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PubMed2000

Ursolic acid isolated from Eucalyptus tereticornis protects against ethanol toxicity in isolated rat hepatocytes.

Ursolic acid is the active material isolated from the leaves of the Eucalyptus hybrid E. tereticornis. In the present study, it has shown a significant preventive effect in vitro against ethanol-induced toxicity in isolated rat hepatocytes. Compared with the incubation of isolated hepatocytes with ethanol only, the simultaneous presence of ursolic acid in the cell suspension preserved the viability of hepatocytes and reversed the ethanol-induced loss in the level of all the marker enzymes (AST, ALT and AP) studied. Ethanol alone resulted in a 48%-54% decrease in the viability and a 42%-54% reduction in the biochemical parameters of the hepatocytes. Ursolic acid showed a concentration dependent (1-100 microg/mL) preventive effect (12%-76%) on alcohol-induced hepatocyte toxicity by restoring the altered parameters. The results thus suggest the effective use of an in vitro test system as an alternative for in vivo assessment of hepatoprotective activity of purified material.

Alanine Transaminase↗

PubMed1991

Inhibition of human leucocyte elastase by ursolic acid. Evidence for a binding site for pentacyclic triterpenes.

Several pentacyclic triterpenoid metabolites of plant origin are inhibitors of hydrolysis of both synthetic peptide substrates and elastin by human leucocyte elastase (HLE). Ursolic acid, the most potent of these compounds, has an inhibition constant of 4-6 microM for hydrolysis of peptide substrates in phosphate-buffered saline. With tripeptide and tetrapeptide substrates, the inhibition is purely competitive, whereas with a shorter dipeptide substrate the inhibition is non-competitive, suggesting that ursolic acid interacts with subsite S3 of the extended substrate-binding domain in HLE, but not with subsites S1 and S2. The carboxy group at position 28 in the pentacyclic-ring system of the triterpenes contributes to binding to HLE, since replacement of this group with a hydroxy group, as in uvaol, the alcohol analogue of ursolic acid, reduces the potency of inhibition. The inhibitory potency of ursolic acid is also reduced by addition of 1 M-NaCl, further supporting a postulated electrostatic interaction between the negative charge on the triterpene and a positively charged residue on the enzyme, which we assign to the side chain of Arg-217, located in the vicinity of subsites S4 and S5 in HLE. These observations are consistent with a binding site for ursolic acid which extends from S3 towards S4 and S5 on the enzyme. Other triterpenes, including oleanolic acid, erythrodiol, hederagenin and 18 beta-glycyrrhetic acid, can also interact with this binding site. On the basis of these results we conclude that the extended substrate-binding domain of HLE can accommodate a variety of hydrophobic ligands, including not only such molecules as fatty acids [Ashe & Zimmerman (1977) Biochem. Biophys. Res. Commun. 75, 194-199; Cook & Ternai (1988) Biol. Chem. Hoppe-Seyler 369, 629-637], but also polycyclic molecules such as the pentacyclic triterpenoids.

Amino Acid Sequence↗

PubMed2004

Ursolic acid, an antagonist for transforming growth factor (TGF)-beta1.

Transforming growth factor-beta (TGF-beta), a multifunctional cytokine which is involved in extracellular matrix modulation, has a major role in the pathogenesis and progression of fibrotic diseases. We now report the effects of ursolic acid on TGF-beta1 receptor binding and TGF-beta1-induced cellular functions in vitro. Ursolic acid inhibited [(125)I]-TGF-beta1 receptor binding to Balb/c 3T3 mouse fibroblasts with an IC(50) value of 6.9+/-0.8 microM. Ursolic acid dose-dependently recovered reduced proliferation of Minc Mv1Lu cells in the presence of 5 nM of TGF-beta1 and attenuated TGF-beta1-induced collagen synthesis and production in human fibroblasts. Molecular dynamics simulations suggest that ursolic acid may interact with the hydrophobic region of the dimeric interface and thereby inhibit the binding of TGF-beta1 to its receptor. All these findings taken together show that ursolic acid functions as an antagonist for TGF-beta1. This is the first report to show that a small molecule can inhibit TGF-beta1 receptor binding and influence functions of TGF-beta1.

Animals↗

PubMed2000

Ursolic acid triggers calcium-dependent apoptosis in human Daudi cells.

