Development of a liquid chromatography-mass spectrometry method for the determination of ursolic acid in rat plasma and tissue: application to the pharmacokinetic and tissue distribution study

Simultaneous quantitation of pentacyclic triterpenoids in fruit peels using liquid chromatography-single quadrupole mass spectrometry

The simultaneous determination of pentacyclic triterpenoids, which are secondary metabolites in plants, is difficult because of the similarity in structure and minimal differences in polarity. In this study, we established a simple and sensitive method for the simultaneous determination of pentacyclic triterpenoids based on liquid chromatography-single-quadrupole mass spectrometry (LC-MS) using a C30 column. The established method completely separated 13 pentacyclic triterpenoids based on their different retention times. Furthermore, the molecular weight and reliability were confirmed for ten compounds. This method was used to quantify pentacyclic triterpenoids in acetone extracts of the peels of ten varieties of apple and eight varieties of persimmon. Therefore, this method is expected to be used in a comprehensive search for pentacyclic triterpenoids in fruit-processing residues.

Improving anti-oxidant stress treatment of subarachnoid hemorrhage through self-assembled nanoparticles of oleanolic acid

Subarachnoid hemorrhage (SAH) is a life-threatening acute hemorrhagic cerebrovascular disease, with early brain injury (EBI) being the main cause of high mortality and severe neurological dysfunction. Oxidative stress plays a crucial role in the pathogenesis of EBI. In this study, we synthesized antioxidant stress nanoparticles based on self-assembled oleanolic acid (OA) using the solvent volatilization method. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM) techniques were employed to analyze and understand the self-assembly mechanism of oleic acid nanoparticles (OA NPs). The TUNEL assay, Nissl staining, and brain water content measurements were conducted to investigate the impact of OA NPs on cortical neuronal injury. Additionally, Western blot analysis was performed to investigate the antioxidant stress mechanism of OA NPs. The result showed that OA NPs exhibited a spherical structure with an average diameter of 168 nm. The application of OA NPs in SAH has been found to contribute to the reduction of keap1 protein levels and an increase in the nuclear level of Nrf2. As a result, the transcription of antioxidant stress proteins, including HO1 and NQO1, is triggered. The activation of the antioxidant stress pathway by OA NPs ultimately leads to a decrease in neuron damage and an improvement in neurological dysfunction. In conclusion, we successfully designed and synthesized OA NPs that can efficiently target the site of SAH. These nanoparticles have demonstrated their potential as antioxidants for the treatment of SAH, offering significant clinical applications.

Promising Ursolic Acid as a Novel Antituberculosis Agent: Current Progress and Challenges

Tuberculosis (TB) stands as the second most prevalent cause of global human mortality from infectious diseases. In 2022, the World Health Organization documented an estimated number of global TB cases reaching 7.5 million, which causes death for 1.13 million patients. The continuous growth of drug-resistant TB cases due to various mutations in the Mycobacterium tuberculosis (MTB) strain, raises the urgency of the exploration of novel anti-TB treatments. Ursolic acid (UA) is a natural pentacyclic triterpene found in various plants that has shown potential as a novel anti-TB agent. This review aims to provide an overview of the therapeutic prospects of UA against MTB, with a particular emphasis on in silico, in vitro, and in vivo studies. Various mechanisms of action of UA against MTB are briefly recapped from in silico studies, such as enoyl acyl carrier protein reductase inhibitors, FadA5 (Acetyl-CoA acetyltransferase) inhibitors, tuberculosinyl adenosine transferase inhibitors, and small heat shock protein 16.3 inhibitor. The potential of UA to overcome drug resistance and its synergistic effects with existing antituberculosis drugs are briefly explained from in vitro studies using a variety of methods, such as Microplate Alamar Blue Assay, Mycobacteria Growth Indicator Tube 960 and Resazurin Assays, morphological change evaluation using transmission electron microscopy, and in vivo studies using BALB/C infected with multi drug resistant clinical isolates. Besides its promising mechanism as an antituberculosis drug, its complex chemical composition, limited availability and supply, and lack of intellectual property are also reviewed as those are the most frequently occurring challenges that need to be addressed for the successful development of UA as novel anti-TB agent.

