Chitin synthase II inhibitory activity of ursolic acid, isolated from Crataegus pinnatifida

Botany, traditional uses, phytochemistry and pharmacological activity of Crataegus pinnatifida (Chinese hawthorn): a review

OBJECTIVES

Crataegus pinnatifida (C. pinnatifida), including C. pinnatifida Bge. and its variant C. pinnatifida Bge. var. major N, E. Br., has traditionally been used as a homologous plant for traditional medicine and food in ethnic medical systems in China. Crataegus pinnatifida, especially its fruit, has been used for more than 2000 years to treat indigestion, stagnation of meat, hyperlipidemia, blood stasis, heart tingling, sores, etc. This review aimed to provide a systematic summary on the botany, traditional uses, phytochemistry, pharmacology and clinical applications of C. pinnatifida.

KEY FINDINGS

This plant contains flavonoids, phenylpropanoids, terpenoids, organic acids, saccharides and essential oils. Experimental studies showed that it has hypolipidemic, antimyocardial, anti-ischemia, antithrombotic, anti-atherosclerotic, anti-inflammatory, antineoplastic neuroprotective activity, etc. Importantly, it has good effects in treating diseases of the digestive system and cardiovascular and cerebrovascular systems.

SUMMARY

There is convincing evidence from both in vitro and in vivo studies supporting the traditional uses of C. pinnatifida. However, multitarget network pharmacology and molecular docking technology should be used to study the interaction between the active ingredients and targets of C. pinnatifida. Furthermore, exploring the synergy of C. pinnatifida with other Chinese medicines to provide new understanding of complex diseases may be a promising strategy.

A Review of Saurauia roxburghii Wall. (Actinidiacaea) as a Traditional Medicinal Plant, Its Phytochemical Study and Therapeutic Potential

Saurauia roxburghii Wall. is an interesting plant, found growing chiefly along the eastern and south-eastern countries of Asia. The various ethnic groups of these regions use the plant as a medication for relieving a wide spectrum of diseases and conditions, including indigestion, boils, fever, gout, piles, eczema, asthma, ulcers, bronchitis, epilepsy, and hepatitis B. This review aims to appraise the vernacular information, botanical characterization, geographical distribution, traditional uses, phytochemistry, and pharmacological activities of S. roxburghii as well as to conduct a critical analysis on the findings. To understand the therapeutic potential and provide an overall idea about the ethnomedicinal practices, phytochemistry, and pharmacological activities of S. roxburghii, relevant information was collected via a library and electronic search of online journals, books, and reputed databases. Phytochemical examination revealed the presence of alkaloids, glycosides, O-glycosides, flavonoids, carbohydrates, saponins, steroids, reducing sugars, tannins, phlobatannins, and triterpenoids. The sterols were identified as Stigmasterol and beta-Sitosterol. The triterpenes were found to be Ursolic acid, Corosolic acid, Maslinic acid, 24-Hydroxy corosolic acid, 3b,7b,24-trihydroxy-urs-12-en-28-oic acid, Oleanolic acid, beta-Amyrin, cis-3-O-p-Hydroxycinnamoyl ursolic acid, trans-3-O-p- Hydroxycinnamoyl ursolic acid, and 7,24-dihydroxyursolic acid. Several in-vivo and in-vitro tests revealed anti-bacterial, anti-cancer, anti-diabetic, anti-oxidant, and anti-viral activities of the plant leaves. Detailed analysis of the information collected on S. roxburghii suggested some promising leads for future drug development. However, many scientific gaps were found in the study of this and further extensive investigation is needed to fully understand the mechanism of action of the active constituents and exploit its therapeutic promises.

Screening and Application of Chitin Synthase Inhibitors

Chitin is an important part of the fungal cell wall, but is not found in plants and mammals, so chitin synthase (CHS) can be a green fungicide target. In this paper, 35 maleimide compounds were designed and synthesized as CHS inhibitors. All the screened compounds showed different degrees of CHS inhibitory activity and antifungal activity in vitro. In particular, the half–inhibitory concentration (IC50) value of compound 20 on CHS was 0.12 mM, and the inhibitory effect was better than that of the control polyoxin B (IC50 = 0.19 mM). At the same time, this compound also showed good antifungal activity and has further development value.

