New robustaflavone from Garcinia latissima Miq. leave and Its antibacterial activity.

Isolation and determination of antibacterial compounds from plants are essential to obtain a new antibacterial as a substitute for conventional resistant antibiotics. This study aims to isolate and identify a new robustaflavone as antibacterial activity from Garcinia latissima Miq. leave. In this study, the isolation process was carried out using column chromatography followed by preparative thin layer chromatography (TLC) based on the TLC profile. The fraction D was tested for anti-bacterial Bacillus subtilis using the TLC bioautography method. The isolates obtained were then identified using 1H-NMR, 13C-NMR, distortionless enhancement by polarization transfer, heteronuclear single quantum coherence, and heteronuclear multiple bond coherence. The Activity assay of the isolate was performed using the microdilution method. A pure compound obtained the result of the separation process with eluent n-hexane: Ethyl acetate (3:2) with Rf 0.6. This spot follows the spot in the contact bioautographic result of fraction D, the spot with Rf 0.6 gives an inhibition zone. After identifying and purifying the isolate were known as Robustaflavone, this compound has activity against B. subtilis with a (minimum inhibitory concentration) value of 2500 ppm. Robustaflavone successfully isolated and identified from G. latissima leave and its antibacterial activity.

Cytotoxic effects of the biflavonoids isolated from Selaginella trichoclada on MCF-7 cells and its potential mechanism.

A new biflavonoid, (2''S)-6''-methyl-2'',3''-dihydroochnaflavone (1), along with two known ochnaflavones (2, 3), four known amentoflavones (4-7) and two known robustaflavones (8, 9) were obtained from the 70% EtOH extract of Selaginella trichoclada. The chemical structures of isolated compounds were elucidated by extensive spectroscopic analyses. Overall, compounds 1-9 displayed moderate cytotoxic effects against human breast cancer MCF-7 cell lines. Among them, compounds 2 and 8 exhibited relatively strong cytotoxic effects against MCF-7 cells with an IC50 value of 7.7 and 6.9 µΜ, respectively. The results of RNA-sequencing and KEGG functional enrichment analysis showed that 8 could induce ferroptosis in MCF-7 cells by down-regulating the expression of ferroptosis-related genes including ACSL4, NOXO1, NOXA1, ACSL5, STEAP3, LPCAT3, ATG7 and TP53. Then 8 could inhibit the expression of ACSL4 proteins through molecule docking analysis, which showed a strong interaction of - 11.89 Kcal/mol binding energy. Those results indicate that 8 could be chemotherapy agents to fight drug resistance in breast cancer by down-regulating the expression level of ACSL4 proteins via ferroptosis, which needs to be further certified in vitro.

Two new biflavanoids from Selaginella trichoclada Alsto.

Two new robustaflavones, (±)-trichocladabiflavone A (1) and uncinatabiflavone E (2), along with seven known biflavanoids (3-9) were isolated from the 70% EtOH extract of Selaginella trichoclada. Their structures and absolute configurations were established by extensive spectroscopic and circular dichroism (CD) analyses. Compound 1 was resoluted into optically pure enantiomers (+)-1 and (-)-1 by chiral-phase HPLC. Moreover, compounds 1 and 2 exhibited moderate cytotoxicity against A549 and HepG2 human cancer cell lines.

Robustaflavone Isolated from Nandina domestica Using Bioactivity-Guided Fractionation Downregulates Inflammatory Mediators.

Nandina domestica (Berberidaceae) has been used in traditional medicine for the treatment of cough. This plant is distributed in Korea, Japan, China, and India This study aimed to investigate the anti-inflammatory phytochemicals obtained from the N. domestica fruits. We isolated a biflavonoid-type phytochemical, robustaflavone (R), from N. domestica fruits through bioactivity-guided fractionation based on its capacity to inhibit inflammation. The anti-inflammatory mechanism of R isolated from N. domestica has not yet been studied. In the present study, we evaluated the anti-inflammatory activities of R using lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. We have shown that R reduces the production of nitric oxide (NO), pro-inflammatory cytokine interleukin-1 beta (IL-1ß), and IL-6. Western blot analysis showed that R suppresses the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), and downregulates the expression of LPS-induced nuclear factor-kappa B (NF-κB) and the phosphorylation of extracellular-regulated kinases (pERK 1/2). Moreover, R inhibited IL-8 release in LPS-induced human colonic epithelial cells (HT-29). These results suggest that R could be a potential therapeutic candidate for inflammatory bowel disease (IBD).

