Feng Qiu

Isolation and Identification of Urinary Metabolites of Berberine in Rats and Humans

The urinary metabolites of berberine, an isoquinoline alkaloid isolated from several Chinese herbal medicines, were investigated in rats and humans. Using macroporous adsorption resin chromatography, open octadecyl silane column chromatography and preparative high-performance liquid chromatography, we isolated seven metabolites (HM1-HM7) from human urine and five metabolites (RM1-RM5) from rat urine after oral administration. Their structures were elucidated by enzymatic deconjugation and analyses of mass spectrometry, 1H NMR, and nuclear Overhauser effect spectroscopy spectra. Besides the three known metabolites demethyleneberberine-2-O-sulfate (HM1 and RM3), jatrorrhizine-3-O-sulfate (HM5), and thalifendine (RM5), six new metabolites were identified, namely, jatrorrhizine-3-O-β-d-glucuronide (HM2), thalifendine-10-O-β-d-glucuronide (HM3), berberrubine-9-O-β-d-glucuronide (HM4 and RM2), 3,10-demethylpalmatine-10-O-sulfate (HM6 and RM4), columbamin-2-O-β-d-glucuronide (HM7), and demethyleneberberine-2,3-di-O-β-d-glucuronide (RM1). These findings suggest that berberine undergoes similar biotransformation in rats and humans. Possible metabolic pathways of berberine in rats and humans are proposed.

Diarylheptanoids from the Rhizomes of Curcuma kwangsiensis

Twelve new diarylheptanoids and six known compounds were isolated from rhizomes of Curcuma kwangsiensis. Structures of the new compounds were elucidated by spectroscopic and chemical methods as (3S)- and (3R)-1,7-bis(4-hydroxyphenyl)-(6E)-6-hepten-3-ol (1a and 1b), (3S)- and (3R)-1-(3,4-dihydroxyphenyl)-7-(4-hydroxyphenyl)-(6E)-6-hepten-3-ol (2a and 2b), (3S)- and (3R)-1-(3,4-dihydroxyphenyl)-7-(4-hydroxyphenyl)heptan-3-ol (3a and 3b), (3R)-1-(3,4-dihydroxyphenyl)-7-phenyl-(6E)-6-hepten-3-ol (4b), (3S)- and (3R)-3-acetoxy-1-(3,4-dihydroxyphenyl)-7-(4-hydroxyphenyl)-(6E)-6-heptene (5a and 5b), (3S)- and (3R)-3-acetoxy-1-(3,4-dihydroxyphenyl)-7-(4-hydroxyphenyl)heptanes (6a and 6b), and (E)-1,7-bis(4-hydroxyphenyl)-6-hepten-3-one (7). The absolute configurations were determined using the modified Moshers method. Separation of the enantiomeric mixtures (1a and 1b, 2a and 2b, 3a and 3b, 4a and 4b, 5a and 5b, 6a and 6b) was achieved on a chiral column using acetonitrile-water mixtures as eluents. The S enantiomers exhibited negative specific optical rotations in MeOH, and the R enantiomers were positive. Inhibitory effects of the compounds on nitric oxide production in lipopolysaccaride-activated macrophages were evaluated.

Molecular mechanisms of oridonin-induced apoptosis and autophagy in murine fibrosarcoma L929 cells

Apoptosis and autophagy are genetically regulated, evolutionarily-conserved processes that can jointly seal the fate of cancer cells; however, substantial gaps remain in our understanding of the molecular mechanisms that mediate the two cellular processes. In the present study, the exposure of murine fibrosarcoma L929 cells to oridonin led to the generation of intracellular reactive oxygen species (ROS) and, subsequently, the ROS triggered apoptosis by Bax translocation, cytochrome c release and ERK activations. In addition, oridonin induced autophagy in L929 cells, and the inhibition of autophagy by 3-MA or siRNA against LC3 and beclin 1 promoted oridonin-induced apoptosis. Furthermore, p38 and NF-κB were confirmed to have roles in inhibiting apoptosis but promoting autophagy. Moreover, the inhibition of autophagy could reduce oridonin-induced activation of p38. Finally, NF-κB activation was inhibited by blocking the p38 pathway. In conclusion, these findings indicate that oridonin-induced apoptosis can be regulated by ROS-mediated signaling pathways, and oridonin-induced autophagy may block apoptosis by up-regulating p38 and NFκB activation.