A new dineolignan with anti-β-amyloid aggregation activity from the fruits of crataegus pinnatifida bge

A new dineolignan, crataeguslignan A (1), along with one known dineolignan (2) were isolated from the fruits of Crataegus pinnatifida Bge. Its chemical structure was identified by comprehensive spectroscopic analyses. All the isolated compounds were investigated with regard to their Aβ_1-42 inhibition activity. Among them, 1 displayed the most potent Aβ_1-42 inhibitory ability with the inhibition rate of 85.2% at the concentration of 20 μM.

Antiobesity Effects of Sansa (Crataegi fructus) on 3T3-L1 Cells and on High-Fat-High-Cholesterol Diet-Induced Obese Rats

This study was performed to investigate the effects of Crataegi fructus ethanol extracts (CFEEs) on the differentiation of 3T3-L1 cells, and to evaluate the effects of C. fructus powder (CFP) on lipid metabolism and its antiobesity effect in rats fed a high-fat and high-cholesterol (HFC) diet. Both in vitro and in vivo studies were performed for physiological activity and antiobesity effects on the serum, liver, and adipose tissues in obesity-induced rats. CFEEs showed significant inhibitory action on differentiation and triglyceride (TG) accumulation in 3T3-L1 mature cells in a dose-dependent manner. Subcutaneous, mesenteric, epididymal, and total adipose tissue weights of HFC diet group were heavier than those of normal diet (N) group, whereas those of groups fed CFP were significantly decreased. Levels of serum TGs, total cholesterol (TC), and low-density lipoprotein cholesterol were significantly decreased in the CFP groups than in the HFC group, whereas the serum high-density lipoprotein cholesterol level decreased in the HFC group and markedly increased in the CFP groups. TC and TG levels in the liver and adipose tissues were significantly lower in CFP groups than in the HFC groups. In addition, feeding with CFP significantly reduced the occurrence of fatty liver deposits and steatosis, and inhibited an HFC diet-induced increase in adipocyte size. These results suggest that C. fructus may improve lipid metabolism in the serum, liver, and adipose tissue, and may potentially reduce lipid storage.

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.

Phenolic Composition and Antioxidant and Antimicrobial Activities of Extracts Obtained from Crataegus azarolus L. var. aronia (Willd.) Batt. Ovaries Calli

Objective. Plant cell culture is an innovative technology to produce a variety of substances. Numerous plants synthesize among their secondary metabolites phenolic compounds which possess antioxidant and antimicrobial effects. Hawthorn (Crataegus) is one of these plants which has long been used in folk medicine and is widely utilized in pharmaceutical preparations mainly in neuro- and cardiosedative actions. Methods and Results. The production of polyphenol by fifty-two-week-old Crataegus azarolus var. aronia calli was studied in relation to growth variation and antioxidant and antimicrobial capacity within a subcultured period. The DPPH and ABTS+ assays were used to characterize the antioxidant actions of the callus cultures. Antimicrobial activity was tested by using disc diffusion and dilution assays for the determination of the minimal inhibitory concentration (MIC) and the minimal bactericidal concentration (MBC) values of each active extract. High TEACDPPH, TEACABTS, and antimicrobial activity was observed when maximal growth was reached. An optimum of total phenol, proanthocyanidins, flavonoid, (−)-epicatechin, procyanidin B2, chlorogenic acid, and hyperoside was produced during this period. Conclusion. Antioxidant and antimicrobial activities were strongly correlated with total phenols and total flavonoids. Crataegus azarolus var. aronia cells culture represents an important alternative source of natural antioxidants and antimicrobials.

Clinically useful anticancer, antitumor, and antiwrinkle agent, ursolic acid and related derivatives as medicinally important natural product

Medicinal plants are becoming an important research area for novel and bioactive molecules for drug discovery. Novel therapeutic strategies and agents are urgently needed to treat different incurable diseases. Many plant derived active compounds are in human clinical trials. Currently ursolic acid is in human clinical trial for treating cancer, tumor, and skin wrinkles. This review includes the clinical use of ursolic acid in various diseases including anticancer, antitumor, and antiwrinkle chemotherapies, and the isolation and purification of this tritepernoid from various plants to update current knowledge on the rapid analysis of ursolic acid by using analytical methods. In addition, the chemical modifications of ursolic acid to make more effective and water soluble derivatives, previous and current information regarding, its natural and semisynthetic analogs, focusing on its anticancer, cytotoxic, antitumor, antioxidant, anti-inflammatory, anti-HIV, acetyl cholinesterase, α-glucosidase, antimicrobial, and hepatoprotective activities, briefly discussion is attempted here for its research perspectives. This review article contains fourteen medicinally important ursolic acid derivatives and 351 references.