Ursolic acid (UA) is a pentacyclic triterpenoid compound which occurs naturally in a large variety of vegetarian foods, medicinal herbs and plants. In the present study, ursolic acid was found to decrease cell viability in human lymphoma Daudi cells in a dose-dependent manner. UA also induced morphological changes in cells as well as loss of membrane asymmetry, DNA fragmentation and nuclei condensation, indicating that the mechanism by which UA induced cell death was through apoptosis. Treatment with UA increased intracellular Ca2+ levels. Use of Ca2+ channel inhibitors like verapamil blocked this Ca2+ influx and also the triggering of apoptosis. We hypothesized that the binding of UA to glucocorticoid receptors and the Ca2+ currents induced constituted the first steps of apoptosis.

Antineoplastic Agents, Phytogenic↗

PubMed1992

Inhibition of lipoxygenase activity and HL60 leukemic cell proliferation by ursolic acid isolated from heather flowers (Calluna vulgaris).

A compound was isolated and purified from heather flowers (Calluna vulgaris) based on its ability to inhibit lipoxygenase activity. This molecule was characterized as ursolic acid by GC-MS. Ursolic acid was found to be an inhibitor of both potato tuber 5-lipoxygenase and soybean 15-lipoxygenase with IC50 values of 0.3 mM. Ursolic acid also inhibits lipoxygenase activity in mouse peritoneal macrophages at 1 microM and HL60 leukemic cells growth (IC50 = 0.85 microM) as well as their DNA synthesis (IC50 = 1 microM). The possible role of lipoxygenase inhibition in the proliferation of leukemic cells is discussed.

Animals↗

PubMed2006

Amelioration of adjuvant-induced arthritis by ursolic acid through altered Th1/Th2 cytokine production.

The objective of the study was to investigate the activity of ursolic acid (UA) on proinflammatory (Th1) and anti-inflammatory (Th2) cytokines in the peripheral blood of arthritic balb/c mice. Ursolic acid is ubiquitous in the plant kingdom and is a constituent of numerous plants which are having diversified phylogenetic origin and taxonomic position. We applied Cytometric bead array (CBA) technology for simultaneously measurement of these cytokines in adjuvant inflammatory arthritis induced mice treated with ursolic acid in graded oral doses. Cytometric bead array uses the sensitivity of amplified fluorescence detection by flowcytometer to measure soluble analytes in a particle based immune assay. This assay can accurately quantitate five cytokines in a 50 microl sample volume. The T-helper (Th1) deviated cells produce detectable level of tumor necrosis factor (TNF-alpha), interleukin-2 (IL-2) and interferon-gamma (IFN-gamma), while the Th2 deviated cells produce significant amount of interleukin-4 (IL-4) and interleukin-5 (IL-5). Oral administration of UA at doses of 10, 20, 40, 80 and 160 mg kg(-1) per oral dose inhibited the presence of IL-2, IFN-gamma and TNF-alpha in the peripheral blood.

Adjuvants, Immunologic↗

PubMed2002

Ursolic acid of Origanum majorana L. reduces Abeta-induced oxidative injury.

Amyloid beta protein (Abeta) increases free radical production and lipid peroxidation in PC12 nerve cells, leading to apoptosis and cell death. The effect of ursolic acid from Origanum majorana L. on Abeta-induced neurotoxicity was investigated using PC12 cells. Pretreatment with isolated ursolic acid and vitamin E prevented the PC12 cell from reactive oxygen species (ROS) toxicity that is mediated by Abeta. The ursolic acid resulted in decreased Abeta toxicity assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), lactate dehydrogenase (LDH), and trypan blue assay. Thus, treatment with these antioxidants inhibited the Abeta-induced neurotoxic effect. Therefore, these results indicate that micromolar Abeta-induced oxidative cell death is reduced by ursolic acid from Origanum majorana L.

Alzheimer Disease↗

PubMed2000

Anti-AIDS agents 38. Anti-HIV activity of 3-O-acyl ursolic acid derivatives.

