An UHPLC/LC-MS illustrated the dynamic profiling of balanophorin B, gallic acid, and 4-hydroxycinnamic acid in rat as 3 molecular entities from Balanophora simaoensis

An UHPLC/LC-MS was founded to detect balanophorin B (B), gallic acid (GA), 4-hydroxycinnamic acid (HC), and their in vivo profiling in rats, after oral administration of the ethanol extract of Balanophora simaoensis S. Y. Chang et Tam. The in vivo dynamic existence of 3 molecular entities in rats and the multistep biotransformation of GA were elucidated by their sensitive mass spectrometry response after efficient UHPLC and/or HPLC separation, through analyzing the bio-samples of rat plasma, bile, liver, kidneys, and excreta. The method was validated with satisfactory calibration curves having correlation coefficients r from 0.996 to 0.999 for concentration scaled from 0.100 nM to 0.100 μM, internal standard normalized matrix factors ranged from 0.923 to 0.993, sextuplicate recoveries valued from 95.0% to 103.6%, as well as accuracy and precision varied from 95.6% to 103.7%. The content of B, GA, and HC in the whole herb was of 4.66, 63.5, and 10.4 μmol/kg in dry weight, respectively. The Cmax for B, GA, and HC in rat systemic circulation was of 76.0 nM, 2.30 μM, and 51.0 μM, with tmax at 3, 2, and 2 h, respectively. B and GA stayed in rat liver over 4 hs to present a material base for the pharmacology and pharmacodynamics of the whole herb. The biotransformation of GA indicated a complicated scheme in rats. As a final metabolite from GA with total biotransformation conversion over 20%, 4-hydroxybenzaldehyde resourced from two steps of dehydroxylation and one step of reduction of GA, but not concerned with HC.

Development and Validation of a UHPLC-DAD Method for the Quantitative Analysis of Major Dihydrochalcone Glucosides from Thonningia sanguinea VAHL

Thonnigia sanguinea is a plant widely used in traditional African medicine against a variety of diseases. The obligate parasite is growing throughout tropical African forests and utilizes a large variety of hosts. Dihydrochalcone glucoside derivatives isolated from the subaerial parts of this plant were identified as potential antidiabetic lead compounds. In this study, an ultrahigh-performance liquid chromatographic method coupled with a photodiode array detector was developed for the quantitation of six major dihydrochalcone derivatives. The analytes were baseline separated in complex samples within 14 minutes on a Phenomenex Luna Omega 1.6 µm C18 column using a mobile phase consisting of water and acetonitrile (each + 0.01% trifluoroacetic acid) in gradient elution. Method validation confirmed the selectivity, linearity (R² ≥ 0.9992), precision (inter-day ≤ 1.98%, intraday ≤ 2.00%), and accuracy (recovery rates of 97.4 - 106.3% for all analytes). At 280 nm, the LODs and LOQs were found to be lower than 1.42 and 4.30 µg/mL, respectively. Eight plant batches from the northern Angolan province of Uíge (collected in the wild or bought on markets) were extracted with methanol using an ultrasound-assisted extraction protocol and subsequently analyzed with the validated method. Results indicated high contents of dihydrochalcone glucosides in all eight samples. Most notably, the two bioactive constituents thonningianin A and B were present in fairly large amounts (2.42 - 5.35 w%).

Dihydrochalcone Glucosides from the Subaerial Parts of Thonningia sanguinea and Their in Vitro PTP1B Inhibitory Activities

Six new and four known dihydrochalcone glucoside derivatives (1-10), the phenylpropanoid coniferin (11), and the lignans (+)-pinoresinol (12) and lariciresinol (13) were isolated from the subaerial plant parts of Thonningia sanguinea in the course of a screening campaign for new antidiabetic lead compounds. The structures of the new substances were elucidated by HRESIMS, NMR, GC-MS, and ECD data evaluation. 2'- O-(3-Galloyl-4,6- O- S_a-hexahydroxydiphenoyl-β-d-glucopyranosyl)-3-hydroxyphloretin (4), 2'- O-(4,6- O- S_a-hexahydroxydiphenoyl-β-d-glucopyranosyl)phloretin (5), 2'- O-(3- O-galloyl-4,6- O- S_a-hexahydroxydiphenoyl-β-d-glucopyranosyl)phloretin (6), and thonningianin B (9) showed moderate protein tyrosine phosphatase-1B inhibition in an enzyme assay (IC₅₀ values ranging from 19 to 25 μM), whereas thonningianin A (10) was identified as a more potent inhibitor (IC₅₀ = 4.4 μM). The observed activity differences could be explained by molecular docking experiments. The activity of 10 could further be confirmed in HEPG2 liver carcinoma cells, where the compound was able to increase the level of phosphorylated insulin receptors in a concentration-dependent manner.