Guaiane-type sesquiterpenes from Curcuma phaeocaulis and their inhibitory effects on nitric oxide production.

Ten new guaiane-type sesquiterpenes (1-10), phaeocaulisins A-J, and 18 known guaiane derivatives were isolated from rhizomes of Curcuma phaeocaulis. Their structures were established on the basis of extensive spectroscopic analyses, X-ray crystallographic analysis, and comparison with literature data. Compound 10 is the first example of a norsesquiterpene with this unusual skeleton isolated from the genus Curcuma. All of the isolated compounds were tested for inhibitory activity against LPS-induced nitric oxide production in RAW 264.7 macrophages. Compounds 1, 2, 20, and 22-24 inhibited nitric oxide production with IC50 values less than 2 μM. Preliminary structure-activity relationships for these compounds are discussed.

Induction of G2/M Phase Arrest and Apoptosis by Oridonin in Human Laryngeal Carcinoma Cells

Oridonin (1), an active component isolated from the plant Rabdosia rubescens, has been reported to exhibit antitumor effects. In this study, the mechanism involved in 1-induced growth inhibition, including apoptosis and G(2)/M phase arrest, in human laryngeal carcinoma HEp-2 cells deficient in functional p53, was investigated for the first time. Compound 1 triggered the mitochondrial apoptotic pathway, as indicated by increased Bax/Bcl-2 ratios, reduction of mitochondrial membrane potential (DeltaPsi(m)), and substantial increase in apoptosis-inducing factor (AIF) and cytochrome c. Inhibition of caspase-9 in HEp-2 cells did not protect the cells from 1-induced apoptosis, and cleaved caspase-9 was not detected, indicating that apoptosis occurred via a caspase-9-independent pathway. The results also suggested that G(2)/M phase arrest and apoptosis mediated by 1 occurred via a p53-independent but in a p21/WAF1-dependent manner in HEp-2 cells. In addition, the generation of reactive oxygen species (ROS) was found to be a critical mediator in growth inhibition induced by 1. Taken together, the results indicate that oridonin (1) is a potentially effective agent for the treatment of laryngeal squamous cell carcinoma.

Physalin A induces apoptotic cell death and protective autophagy in HT1080 human fibrosarcoma cells.

Physalin A (1) is a withanolide isolated from Physalis alkekengi var. franchetii. In this study, the selective growth inhibitory effects on tumor cells induced by 1 were screened, and the mechanism was investigated on 1-induced growth inhibition, including apoptosis and autophagy, in human fibrosarcoma HT1080 cells. Apoptosis induced by 1 in HT1080 cells was associated with up-regulation of caspase-3 and caspase-8 expression. However, there were no significant changes in caspase-9, Bid, Bax, and Bcl-2 expression, indicating that 1-induced apoptosis in HT1080 cells occurs mainly through activation of the death receptor-associated extrinsic apoptotic pathways. Autophagy induced by 1 was found to antagonize apoptosis in HT1080 cells. This effect was enhanced by rapamycin and suppressed by the autophagy inhibitor 3-methyladenine (3MA). Loss of beclin 1 (as an autophagic regulator) function led to similar results to 3MA. However, 1 did not show inhibitory effects on normal human cells (human peripheral blood mononuclear cells). Taken together, these results suggest that 1 may be a promising agent for the treatment of cancer.

Metabolites of protoberberine alkaloids in human urine following oral administration of Coptidis Rhizoma decoction.

Coptidis Rhizoma has been used as a traditional Chinese herbal medicine to treat typhoid, pharyngolaryngitis, diabetes mellitus, gastroenteritis and secretory diarrhea for more than a thousand years in China. However, there is little information on the IN VIVO chemical constituents of Coptidis Rhizoma following oral administration. In this paper, the alkaloid constituents in urine were studied in humans following oral administration of Coptidis Rhizoma decoction. Using macroporous adsorption resin chromatography, open ODS column chromatography, and preparative high-performance liquid chromatography, twelve protoberberine alkaloid constituents were isolated. Their structures were elucidated by chemical evidence, enzymatic deconjugation and analyses of mass, (1)H-NMR and NOESY spectra. The identified alkaloid constituents include berberine ( P1), groenlandicine 3-O- β-D-glucuronide (M1), dehydrocheilanthifoline 2-O-β-D-glucuronide (M2), thalifendine 10-O-β-D-glucuronide (M3), jatrorrhizine 3-O-β-D-glucuronide (M4), columbamine 2-O-β-D-glucuronide (M5), berberrubine 9-O-β-D-glucuronide (M6), jatrorrhizine 3-O-sulfate (M7), demethyleneberberine 2-O-sulfate (M8), dehydrocorydalmine 10-O-sulfate (M9), 3,10-demethylpalmatine 10-O-sulfate (M10) and 2,3,10-trihydroxyberberine 2-O-sulfate ( M11). No other parent protoberberine alkaloids from Coptidis Rhizoma except for a trace of berberine were found in the urine. These findings suggested that the protoberberine alkaloids, which were absorbed in vivo following oral administration of Coptidis Rhizoma decoction, were mainly conjugated with glucuronic acid or sulfuric acid to form phase II metabolites directly or after biotransformation to phase I metabolites, and finally excreted in urine.