Based on our previous finding that 3-O-acyl-betulinic and -oleanolic acids, especially the 3-O-(3',3'-dimethyl)-succinyl derivatives (2 and 4), demonstrated potent anti-HIV activity [EC(50) < 0.00035 and 0.00086 microM; therapeutic index (TI) > 20 000 and 22 326, respectively], several 3-O-acyl-ursolic acids were prepared and evaluated for anti-HIV activity. Ursolic acid (6) was equipotent (EC(50) 4.4 microM) with oleanolic acid (EC(50) 3.7 microM), although it was slightly toxic (IC(50) 14.3 microM, TI 3.3). 3-O-Diglycoryl-ursolic acid (10) demonstrated relatively potent anti-HIV activity with an EC(50) of 0. 31 microM and a TI of 155.5. In contrast, 3-O-(3', 3'-dimethylsuccinyl)-ursolic acid (8), which is analogous to the extremely potent anti-HIV betulinic acid and oleanolic acid derivatives 2 and 4, displayed only weak anti-HIV activity (EC(50) 2.1 microM, TI 23.6).

Anti-HIV Agents↗

PubMed2006

Amelioration of obesity and glucose intolerance in high-fat-fed C57BL/6 mice by anthocyanins and ursolic acid in Cornelian cherry (Cornus mas).

Much attention has been focused on food that may be beneficial in preventing diet-induced body fat accumulation and possibly reduce the risk of diabetes and heart disease. Cornelian cherries (Cornus mas) are used in the preparation of beverages in Europe and also to treat diabetes-related disorders in Asia. In this study, the most abundant bioactive compounds in C. mas fruits, the anthocyanins and ursolic acid, were purified, and their ability to ameliorate obesity and insulin resistance in C57BL/6 mice fed a high-fat diet was evaluated. Mice were initially fed a high-fat diet for 4 weeks and then switched to a high-fat diet containing anthocyanins (1 g/kg of high-fat diet) and ursolic acid (500 mg/kg of high-fat diet) for an additional 8 weeks. The high-fat diet induced glucose intolerance, and this was prevented by anthocyanins and ursolic acid. The anthocyanin-treated mice showed a 24% decrease in weight gain. These mice also showed decreased lipid accumulation in the liver, including a significant decrease in liver triacylglycerol concentration. Anthocyanin and ursolic acid treated mice exhibited extremely elevated insulin levels. Both treatments, however, showed preserved islet architecture and insulin staining. Overall, these data suggest that anthocyanins and ursolic acid purified from C. mas fruits have biological activities that improve certain metabolic parameters associated with diets high in saturated fats and obesity.

Animals↗

PubMed2006

Ursolic acid inhibits neointima formation in the rat carotid artery injury model.

Triterpenoids are natural compounds that are found in a large variety of plants and vegetarian foods, and are used for medicinal purposes in many Asian countries. Pentacyclic triterpenes, such as ursolic acid, have been reported to exhibit anticancer and anti-inflammatory properties. The present study was designed to assess the effects of ursolic acid in the migration and proliferation of vascular smooth muscle cells (VSMC), and in a vascular injury model. The exposure of VSMC to ursolic acid results in a chemotaxis inhibition, in a reduction of the expression of proliferating cell nuclear antigen (PCNA) and in a disorganization of beta-tubulin and vimentin cytoskeletal proteins. Administration of ursolic acid in the rat carotid balloon catheter injury model shows a significant inhibition of neointimal hyperplasia. Thus, we have demonstrated that daily doses of 6 mg/kg body weight for 10 days reduce both the ratio of intimal to medial areas and the degree of stenosis by 80%, and suppress the expression of PCNA in both neointima and media. These results suggest that pentacyclic triterpenes may be of potential therapeutic value in vascular injury, and a possible treatment strategy for the prevention of the progression of atherosclerosis and restenosis after angioplasty.

Animals↗

PubMed2006

Isomers (oleanolic and ursolic acids) differ in their protective effect against isoproterenol-induced myocardial ischemia in rats.

The efficiency and safety of oleanolic acid (OA) and its isomer, ursolic acid (UA) in myocardial ischemia are poorly documented. This study appraised the efficacy of OA and UA in protecting the heart against oxidative damage induced by isoproterenol, since oxidative injury has been investigated as a potential initiator of myocardial necrosis. The level of TBARS increased whereas the antioxidants decreased significantly in the myocardium of ischemic animals. The levels were brought back to near normalcy in OA and UA pre-treated rats by scavenging the free radicals and blocking the induction of lipid peroxidation. These findings provide evidence that OA and UA protect rat myocardium against ischemic insult and the protective effect could be attributed to its antioxidant property and/or to a strengthening of myocardial membrane by its membrane stabilizing action. Among the two isomeric compounds, UA showed higher activity than OA.

