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PubMed1998

[The structures elucidation of isodopharicin D and F].

Two new compounds were isolated from Isodon pharicus (Prain) Murata. Their structures were determined to be 3 alpha, 11 beta, 13 alpha-trihydroxy-entkaur-16-en-15-one (1), named isodopharicin D, and 11 beta, 13 alpha, 15 alpha-trihydroxy-entkaur-16-en-3 alpha-beta-D-glucoside (2), named isodopharicin F by chemical and spectral evidence.

Diterpenes↗
PubMed2006

Eriocalyxin B induces apoptosis of t(8;21) leukemia cells through NF-kappaB and MAPK signaling pathways and triggers degradation of AML1-ETO oncoprotein in a caspase-3-dependent manner.

Diterpenoids isolated from Labiatae family herbs have strong antitumor activities with low toxicity. In this study, Eriocalyxin B (EriB), a diterpenoid extracted from Isodon eriocalyx, was tested on human leukemia/lymphoma cells and murine leukemia models. Acute myeloid leukemia cell line Kasumi-1 was most sensitive to EriB. Significant apoptosis was observed, concomitant with Bcl-2/Bcl-XL downregulation, mitochondrial instability and caspase-3 activation. AML1-ETO oncoprotein was degraded in parallel to caspase-3 activation. EriB-mediated apoptosis was associated with NF-kappaB inactivation by preventing NF-kappaB nuclear translocation and inducing IkappaBalpha cleavage, and disturbance of MAPK pathway by downregulating ERK1/2 phosphorylation and activating AP-1. Without affecting normal hematopoietic progenitor cells proliferation, EriB was effective on primary t(8;21) leukemia blasts and caused AML1-ETO degradation. In murine t(8;21) leukemia models, EriB remarkably prolonged the survival time or decreased the xenograft tumor size. Together, EriB might be a potential treatment for t(8;21) leukemia by targeting AML1-ETO oncoprotein and activating apoptosis pathways.

Animals↗
PubMed1993

Onchocerca-like lesions induced by the filarioid nematode Cercopithifilaria johnstoni, in its natural hosts and in the laboratory rat.

Histo-pathological analysis of the eyes, ears, skin and associated skeletal muscles of the back of 14 animals infected with a filarioid worm with dermal microfilariae, Cercopithifilaria johnstoni: seven Rattus fuscipes, of which four were naturally infected, two marsupials, Perameles nasuta and Isodon macrourus, and five R. norvegicus. This filarioid nematode induces skin and eye lesions in all the infected animals. These lesions are similar to those described earlier with other filarioid species with dermal microfilariae, such as Monanema martini and Onchocerca volvulus; the pathogeny is similar: microfilariae live inside the lymphatic vessels and their accidental exit gives rise to a localized inflammatory reaction leading to fibrosis. C. johnstoni is particularly interesting because it may be adapted to the laboratory rat, and because the ocular lesions are severe.

Animals↗
PubMed2006

Eriocalyxin B inhibits nuclear factor-kappaB activation by interfering with the binding of both p65 and p50 to the response element in a noncompetitive manner.

Nuclear factor-kappaB (NF-kappaB) has been recognized to play a critical role in cell survival and inflammatory processes. It has become a target for intense drug development for the treatment of cancer, inflammatory, and autoimmune diseases. Here, we describe a potent NF-kappaB inhibitor, eriocalyxin B (Eri-B), an ent-kauranoid isolated from Isodon eriocalyx, an anti-inflammatory remedy. The presence of two alpha,beta-unsaturated ketones give this compound the uniqueness among the ent-kauranoids tested. Eri-B inhibited the NF-kappaB transcriptional activity but not that of cAMP response element-binding protein. It suppressed the transcription of NF-kappaB downstream gene products including cyclooxygenase-2 and inducible nitric-oxide synthase induced by tumor necrosis factor-alpha or lipopolysaccharide in macrophages and hepatocarcinoma cells. Chromatin immunoprecipitation assay indicated that Eri-B selectively blocked the binding between NF-kappaB and the response elements in vivo without affecting the nuclear translocation of the transcription factor. Down-regulation of the endogenous p65 protein sensitized the cells toward the action of the compound. Furthermore, in vitro binding assays suggested that Eri-B reversibly interfered with the binding of p65 and p50 subunits to the DNA in a noncompetitive manner. In summary, this study reveals the novel action of a potent NF-kappaB inhibitor that could be potentially used for the treatment of a variety of NF-kappaB-associated diseases. Modification of the structure of this class of compounds becomes the key to the control of the behavior of the compound against different cellular signaling pathways.

Base Sequence↗
PubMed2006

Isolation and purification of oridonin from Rabdosia rubescens using upright counter-current chromatography.

A preparative counter-current chromatography (CCC) method for isolation and purification of oridonin, a new cancer chemoprevention agent, from the Chinese medicinal plant Rabdosia rubescens was successfully established. The crude oridonin was obtained by elution with a light petroleum/acetone solvent mixture from ethanol extracts of R. rubescens using column chromatography on silica gel. With a two-phase solvent system composed of n-hexane/ethyl acetate/methanol/water (1:2:1:2, v/v), 120 mg of oridonin at the purity of 97.8% was obtained from 200 mg of the crude sample in a single-step CCC separation. The structure of oridonin was identified by ESI-MS, 1H NMR, and 13C NMR.

Chromatography, High Pressure Liquid↗
PubMed2004

Antibacterial activity of ent-kaurene diterpenoids from Rabdosia rosthornii.

Biological activities of ent-kaurene diterpenoids, rosthornins A-D, isolated from the ether extract of the dried leaves of Rabdosia rosthornii (Diels) Hara (Labiatae) were tested. They exhibited antibacterial activity specifically against Gram-positive bacteria, among which Propionibacterium acnes was noted to be the most susceptible.

