Diabetic retinopathy, a prevalent and vision-threatening microvascular complication of diabetes mellitus, is the leading cause of blindness among middle-aged and elderly individuals. Natural diterpenoids isolated from Siegesbeckia pubescens demonstrate potent anti-inflammatory properties. This study aimed to identify novel bioactive diterpenoids from S. pubescens and investigate their effects on oxidative stress and inflammatory responses in diabetic retinopathy, both in vitro and in vivo. Three new ent-pimarane-type diterpenoids (1-3) and six known compounds (4-9) were isolated from the aerial parts of S. pubescens. Their structures were elucidated through spectroscopic data interpretation, and absolute configurations were determined by comparing calculated and experimental electronic circular dichroism (ECD) spectra. Among these compounds, 14β,16-epoxy-ent-3β,15α,19-trihydroxypimar-7-ene (5) exhibited the most potent protective effect against high glucose and interleukin-1β (IL-1β)-stimulated human retinal endothelial cells. Mechanistically, compound 5 promoted endothelial cell survival while ameliorating oxidative stress and inflammatory response in diabetic retinopathy, both in vivo and in vitro. These findings not only suggest that diterpenoids such as compound 5 are important anti-inflammatory constituents in S. pubescens, but also indicate that compound 5 may serve as a lead compound for preventing or treating vascular complications associated with diabetic retinopathy.
Diabetic Retinopathy/metabolism* ; Humans ; Oxidative Stress/drug effects* ; Animals ; Diterpenes, Kaurane/administration & dosage* ; Asteraceae/chemistry* ; Male ; Endothelial Cells/drug effects* ; Abietanes/administration & dosage* ; Molecular Structure ; Mice ; Anti-Inflammatory Agents/chemistry* ; Plant Extracts/chemistry* ; Mice, Inbred C57BL

OBJECTIVETo prepare freeze-dried long-circulation oridonin liposomes with optimized parameters.

METHODSEthanol injection method followed by freeze-drying was used to prepare the liposomes. Sephadex column was used to purify liposomes. Effects of formulation factors on entrapment efficiency of long-circulation oridonin liposomes were studied. The particle size, distribution and in vitro release were determined. Pharmacokinetics of oridonin liposomes in rats was determined by HPLC and the pharmacokinetic parameters calculated by Kinetica(TM) software were compared with conventional oridonin liposomes and solution.

RESULTSThe optimized lipid formulation for long-circulation liposomes was composed of soy lecithin, cholesterol and DSPE-PEG 2000 with a ratio of 1:0.5:1.8(w/w). The ratio of drug to lipid was 1:6. Freeze-drying protectant was a mixture of glucose and mannitol (3:1). The entrapment efficiency (EE) of long-circulation oridonin liposomes was about 65%. The particle size of liposomes after hydrolyzation was 164 nm with good DPI. The liposomes showed a sustained drug release in vitro. Intravenous injected oridonin fitted with two-compartment pharmacokinetic model. The MRT of long-circulation liposomes was 2 times and 6 times and AUC was about 2 times and 3 times of conventional liposomes and oridonin solution, respectively.

CONCLUSIONFreeze-dried liposomes with high EE have been obtained by the proposed approach. This long-circulation liposomes extend oridonin half time and significantly increase AUC in rats.

Animals ; Delayed-Action Preparations ; Diterpenes, Kaurane ; administration & dosage ; pharmacokinetics ; Drug Stability ; Freeze Drying ; Liposomes ; administration & dosage ; pharmacokinetics ; Male ; Rats ; Rats, Sprague-Dawley ; Tissue Distribution

OBJECTIVETo investigate the inhibitory effect of Oridonin injection on heterotransplanted tumors of human gastric adenocarcinoma cell line BGC823 cells in nude mice and explore its mechanism.

METHODSHeterotransplanted models of human gastric adenocarcinoma cell line BGC823 cells in nude mice were established. They were divided at random into three groups as control group, low-dose group and high-dose group. The Oridonin solution at concentration of 37.5 mg x kg(-1 x d(-1) and 75 mg x kg(-1) x d(-1) were injected to the mice in low-dose group and high-dose group, respectively, and 0.9% sodium chloride was injected to the mice of control group per day for 10 days sequentially. The mice of the three groups were sacrificed at 11th day after the first injection of Oridonin. The tumor weight of the sacrificed mice was measured. Morphological and ultrastructural examinations of the tumors were carried out by light and electron microscopy. The expression of bcl-2, Bax, Fas and FasL was detected by immunohistochemistry.

RESULTSOridonin injection showed a suppressive effect on the growth of heterotransplanted tumors in the nude mice. The tumor growth inhibition rates were 48.5% and 70.7% in the low-dose and high-dose groups, respectively. The morphological study demonstrated that tumor cells displayed a typical appearance of apoptosis. The expression of bcl-2 was down-regulated, while Bax, Fas and FasL were up-regulated.

CONCLUSIONOridonin can markedly inhibit the growth of heterotransplanted human gastric adenocarcinoma in nude mice. It was due, at least in part, to the induction of apoptosis in cancer cells.

Adenocarcinoma ; metabolism ; pathology ; Animals ; Antineoplastic Agents, Phytogenic ; administration & dosage ; pharmacology ; Apoptosis ; drug effects ; Cell Line, Tumor ; Diterpenes, Kaurane ; administration & dosage ; pharmacology ; Dose-Response Relationship, Drug ; Fas Ligand Protein ; metabolism ; Humans ; Injections ; Mice ; Mice, Inbred BALB C ; Mice, Nude ; Neoplasm Transplantation ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; Random Allocation ; Stomach Neoplasms ; metabolism ; pathology ; bcl-2-Associated X Protein ; metabolism ; fas Receptor ; metabolism

OBJECTIVETo investigate the change of Bcl-2 expression and telomerase during the apoptosis induced by oridonin on human hepatocelluar carcinoma BEL7402 cells.

