Effects of ursolic acid and oleanolic acid on human colon carcinoma cell line HCT15

Biological Activities of Triterpenoids and Phenolic Compounds from Myrica cerifera Bark

Seven triterpenoids, 1 - 7, two diarylheptanoids, 8 and 9, four phenolic compounds, 10 - 13, and three other compounds, 14 - 16, were isolated from the hexane and MeOH extracts of the bark of Myrica cerifera L. (Myricaceae). Among these compounds, betulin (1), ursolic acid (3), and myricanol (8) exhibited cytotoxic activities against HL60 (leukemia), A549 (lung), and SK-BR-3 (breast) human cancer cell lines (IC₅₀ 3.1 - 24.2 μm). Compound 8 induced apoptotic cell death in HL60 cells (IC₅₀ 5.3 μm) upon evaluation of the apoptosis-inducing activity by flow cytometric analysis and by Hoechst 33342 staining method. Western blot analysis on HL60 cells revealed that 8 activated caspases-3, -8, and -9 suggesting that 8 induced apoptosis via both mitochondrial and death receptor pathways in HL60. Upon evaluation of the melanogenesis-inhibitory activity in B16 melanoma cells induced with α-melanocyte-stimulating hormone (α-MSH), erythrodiol (7), 4-hydroxy-2-methoxyphenyl β-d-glucopyranoside (13), and butyl quinate (15) exhibited inhibitory effects (65.4 - 86.0% melanin content) with no, or almost no, toxicity to the cells (85.9 - 107.4% cell viability) at 100 μm concentration. In addition, 8, myricanone (9), myricitrin (10), protocatechuic acid (11), and gallic acid (12) revealed potent DPPH radical-scavenging activities (IC₅₀ 6.9 - 20.5 μm).

Ethanol Extract of Oldenlandia diffusa - an Effective Chemotherapeutic for the Treatment of Colorectal Cancer in Humans: -Anti-Cancer Effects of Oldenlandia diffusa

Objectives:

Oldenlandia diffusa is traditionally used to relieve the symptoms of and to treat various diseases, but its anti-cancer activity has not been well studied. In the present study, the authors investigated the anti-cancer effects of an ethanol extract of Oldenlandia diffusa (EOD) on HT-29 human adenocarcinoma cells.

Methods:

Cells were treated with different concentrations of an EOD, and cell death was assessed by using a 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Analyses of the sub G1 peak, the caspase-3 and -9 activities, and the mitochondrial membrane depolarizations were conducted to confirm cell death by apoptosis. Also, intracellular reactive oxygen species (ROS) generation was determined using carboxy-H2DCFDA (5-(and-6)-carboxy-20,70-dichlorodihydrofluorescein diacetate).

Results:

EOD inhibited the proliferation of HT-29 cells for 24 hours by 78.6% ± 8.1% at 50 μg/mL, 74.4% ± 4.6% at 100 μg/mL, 65.9% ± 5.2% at 200 μg/mL, 51.4% ± 6.2% at 300 μg/mL, and by 41.7% ± 8.9% at 400 μg/mL, and treatment for 72 hours reduced the proliferation at the corresponding concentrations by 43.3% ± 8.8%, 24.3 ± 5.1 mV, 13.5 ± 3.2 mV, 6.5 ± 2.3 mV, and by 2.6 ± 2.3 mV. EOD increased the number of cells in the sub-G1 peak in a dose-dependent manner. The mitochondrial membrane depolarization was elevated by EOD. Also, caspase activities were dose-dependently elevated in the presence of EOD, and these activities were repressed by a pan-caspase inhibitor (zVAD-fmk). The ROS generation was significantly increased by EOD and N-acetyl-L-cysteine (NAC; a ROS scavenger) remarkably abolished EOD-induced cell death. In addition, a combination of sub-optimal doses of EOD and chemotherapeutic agents noticeably suppressed the growth of HT-29 cancer cells.

Conclusion:

These results indicate that EOD might be an effective chemotherapeutic for the treatment of human colorectal cancer.

Solid inclusion complexes of oleanolic acid with amino-appended β-cyclodextrins (ACDs): Preparation, characterization, water solubility and anticancer activity

Oleanolic acid (OA) is a pentacyclic triterpenoid acid of natural abundance in plants which possesses important biological activities. However, its medicinal applications were severely impeded by the poor water solubility and resultant low bioavailability and potency. In this work, studies on solid inclusion complexes of OA with a series of amino-appended β-cyclodextrins (ACDs) were conducted in order to address this issue. These complexes were prepared by suspension method and were well characterized by NMR, SEM, XRD, TG, DSC and Zeta potential measurement. The 2:1 inclusion mode of ACDs/OA complexes was elucidated by elaborate 2D NMR (ROESY). Besides, water solubility of OA was dramatically promoted by inclusion complexation with ACDs. Moreover, in vitro anticancer activities of OA against human cancer cell lines HepG2, HT29 and HCT116 were significantly enhanced after formation of inclusion complexes, while the apoptotic response results indicated their induction of apoptosis of cancer cells. This could provide a novel approach to development of novel pharmaceutical formulations of OA.

Synthesis and screening of ursolic acid-benzylidine derivatives as potential anti-cancer agents

Ursolic acid present abundantly in plant kingdom is a well-known compound with various promising biological activities including, anti-cancer, anti-inflammatory, hepatoprotective, antiallergic and anti-HIV properties. Herein, a library of ursolic acid-benzylidine derivatives have been designed and synthesized using Claisen Schmidt condensation of ursolic acid with various aromatic aldehydes in an attempt to develop potent antitumor agents. The compounds were evaluated against a panel of four human carcinoma cell lines including, A-549 (lung), MCF-7 (breast), HCT-116 (colon), THP-1 (leukemia) and a normal human epithelial cell line (FR-2). The results from MTT assay revealed that all the compounds displayed high level of antitumor activities compared with the triazole analogs (previously reported) and the parent ursolic acid. However, compound 3b, the most active derivative was subjected to mechanistic studies to understand the underlying mechanism. The results revealed that compound 3b induced apoptosis in HCT-116 cell lines, arrest cell cycle in the G1 phase, caused accumulation of cytochrome c in the cytosol and increased the expression levels of caspase-9 and caspase-3 proteins. Therefore, compound 3b induces apoptosis in HCT-116 cells through mitochondrial pathway.

