New Naphthalene Derivatives from the Bulbs of Eleutherine americana with Their Protective Effect on the Injury of HUVECs

NMR-based metabolic profiling and antioxidant activity of Eleutherine bulbosa bulb ethanol extract

The metabolite profile of the ethanol extract from Eleutherine bulbosa was assessed using the 1D NMR approach amalgamated with 2D NMR. E. bulbosa, an indigenous plant found in Indonesia, possesses considerable promise as a raw material for medicinal products. We examined the antioxidant capacity of the E. bulbosa extract using DPPH and ABTS methods. The antioxidant evaluation demonstrated that the ethanol extract exhibits strong antioxidant properties. Furthermore, we have successfully identified thirteen metabolites in the ethanol extract without separation. These metabolites include eleutherol A, eleutherol B, eleutherol C, eleuthione B, eleuthione C, hongconin, karwinaphthol, isoeleuthoside C, quinic acid, chlorogenic acid, isoeleutherin, cyanidin-3-o-β-glucopyranoside, and kadsuric acid. Metabolite Cyanidin-3-o-β-glucopyranoside (4.89 mM ± 0.02) was the highest metabolite contained in this extract. This result showed that NMR methods could detect and measure metabolites in the E. bulbosa ethanol extract without requiring separation.

In Vitro Cytotoxic Effects and Mechanisms of Action of Eleutherine Isolated from Eleutherine plicata Bulb in Rat Glioma C6 Cells

Gliomas are the most common primary malignant brain tumors in adults, and have a poor prognosis, despite the different types of treatment available. There is growing demand for new therapies to treat this life-threatening tumor. Quinone derivatives from plants have received increased interest as potential anti-glioma drugs, due to their diverse pharmacologic activities, such as inhibiting cell growth, inflammation, tumor invasion, and promoting tumor regression. Previous studies have demonstrated the anti-glioma activity of Eleutherine plicata, which is related to three main naphthoquinone compounds-eleutherine, isoeleutherine, and eleutherol-but their mechanism of action remains elusive. Thus, the aim of this study was to investigate the mechanism of action of eleutherine on rat C6 glioma. In vitro cytotoxicity was evaluated by MTT assay; morphological changes were evaluated by phase-contrast microscopy. Apoptosis was determined by annexin V-FITC-propidium iodide staining, and antiproliferative effects were assessed by wound migration and colony formation assays. Protein kinase B (AKT/pAKT) expression was measured by western blot, and telomerase reverse transcriptase mRNA was measured by quantitative real-time polymerase chain reaction (qRT-PCR). Eleutherine reduced C6 cell proliferation in a dose-dependent manner, suppressed migration and invasion, induced apoptosis, and reduced AKT phosphorylation and telomerase expression. In summary, our results suggest that eleutherine has potential clinical use in treating glioma.

The Effect of Tiwari Onion (Eleutherine americana Merr) Tablet on Blood Pressure Stability in Diagnosed Hypertension Patients

BACKGROUND: Non-pharmacological management is carried out by adjusting the lifestyle and non-pharmacological therapy for hypertension sufferers. They use herbal therapy, which is believed to have low side effects, easy, and inexpensive, such as Eleutherine americana Merr Tea. AIM: This study aimed to analyze Effect of E. americana Merr Tablet on blood pressure in hypertensive patients to be used as supportive therapy to reduce and stabilize blood pressure. METHODS: This study used a quasi-experimental research design pre-post-test with a control group design, involving 30 respondents. Data collection was carried out for 1 month. Then blood pressure observations were carried out every 1 week for a month after giving E. americana tablets. The sampling technique was purposive sampling method. The data analysis used was the Independent Sample T-Test with a significance level of p < 0.05. RESULTS: The majority of respondents according to age were in the final elderly age range; 15 people (50%) were 56–65 years old. Most of the respondents involved were female, about 18 people (60%). The respondents’ hypertension category included hypertension Grade 1 (57%) and hypertension Grade II (43%). The independent sample t-test obtained p = systole was 0.029 and diastole was 0.000 (p < 0.005). It showed a significant difference in blood pressure before and after being given E. americana tablets in hypertensive patients. CONCLUSION: Significant decrease in systolic and diastolic blood pressure in patients with suspected hypertension who obtained E. americana tablets.

Eleutherine bulbosa (Mill.) Urb. Bulb: Review of the Pharmacological Activities and Its Prospects for Application

Natural product is an excellent candidate for alternative medicine for disease management. The bulb of E. bulbosa is one of the notable Iridaceae family with a variety therapeutic potential that is widely cultivated in Southeast Asia. The bulb has been used traditionally among the Dayak community as a folk medicine to treat several diseases like diabetes, breast cancer, nasal congestion, and fertility problems. The bulb is exceptionally rich in phytochemicals like phenolic and flavonoid derivatives, naphthalene, anthraquinone, and naphthoquinone. The electronic database was searched using various keywords, i.e., E. bulbosa, E. americana, E. palmifolia, E. platifolia, and others due to the interchangeably used scientific names of different countries. Scientific investigations revealed that various pharmacological activities were recorded from the bulb of E. bulbosa including anti-cancer, anti-diabetic, anti-bacterial, anti-fungi, anti-viral, anti-inflammatory, dermatological problems, anti-oxidant, and anti-fertility. The potential application of the bulb in the food industry and in animal nutrition was also discussed to demonstrate its great versatility. This is a compact study and is the first study to review the extensive pharmacological activities of the E. bulbosa bulb and its potential applications. The development of innovative food and pharma products from the bulb of E. bulbosa is of great interest.

Eleucanainones A and B: Two Dimeric Structures from the Bulbs of Eleutherine americana with Anti-MRSA Activity

Two naphthoquinone-derived heterodimers with unprecedented carbon skeletons, eleucanainones A (1) and B (2), were isolated from the bulbs of Eleutherine americana. Their structures were elucidated by comprehensive spectroscopic methods. The structures of 1 and 2 were determined to be the first examples of dibenzofuran- and naphthalenone-containing naphthoquinone dimers. Compound 1 exhibited significant anti-MRSA activity in vitro with minimum inhibitory concentration (MIC) values of 0.78 μg/mL by downregulation of basal expression of agrA, cidA, icaA and sarA in methicillin-resistant S. aureus (MRSA).

Anthraquinone-Based Specialized Metabolites from Rhizomes of Bulbine natalensis

The rhizomes of Bulbine natalensis furnished six previously unreported anthraquinone derivatives (1-6), together with eight known specialized metabolites. Their structures were determined by interpretation of 1D and 2D NMR and HRESIMS data. The absolute configurations of compounds 1-6 were determined by specific rotation and circular dichroism experiments. The isolated compounds were evaluated for antimicrobial activities, and compound 1 was found to be a moderate inhibitor (IC₅₀ 0.02 μM) against methicillin-resistant Staphylococcus aureus (MRSA).