METHODBEL-7402 cells in culture medium were given 8,16,24,32 micromol x L(-1) different concentrations of oridonin. The cell apoptotic rate was detected by flow cytometry (FCM), morphology of cell apoptosis was observed by Hoechst 3325 staining. Bcl-2 and Bax expressions were detected by Western blotting. Reverse transcriptase polymerase chain reaction (RT-PCR) and PCR enzyme-linked immunosorbent assay (ELISA) were used to detect hTERT mRNA expression and telomerase activity.

RESULTOridonin induced BEL-7402 cells apoptosis significantly, and the apoptosis rate was both in time-and dose-dependent manner. Marked morphological changes of cell apoptosis were observed very clearly by Hoechst 33258 staining after the cells exposed to oridonin for 60 hours; Western blotting showed that Bcl-2 expression was down-regulated and Bax expression up-regulated concurrently along with the apoptotic process, and the expression of hTERT mRNA as well as activity of telomerase were decreased concurrently.

CONCLUSIONOridonin could decrease the expression of hTERT mRNA and telomerase activity as well as down-regulation of Bcl-2 and up-regulation of Bax expression during the apoptosis of BEL-7402 cells.

Apoptosis ; drug effects ; Carcinoma, Hepatocellular ; metabolism ; pathology ; Cell Line, Tumor ; Diterpenes ; administration & dosage ; isolation & purification ; pharmacology ; Diterpenes, Kaurane ; administration & dosage ; isolation & purification ; pharmacology ; Dose-Response Relationship, Drug ; Humans ; Isodon ; chemistry ; Liver Neoplasms ; metabolism ; pathology ; Plants, Medicinal ; chemistry ; Proto-Oncogene Proteins c-bcl-2 ; metabolism ; RNA, Messenger ; biosynthesis ; genetics ; Telomerase ; biosynthesis ; genetics ; bcl-2-Associated X Protein ; metabolism

OBJECTIVETo study the mechanisms of oridonin-induced U937 cell apoptosis, and to examine the role of ERK MAPK.

METHODMTT, Hoechst 33258 staining, DNA agarose gel electrophoresis and Western blot analysis were used.

RESULTOridonin inhibited U937 cell growth in a time- and dose-dependent manner. Apoptotic bodies were found with Hoechst 33258 staining after treatment with 27 micromol x L(-1) oridonin. Simultaneously, ERK phosphorylation was significant. ERK inhibitor PD98059 partially blocked the growth-inhibitory effect as well as DNA fragmentation. The expression of antiapoptotic mitochondrial protein Bcl-XL decreased time-dependently, and that of proapoptotic protein Bax increased. However, PD98059 reversed the effect of oridonin on Bcl-XL and Bax.

CONCLUSIONOridonin induces U937 cell apoptosis through activation of ERK and alteration of the ratio of Bax/Bcl-XL.

Apoptosis ; drug effects ; Cell Proliferation ; drug effects ; DNA Fragmentation ; drug effects ; Diterpenes ; administration & dosage ; isolation & purification ; pharmacology ; Diterpenes, Kaurane ; administration & dosage ; isolation & purification ; pharmacology ; Dose-Response Relationship, Drug ; Extracellular Signal-Regulated MAP Kinases ; antagonists & inhibitors ; metabolism ; Flavonoids ; pharmacology ; Humans ; Isodon ; chemistry ; Phosphorylation ; Plants, Medicinal ; chemistry ; U937 Cells ; bcl-2-Associated X Protein ; metabolism ; bcl-X Protein ; metabolism

AIMTo investigate the tissue distribution and pharmacokinetics of oridonin-solid lipid nanoparticles in animals.

METHODSHPLC method was established to determine the concentration of oridonin in serum of rabbits and in different tissues of mice. The results after tail iv administration of oridonin and oridonin solid lipid nanoparticles were compared.

RESULTSThe relative tissue content of oridonin of solid lipid nanoparticles in the liver, spleen, lung, heart and kidney were 4.25%, 3.44%, 1.19%, 0.52% and 0.60%, respectively. The concentration-time curves of oridonin and oridonin solid lipid nanoparticles were both fitted to the three-compartment model. T(1/2)pi = 0.087 h, T(1/2)alpha = 1.65 h, T(1/2)beta = 32.36 h, V(C) = 0.66 mL.kg(-1).

CONCLUSIONSolid lipid nanoparticles could increase the hepatic and lienic targeting efficiency of oridonin in mice and improve its bioavailability. Solid lipid nanoparticles were helpful for oridonin to reach a long circulation time and were hopeful to be its novel drug carrier.

Animals ; Antineoplastic Agents, Phytogenic ; administration & dosage ; isolation & purification ; pharmacokinetics ; Area Under Curve ; Diterpenes ; administration & dosage ; isolation & purification ; pharmacokinetics ; Diterpenes, Kaurane ; administration & dosage ; isolation & purification ; pharmacokinetics ; Drug Carriers ; Drug Delivery Systems ; Female ; Injections, Intravenous ; Isodon ; chemistry ; Lipids ; Liver ; metabolism ; Male ; Mice ; Nanoparticles ; Plants, Medicinal ; chemistry ; Rabbits ; Spleen ; metabolism ; Tissue Distribution