Diuretic activity of Lophophytum leandri

A bioassay-oriented study was carried-out in order to validate the traditional uses of Lophophytum leandri, a parasitic plant used as a diuretic in traditional medical practices of Argentina. Four known flavonoids have been isolated from the active fraction. Quercetin-3-O-beta-D-glucopyranoside was identified as the active principle of the fraction. However, the diuretic activity of the extract and of the most active fraction had greater activity than that of the pure isolated compounds.

[A new natural polyphenol BJA32531 inhibited the proliferation and regulated miRNA expression in human HepG2 hepatocarcinoma cells]

OBJECTIVE

To study the effect of 1,2,6-Tri-O-galloyl-beta-D-glucopyranose (BJA32531) on the miRNA expression during BJA32531-induced cytotoxicity in human HepG2 hepatocarcinoma cells.

METHODS

Cell proliferation was assessed using a colorimetric assay (cell counting kit-8). Apoptosis was assessed by annexin V and propidium iodide staining. The miRNA expression profile of the cancer cells was analyzed by a miRNA array and quantitative real-time PCR.

RESULTS

BJA32531 inhibited the cell proliferation and increased apoptosis in HepG2 cancer cells. Cellular exposure to BJA32531 influenced the miRNA expression pattern in the cells, including 19 upregulated and 85 down-regulated miRNAs in the cells. The up-regulations of let-7a and miR-10b as well as the down-regulations of miR-132 and miR-125b were verified to be consistent with the the results of the miRNA array.

CONCLUSION

Our study suggests that the mechanisms by which BJA32531 exerted the antiproliferative effects on HepG2 cancer cells may be related to its regulation of miRNA.

1,3,4-tri-O-galloyl-6-O-caffeoyl-β-D-glucopyranose, a new anti-proliferative ellagitannin, regulates the expression of microRNAs in HepG(2) cancer cells

OBJECTIVE

MicroRNAs (miRNAs) play important roles in cell proliferation, differentiation and apoptosis. 1, 3, 4-tri-O-galloyl-6-O-caffeoyl-β-D-glucopyranose (BJA32515) is a new natural ellagitannin compound extracted from Balanophora Japonica MAKINO. The effect of BJA32515 on the expression of miRNAs in cancer cells has not yet been explored. Objective The present study was carried out to examine the changes in miRNA expression profiles in human HepG(2) hepatocarcinoma cells following BJA32515 exposure.

METHODS

The proliferation of BJA32515-exposed HepG(2) cells was assessed using a colorimetric assay (cell counting kit-8). The miRNA expression profile of the cancer cells was analyzed using a miRNA array and quantitative real-time PCR. Apoptosis was assessed by annexin V and propidium iodide staining.

RESULTS

BJA32515 inhibited the cell proliferation and increased apoptosis in HepG(2) cancer cells. The exposure to BJA32515 also caused alterations in the miRNA expression profile in the cells, with 33 miRNAs upregulated and 59 down-regulated. The up-regulation of let-7a and miR-29a and the down-regulation of miR-373 and miR-197 were verified by quantitative real-time PCR. CONCLSION: BJA32515-modifed miRNA expression may mediate the antiproliferative effect of this compound in HepG(2) cancer cells.

Two micro-scale protocols for the isolation of DNA from polysaccharide-rich plant tissue

The high polysaccharide content of some plant species hinders the successful isolation of their DNA. As an alternative to the macro-extraction methods previously published for polysaccharide-rich plants, we present two techniques (STE/CTAB and HEPES/CTAB), which are performed in microcentrifuge tubes. These protocols are suitable for small amounts of silica gel-preserved plant tissue such as are commonly available from endangered plants. The critical step to remove polysaccharides was performing initial washes in either STE (0.25 M sucrose, 0.03 M Tris, 0.05 M EDTA) or HEPES (2% β-mercaptoethanol, 0.2% PVP, 0.1 M HEPES, pH 8.0) buffer. Precipitating the DNA at room temperature with isopropanol also aided in decreasing polysaccharide co-precipitation. Of the two protocols we present the STE/CTAB method has the advantages of being more cost-effective and avoiding the use of the hazardous chemical β-mercaptoethanol.