Ursolic acid (UA): A metabolite with promising therapeutic potential

Plants are known to produce a variety of bioactive metabolites which are being used to cure various life threatening and chronic diseases. The molecular mechanism of action of such bioactive molecules, may open up new avenues for the scientific community to develop or improve novel therapeutic approaches to tackle dreadful diseases such as cancer and cardiovascular and neurodegenerative disorders. Ursolic acid (UA) is one among the categories of such plant-based therapeutic metabolites having multiple intracellular and extracellular targets that play role in apoptosis, metastasis, angiogenesis and inflammatory processes. Moreover, the synthetic derivatives of UA have also been seen to be involved in a range of pharmacological applications, which are associated with prevention of diseases. Evidences suggest that UA could be used as a potential candidate to develop a comprehensive competent strategy towards the treatment and prevention of health disorders. The review article herein describes the possible therapeutic effects of UA along with putative mechanism of action.

Triterpene Constituents of Euphorbia Erythradenia Bioss. and their Anti-HIV Activity

Phytochemical investigation of the aerial parts of Euphorbia erythradenia Bioss. (Euphorbiaceae), one of Iranian endemic Euphorbias, with particular attention to triterpene constituents, using methanol solvent extraction was carried out. Five known triterpenes, including four cycloartanes and oleanolic acid, were isolated for the first time and identified using NMR and Mass techniques. Anti HIV activity of the isolated triterpenes and ingenoid diterpenes was evaluated using single cycle replicable HIV-1 (SCR HIV-1) virions. Molecular features of the most active compound (IC50 = 0.008 μM, CC50 = 3.264 μM, TI = 380.64), which showed higher therapeutic index than nevirapine, was assessed using molecular docking. Docking studies demonstrated three hydrogen bonds between HIV-1 virion protease active site and this compound with a distance less than 3 A° which can be responsible for the observed anti HIV-1 activity.

Modulation of oxidized-LDL receptor-1 (LOX1) contributes to the antiatherosclerosis effect of oleanolic acid

Oleanolic acid (OA) is a bioactive pentacyclic triterpenoid. The current work studied the effects and possible mechanisms of OA in atherosclerosis. Quails (Coturnix coturnix) were treated with high fat diet with or without OA. Atherosclerosis was assessed by examining lipid profile, antioxidant status and histology in serum and aorta. Human umbilical vein endothelial cells (HUVECs) were exposed to 200μg/mL ox-LDL for 24h, then cell viability was assessed with MTT assay; reactive oxygen species (ROS) was assessed with DCFDA staining. Expression levels of LOX-1, NADPH oxidase subunits, nrf2 and ho-1 were measured with real time PCR and western blotting. Furthermore, LOX-1 was silenced with lentivirus and the expression levels assessment was repeated. OA treatment improved the lipid profile and antioxidant status in quails fed with high fat diet. Histology showed decreased atherosclerosis in OA treated animals. Ox-LDL exposure decreased viability and induced ROS generation in HUVECs, and this progression was alleviated by OA pretreatment. Moreover, elevated expression of LOX-1, NADPH oxidase subunits, nrf2 and ho-1 were observed in ox-LDL exposed HUVECs. OA pretreatment prevented ox-LDL induced increase of LOX-1 and NADPH oxidase subunits expression, while further increased nrf2 and ho-1 expression. Silencing of LOX-1 abolished ox-LDL induced effects in cell viability, ROS generation and gene expression. OA could alleviate high fat diet induced atherosclerosis in quail and ox-LDL induced cytotoxicity in HUVECs; the potential mechanism involves modulation of LOX-1 activity, including inhibition of expression of NADPH oxidase subunits and increase of the expression of nrf2 and ho-1.

"Ziziphus jujuba": A red fruit with promising anticancer activities

Ziziphus jujuba Mill. (Z. jujuba) is a traditional herb with a long history of use for nutrition and the treatment of a broad spectrum of diseases. It grows mostly in South and East Asia, as well as in Australia and Europe. Mounting evidence shows the health benefits of Z. jujuba, including anticancer, anti-inflammation, antiobesity, antioxidant, and hepato- and gastrointestinal protective properties, which are due to its bioactive compounds. Chemotherapy, such as with cis-diamminedichloroplatinium (CDDP, cisplatin) and its derivatives, is widely used in cancer treatment. It is an effective treatment for human cancers, including ovarian cancer; however, drug resistance is a major obstacle to successful treatment. A better understanding of the mechanisms and strategies for overcoming chemoresistance can greatly improve therapeutic outcomes for patients. In this review article, the bioactive compounds present in Z. jujuba are explained. The high prevalence of many different cancers worldwide has recently attracted the attention of many researchers. This is why our research group focused on studying the anticancer activity of Z. jujuba as well as its impact on chemoresistance both in vivo and in vitro. We hope that these studies can lead to a promising future for cancer patients.

Glycol chitosan incorporated retinoic acid chlorochalcone (RACC) nanoparticles in the treatment of Osteosarcoma

Background

Osteosarcoma is the most common of all the bone malignancies and accounts for 30-80 % of the primary skeletal sarcomas. The overall survival rate of patients with osteosarcoma is < 20 % suggesting poor prognosis.

Methods

The present study demonstrates the effect of retinoic acid chlorochalcone (RACC) incorporated glycol chitosan (GC) nanoparticle transfection in osteosarcoma cells. MG-63 and Saos-2 osteosarcoma cells were transfected with various concentrations of RACC-incorporated GC nanoparticle for 24 h. The effect on cell proliferation, Ezh2 expression, apoptosis, cell cycle arrest, cell migration and invasiveness, Akt phosphorylation and local tumour growth and metastases were studied.