Anti-Bacterial Agents↗
PubMed2006

Antioxidants from Rabdosia japonica.

The antioxidant activities of phenolic compounds: pedalitin, quercetin, rutin, isoquercitrin, and rosmarinic acid, isolated from the dried leaves of Rabdosia japonica Hara (Labiatae) were elucidated. All the phenolics tested exhibited superoxide scavenging activity and an inhibitory effect on xanthine oxidase (EC 1.1.3.22), and pedalitin showed the most potent antioxidant activity. Pedalitin prevents the generation of superoxide radicals in part by inhibiting xanthine oxidase competitively. Both pedalitin and quercetin inhibited uric acid formation by xanthine oxidase, and the inhibition kinetics analysed by Lineweaver-Burk plots found both flavonoids to be competitive inhibitors. On the other hand, isoquercitrin, rutin and rosmarinic acid were effective in scavenging superoxide radicals generated by the xanthine-xanthine oxidase system without inhibiting the enzyme.

Antioxidants↗
PubMed2005

Differential control of growth, cell cycle progression, and expression of NF-kappaB in human breast cancer cells MCF-7, MCF-10A, and MDA-MB-231 by ponicidin and oridonin, diterpenoids from the chinese herb Rabdosia rubescens.

Ponicidin and oridonin are novel diterpenoids isolated from Rabdosia rubescens. We tested their effects in MCF-7 and MDA-MB-231 cells, as representing low and high invasive breast carcinoma, with normal MCF-10A cells. Clonogenicity and proliferation in MCF-7 cells were inhibited more significantly by ponicidin than oridonin, while the reverse was observed in MCF-10A cells. Ponicidin and oridonin induced S/G2M arrest and G1/S block in MCF-7 cells. In MCF-10A cells treated with either diterpenoid, induction of apoptosis was observed. Moreover, oridonin almost completely blocked MCF-10A progression from S to G2/M phase; in contrast, ponicidin-treated MCF-10A cells showed no discernable changes in cell cycle phase distribution. Neither diterpenoid affected growth of MDA-MB-231 cells, at the dose range effective for MCF-7 or MCF-10A cells. Ponicidin-treated MCF-7 cells expressed reduced levels of cyclin B1, cdc2, transcription factor E2F, and Rb including phosphorylation at S780. Less pronounced effects were found in cells treated with oridonin. Neither compound altered cyclin D1 and cdk4 in MCF-7 cells. In MCF-10A cells, oridonin was more active than ponicidin in inhibiting the expression of cyclin B1, cdc2, S780-phosphorylated Rb, and E2F. To further investigate induction of apoptosis in MCF-10A cells, we measured changes in NF-kappaB. Decreases in p65 or p50 forms of NF-kappaB and its upstream regulator I-kappaB were found in oridonin-treated MCF-10A and not MCF-7 cells. Taken together, these results provide a mechanistic framework for the cellular effects of ponicidin and oridonin in different stage breast cancer cells.

Antineoplastic Agents, Phytogenic↗
PubMed2003

ent-Isopimarane diterpenoids of the leaves from Rabdosia forrestii.

Two new diterpenes, forrestin H, ent-isopimaran-8 beta, 15R, 16-triol (1), forrestin I, ent-isopimaran-16-acetoxy-8 beta, 15R-diol (2) and the acetonide derivative of forrestin H were isolated from the leaves of Rabdosia forrestii. The structures were established on the basis of NMR spectroscopic analysis and of the modified Mosher's (1H) method.

Abietanes↗
PubMed2005

The effects of oridonin on cell growth, cell cycle, cell migration and differentiation in melanoma cells.

Oridonin, a diterpenoid isolated from Rabdosia rubescens (Hemsl.) Hara, is currently one of the most important traditional Chinese herbal medicines. We investigated the anti-proliferation effect of oridonin on the cultured murine melanoma cell line K1735M2. The growth inhibition activity of oridonin for K1735M2 cells occurred in a time- and dose-dependent manner (IC50 was 7.4+/-0.6 microM). Further studies showed that these inhibition effects were associated with dose-dependent G2/M phase arrest and differentiation induction. Detection of morphological observation showed that oridonin could induce K1735M2 cells to produce dendrite-like structures. The results of the migration indicated that oridonin affected motility of K1735M2 cells in a dose-dependent manner. These results suggested that oridonin is a potential candidate for melanoma cancer therapy.

Animals↗
PubMed2006

Determination of oridonin in rat plasma by reverse-phase high-performance liquid chromatography.

A method for quantitative determination of oridonin in rat plasma using reversed-phase high-performance liquid chromatography (RP-HPLC) coupled with UV spectrometry was established and the method was applied to a pharmacokinetics study of oridonin in rats. From a variety of compounds and solvents tested, ticolpidine was selected as the internal standard (IS) and ethyl acetate was found to be the best solvent for extracting oridonin from plasma samples. RP-HPLC analysis of the extracts was performed on an analytical column (DIKMA ODS, 200 mm x 4.6 mm; i.d., 5 microm) equipped with a security guard pre-column system. There was a good linearity over the range 0.05-8.0 microg/mL (r>0.99). The recoveries were about 95.0% in plasma, and the intra- and inter-day coefficients of variation were less than 9.0% in all cases. The limit of detection (LOD) was 0.025 microg/mL and the lower limit of quantification (LLOQ) was 0.05 microg/mL. The RP-HPLC method was readily applied to quantitate oridonin in rat plasma within 24 h in a pharmacokinetics study where experimental rats received a single dose of oridonin (12.5 mg/kg) and the result was presented.

Acetates↗