Oleanolic acid and related derivatives as medicinally important compounds

Oleanolic acid has been isolated from chloroform extract of Olea ferruginea Royle after removal of organic bases and free acids. The literature survey revealed it to be biologically very important. In this review the biological significance of oleanolic acid and its derivatives has been discussed. The aim of this review is to update current knowledge on oleanolic acid and its natural and semisynthetic analogs, focussing on its cytotoxic, antitumer, antioxidant, anti-inflamatory, anti-HIV, acetyl cholinesterase, alpha-glucosidase, antimicrobial, hepatoprotective, anti-inflammatory, antipruritic, spasmolytic activity, anti-angiogenic, antiallergic, antiviral and immunomodulatory activities. We present in this review, for the first time, a compilation of the most relevant scientific papers and technical reports of the chemical, pre-clinical and clinical research on the properties of oleanolic acid and its derivatives.

Hsian-tsao (Mesona procumbens Heml.) prevents against rat liver fibrosis induced by CCl(4) via inhibition of hepatic stellate cells activation

In this study, the protective effect of extract of Hsian-tsao (Mesona procumbens) (EHT) against liver fibrogenesis in carbon tetrachloride (CCl(4))-injured rats was evaluated. The inhibitory effect of oleanolic acid (OA) and ursolic acid (UA), which are the active compounds in EHT, on the activation of hepatic stellate cells (HSC) was also determined. The results showed that EHT at a dosage of 1.2g/kg of b.w. significantly reduced the liver injury induced by CCl(4) in rats. It also decreased the activity of serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) and the deposition of collagen in the liver. Oral administration of EHT reduced the levels of alpha-smooth muscle actin (alpha-SMA) and the activity of metalloproteinases (MMPs) in rats injured by treatment with CCl(4). In addition, we performed experiments with the rat hepatic stellate cell line HSC-T6 in which we induced the expression of MMP-2 and alpha-SMA with phorbol-12-myristate-13-acetate (PMA). Treating these cells with OA (20microM) or UA (10microM) caused a decrease in the levels of both proteins. Taken together, our data indicate that EHT can efficiently inhibit CCl(4)-induced liver fibrosis in rats. EHT may therefore be a useful functional food for preventing liver fibrosis.

Improved dissolution of oleanolic acid with ternary solid dispersions

The purpose of this study was to enhance the dissolution of oleanolic acid by solid dispersions consisting of the drug, a polymeric carrier, and a surfactant. Binary solid dispersions consisting of oleanolic acid and polyvinylpyrrolidone were prepared for comparison. Polysorbate 80, a nonionic surfactant, was incorporated into binary solid dispersions as the third component to prepare ternary solid dispersions. Solid dispersions were characterized by differential scanning calorimetry, Fourier transform infrared spectroscopy, and dissolution tests. The crystallinization of OA was prohibited in solid dispersions. Both the binary and ternary solid dispersions enhanced the dissolution of OA. Moreover, the dissolution of ternary solid dispersion was faster compared with that of binary solid dispersion. Polysorbate 80 played an important positive role in dissolution of the solid dispersion.

Simultaneous effect of ursolic acid and oleanolic acid on epidermal permeability barrier function and epidermal keratinocyte differentiation via peroxisome proliferator-activated receptor-alpha

Ursolic acid (UA) and oleanolic acid (ONA) are pentacyclic triterpenoids, which naturally occur in many medicinal herbs and plants. Recent research revealed that several pharmacological effects could be attributed to UA and ONA, such as anti-tumor, anti-inflammatory and anti-microbial activities. To evaluate the effects of UA and ONA on epidermal permeability barrier recovery and normal skin, both flanks of hairless mice were topically treated with either 0.01-0.1 mg/mL UA or 0.1-1.0 mg/mL ONA after tape stripping and transepidermal water loss (TEWL) were assessed, and then hydration and TEWL were measured for 3 weeks with application of UA and ONA (2 mg/mL). We also investigated the morphological changes using light (LM) and electron microscopic (EM) examination. Finally, we observed that UA and ONA stimulated epidermal keratinocyte differentiation via peroxisome proliferator-activated receptor (PPAR)-alpha using Western immunoblotting. The recovery rate of epidermal permeability barrier after tape stripping increased in the UA- and ONA-treated groups (0.1 mg/mL UA and 0.5 mg/mL ONA) at 6 h to more than 20% when compared to the vehicle-treated group (P < 0.05). In both groups, hydration was increased compared to the vehicle group from 1 week without TEWL alteration (P < 0.05). An LM finding showed that epidermal thickening was frequently observed (UA > ONA > vehicle). EM examination revealed an increase in secretion and in the number of lamellar bodies in treated groups and that complete formation of lipid bilayers was also prominent (ONA > UA > vehicle). Protein expression of PPAR-alpha, involucrin, loricrin and filaggrin increased twofold and threefold in HaCaT cells treated for 24 h with either ONA (10 micromol/L) or UA (10 micromol/L), respectively, reflecting that the UA and ONA can improve the recovery of skin barrier function and induce epidermal keratinocyte differentiation via PPAR-alpha. Taken together, these results suggest that UA and ONA will be pertinent candidates for the improvement of epidermal permeability barrier function.