Results

MG-63 and Saos-2 osteosarcoma cells on RACC-incorporated GC nanoparticle transfection for 24 h showed a concentration-dependent inhibition of cell proliferation. Of the various concentrations of RACC tested, the effective concentration started from 5 μM with an IC₅₀ of 20 μM. Wound healing assay also showed that RACC-incorporated GC nanoparticles inhibited migration of tumor cells more effectively compared to the parent RA. RACC transfection resulted in inhibition of cell proliferation, Ezh2 expression inhibition, apoptosis through mitochondrial pathway by decrease in membrane potential and release of cytochrome c and cell cycle arrest in the G0/G1 phase. The invasiveness of cells treated with 5 and 20 μM RACC was decreased by 49 and 76 % respectively, compared to the control. RACC-treated mice showed significantly lower number of metastases compared to that in the control mice.

Conclusions

Thus, RACC-incorporated glycol chitosan nanoparticle strategy can be promising for the treatment of osteosarcoma.

Oleanolic Acid Induces Differentiation of Neural Stem Cells to Neurons: An Involvement of Transcription Factor Nkx-2.5

Neural stem cells (NSCs) harbor the potential to differentiate into neurons, astrocytes, and oligodendrocytes under normal conditions and/or in response to tissue damage. NSCs open a new way of treatment of the injured central nervous system and neurodegenerative disorders. Thus far, few drugs have been developed for controlling NSC functions. Here, the effect as well as mechanism of oleanolic acid (OA), a pentacyclic triterpenoid, on NSC function was investigated. We found OA significantly inhibited neurosphere formation in a dose-dependent manner and achieved a maximum effect at 10 nM. OA also reduced 5-ethynyl-2'-deoxyuridine (EdU) incorporation into NSCs, which was indicative of inhibited NSC proliferation. Western blotting analysis revealed the protein levels of neuron-specific marker tubulin-βIII (TuJ1) and Mash1 were increased whilst the astrocyte-specific marker glial fibrillary acidic protein (GFAP) decreased. Immunofluorescence analysis showed OA significantly elevated the percentage of TuJ1-positive cells and reduced GFAP-positive cells. Using DNA microarray analysis, 183 genes were differentially regulated by OA. Through transcription factor binding site analyses of the upstream regulatory sequences of these genes, 87 genes were predicted to share a common motif for Nkx-2.5 binding. Finally, small interfering RNA (siRNA) methodology was used to silence Nkx-2.5 expression and found silence of Nkx-2.5 alone did not change the expression of TuJ-1 and the percentage of TuJ-1-positive cells. But in combination of OA treatment and silence of Nkx-2.5, most effects of OA on NSCs were abolished. These results indicated that OA is an effective inducer for NSCs differentiation into neurons at least partially by Nkx-2.5-dependent mechanism.

Oldenlandia diffusa Promotes Antiproliferative and Apoptotic Effects in a Rat Hepatocellular Carcinoma with Liver Cirrhosis

Oldenlandia diffusa (OD) is commonly used with various diseases such as cancer, arthritis, and autoimmune disease. Liver cirrhosis is a predominant risk factor for hepatocellular carcinoma (HCC). Here, we show that the therapeutic effect of OD, which was investigated both in vitro and chemically, induced HCC model. OD significantly enhanced apoptosis and antiproliferative activity and reduced migration ability of HCC cells. In vivo, OD was treated twice a day for 28 days after confirmed HCC model through 2-[¹⁸F]-fluoro-2-deoxy-D-glucose (¹⁸F-FDG) imaging. The survival in OD treated groups was shown to have a greater therapeutic effect than the control group. 28 days after OD treatment, OD treated groups resulted in a significant reduction in tumor number, size, ¹⁸F-FDG uptake, and serum levels such as alanine transaminase, aspartate transaminase, and alkaline phosphate compared to the control group. Also, proliferated cells in tumor sites by OD were reduced compared to the control group. Furthermore, several rats in OD treated group survived over 60 days and liver morphology of these rats showed the difference between tumor mass and normal tissue. These results suggest that OD may have antiproliferative activity, inhibition of metastasis, and apoptotic effects in chemically induced HCC model and can have the potential use for clinical application as anticancer drug of the herbal extract.

Ursolic Acid and Oleanolic Acid from Eriobotrya fragrans Inhibited the Viability of A549 Cells

Loquat { Eriobotrya japonica (Lindl.)}, a kind of Chinese herb, has many efficacies such as anti-inflammatory, antimicrobial and curing chronic bronchitis. However, reports on the pharmacological action of wild loquat extract are limited. In this work, the A549 cell line was selected to study the inhibitory effect of ursolic acid and oleanolic acid (UA, OA) from the leaves of E. fragrans. Results showed that UA/OA inhibited A549 cell viability and induced apoptosis in a dose and time dependent manner. The cell fraction in the G0/G1 phase dramatically increased under treatment with UA/OA. Data showed that UA activated the expression of PARP. UA and OA down-regulated MMP-2 and Bcl-2; on the contrary, they up-regulated Bid. This work demonstrated that UA/OA extracted from wild loquat leaves can significantly inhibit the viability of A549 cells.

Suppressive effects of saponin-enriched extracts from quinoa on 3T3-L1 adipocyte differentiation

This study was performed to investigate the effect of quinoa saponins (QS) on the differentiation of 3T3-L1 preadipocytes.

Preparation and study on anti-tumor effect of chitosan-coated oleanolic acid liposomes

Chitosan modified OA liposomes can achieve the desired effect of tumor-targeting drug delivery and improve the anti-tumor efficacy.