Triterpenoid Saponins from Ardisia pusilla and their Cytotoxic Activity

Three new triterpenoid saponins 3, 4 and 5, together with two known saponins, ardisiacrispin B (1) and ardisiacrispin A (2), were isolated from the whole plants of Ardisia pusilla A. DC. Their structures were elucidated by extensive spectral analysis and chemical evidence. Compound 3 is a hexaglycoside with a 13,28-epoxyoleanane type aglycone, while both 4 and 5 are triterpenoid tetraglycosides related to the olean-12-ene skeleton. Saponins 1-4 exhibited significant cytotoxicity against human glioblastoma U251MG cells, but did not affect the growth of primary cultured human astrocytes.

Isolation and Identification of Phase 1 Metabolites of Demethoxycurcumin in Rats

Curcuminoids are a safe natural food coloring additive with anti-inflammatory, antioxidant, and anticarcinogenic activities. Although demethoxycurcumin is one of the major bioactive constituents of curcuminoids, knowledge about its metabolic fate is scant. In the present study, four new metabolites, 5-dehydroxy-hexahydro-demethoxycurcumin-A (M-1), 5-dehydroxy-hexahydro-demethoxycurcumin-B (M-2), 5-dehydroxy-octahydro-demethoxy-curcumin-A (M-3) and 5-dehydroxy-octahydro-demethoxycurcumin-B (M-4), were isolated from feces of male Wistar-derived rats and from urine; three new metabolites, 5-O-methyl-hexahydrodemethoxycurcumin-A (M-7), 5-O-methyl-hexahydro-demethoxycurcumin-B (M-8), and 5-dehydroxy-dihydro-demethoxycurcumin-B (M-9), and two known metabolites, hexahydro-demethoxycurcumin-A (M-5) and hexahydro-demethoxycurcumin-B (M-6), were isolated. Their structures were established by chemical and spectral methods. ll of them were reductive metabolites. Possibly of greater importance is that they occurred as pairs of isomers with a methoxyl group substituted on a different benzene ring. This finding in the metabolism of curcuminoids is reported here for the first time. In addition, the 5-dehydroxy or 5-O-methylated metabolites are also a novel finding. The fact that the metabolites occurred as pairs of the isomers suggests that demethoxycurcumin possibly undergoes tautomerization between 3-keto-5-enol (form A) and 3-keto-5-enol (form B) in rats. Based on the metabolite profiles, metabolic pathways of demethoxycurcumin in rats are proposed.

Antiproliferative and Anti-inflammatory Withanolides from Physalis angulata

Sixteen new withanolides, physangulatins A-N (1-14) and withaphysalins Y and Z (15 and 16), as well as 12 known analogues, were isolated from the stems and leaves of Physalis angulata L. Their structures were established using extensive spectroscopic data analyses. The absolute configurations of 1 and 9 were assigned via X-ray crystallography. The isolated compounds were tested for their antiproliferative effects against human prostate cancer cells (C4-2B and 22Rvl), human renal carcinoma cells (786-O, A-498, and ACHN), and human melanoma cells (A375-S2), as well as inhibitory effects on NO production induced by LPS in macrophages. Compounds 9, 17, 20, 21, 25, and 27 showed antiproliferative effects against all tested cancer cells, with IC50 values of 0.18-7.43 μM. Compounds 3-5, 9-11, 17, 20-22, 24, 25, and 27 displayed inhibitory effects against NO production, with IC50 values of 1.36-11.59 μM.