Flavonoids from the capitula of Eriocaulon australe

Three new feruloyl glucuronopyranosyl glycerols from Eriocaulon buergerianum with their anti-fibrotic effects on hepatic stellate cells

Three new feruloyl glucuronopyranosyl glycerols, 1-O-α-D-(2'-feruloyl) glucuronopyranosyl glycerol (1), 1-O-α-D-(3'-feruloyl) glucuronopyranosyl glycerol (2), and 1-O-α-D-(4'-feruloyl) glucuronopyranosyl glycerol (3) were isolated and purified from the capitulum of Eriocaulon buergerianum Koern. Their structures were identified by spectroscopic and chemical methods. Molecular docking study showed that 1 is a potential inhibitor of TGF-β1 receptor. Bioassay results revealed that 1 exhibited strong inhibitory activity against the TGF-β-induced expression of α-smooth muscle actin (α-SMA) and fibronectin in human hepatic stellate LX-2 cells. The results in this study indicated that the new feruloyl glucuronopyranosyl glycerol 1 has preventive and therapeutic potentials against hepatic fibrosis.

Cytotoxic activity of flavonoid from local plant Eriocaulon cinereum R.B against MCF-7 breast cancer cells

Eriocaulon cinereum R. Br is used as traditional medicine by the local community in Bangka Belitung Island, Indonesia. The plant is processed as an infusion for fever, boosts the immune system, and treats tumor cells. However, scientific research on this species is still limited. The aims of this study were to determine the cytotoxic of E. cinereum against MCF-7 cells. The results suggested that one of the compounds has a good cytotoxic activity. Therefore, it is quite promising in the effort of cancer drug discovery. The active compound has a flavonoid, which plays a role in several anticancer mechanisms. This study provided scientific evidence regarding the utilization of E. cinereum by the local community for cancer therapy. The plant can be further developed as an alternative agent to treat cancer or as cancer adjuvant therapy.

Stevia Genus: Phytochemistry and Biological Activities Update

The Stevia genus (Asteraceae) comprises around 230 species, distributed from the southern United States to the South American Andean region. Stevia rebaudiana, a Paraguayan herb that produces an intensely sweet diterpene glycoside called stevioside, is the most relevant member of this genus. Apart from S. rebaudiana, many other species belonging to the Stevia genus are considered medicinal and have been popularly used to treat different ailments. The members from this genus produce sesquiterpene lactones, diterpenes, longipinanes, and flavonoids as the main types of phytochemicals. Many pharmacological activities have been described for Stevia extracts and isolated compounds, antioxidant, antiparasitic, antiviral, anti-inflammatory, and antiproliferative activities being the most frequently mentioned. This review aims to present an update of the Stevia genus covering ethnobotanical aspects and traditional uses, phytochemistry, and biological activities of the extracts and isolated compounds.

Understanding evolution in Poales: Insights from Eriocaulaceae plastome

In this study, we report the plastome of Eriocaulon decemflorum (Eriocaulaceae) and make an effort to understand the genome evolution, structural rearrangements and gene content of the order Poales by comparing it with other available plastomes. The size of complete E. decemflorum plastome is 151,671 bp with an LSC (81,477bp), SSC (17,180bp) and a pair of IRs (26,507 bp). The plastome exhibits GC content of 35.8% and 134 protein-coding genes with 19 genes duplicated in the IR region. The Eriocaulaceae plastome is characterized by the presence of accD, ycf1 and ycf2 genes and presence of introns in clpP and rpoC1 genes which have been lost in the Graminid plastomes. Phylogenomic analysis based on 81 protein-coding genes placed Eriocaulaceae sister to Mayacaceae. The present study enhances our understanding of the evolution of Poales by analyzing the plastome data from the order.