Identification of nitric oxide-releasing derivatives of oleanolic acid as potential anti-colon cancer agents

NO-releasing hybrid 6 regulates colon cancer-related signaling pathways, exhibiting potent anti-colon cancer activity in vitro and in vivo.

New insights into the chemical and biochemical basis of the "yang-invigorating" action of chinese yang-tonic herbs

In the practice of traditional Chinese medicine, many Yang-tonic herbs have been used for retarding the decline in bodily function and delaying the onset of age-related diseases. Our earlier studies have demonstrated that Yang-invigorating herbs/formulations protect against oxidative injury in various organs and also extend the median lifespan in mice. This lifespan extension was associated with an upregulation of cellular antioxidant status including that of mitochondria whose functional capacity is also increased by “Yang-invigorating” herbs/formulations. In this paper, we propose that triterpenes and phytosterols, which are ubiquitously found in Yang-tonic herbs, may be the chemical entities responsible for enhancing mitochondrial functional and antioxidant capacity and thus the “Yang-invigorating” action. The biochemical mechanism underlying this “Yang-invigorating” action may involve a sustained production of low levels of mitochondrial reactive oxygen species (ROS) secondary to an increased activity of the electron transport chain, with the possible involvement of mitochondrial uncoupling. The increase in mitochondrial functional capacity can retard the decline in bodily function during aging, whereas the mitochondrial ROS production is instrumental in eliciting a glutathione antioxidant response via redox-sensitive signaling pathways, which can delay the onset of age-related diseases.

Oleanolic acid induces apoptosis of MKN28 cells via AKT and JNK signaling pathways

CONTEXT

Oleanolic acid (OA) belongs to the triterpenoid compound group existing widely in food, medicinal herbs and other plants. Its effects on gastric cancer cells and the mechanisms involved have not been investigated.

OBJECTIVE

This study aimed to substantiate whether OA induces apoptosis of gastric cancer cell line (MKN28) and to elucidate the molecular mechanism involved.

MATERIALS AND METHODS

Cell viability was assessed by MTT assay within the range of 0-160 μg/mL. The effects of OA (5, 10 and 20 μg/mL) on apoptosis of MKN28 cells were evaluated by flow cytometry, DNA fragmentation and mitochondrial membrane potential assays. Western blot and FQRT-PCR assays were used to investigate the mechanism of cell apoptosis induced by OA (5 and 10 μg/mL).

RESULTS

OA evidently inhibited cell viability with IC50 of 44.8 and 15.9 μg/mL at 12 and 24 h, respectively. Furthermore, OA increased JNK phosphorylation, decreased AKT phosphorylation, but did not affect p38 and ERK phosphorylation in MKN28 cells. In contrast, OA also significantly enhanced the mRNA expression levels of caspase 3, caspase 9 and Apaf-1 in MKN28 cells.

CONCLUSION

OA induces apoptosis of MKN28 cells via the mitochondrial pathway regulated by AKT and JNK signaling pathways.

Ursolic acid inhibits tumor angiogenesis and induces apoptosis through mitochondrial-dependent pathway in Ehrlich ascites carcinoma tumor

Ursolic acid (UA) is a pentacyclic triterpene naturally occurring in many plant foods. In the present study, we investigated anti-cancer activity of UA in vivo in Ehrlich ascites carcinoma (EAC) tumor. 15 × 10(6) EAC cells were implanted intraperitoneally (i.p., ascitic tumor) and subcutaneous (s.c., solid tumor) in Swiss albino mice. Mice with established tumors received UA i.p. at 25, 50 and 100mg/kg bw for 14 d in ascitic and 100mg/kg bw in solid tumor for 30 d. On day 15, blood samples were collected for hematological assessment of hemoglobin (Hb%), RBCs, WBCs and PCV. Tumor volume, cell viability, angiogenic, anti-angiogenic, anti-inflammatory factors and antioxidant parameters were determined. Immunohistochemistry analysis for VEGF, iNOS, CD31, caspase-3 and Bax were also performed. UA significantly inhibited tumor growth, cell viability, in both ascites and solid tumor model in vivo (p<0.001). The anti-angiogenic effects were accompanied with decreased VEGF, iNOS, TNF-α and increased IL-12 levels. UA at 100mg/kg bw dose significantly increased SOD and CAT activity (p<0.01). GSH and TBARS were increased as compared to control group (p<0.001). Furthermore, UA increased total RBCs, WBCs as well as Hb% significantly (p<0.05) compared to cyclophosphamide (CP). Histopathological examination of tumor cells in the treated group demonstrated signs of apoptosis with chromatin condensation and cell shrinkage. Decreased peritoneal angiogenesis showed the anti-angiogenic potential. UA downregulated VEGF & iNOS expression whereas bax and caspase-3 expressions were upregulated suggesting drug induced tumor cell apoptosis through activating the pro-apoptotic bcl-2 family and caspase-3 and downregulation of VEGF. The present study sheds light on the potent antitumor property of the UA and can be extended further to develop therapeutic protocols for treatment of cancer.

Synthesis and biological evaluation of ursolic acid-triazolyl derivatives as potential anti-cancer agents

A series of ursolic acid-1-phenyl-1H-[1,2,3]triazol-4-ylmethylester congeners have been designed and synthesized in an attempt to develop potent antitumor agents. A regioselective approach using Huisgen 1,3-dipolar cycloaddition reaction of ursolic acid-alkyne derivative with various aromatic azides was employed to target an array of triazolyl derivatives in an efficient manner. Their structures were confirmed by using (1)H NMR, (13)C NMR, IR and MS analysis. All the compounds were evaluated for anti-cancer activity against a panel of four human cancer cell lines including A-549 (lung), MCF-7 (breast), HCT-116 (colon), THP-1 (leukemia) and a normal human epithelial cell line (FR-2) using sulforhodamine-B assay. The pharmacological results showed that most of the compounds displayed high level of antitumor activities against the tested cancer cell lines compared with ursolic acid. Compounds 7b, 7g, 7p and 7r were found to be the most potent compounds in this study.