Inhibition of chitin synthases and antifungal activities by 2'-benzoyloxycinnamaldehyde from Pleuropterus ciliinervis and its derivatives

In the course of search for potent chitin synthase inhibitors from natural resources, a novel chitin synthases inhibitor, 2'-benzoyloxycinnamaldehyde (2'-BCA) (I), was isolated from the aerial parts of Pleuropterus ciliinervis NAKAI. 2'-BCA inhibited chitin synthase 1 and 2 of Saccharomyces cerevisiae with the IC50s of 54.9 and 70.8 microg/ml, respectively, whereas it exhibited no inhibitory activity for chitin synthase 3 up to 280 microg/ml. Its derivatives, 2'-chloro- (V) and 2(-bromo-cinnamaldehyde (VI), each showed 1.9 and 2.7-fold stronger inhibitory activities than 2'-BCA, with the IC50s of 37.2 and 26.6 microg/ml, respectively. Especially, the IC50 of compound VI against chitin synthase 2 represented 1.7-fold more potent inhibitory activity than polyoxin D, a well-known chitin synthase inhibitor. Furthermore, compounds V and VI showed potent antifungal activities against various fungi including human pathogenic fungi, with a particularly strong inhibitory activity against Cryptococcus neoformans (MIC = 16 microg/ml). Although the chemical synthesis of this compound has been reported, the present study is the first report to describe the isolation of 2'-BCA from natural resources and chitin synthases inhibitory activities of its derivatives. These results suggested that 2'-BCA and its derivatives can potentially serve as useful lead compounds for development of antifungal agents.

Human ACAT-1 and ACAT-2 inhibitory activities of pentacyclic triterpenes from the leaves of Lycopus lucidus TURCZ

Acyl-CoA: cholesterol acyltransferase (ACAT) catalyzes the acylation of cholesterol to cholesteryl ester with long chain fatty acids and ACAT inhibition is a useful strategy for treating hypercholesterolemia or atherosclerosis. Pentacyclic triterpenes, ursolic acid (1), oleanolic acid (2), and betulinic acid (3) were isolated from the methanol extracts of the leaves of Lycopus lucidus TURCZ. by bioassay-guided fractionation. The structures of compounds 1-3 were elucidated by their spectroscopic data analysis. Among them, betulinic acid (3) exhibited more potent human ACAT-1 and ACAT-2 inhibitory activities with IC(50) values of 16.2+/-0.6 and 28.8+/-1.3 microM, respectively.

Determination of oleanolic acid in human plasma and study of its pharmacokinetics in Chinese healthy male volunteers by HPLC tandem mass spectrometry