Adrenergic beta-Agonists↗

PubMed2006

Antimutagenicity of ursolic acid and oleanolic acid against doxorubicin-induced clastogenesis in Balb/c mice.

Ursolic acid (UA) and oleanolic acid (OA) are triterpenoid compounds found in food, medicinal herbs and various other plants in free form or bound to glycosides. Both substances are known for their antimicrobial, hepatoprotective, anti-inflammatory, antiallergic, antiviral and cytotoxic activities. In the present study, we evaluated the antimutagenic potential of UA and OA using the micronucleus test in peripheral blood and bone marrow of Balb/c mice. The animals were divided into 10 treatment groups: mice treated with UA (80 mg/kg b.w.); OA (80 mg/kg b.w.); a mixture of UA and OA (80 mg/kg b.w.); the antineoplastic agent doxorubicin (DXR, 90 mg/kg b.w.); DMSO and DXR; UA and DXR; OA and DXR; UA, OA and DXR, and negative and solvent controls. UA, OA and a mixture of UA and OA were administered to the animals by gavage, followed by the intraperitoneal injection of DXR. The results showed a significant reduction in micronucleus frequency in the groups concomitantly treated with the triterpenoid compounds and DXR compared to that treated with DXR alone. The present results demonstrate the antimutagenic activity of UA and OA under the experimental conditions used in this study.

Animals↗

PubMed2005

Synthesis of two bidesmosidic ursolic acid saponins bearing a 2,3-branched trisaccharide residue.

The focus of this work was on the synthesis of two bidesmosidic ursolic acid saponins bearing a 2,3-branched trisaccharide residue. Therefore, 3-O-{[beta-D-glucopyranosyl-(1-->2)]-[alpha-L-arabinopyranosyl-(1-->3)]-alpha-L-arabinopyranosyl}ursolic acid-28-O-[beta-D-glucopyranosyl] ester 1 was concisely synthesized by two strategies in 22% and 41% overall yield, respectively, and another congener 3-O-{[beta-D-xylopyranosyl-(1-->2)]-[beta-D-glucopyranosyl-(1-->3)]-alpha-L-arabinopyranosyl}ursolic acid-28-O-[beta-D-glucopyranosyl] ester 2 was also efficiently prepared in 81% overall yield. The (1)H NMR and (13)C NMR signals of saponin 2 are all consistent with those reported for the natural product.

Carbohydrate Sequence↗

PubMed2004

Effects of ursolic acid, betulin and sulfur-containing compounds on mucin release from airway goblet cells.

In this study, we investigated whether ursolic acid, betulin and 2 kinds of sulfur-containing compounds--NAC and MESNA--affect mucin release from airway goblet cells and compared the possible activities of these agents with the inhibitory action on mucin release by PLL and the stimulatory action by ATP. Confluent primary hamster tracheal surface epithelial (HTSE) cells were metabolically radiolabeled using 3H-glucosamine for 24 h and chased for 30 min in the presence of varying concentrations of each agent to assess the effects on 3H-mucin release. The results were as follows: ursolic acid, betulin, MESNA and NAC increased mucin release (40-50 % above control) at the highest concentrations (10(-5) M-10(-3) M). We conclude that ursolic acid and betulin can stimulate mucin release by directly acting on airway mucin-secreting cells and suggest that these agents be further investigated for the possible use as mucoregulators in the treatment of chronic airway diseases.

Acetylcysteine↗

PubMed2005

[Experimental study on MCF-7 cell apoptosis induced by ursolic acid].