Oleanolic acid inhibits proliferation and induces apoptosis in NB4 cells by targeting PML/RARα

Oleanolic acid (OA), a naturally occurring pentacyclic triterpenoid contained in a variety of plant species, exhibits broad biological properties, including anticancer effects. Acute promyelocytic leukemia (APL) is a distinct subtype of acute myeloid leukemia. APL has a unique and specific chromosomal aberration, t(15;17), which results in the formation of a fusion gene and protein PML/RARα, which is not only necessary for the diagnosis of APL, but is also critical for APL pathogenesis. In the present study, the cytotoxic effect of OA on NB4 cells was investigated. Cell viability was assessed via the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The expression levels of bax and bcl-2 mRNA were determined by quantitative PCR. Apoptosis was analyzed using DNA fragment analysis and cell cycle distributions were analyzed by flow cytometry. The activity of caspase-3 and caspase-9 was determined by colorimetric assays. The expression of the PML/RARα fusion protein was analyzed by western blotting. The MTT assay showed that OA inhibited the proliferation of the NB4 cells. The expression levels of pro-apoptotic bax mRNA were increased and the levels of anti-apoptotic bcl-2 mRNA were decreased following the treatment of the NB4 cells with OA at 80 μmol/l. Treatment of the NB4 cells with OA at 80 μmol/l induced apoptosis and G₁ phase arrest, while caspase-9 and caspase-3 activity was significantly increased. Furthermore, the expression of the PML/RARα fusion protein was decreased. Together, these data suggest that OA exerts a cytotoxic effect that inhibits proliferation and induces apoptosis in NB4 cells by targeting PML/RARα, making it a potent therapeutic agent against leukemia.

Cytotoxic activity of ursolic acid derivatives obtained by isolation and oxidative derivatization

Structure-activity relationships of ursane-type pentacyclic triterpenes obtained from natural sources and by chemical derivatization are reviewed. Ursolic acid, corosolic acid, and a new ursane-type pentacyclic triterpene, 7,24-dihydroxyursolic acid, were isolated from the methanolic extract of the leaves of the Bangladeshi medicinal plant, Saurauja roxburghii. Derivatization of ursolic acid by oxidation with dioxoruthenium (VI) tetraphenylporphyrins was investigated. Oxidation selectivity on the terpene structure was modulated by the auxiliaries introduced on the tetraphenylporphyrin. The natural triterpenes and oxidized derivatives were tested for cytotoxicity against the C6 rat glioma and A431 human skin carcinoma cell lines. Although they have the same ursane-type pentacyclic triterpene cores, the position and numbers of hydroxyls on the terpene structures significantly affected the activity and the selectivity towards the tested cell lines.

Comparative protective effect of hawthorn berry hydroalcoholic extract, atorvastatin, and mesalamine on experimentally induced colitis in rats

The protective effect of hydroalcoholic extract of hawthorn berries (HBE) on acetic acid (AA)-induced colitis in rats was investigated. Forty-two Wistar rats were divided into seven groups, including control and test groups (n=6). The control animals received saline, and the test animals were treated with saline (sham group), mesalamine (50 mg/kg; M group), atorvastatin (20 mg/kg; A group), HBE (100 mg/kg; H group), mesalamine and HBE (HM group), or atorvastatin plus HBE (HA group), 3 days before and a week after colitis induction. Colitis was induced by administration of 1 mL AA (4%) via a polyethylene catheter intrarectally. High-performance liquid chromatography analyses showed that HBE contained 0.13% and 0.5% oleanolic acid and ursolic acid, respectively. Elevated myeloperoxidase activity and lipid peroxidation were attenuated in the HA group. The H and HM groups showed marked reductions in colitis-induced decreases in total thiol molecules and body weight. The histopathological studies revealed that HBE decreased colitis-induced edema and infiltration of neutrophils. Our data suggest the anti-inflammatory and antioxidant effects of HBE and atorvastatin protect against AA-induced colitis. The anti-inflammatory effect of HBE may be attributable to its ability to decrease myeloperoxidase activity as a biomarker of neutrophil infiltration.

Ethnopharmacological and bioactivity guided investigation of five TCM anticancer herbs

ETHNOPHARMACOLOGICAL RELEVANCE

Five herbs, Curcuma longa L. (CL), Scutellaria baicalensis Georgi (SBC), Scutellaria barbata D. Don (SBB), Hedyotis diffusa Willd. (HD) and Solanum nigrum L. (SN), are often prescribed in the polyherbal formulas for cancer treatment by traditional Chinese medicine (TCM) practitioners. The purpose of the present study was to identify important anticancer herbs used in TCM and carry out bioactivity-directed fractionation and isolation (BDFI) using six cancer cell lines as well as peripheral blood mononuclear cells (PBMCs), to identify constituents with anticancer activity but devoid of toxic effects against healthy immune cells.

MATERIALS AND METHODS

Of 243 document anticancer TCM treatments, 199 anticancer TCM herbs were ranked by the number of literature reports for each herb. Five herbs were identified from the top 50 ranked herbs by at least two out of three TCM practitioners as frequently used in the TCM treatment of cancer. BDFI using MTS assay was applied to determine the active anticancer extracts, fractions, and finally discrete compounds.

RESULTS

Five herbs were selected for study of their anticancer activities. The extracts of Curcuma longa L., Scutellaria barbata D. Don, and Hedyotis diffusa showed antiproliferative activity to various extents, extracts of Scutellaria baicalensis Georgi and Solanum nigrum L. showed little anticancer activity. Seven out of the 21 fractions obtained from Hedyotis diffusa Willd. showed anticancer activity. One new compound, ethyl 13(2) (S)-hydroxy-chlorophyllide a(1), along with 10 known compounds, i.e. 2-methyl-3-methoxyanthraquinone (2), 2-hydroxymethylanthraquinone(3), 2-hydroxy-3-methylanthraquinone(4), 2-hydroxymethy-1-hydroxyanthraquinone(5), 1-methoxy-2-hydroxyanthraquinone(6), 2-hydroxy-3-methyl-1-methoxyanthraquinone (7), oleanolic acid (8), ursolic acid (9), stigmasterol (10) and docosanoic acid (11), were isolated and identified. Compounds 2-6, 8 and 9 dose-dependently inhibited the cell viability of cancer cells within a concentration range of 1-200µM. Furthermore, compounds 2, 3, 5 and 9 showed significantly stronger inhibition of tested cancer cell lines than on that of PBMCs.