New phenylpropanoids and in vitro α-glucosidase inhibitors from Balanophora japonica

Five new phenylpropanoids, named balajaponins A-E (1-5), were isolated from Balanophora japonica, along with 24 known compounds. Among them, three hydrolysable tannins (6-8) showed specific in vitro α-glucosidase inhibition, with IC₅₀ values in the range of 1-4 µM. Kinetic analysis revealed that they all acted in a noncompetitive mode.

Melanin synthesis inhibitors from Balanophora fungosa

Tyrosinase, trypsin, and tryptase are known to play important roles in melanin production of human skin. This paper describes the study of the inhibitory effect of Balanophora fungosa on melanin. The 50% EtOH extract obtained from B. fungosa indicated an inhibitory effect on mushroom tyrosinase activity with an IC(50) value of 15 μg/mL. Bioassay-guided fractionation of the active extract resulted in the isolation of four known compounds. Their structures were identified as 1-O-(E)-caffeoyl-3-O-galloyl-4,6-(S)-HHDP-β-d-glucopyranose (1), 1-O-(E)-caffeoyl-3,4,6-tri-O-galloyl-β-d-glucopyranose (2), caffeoyl-β-d-glucopyranose (3), and abietin (4) on the basis of spectroscopic analyses and comparison of their spectral data with those in the literature. Compounds 1 and 2 prevented pigmentation of melanin in a three-dimensional cultured human skin model. Furthermore, compounds 1 and 2 indicated inhibitory activities against trypsin and tryptase.

[Study of the mechanism of caffeoyl glucopyranoses in inhibiting HIV-1 entry using pseudotyped virus system]

OBJECTIVE

To investigate the inhibitory activities of caffeoyl glucopyranoses purified from Balanophora japonica Makino on HIV entry and their mechanism.

METHODS

HIV-1 Env pseudovirus was used to evaluate the anti-HIV-1 activity of those compounds. ELISA and molecular docking were used to study the mechanism of the actions of the active compounds.

RESULTS

We used the HIV-1 Env pseudovirus to test the anti-HIV-1 activity of the six phenolic compounds (final concentration 25 microg/ml), and found that only 1,2,6-Tri-O-caffeoyl-beta-D-glucopyranose (TCGP) and 1,3-Di-O-caffeoyl-4-O-galloyl-beta-D- glucopyranose (DCGGP) could effectively inhibit the entry of HIV-1 Env pseudovirus into the target cells in a dose-dependent manner, with IC(50) values of 5.5-/+0.2 and 5.3-/+0.1 microg/ml, respectively. These two compounds could also blocked the gp41 six-helix bundle formation. Molecular docking analysis suggested that they might bind to the hydrophobic cavity of the gp41 N-trimeric coiled-coil.

CONCLUSION

TCGP and DCGGP are potent HIV-1 entry inhibitors targeting gp41 and can serve as lead compounds for developing novel anti-HIV-1 microbicides for prevention of sexual HIV-1 transmission.

[Studies on the chemical constituents of Balaophora polyandra]

OBJECTIVE

To study the chemical constituents of Balaophora polyandra.

METHODS

The chemical constituents were isolated by column chromatography on silica gel, Toyopearl HW-40C and Sephadex LH-20. Their structures were elucidated on the basis of spectral analysis.

RESULTS

8 compounds have isolated from this plant, and the structure of them have identified as Gallic acid (1), Ellagic acid (2), Ferulic acid (3), Caffeic acid (4), p-hydroxylcinnamic acid (5), 1,3-di-O-galloyl-4,6-(S) - hexahydroxydiphenyl-beta-D-glucopyrannose (6),1-O-(E) - caffeoyl- 3-O-galloyl-beta-D-glucopyrannose (7), 2-O-(E) - caffeoyl-1-O-[see symbol] - (E) - coumaroyl-beta-D-glucopyrannose (8).

CONCLUSION

Compounds 1 - 8 are isolated from this plant for the first time.