Targeting vulnerable microcircuits in the ventral hippocampus of male transgenic mice to rescue Alzheimer-like social memory loss

BACKGROUND

Episodic memory loss is a prominent clinical manifestation of Alzheimer's disease (AD), which is closely related to tau pathology and hippocampal impairment. Due to the heterogeneity of brain neurons, the specific roles of different brain neurons in terms of their sensitivity to tau accumulation and their contribution to AD-like social memory loss remain unclear. Therefore, further investigation is necessary.

METHODS

We investigated the effects of AD-like tau pathology by Tandem mass tag proteomic and phosphoproteomic analysis, social behavioural tests, hippocampal electrophysiology, immunofluorescence staining and in vivo optical fibre recording of GCaMP6f and iGABASnFR. Additionally, we utilized optogenetics and administered ursolic acid (UA) via oral gavage to examine the effects of these agents on social memory in mice.

RESULTS

The results of proteomic and phosphoproteomic analyses revealed the characteristics of ventral hippocampal CA1 (vCA1) under both physiological conditions and AD-like tau pathology. As tau progressively accumulated, vCA1, especially its excitatory and parvalbumin (PV) neurons, were fully filled with mislocated and phosphorylated tau (p-Tau). This finding was not observed for dorsal hippocampal CA1 (dCA1). The overexpression of human tau (hTau) in excitatory and PV neurons mimicked AD-like tau accumulation, significantly inhibited neuronal excitability and suppressed distinct discrimination-associated firings of these neurons within vCA1. Photoactivating excitatory and PV neurons in vCA1 at specific rhythms and time windows efficiently ameliorated tau-impaired social memory. Notably, 1 month of UA administration efficiently decreased tau accumulation via autophagy in a transcription factor EB (TFEB)-dependent manner and restored the vCA1 microcircuit to ameliorate tau-impaired social memory.

CONCLUSION

This study elucidated distinct protein and phosphoprotein networks between dCA1 and vCA1 and highlighted the susceptibility of the vCA1 microcircuit to AD-like tau accumulation. Notably, our novel findings regarding the efficacy of UA in reducing tau load and targeting the vCA1 microcircuit may provide a promising strategy for treating AD in the future.

Neuroprotective properties of Betulin, Betulinic acid, and Ursolic acid as triterpenoids derivatives: a comprehensive review of mechanistic studies

Cognitive deficits are the main outcome of neurological disorders whose occurrence has risen over the past three decades. Although there are some pharmacologic approaches approved for managing neurological disorders, it remains largely ineffective. Hence, exploring novel nature-based nutraceuticals is a pressing need to alleviate the results of neurodegenerative diseases, such as Alzheimer's disease (AD) and other neurodegenerative disorders. Some triterpenoids and their derivates can be considered potential therapeutics against neurological disorders due to their neuroprotective and cognitive-improving effects. Betulin (B), betulinic acid (BA), and ursolic acid (UA) are pentacyclic triterpenoid compounds with a variety of biological activities, including antioxidative, neuroprotective and anti-inflammatory properties. This review focuses on the therapeutic efficacy and probable molecular mechanisms of triterpenoids in damage prevention to neurons and restoring cognition in neurodegenerative diseases. Considering few studies on this concept, the precise mechanisms that mediate the effect of these compounds in neurodegenerative disorders have remained unknown. The findings can provide sufficient information about the advantages of these compounds against neurodegenerative diseases.

Ursolic acid derivative UAOS-Na treats experimental autoimmune encephalomyelitis by immunoregulation and protecting myelin

Introduction

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS). Ursolic acid (UA) can be used in the MS treatment with anti-inflammatory and neuroprotective activities. However, UA is insoluble in water, which may affect its medication effectiveness. In our previous study, UAOS-Na, a water-soluble derivative of UA was obtained. In this study, we evaluated the pharmacological effects and explored its underlying mechanism of UAOS-Na on experimental autoimmune encephalomyelitis (EAE).