CONCLUSION

This study identified anticancer herbs, extracts, fractions and eventually compounds from the documented anticancer TCM herbs by using BDFI. It also determined the antiproliferative activity in cancer and healthy immune cells of the isolated compounds from Hedyotis diffusa. The results will be useful in the validation of the clinical application of these herbs and the development of novel anticancer therapeutics.

An evaluation of the anti-tumor efficacy of oleanolic acid-loaded PEGylated liposomes

The effective delivery of oleanolic acid (OA) to the target site has several benefits in therapy for different pathologies. However, the delivery of OA is challenging due to its poor aqueous solubility. The study aims to evaluate the tumor inhibition effect of the PEGylated OA nanoliposome on the U14 cervical carcinoma cell line. In our previous study, OA was successfully encapsulated into PEGylated liposome with the modified ethanol injection method. Oral administration of PEGylated OA liposome was demonstrated to be more efficient in inhibiting xenograft tumors. The results of organ index indicated that PEG liposome exhibited higher anti-tumor activity and lower cytotoxicity. It was also found that OA and OA liposomes induced tumor cell apoptosis detected by flow cytometry. Furthermore, effects of OA on the morphology of tumor and other tissues were observed by hematoxylin and eosin staining. The histopathology sections did not show pathological changes in kidney or liver in tested mice. In contrast, there was a significant difference in tumor tissues between treatment groups and the negative control group. These observations imply that PEGylated liposomes seem to have advantages for cancer therapy in terms of effective delivery of OA.

Synthesis and cytotoxicity evaluation of oleanolic acid derivatives

Twelve derivatives of oleanolic acid (1) have been synthesized and evaluated for their inhibitory activities against the growth of prostate PC3, breast MCF-7, lung A549, and gastric BGC-823 cancer cells by MTT assays. Within these series of derivatives, compound 17 exhibited the most potent cytotoxicity against PC3 cell line (IC50=0.39 μM) and compound 28 displayed the best activity against A549 cell line (IC50=0.22 μM). SAR analysis indicates that H-donor substitution at C-3 position of oleanolic acid may be advantageous for improvement of cytotoxicity against PC3, A549 and MCF-7 cell lines.

Anti-herpes virus activities of Achyranthes aspera: an indian ethnomedicine, and its triterpene acid

The aim of this study was to evaluate the antiviral potential of methanolic extract (ME) of Achyranthes aspera, an Indian folk medicine and one of its pure compound oleanolic acid (OA) against herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2). The ME possessed weak anti-herpes virus activity (EC50 64.4μg/ml for HSV-1 and 72.8μg/ml for HSV-2). While OA exhibited potent antiherpesvirus activity against both HSV-1 (EC50 6.8μg/ml) and HSV-2 (EC50 7.8μg/ml). The time response study revealed that the antiviral activity of ME and OA is highest at 2-6h post infection. The infected and drug-treated peritoneal macrophage at specific time showed increased level of pro-inflammatory cytokines (IL6 and IL12). Further, the PCR of DNA from infected cultures treated with ME and OA, at various time intervals, failed to show amplification at 48-72h, similar to that of HSV infected cells treated with acyclovir, indicating that the ME and OA probably inhibit the early stage of multiplication (post infection of 2-6h). Thus, our study demonstrated that ME and OA have good anti-HSV activity, with SI values of 12, suggesting the potential use of this plant.

Synthesis and cytotoxicity of novel ursolic acid derivatives containing an acyl piperazine moiety

This study designed and synthesized a series of novel ursolic acid derivatives in an attempt to develop potent antitumor agents. Their structures were confirmed using MS, IR, (1)H NMR and (13)C NMR. The inhibitory activities of the title compounds against the MGC-803 (gastric cancer cell) and Bcap-37 (breast cancer cell) human cancer cell lines were evaluated using standard MTT assay in vitro. The pharmacological results showed that some of the compounds displayed moderate to high levels of antitumor activities against the tested cancer cell lines and that most exhibited more potent inhibitory activities compared with ursolic acid. The mechanism of compound 4b was preliminarily investigated by acridine orange/ethidium bromide staining, Hoechst 33258 staining, TUNEL assay and flow cytometry, which revealed that the compound can induce cell apoptosis in MGC-803 cells.

Oleanolic acid derivative methyl 3,11-dioxoolean-12-en-28-olate targets multidrug resistance related to ABCB1

Multidrug resistance (MDR) in leukemia patients is a great incentive to the development of new drugs. In a search for potential multidrug resistance modulators we tested a group of oleanolic acid (OA) analogues modified at C-3, C-11, C-12 and C-28 using an experimental model consisting of three human acute lymphoblastic leukemia cell lines (CCRF-CEM and the multidrug resistant sublines CCRF-VCR1000 and CCRF-ADR5000). The most effective compound, methyl 3,11-dioxoolean-12-en-28-olate (DIOXOL) was more potent in cell viability inhibition than its precursor - OA, and showed similar or even higher activity in the drug resistant than in the wild-type cells. Resistance factor (RF) values obtained for CCRF-VCR1000 and CCRF-ADR-5000 cells using MTT assay were 0.7 and 0.8 (24 h of treatment) and after 72 h of treatment 0.9 and 1.1, respectively. Moreover, 5 μM DIOXOL significantly reduced the expression of the ABCB1 gene in MDR cells by around 30%, and also decreased the level of P-gp protein. Compared to untreated control cells, DIOXOL treatment resulted in a significant P-gp decrease (30% in CCRF-ADR5000 and 50% in CCRF-VCR1000), that was detected by western blot and confirmed by flow cytometry analysis. Moreover, DIOXOL (at 10 μM) significantly inhibited P-gp transport function by more than twofold comparing to control, untreated cells that was demonstrated using rhodamine 123-based functional test. The compound exhibited synergistic activity with ABCB1 substrate - adriamycin in CCRF-VCR1000 cells, indicating partial but significant MDR reversing ability.