OBJECTIVE: To study the effects of ursolic acid (UA), apentacyclic triterpene acid, on MCF-7 cell apoptosis. METHODS: MCF-7 cells were cultured with different concentrations of UA. Viability of UA-induced MCF-7 cells was evaluated by MTT assay. Cell cycle and sub-G1 peak were performed by FCM. Morphologic changes of UA-treated cells were observed by light microscope. Apoptotic cells with condensed or fragmented nuclei were visualized by Ho33258 and PI staining by a fluorescence microscope (EX: U.V., Green light). p 53 protein expression was analyzed by fluorescence immunohistochemical method (SABC-Cy3). RESULT: 24 hours after UA treatment, inhibition of MCF-7 cell proliferation was concentration-dependent. The IC50 value for UA was 22.6 +/- 3.0 micromol/L. Cell cycle analysis by FCM showed that 50 micromol/L of the drug arrested MCF-7 cell cycle at G0-G1 phase. Morphological changes of MCF-7 cells exhibited many of the hallmark features of apoptosis, including condensation of chromatin and DNA fragmentation. UA increased p 53 protein expression. CONCLUSION: The results suggest that UA evokes MCF-7 cell apoptosis is correlation with the up-regulation of p 53. The study indicated that UA might be a potential Chinese medical component for breast neoplasm.

Antineoplastic Agents, Phytogenic↗

PubMed2006

[Determination of ursolic acid of Liuwei Dihuangwan simulation samples by NIR].

OBJECTIVE: Determine the content of ursolic acid of Liuwei Dihuangwan. METHOD: Using NIR with PLS, PCA-BPANN and WT-BPANN. RESULT: The predication recovery were 100.7%, 100.6%, 100.1%, and the RSD were 5.42%, 6.49%, 6.52% respectively. CONCLUSION: NIR can be used in the determination of ursolic acid, which set up the foundation of on-line control of traditional Chinese medicine.

Cornus↗

PubMed1998

Synthesis and anti-ulcer activity of new derivatives of glycyrrhetic, oleanolic and ursolic acids.

A review is made of the literature describing the structural changes to glycyrrhetic, oleanolic and ursolic acids and their influence on anti-ulcer activity. For the glycyrrhetic acid derivatives some analogues were prepared in which the ketonic group in position 11 was removed and the carboxylic function at position 30 was either intact, reduced to alcohol or transformed into ketone. This first series of compounds suggests the possibility of obtaining compounds devoid of the conjugated ketonic group, maintaining anti-ulcer activity but with reduced or lacking mineralocorticoid activity. Based on these findings, a series of carbenoxolone analogues in the beta-amyrin series of glycyrrhetic and oleanolic acid was prepared. In particular, the delta 9,11 unsaturated compounds 14b and 23b and the 11-methylene derivative 18 present advantages in terms of acute toxicity and mineralocorticoid activity as compared to the reference compound. The derivative 14b in the volunteer showed an increase of gastric PGE2 levels with minor pseudoaldosteronic effect. Among the ursolic acid derivatives, the dihemisuccinate sodium salt 35b demonstrated a good separation between anti-ulcer and mineralocorticoid activities. Nevertheless, kidney and liver toxicity was observed in the monkey thus jeopardizing its further development. Better results were obtained with the uvaol dihemiphthalate sodium salt and the diene analogue 39b. In particular, 38b and 39b showed a potent anti-ulcer activity, 3- to 25-fold higher than carbenoxolone. Furthermore, compound 38b does not show signs of liver toxicity in the monkey.

Animals↗

PubMed2006

Ursolic acid and its derivative inhibit protein tyrosine phosphatase 1B, enhancing insulin receptor phosphorylation and stimulating glucose uptake.

Protein tyrosine phosphatase 1B (PTP1B) is a key element in the negative regulation of the insulin signaling pathway and may play an important role in diabetes and obesity. We identified ursolic acid, a natural pentacyclic triterpenoid that occurs widely in traditional Chinese medicinal herbs, as an inhibitor of PTP1B by screening an extract library of the traditional Chinese medicinal herbs used a diabetes clinic. By modifying urosolic acid, we designed and synthesized a derivative with a K(i) of 283 nM. As competitive inhibitors of PTP1B, ursolic acid and its derivative also inhibit T-cell protein tyrosine phosphatase and src homology phosphatase-2 but not leucocyte antigen-related phosphatase or protein tyrosine phosphatase alpha and epsilon, which are all possibly involved in the insulin pathway. The ursolic acid derivative enhanced insulin receptor phosphorylation in CHO/hIR cells and stimulate glucose uptake in L6 myotubes.

Animals↗