Flavonoids isolated from the fresh sweet fruit of Averrhoa carambola, commonly known as star fruit

Thirteen flavonoids were isolated from the fresh sweet fruit of Averrhoa carambola L. (Oxalidaceae), commonly known as star fruit, and their structures were determined by spectroscopic and chemical methods. 8-Carboxymethyl-(+)-epicatechin methyl ester, pinobanksin 3-O-β-d-glucoside, and carambolasides M-Q were undescribed structures. (+)-Epicatechin, aromadendrin 3-O-β-d-glucoside, helicioside A, taxifolin 3'-O-β-d-glucoside, galangin 3-O-rutinoside, and isorhamnetin 3-O-rutinoside were reported from this species for the first time. Pinobanksin 3-O-β-d-glucoside and carambolasides M-Q showed more potent 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical cation scavenging activity (IC₅₀ = 5.3-2.3 μM) than l-ascorbic acid (10.5 μM). Further, (+)-epicatechin, pinobanksin 3-O-β-d-glucoside, isorhamnetin 3-O-rutinoside, and carambolasides O-Q exhibited weak porcine pancreatic lipase inhibitory activity.

Morphological and chemical analyses of Eriocauli Flos sold in Taiwan markets

Eriocauli Flos (Gujingcao; EF), the dried capitulum with the peduncle of Eriocaulon buergerianum Koern. (Eriocaulaceae), is a Chinese herbal medicine for treating eye diseases and inflammation. However, several species of the Eriocaulon genus are used as substitutes in different areas. To examine the species of EF used in Taiwan and to establish the quality control platform, morphological and chemical analyses have been performed. Ten major compounds, including apigenin (7) and its 7-O-β-D-glucopyranoside (1) and 7-O-(6-O-E-coumaroyl)-β-D-glucopyranoside (6), hispidulin (8) and its 7-O-β-D-glucopyranoside (2) and 7-O-(6-O-E-coumaroyl)-β-D-glucopyranoside (5), jaceosidin (9) and its 7-O-β-D-glucopyr-anoside (3), and toralactone (10) and its 9-O-β-D-glucopyranosyl(1→6)-β-D-glucopyranoside (4), were isolated and identified from commercially available EF. Morphological investigation showed that two kinds of EFs and most of the EFs sold in Taiwan herbal markets are capitulum without the peduncle. A simultaneous high performance liquid chromatography and ultra performance liquid chromatography analyses of multiple components (1–10) in commercially available EFs, collected from different areas of Taiwan, was conducted. Results showed wide variations in morphology and chemical profiles between capitulum with and without the peduncle. In comparison with an authentic E. buergerianum, we found not only the morphology but also the chemical profile was different from both collected samples. In terms of the morphological examination, the samples without peduncle are closer to the authentic one. To ensure the correct EF materia medica is used in Taiwan so as to guarantee their therapeutic efficacy in clinical practice, further monitoring is necessary.

Hispidulin alleviated methamphetamine-induced hyperlocomotion by acting at α6 subunit-containing GABAA receptors in the cerebellum

RATIONALE

Hispidulin is a flavonoid we isolated from Clerodendrum inerme, an herb that effectively remitted a case of intractable motor tic disorders. Hispidulin was shown to be a positive allosteric modulator (PAM) of GABAA receptors, including the α6 subunit-containing subtype (α6GABAAR) that is predominantly expressed in cerebellar granule cells and insensitive to diazepam.

OBJECTIVES

We explored the action mechanism(s) of hispidulin using hyperdopaminergic mouse models induced by methamphetamine and apomorphine, based on the hyperdopaminergic nature of tic disorders.

RESULTS

Hispidulin significantly inhibited methamphetamine-induced hyperlocomotion (MIH) at i.p. doses without affecting apomorphine-induced hyperlocomotion and stereotypy behaviors or having significant benzodiazepine-like effects (BZLE), including sedation, anxiety, and motor impairment. When given by intracerebellar (i.c.b.) microinjection, hispidulin also alleviated MIH and this effect was prevented by i.c.b. coadministration of furosemide, an α6GABAAR antagonist, and mimicked by i.c.b. Ro 15-4513, an α6GABAAR PAM. Conversely, i.c.b. diazepam did not affect MIH while it reduced MIH at i.p. doses having significant BZLE. In a screening assay for 92 neurotransmitter receptors/degradation enzymes/transporters, hispidulin displayed significant (>50 % inhibition of radiolabeled ligand binding at 10 μM) binding affinity only at the benzodiazepine binding site of GABAARs (IC50 0.73∼1.78 μM) and catecholamine-o-methyl-transferase (COMT) (IC50 1.32 μM). OR-486, a more potent COMT inhibitor than hispidulin, did not affect MIH.