A highly selective and sensitive HPLC-ESI-MS-MS method was developed for the determination of oleanolic acid in human plasma. The oleanolic acid and glycyrrhetinic acid (internal standard) were recovered from plasma with ethyl acetate liquid-liquid extraction. The organic extracts were dried under a stream of warm nitrogen, reconstituted in mobile phase and injected into a Zorbax-Extend ODS analytical column (150 mm x 4.6 mm i.d., 5 microm), with the mobile phase consisting of methanol-ammonium acetate (32.5 mM) (85:15, v/v) pumped at a flow rate of 1.0 ml/min, and 30% of the eluent was split into a MS system with electrospray ionization tandem mass (ESI-MS-MS) detection in negative ion mode. The tandem mass detection was performed on a Finnigan Surveyor LC-TSQ Quantum Ultra AM tandem mass spectrometer operated in selected reaction monitoring mode. The parent to product ion combinations of m/z 455.4-->455.4 and 469.3-->425.2 at 38 V 1.5 mTorr Ar CID were used to quantify oleanolic acid and glycyrrhetinic acid, respectively. The assay was validated in the concentration range of 0.02-30.0 ng/ml for oleacolic acid when 0.5 ml of plasma was processed. The precision of the assay (expressed as relative standard deviation, R.S.D.%) was less than 15% at all concentrations levels within the tested range and adequate accuracy, and the limit of quantification was 0.02 ng/ml. The established method was applied for the pharmacokinetics study of oleanolic acid capsules in 18 healthy male Chinese volunteers with the mean values of C(max), T(max), AUC(0-48), AUC(0-infinity), t(1/2,) CL/F, and V/F of oleanolic acid after p.o. a single 40 mg dose obtained were 12.12 +/- 6.84 ng/ml, 5.2 +/- 2.9h, 114.34 +/- 74.87 ng h/ml, 124.29 +/- 106.77 ng h/ml, 8.73 +/- 6.11 h, 555.3 +/- 347.7 L/h, and 3371.1 +/- 1,990.1 L, respectively.

Triterpenoids from Acanthopanax koreanum root and their inhibitory activities on NFAT transcription

Two triterpenoids (1,4) and two triterpenoid glycosides (2,3) were isolated from the root of Acanthopanax koreanum (Araliaceae). Their structures were identified as impressic acid (1), acankoreoside A (2), 3-epi-betulinic acid 28-O-[alpha-L-rhamnopyranosyl(1 --> 4)-beta-D-glucopyranosyl(1 --> 6)]-beta-D-glucopyranosyl] ester (3), and ursolic acid (4) by physicochemical and spectroscopic methods. Of these compounds, impressic acid (1) exhibited a potent inhibitory activity against NFAT transcription factor (IC50: 12.65 microM).

Chemistry, biological activity, and chemotherapeutic potential of betulinic acid for the prevention and treatment of cancer and HIV infection

3beta-Hydroxy-lup-20(29)-en-28-oic acid (betulinic acid) is a pentacyclic lupane-type triterpene that is widely distributed throughout the plant kingdom. A variety of biological activities have been ascribed to betulinic acid including anti-inflammatory and in vitro antimalarial effects. However, betulinic acid is most highly regarded for its anti-HIV-1 activity and specific cytotoxicity against a variety of tumor cell lines. Interest in developing even more potent anti-HIV agents based on betulinic acid has led to the discovery of a host of highly active derivatives exhibiting greater potencies and better therapeutic indices than some current clinical anti-HIV agents. While its mechanism of action has not been fully determined, it has been shown that some betulinic acid analogs disrupt viral fusion to the cell in a post-binding step through interaction with the viral glycoprotein gp41 whereas others disrupt assembly and budding of the HIV-1 virus. With regard to its anticancer properties, betulinic acid was previously reported to exhibit selective cytotoxicity against several melanoma-derived cell lines. However, more recent work has demonstrated that betulinic acid is cytotoxic against other non-melanoma (neuroectodermal and malignant brain tumor) human tumor varieties. Betulinic acid appears to function by means of inducing apoptosis in cells irrespective of their p53 status. Because of its selective cytotoxicity against tumor cells and favorable therapeutic index, even at doses up to 500 mg/kg body weight, betulinic acid is a very promising new chemotherapeutic agent for the treatment of HIV infection and cancer.

Inhibition of cytochrome P450 activities by oleanolic acid and ursolic acid in human liver microsomes

Oleanolic acid (OA) and ursolic acid (UA), triterpene acids having numerous pharmacological activities including anti-inflammatory, anti-cancer, and hepato-protective effects, were tested for their ability to modulate the activities of several cytochrome P450 (CYP) enzymes using human liver microsomes. OA competitively inhibited CYP1A2-catalyzed phenacetin O-deethylation and CYP3A4-catalyzed midazolam 1-hydroxylation, the major human drug metabolizing CYPs, with IC50 (Ki) values of 143.5 (74.2) microM and 78.9 (41.0) microM, respectively. UA competitively inhibited CYP2C19-catalyzed S-mephenytoin 4'-hydroxylation with an IC50 (Ki) value of 119.7 (80.3) microM. However, other CYPs tested showed no or weak inhibition by both OA and UA. The present study demonstrates that OA and UA have inhibitory effects on CYP isoforms using human liver microsomes. It is thus likely that consumption of herbal medicines containing OA or UA, or administration of OA or UA, can cause drug interactions in humans when used concomitantly with drugs that are metabolized primarily by CYP isoforms. In addition, it appears that the inhibitory effect of OA on CYP1A2 is, in part, related to its anti-inflammatory and anticancer activities.