Improvement of high-fat-diet-induced metabolic syndrome by a compound from Balanophora polyandra Griff in mice

This study was to explore the effects of a compound (BPG) from Balanophora polyandra Griff on metabolic syndrome in mice. The animal models, developed obesity, dyslipidemia and insulin resistance, were induced by high-fat-diet in C57BL/6 mice, and were treated orally with 100 mg/kg/day BPG and 15 mg/kg/day rosiglitazone, respectively. The age-matched C57BL/6 mice fed with standard chow were used as normal control. The blood glucose, the value of serum triglyceride and the content of triglyceride in the skeletal muscle were determined by biochemical methods. The protein expression was evaluated by western blot. BPG administration decreased body weight gain, adiposity index, serum triglyceride levels, and triglyceride accumulation in skeletal muscle significantly. At the same time, BPG administration also exhibited extensive effects on insulin resistance by improving oral glucose tolerance test, insulin tolerance test and glucose infusion rate in hyperinsulinemic-euglycemic clamp test. Furthermore, in skeletal muscle, BPG reversed the defect expression of IRbeta, IRS-1 and PTP1B, and also decreased the expression of ACCbeta and increased the expression of p-AMPK in the high-fat-diet-induced mice. All the results suggest that BPG improves metabolic syndrome may by the enhancement of insulin sensitivity and fatty acid oxidation.

Cytotoxic hydrolyzable tannins from Balanophora japonica

Four hydrolyzable tannins named balanophotannins D-G ( 1- 4) were isolated from the aerial parts of the parasitic plant Balanophora japonica. Their structures were characterized on the basis of spectroscopic and chemical evidence. Balanophotannins D-G contain an oxidized hexahydroxydiphenoyl (HHDP) group. The absolute configurations of balanophotannins D ( 1) and F ( 3) were determined via the PGME method. Balanophotannin E ( 2) showed cytotoxicity to Hep G2 cancer cells with an IC 50 value of 4.22 microM.

[Studies on chemical constituents of Balanophora spicata]

OBJECTIVE

To investigate the chemical constituents of Balanophora spicata.

METHOD

Various chromatographic and spectral techniques were used to isolate the constituents and elucidate their structures.

RESULT

Eight compounds were isolated from whole plant of B. spicata and elucidated as balanophorin A (1), balanophorin B (2), beta-amyrin acetate (3), monogynol A (4), lupeone (5), caffeic acid ethyl ester (6), catechin (7), 1-O-(E)-caffeoyl-3-O-galloyl-beta-D-glucopyranose (8), respectively.

CONCLUSION

Compounds of 1-8 were obtained from B. spicata for the first time and the compound 4 was isolated from this genus for the first time.

Antibacterial activities of four Thai medicinal plants

Medicinal plants have long been used and prescribed in Thailand for centuries. Some of them have been used for treating various diseases including infectious diseases. Pouzolzia pentandra Benn., Gelonium multiflorum A. Juss., Erycibe elliptilimba Merr. and Chun., Balanophora abbreviate Bl. are Thai medicinal plants from the Thai pharmacopoeia that have been prescribed for treating unknown fevers including some specific infectious diseases. This investigation demonstrated the effects of these Thai medicinal plants for their antibacterial activities by using the macrodilution assay. Based on the present study, the water methanol fraction (fraction 2) of Balanophora abbreviate Bl. showed the antibacterial activity at the MIC level of 250 microg/ml but the activity was bacteriostatic in its effects. Therefore, the use of these medicinal plants in controlling fever and infectious diseases appears to be justified and further investigations may be required to obtain more information.

Ellagitannins and lignan glycosides from Balanophora japonica (Balanophoraceae)

Three new ellagitannins named balanophotannins A-C having a 1,1'-(3,3',4,4'-tetrahydroxy)dibenzofurandicarboxyl group in their molecules and four known lignan glycosides were isolated from the extracts of fresh aboveground and underground parts of a medicinal parasitic plant Balanophora japonica (Balanophoraceae). Their structures were elucidated on the basis of spectral and chemical evidence. Chemotaxonomic significance of the known lignan glycosides in Balanophora japonica was discussed.