Involvement of arginine-vasopressin in the diuretic and hypotensive effects of Pereskia grandifolia Haw. (Cactaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Pereskia grandifolia Haw. (Cactaceae), popularly known as "ora-pro-nobis" is well recognized in Brazilian traditional medicine as a diuretic agent, although no scientific data have been published to support this effect. The aim of this work is to evaluate the diuretic and hypotensive activities of the infusion (INFPG) and the ethanol extract (HEPG) of Pereskia grandifolia and possible mechanism of action.

MATERIALS AND METHODS

The infusions (2.5-10%) and the HEPG (3-100 mg/kg) were orally administered in a single dose or daily (for seven days) to rats. The urine excretion rate, pH, density, conductivity and content of Na(+), K(+), Cl(-) and HCO(3)(-) were measured in the urine of saline-loaded animals. In collected serum samples the concentration of electrolytes, urea, creatinine, aldosterone, vasopressin and angiotensin converting enzyme (ACE) activity were evaluated. The involvement of V(2) vasopressin receptor in the diuretic activity and the hypotensive effect of HEPG were also determined.

RESULTS

Water excretion rate was significantly increased by HEPG, while the urinary K(+) and Cl(-) excretion was significantly reduced in acute and prolonged treatment. The oral administration of the HEPG (30mg/kg) significantly reduced serum levels of vasopressin and the mean arterial pressure (MAP) in normotensive rats. All other evaluated parameters have not been affected by any treatment.

CONCLUSION

The results showed that HEPG could present compound(s) responsible for aquaretic activities with no signs of toxicity, and this effect could involve a reduction in the arginine-vasopressin release.

Ursane-type pentacyclic triterpenoids as useful platforms to discover anticancer drugs

This review highlights the potential of natural and semisynthetic ursane-type triterpenoids as candidates for the design of multi-target bioactive compounds, with focus on their anticancer effects. A brief illustration of the biosynthesis, sources, and general biological effects of the main classes of naturally occurring pentacyclic triterpenoids (PTs) are provided.

Oldenlandia diffusa extracts exert antiproliferative and apoptotic effects on human breast cancer cells through ERα/Sp1-mediated p53 activation

Breast cancer is the most frequent tumor and a major cause of death among women. Estrogens play a crucial role in breast tumor growth, which is the rationale for the use of hormonal antiestrogen therapies. Unfortunately, not all therapeutic modalities are efficacious and it is imperative to develop new effective antitumoral drugs. Oldenlandia diffusa (OD) is a well-known medicinal plant used to prevent and treat many disorders, especially cancers. The aim of this study was to investigate the effects of OD extracts on breast cancer cell proliferation. We observed that OD extracts strongly inhibited anchorage-dependent and -independent cell growth and induced apoptosis in estrogen receptor alpha (ERα)-positive breast cancer cells, whereas proliferation and apoptotic responses of MCF-10A normal breast epithelial cells were unaffected. Mechanistically, OD extracts enhance the tumor suppressor p53 expression as a result of an increased binding of ERα/Sp1 complex to the p53 promoter region. Finally, we isolated ursolic and oleanolic acids as the bioactive compounds able to upregulate p53 expression and inhibit breast cancer cell growth. These acids were greatly effective in reducing tamoxifen-resistant growth of a derivative MCF-7 breast cancer cell line resistant to the antiestrogen treatment. Our results evidence how OD, and its bioactive compounds, exert antiproliferative and apoptotic effects selectively in ERα-positive breast cancer cells, highlighting the potential use of these herbal extracts as breast cancer preventive and/or therapeutic agents.

In vitro anti-breast cancer activity of ethanolic extract of Wrightia tomentosa: role of pro-apoptotic effects of oleanolic acid and urosolic acid

ETHNOPHARMACOLOGICAL RELEVANCE

Wrightia tomentosa Roem. & Schult. (Apocynaceae) is known in the traditional medicine for anti-cancer activity along with other broad indications like snake and scorpion bites, renal complications, menstrual disorders etc. However, the anti-cancer activity of this plant or its constituents has never been studied systematically in any cancer types so far.

AIM OF THE STUDY

To evaluate the anti-cancer activities of the ethanolic extract of W. tomentosa and identified constituent active molecule(s) against breast cancer.

MATERIAL AND METHODS

Powdered leaves of W. tomentosa were extracted with ethanol. The ethanolic extract, subsequent hexane fractions and fraction F-4 of W. tomentosa were tested for its anti-proliferative and pro-apoptotic effects in breast cancer cells MCF-7 and MDA-MB-231.

RESULTS

The ethanolic extract, subsequent hexane fractions and fraction F-4 of W. tomentosa inhibited the proliferation of human breast cancer cell lines, MCF-7 and MDA-MB-231. The fraction F-4 obtained from hexane fraction inhibited proliferation of MCF-7 and MDA-MB-231 cells in concentration and time dependent manner with IC₅₀ of 50 μg/ml and 30 μg/ml for 24 h, 28 μg/ml and 22 μg/ml for 48 h and 25 μg/ml and 20 μg/ml for 72 h respectively. The fraction F-4 induced G1 cell cycle arrest, reactive oxygen species (ROS) generation, loss of mitochondrial membrane potential and subsequent apoptosis. Apoptosis is indicated in terms of increased Bax/Bcl-2 ratio, enhanced Annexin-V positivity, caspase 8 activation and DNA fragmentation. The active molecule isolated from fraction F-4, oleanolic acid and urosolic acid inhibited cell proliferation of MCF-7 and MDA-MB-231 cells at IC₅₀ value of 7.5 μM and 7.0 μM respectively, whereas there is devoid of significant cell inhibiting activity in non-cancer originated cells, HEK-293. In both MCF-7 and MDA-MB-231, oleanolic acid and urosolic acid induced cell cycle arrest and apoptosis as indicated by significant increase in Annexin-V positive apoptotic cell counts.

