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.
OBJECTIVE: This review was aimed to critically analyze the therapeutic viability and anticancer efficacy of Eurycoma longifolia in the treatment of cancer and also to propose its molecular and translational mechanism of cytotoxicity against cancerous cells.
RESULTS: Among a range of medicinally active compounds isolated from various parts (roots, stem, bark and leaves) of Eurycoma longifolia, 16 compounds have shown promising anti-proliferative and anticancer efficacies. Eurycomanone, one of the most active medicinal compounds of Eurycoma longifolia, displayed a strong dose-dependent anticancer efficacy against lung carcinoma (A-549 cells) and breast cancer (MCF-7 cells); however, showed moderate efficacy against gastric (MGC-803 cells) and intestinal carcinomas (HT-29 cells). The prime mode of cytotoxicity of Eurycoma longifolia and its medicinal compounds is the induction of apoptosis (programmed cell death) via the up-regulation of the expression of p53 (tumor suppressor protein) and pro-apoptotic protein (Bax) and downregulation of the expression of anti-apoptotic protein (Bcl-2). A remarkable alleviation in the mRNA expression of various cancer-associated biomarkers including heterogeneous nuclear ribonucleoprotein (hnRNP), prohibitin (PHB), annexin-1 (ANX1) and endoplasmic reticulum protein-28 (ERp28) has also been evidenced.
CONCLUSION: Eurycoma longifolia and its medicinal constituents exhibit promising anticancer efficacy and thus can be considered as potential complementary therapy for the treatment of various types of human cancers.