Galloyl, caffeoyl and hexahydroxydiphenoyl esters of dihydrochalcone glucosides from Balanophora tobiracola

Seven galloyl, caffeoyl and (S)-hexahydroxydiphenoyl (HHDP) esters of dihydrochalcone glucosides were isolated from Balanophora tobiracola; based on spectroscopic and chemical evidence, their structures were determined to be 6''-O-galloyl-, 3'',4''-di-O-galloyl-, 4'',6''-di-O-galloyl-, 4'',6''-O-(S)-HHDP-, 3''-O-galloyl-4'',6''-O-(S)-HHDP-, 3''-O-caffeoyl-4'',6''-O-(S)-HHDP-3-hydroxyphloretin 4'-O-beta-D-glucosides and 3''-O-galloyl-4'',6''-O-(S)-HHDP-phloretin 4'-O-beta-D-glucoside, respectively. By contrast, these compounds were not found in the taxonomically related B. japonica. The 3''-galloyl-4'',6''-HHDP esters of the dihydrochalcone glucosides showed strong inhibitory activities against alpha-glucosidase. Four known compounds were also isolated namely, (+/-)-eriodictyol 7-O-beta-D-glucoside, 1-O-caffeoyl-3-O-galloyl-beta-D-glucose, phloretin 4'-O-beta-D-glucoside, and 3-hydroxyphloretin 4'-O-beta-D-glucoside.

Inhibition of glutathione S-transferases by thonningianin A, isolated from the African medicinal herb, Thonningia sanguinea, in vitro

There is evidence that increased expression of glutathione S-transferase (EC: 2.5.1.18, GST) is involved in resistance of tumor cells against chemotherapeutic agents. In this study we investigated the inhibitory effects of thonningianin A (Th A), a novel antioxidant isolated from the medicinal herb, Thonningia sanguinea on uncharacterized rat liver GST and human GST P1-1. Using 1-chloro-2,4-dinitrobenzene (CDNB) as substrate, rat liver cytosolic GST activity was inhibited by Th A in a concentration dependent manner with 50% inhibition concentration (IC50) of 1.1 microM. When Th A was compared with known potent GST inhibitors the order of inhibition was tannic acid>cibacron blue>hematin>Th A>ethacrynic acid with CDNB as substrate. Th A also exhibited non-competitive inhibition towards both CDNB and glutathione. Furthermore, using 1,2-dichloro-4-nitrobenzene, ethacrynic acid and 1,2-epoxy-3-(p-nitrophenoxy) propane as substrates Th A at 1.0 microM inhibited cytosolic GST by 2%, 12% and 36% respectively. Human GST P1-1 was also inhibited by Th A with an IC50 of 3.6 microM. While Th A showed competitive inhibition towards CDNB it exhibited non-competitive inhibition towards GSH of the human GST P1-1. These results suggest that Th A represents a new potent GST in vitro inhibitor.

Selective suppression of cytochrome P450 gene expression by the medicinal herb, Thonningia sanguinea in rat liver

The effect of the administration of Thonningia sanguinea (T. S.) on the abundance of individual components of the cytochrome P450 monooxygenase enzyme was examined using Western blotting and competitive reverse-transcriptase-polymerase chain reaction (RT-PCR). We also investigated the time-course of inhibition of T. S. on drug metabolizing enzymes. A single intraperitoneal dose of T. S. extract (5 ml/kg) suppressed CYP, cytochrome b5 and NADPH-CYP reductase activity by 45%, 34% and 22% respectively 24 h after T. S. administration. While T. S. did not have any significant effect on microsomal glutathione S-transferase activity, it inhibited p-nitrophenol hydroxylase (PNPH, CYP2E1) and 7-methoxyresorufin O-demethylase (MROD, CYP 1A2) activities by 37% and 32% respectively at 12 h post-T. S. administration. PNPH, erythromycin N-demethylase (ERDM, CYP 3A1/2) and MROD activities were inhibited by 28-36% 24 h after T. S. injection. Consistent with these observations, the levels of CYP2E1, CYP1A2 and CYP3A2 proteins were also suppressed 24 h post-T. S. administration. While CYP2E1 mRNA was unaffected by T. S. administration, CYP1A2 and CYP3A2 mRNAs were decreased by T. S. Cytosolic glutathione S-transferase activity was increased by 30%, 6 h after T. S injection. These data demonstrate that administration of T. S. differentially affect CYP isoforms in the liver of rats and that T. S. selectively suppresses CYP3A2 and CYP1A2 gene expression.