CONCLUSION

Our results suggest that W. tomentosa extracts has significant anti-cancer activity against breast cancer cells due to induction of apoptosis pathway. Olenolic and urosolic acid are important constituent molecules in the extract responsible for anti-cancer activity of W. tomentosa.

The effects of Syzygium aromaticum-derived oleanolic acid on kidney function of male Sprague-Dawley rats and on kidney and liver cell lines

Studies indicate that Syzygium spp-derived oleanolic acid (OA) enhances renal function of streptozotocin (STZ)-induced diabetic rats as evidenced by its reversal of the previously reported inability of the kidney to excrete Na(+) in these animals. We postulated that OA influences Na(+) excretion in the proximal tubule, the site where two-thirds of filtered NaCl is reabsorbed through a process mediated by transport proteins. Therefore, the study investigated the effects of OA on proximal tubular Na(+) handling in male Sprague-Dawley rats using renal lithium clearance (C(Li)). Renal C(Li) has been used widely in animal and clinical studies to assess proximal tubular function. Sub-chronic doses of OA were administered to rats twice every third day for 5 weeks. Rats treated with deionized water served as control animals. Cytotoxicity of OA on kidney and liver cell lines was assessed by the MTT and comet assays. OA increased Na(+) excretion of conscious male Sprague-Dawley rats from week 3 to week 5. By the end of the 5-week experimental period, OA treatment significantly reduced (p < 0.05) plasma creatinine concentration of STZ-induced diabetic rats with a concomitant elevation in glomerular filtration rate (GFR). Acute OA infusion was also associated with increases in fractional excretion of sodium (FE(Na)) and lithium (FE(Li)) in anesthetized rats in the absence of significant changes in GFR. The MTT assay studies demonstrated that OA increased the metabolic activity of kidney and liver cell lines. Taken together with previous observations, this study implicates the proximal tubule in OA-evoked increases in urinary Na(+) output.

3-O-acetyloleanolic acid induces apoptosis in human colon carcinoma HCT-116 cells

The cytotoxic effect of 3-O-acetyloleanolic acid, an oleanolic acid derivative isolated from the seeds of Vigna sinensis K., was investigated in human colon carcinoma HCT-116 cells. 3-O-acetyloleanolic acid dose-dependently inhibited the viability of HCT-116 cells. Apoptosis was characterized by detection of cell surface annexin V and sub-G1 apoptotic cell populations. The number of immunostained cells with annexin V-FITC was increased after treatment with 3-O-acetyloleanolic acid. The sub-G1 cell population was also increased. Expression of TRAIL-mediated apoptosis signaling-related death receptor DR5 was increased in 3-O-acetyloleanolic acid-treated HCT-116 cells. Activation of caspase-8 and caspase-3, critical mediators of extrinsic apoptosis signaling, was also increased by 3-O-acetyloleanolic acid. The results indicate that 3-O-acetyloleanolic acid induces apoptosis in HCT-116 cells mediated by an extrinsic apoptosis signaling cascade via up-regulation of DR5.

Synthesis and biological evaluation of oleanolic acid derivatives as antitumor agents

Derivatives of oleanolic acid were synthesized and evaluated in vitro for their growth inhibition against human hepatocellular carcinoma cell line (HepG2) and colon cancer cell line (Col-02). Several derivatives exhibited moderate-to-good inhibitory activity, with 3 displaying the most promising inhibition [GI₅₀ = 1.75 μM (HepG2), 0.71 μM (Col-02)]. Structure-activity relationship analyses of these derivatives demonstrated that a 1-en-2-cyano-3-oxo in ring A and a nitro at C-17 were important in retention of the inhibition against HepG2 and Col-02 cells.

Oleanolic acid initiates apoptosis in non-small cell lung cancer cell lines and reduces metastasis of a B16F10 melanoma model in vivo

Background

Drug resistance, a process mediated by multiple mechanisms, is a critical determinant for treating lung cancer. The aim of this study is to determine if oleanolic acid (OA), a pentacyclic triterpene present in several plants, is able to circumvent the mechanisms of drug resistance present in non-small cell lung cancer (NSCLC) cell lines and to induce their death.

Principal Findings

OA decreased the cell viability of the NSCLC cell lines A459 and H460 despite the presence of active, multidrug-resistant (MDR) MRP1/ABCC1 proteins and the anti-apoptotic proteins Bcl-2 and survivin. These effects are due to apoptosis, as evidenced by the capacity of OA to induce fragmentation of DNA and activate caspase 3. Induction of NSCLC cell death by OA cannot be explained by inhibition of the MDR proteins, since treatment with triterpene had little or no effect on the activity or expression of MRP1. Moreover, treatment with OA had no effect on the expression of the anti-apoptotic protein Bcl-2, but increased the expression of the pro-apoptotic protein Bax, altering the Bcl-2/Bax balance towards a pro-apoptotic profile. OA also decreased the expression of the anti-apoptotic protein survivin. Furthermore, OA decreased the expression of the angiogenic vascular endothelial growth factor (VEGF) and decreased the development of melanoma-induced lung metastasis.

Conclusion

Our data provide a significant insight into the antitumoral and antimetastatic activity of OA in NSCLC and suggest that including OA in the NSCLC regimens may help to decrease the number of relapses and reduce the development of metastases.