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

AIM

Ursolic acid (UA) and oleanolic acid (OA) are triperpene acids having a similar chemical structure and are distributed wildly in plants all over the world. In recent years, it was found that they had marked anti-tumor effects. There is little literature currently available regarding their effects on colon carcinoma cells. The present study was designed to investigate their inhibitory effects on human colon carcinoma cell line HCT15.

METHODS

HCT15 cells were cultured with different drugs. The treated cells were stained with hematoxylin-eosin and their morphologic changes observed under a light microscope. The cytotoxicity of these drugs was evaluated by tetrazolium dye assay. Cell cycle analysis was performed by flow cytometry (FCM). Data were expressed as means +/-SEM and Analysis of variance and Student' t-test for individual comparisons.

RESULTS

Twenty-four to 72 h after UA or OA 60 micromol/L treatment, the numbers of dead cells and cell fragments were increased and most cells were dead at the 72nd hour. The cytotoxicity of UA was stronger than that of OA. Seventy-eight hours after 30 micromol/L of UA or OA treatment, a number of cells were degenerated, but cell fragments were rarely seen. The IC(50) values for UA and OA were 30 and 60 micromol/L, respectively. Proliferation assay showed that proliferation of UA and OA-treated cells was slightly increased at 24h and significantly decreased at 48 h and 60 h, whereas untreated control cells maintained an exponential growth curve. Cell cycle analysis by FCM showed HCT15 cells treated with UA 30 and OA 60 for 36 h and 72 h gradually accumulated in G(0)/G(1) phase (both drugs P<0.05 for 72 h), with a concomitant decrease of cell populations in S phase (both drugs P<0.01 for 72 h) and no detectable apoptotic fraction.

CONCLUSION

UA and OA have significant anti-tumor activity. The effect of UA is stronger than that of OA. The possible mechanism of action is that both drugs have an inhibitory effect on tumor cell proliferation through cell-cycle arrest.

Gastroprotective activity of oleanolic acid derivatives on experimentally induced gastric lesions in rats and mice

The gastroprotective effect of the triterpene oleanolic acid (OA) was assessed on gastric ulceration in rats. The effect of a single oral dose of OA was evaluated at 50, 100 and 200 mg kg(-1) in the following models: pylorus ligature (Shay), and aspirin- and ethanol-induced gastric ulcers. A single oral administration of OA at doses of 50, 100 and 200 mg kg-' inhibited the appearance of gastric lesions induced by ethanol, aspirin and pylorus ligature. In the pylorus ligature and aspirin models, the effect of OA at the selected concentrations was comparable with that of ranitidine at 50 mg kg(-1). In the ethanol-induced gastric lesion model, OA showed a dose-dependent activity, and at 100 and 200 mg kg(-1) was as active as omeprazole at 20 mg kg(-1). The effect of OA, its acetylated and methoxylated derivatives, oleanonic acid and its methyl ester were assessed on HCI/ethanol-induced ulcers in mice at 200 mg kg(-1). OA and its methoxylated (OAM) and acetylated (OAAM, OAA) derivatives proved to be active in this animal model. The semisynthetic derivatives OAM and OAAM had the greatest gastroprotective activity, but their effect was not significantly greater than OA. In an acute toxicity test on mice, intraperitoneal administration of OA showed no toxicity at doses up to 600 mg kg(-1).

Cytotoxic triterpenes from Crataegus pinnatifida

Bioassay-guided fractionation of Crataegus pinnatifida (Rosaceae) gave two cytotoxic ursane-type triterpenes which were identified as uvaol (1) and ursolic acid (2) by physicochemical and spectroscopic methods. 3-Oxo-ursolic acid (3) was synthesized from ursolic acid (2) by Jones method. The cytotoxic activities of these compounds were tested against murine L1210 and human cancer cell lines (A549, SK-OV-3, SK-MEL-2, XF498, and HCT15) in vitro. Compounds 1 and 2 showed moderate cytotoxicities against L1210, whereas they showed weak activities against human cancer cell lines. However, compound 3 exhibited potent cytotoxic activities both in murine and in human cancer cell lines.