies. Non-toxicity-related changes were observed in the food and water consumption parameters. Body weight showed normal increments and none of the animals had any clinical signs of toxicity. Microscopically assessed organ tissues did not reveal any abnormalities. There was significant decrease of platelet count in all the chronic study male treated groups. Significant elevation of renal profile parameters in both gender groups given 0.29 g/kg BW, along with liver and lipid profile elevation in some female groups of the chronic study were noted. No dose-dependent relationship was apparent in the dosage range tested, though these changes may suggest an initial safety indication to the TA coffee. The study concludes that the no observed adverse effect level (NOAEL) for this commercial TA coffee was 1 g/kg BW.

Metabolism of a Kratom Alkaloid Metabolite in Human Plasma Increases Its Opioid Potency and Efficacy

Kratom is widely consumed in the United States for self-treatment of pain and opioid withdrawal symptoms. Mitragynine is the most abundant alkaloid in kratom and is a μ-opioid receptor agonist. 7-Hydroxymitragynine (7-HMG) is a mitragynine metabolite that is a more potent and efficacious opioid than its parent mitragynine. 7-HMG contributes to mitragynine's antinociceptive effects in mice, but evidence suggests it may also have a higher abuse potential. This in vitro study demonstrates that 7-HMG is stable in rodent and monkey plasma but is unstable in human plasma. Surprisingly, in human plasma 7-HMG is converted to mitragynine pseudoindoxyl, an opioid that is even more potent than either mitragynine or 7-HMG. This novel metabolite is formed in human plasma to a much greater extent than in the preclinical species tested (mouse, rat, dog, and cynomolgus monkey) and due to its μ-opioid potency may substantially contribute to the pharmacology of kratom in humans to a greater extent than in other tested species.