CONCLUSIONS

It is suggested that hispidulin alleviates MIH via acting as a PAM of cerebellar α6GABAARs, but not through COMT inhibition or affecting dopamine receptor responsiveness. Thus, selective α6GABAAR PAMs may have the potential to be a novel treatment for hyperdopaminergic disorders.

Effect of active fraction of Eriocaulon sieboldianum on human leukemia K562 cells via proliferation inhibition, cell cycle arrest and apoptosis induction

Eriocaulon sieboldianum (Sieb. & Zucc. ex Steud.), a genus of Eriocaulon in the Eriocaulaceae family, is an edible and medicinal plant used in traditional Chinese medicine. It was processed into healthcare beverages for expelling wind-heat, protecting eyes, and reducing blood fat. Also, it has been used with other herbs as Traditional Chinese herbal compound to treat cancer as adjuvants in tumor therapy in China. However, the active fractions and precise cellular mechanisms of E. sieboldianum extract remain to be illustrated. The goal of this study was to investigate the effects of the active fraction of E. sieboldianum on the growth of K562 cells and understand the possible mechanisms of its action. Our findings suggested that the fraction E3 of E. sieboldianum could effectively inhibit the activity of Aurora kinase and induce apoptosis via blocking cell cycle, up-regulating the expression of proapoptotic proteins including p53 and Bax and reducing the expression of Bcl-2. The levels of Cytochrome C, cleaved caspase-9, cleaved caspase-3 and cleaved PARP were also found to be increased after treatment with fraction E3 of E. sieboldianum. This study could improve the development of E. sieboldianum and raise its application value in cancer adjuvant therapy. Considering it is both a dietary supplement and a traditional Chinese herbal medicine which exhibits anticancer activities, it can be developed into functional food.

Characteristic features of cytotoxic activity of flavonoids on human cervical cancer cells

Cervical cancer is the most common gynecologic malignancy worldwide and development of new therapeutic strategies and anticancer agents is an urgent priority. Plants have remained an important source in the search for novel cytotoxic compounds and several polyphenolic flavonoids possess antitumor properties. In this review article, data about potential anticarcinogenic activity of common natural flavonoids on various human cervical cancer cell lines are compiled and analyzed showing perspectives for the use of these secondary metabolites in the treatment of cervical carcinoma as well as in the development of novel chemotherapeutic drugs. Such anticancer effects of flavonoids seem to differentially depend on the cellular type and origin of cervical carcinoma creating possibilities for specific targeting in the future. Besides the cytotoxic activity per se, several flavonoids can also contribute to the increase in efficacy of conventional therapies rendering tumor cells more sensitive to standard chemotherapeutics and irradiation. Although the current knowledge is still rather scarce and further studies are certainly needed, it is clear that natural flavonoids may have a great potential to benefit cervical cancer patients.

Vibrational spectroscopy and density functional theory study of 3-[4,5-dimethyl-2-thiazolyl]-2,5-diphenyl-2H-tetrazolium bromide

In this work, the structural parameters of the title molecule (MTT) have been obtained at the B3LYP/6-311++G(**) level of theory. The two phenyl rings and the two heterocyclic rings are found in four different planes. The tetrazolium ring was connected with other three rings and their distances are also different in decrease order of 1.461 Å (from tetrazolium ring to carbon connected phenyl)>1.445 Å (from tetrazolium ring to nitrogen connected phenyl)>1.425 Å (from tetrazolium ring to thiazolyl ring). Fourier transform infrared (FTIR) and Raman spectra of the compound were obtained experimentally. All FTIR and Raman bands of the compound obtained experimentally were assigned based on the modeling results obtained at the B3LYP/6-311++G(**) level. The calculated vibrational frequencies were in good agreement with the experimental values. In addition, the UV-Vis spectra were obtained experimentally and theoretically. Considering the effect of the PCM modelling error, the calculated absorbance peaks obtained at the B3LYP/6-311++G(**) level were also in good agreement with the experimental values. The HOMO-LUMO gap was predicted to be 1.83 eV at the B3LYP/6-311++G(**) level.