Evaluation of the diuretic activity in two Mexican medicinal species: Selaginella nothohybrida and Selaginella lepidophylla and its effects with ciclooxigenases inhibitors.

ETHNOPHARMACOLOGICAL RELEVANCE: Doradilla is a plant that has a long history in the Mexican traditional system of medicine for gall and renal stones, diuresis, stomach and liver inflammation among other diseases. Major components isolated from these plants include biflavonoids as amentoflavone (1), robustaflavone (2) and (S)-2,3-dihydrorobustaflavone (3) and the carbohydrate trehalose (4). The aim of this study was to evaluate the diuretic effect of the decoction of Selaginella nothohybrida Valdespino and Selaginella lepidophylla (Hook & Grev) Spring (Selaginellaceae), and compounds 1-4. We also explored the probable mode of action comparing the effects when using nonspecific and specific COX׳s inhibitors. MATERIALS AND METHODS: Three biflavonoids (1-3) were isolated from the ethyl acetate extraction of the aqueous decoction and the carbohydrate trehalose (4) from the aqueous phase. The structures of all compounds were elucidated by spectroscopic methods and comparisons were made against published data. The diuretic activity was assessed in mice by oral administration of the decoctions in doses of 1000 and 2000mg/kg and biflavonoids 1-3 and trehalose (4) in a dose range of 10mg/kg using furosemide as a standard drug. Inhibitors of COX׳s such as acetyl salicylic acid, sodium naproxen, indomethacin and Celebrex were also assayed to analyze the involvement of renal prostaglandins in diuresis. Water excretion rate, pH, density, conductivity, and contents of Na(+) and K(+) were measured in the urine of mice. RESULTS: Decoction of Selaginella lepidophylla showed lower effect in the urine output at doses of 1000 and 2000mg/kg, while decoction of Selaginella nothohybrida produced an increase at 2000mg/kg (P<0.05). Urinary electrolytes excretion was also affected by this last extract and pure compounds: decoction diminished urinary excretion of sodium and potassium ions, so as compounds 1 and 4; compounds 2 and 3 observed just a natriuretic effect. Pretreated mice with COX׳s inhibitors and then with test compounds 1, 2, 4 and decoction showed inhibition of diuresis in all cases exception for treatment with trehalose (4); natriuretic effect was observed in all cases except for biflavonoid robustaflavone (2) which behaved as the reference compound furosemide. Selaginella nothohybrida decoction behaved similarly to COX-2 inhibitor Celebrex (8), inhibiting diuresis. CONCLUSIONS: Selaginella nothohybrida presents a moderate diuretic effect, which appears to be in partly mediated by the presence of biflavonoids and trehalose. Renal prostaglandins may be involved in the mechanism of diuresis. The present results provide a quantitative basis explaining the traditional folk medicine use of Selaginella nothohybrida as a diuretic agent by Mexican population.

In vitro activity of the hydroethanolic extract and biflavonoids isolated from Selaginella sellowii on Leishmania (Leishmania) amazonensis

This study is the first phytochemical investigation of Selaginella sellowii and demonstrates the antileishmanial activity of the hydroethanolic extract from this plant (SSHE), as well as of the biflavonoids amentoflavone and robustaflavone, isolated from this species. The effects of these substances were evaluated on intracellular amastigotes of Leishmania (Leishmania) amazonensis, an aetiological agent of American cutaneous leishmaniasis. SSHE was highly active against intracellular amastigotes [the half maximum inhibitory concentration (IC50) = 20.2 µg/mL]. Fractionation of the extract led to the isolation of the two bioflavonoids with the highest activity: amentoflavone, which was about 200 times more active (IC50 = 0.1 μg/mL) and less cytotoxic than SSHE (IC50 = 2.2 and 3 μg/mL, respectively on NIH/3T3 and J774.A1 cells), with a high selectivity index (SI) (22 and 30), robustaflavone, which was also active against L. amazonensis (IC50 = 2.8 µg/mL), but more cytotoxic, with IC50 = 25.5 µg/mL (SI = 9.1) on NIH/3T3 cells and IC50 = 3.1 µg/mL (SI = 1.1) on J774.A1 cells. The production of nitric oxide (NO) was lower in cells treated with amentoflavone (suggesting that NO does not contribute to the leishmanicidal mechanism in this case), while NO release was higher after treatment with robustaflavone. S. sellowii may be a potential source of biflavonoids that could provide promising compounds for the treatment of cutaneous leishmaniasis.