Methods

Firstly, the pharmacodynamics of UAOS-Na was investigated in EAE and Cuprizone-induced mice. And then the possible mechanisms were investigated by TMT proteomics and verified by in vitro and in vivo experiments.

Results

UAOS-Na (30 mg/kg/d) delayed the onset time of EAE from 11.78 days post immunization (dpi) to 14.33 dpi, reduced the incidence from 90.0% to 42.9%. UAOS-Na (60 mg/kg/d) reduced the serum levels of IFN-γ, IL-17A, TNF-α and IL-6, reduced the mononuclear cell infiltration of spinal cord, and inhibited the overexpression of key transcription factors T-bet and ROR-γt of EAE mouse spinal cord. In addition, UAOS-Na attenuated demyelination and astrogliosis in the CNS of EAE and cuprizone-induced mice. Mechanistically, proteomics showed that 96 differential expression proteins (DEPs) were enriched and 94 were upregulated in EAE mice compared with normal group. After UAOS-Na treatment, 16 DEPs were enriched and 15 were downregulated, and these DEPs were markedly enriched in antigen processing and presentation (APP) signaling pathway. Moreover, UAOS-Na downregulated the protein levels of Tapbp and H2-T23 in MHC-I antigen presentation pathway and reduced the proliferation of splenic CD8 T cells, thereby inhibiting the CNS infiltration of CD8 T cells.

Conclusion

Our findings demonstrated that UAOS-Na has both myelin protective and anti-inflammatory effects. And it could reduce the inflammation of MS by downregulating the expression of Tapbp and H2-T23 in the MHC-I antigen presentation pathway.

Effects of oleanolic acid and ursolic acid on depression-like behaviors induced by maternal separation in mice

Oleanolic acid (OA) and ursolic acid (UA) are structural isomeric triterpenoids. Both triterpenoids have been reported to be able to improve depression. However, no studies have compared their effects in the same system. Whether OA or UA could ameliorate depression-like behaviors in maternal separation (MS)-induced depression-like model was investigated. MS model is a well-accepted mouse model that can reflect the phenotype and pathogenesis of depression. Depression is a mental illness caused by neuroinflammation or changes in neuroplasticity in certain brain regions, such as the prefrontal cortex and hippocampus. Depression-like behaviors were measured using splash test or forced swimming test. In addition, anxiety-like behaviors were also measured using the open field test or elevated plus-maze test. MS-treated female mice showed greater depression-like behaviors than male mice, and that OA improved several depression-like behaviors, whereas UA only relieved anxiety-like behavior of MS-treated mice. Microglial activation, expression levels of TNF-α, and mRNA levels of IDO1 were increased in the hippocampi of MS-treated female mice. However, OA and UA treatments attenuated such increases. In addition, expression levels of synaptophysin and PSD-95 were decreased in the hippocampi of MS-treated female mice. These decreased expression levels of synaptophysin were reversed by both OA and UA treatments, although decreased PSD-95 expression levels were only reversed by OA treatment. Our findings suggest that MS cause depression-like behaviors through female-specific neuroinflammation, changes of tryptophan metabolism, and alterations of synaptic plasticity. Our findings also suggest that OA could reverse MS-induced depression-like behaviors more effectively than UA.

Oleanolic acid and ursolic acid: therapeutic potential in neurodegenerative diseases, neuropsychiatric diseases and other brain disorders

Brain disorders such as neurodegenerative diseases and neuropsychiatric diseases have become serious threatens to human health and quality of life. Oleanolic acid (OA) and ursolic acid (UA) are pentacyclic triterpenoid isomers widely distributed in various plant foods and Chinese herbal medicines. Accumulating evidence indicates that OA and UA exhibit neuroprotective effects on multiple brain disorders. Therefore, this paper reviews researches of OA and UA on neurodegenerative diseases, neuropsychiatric diseases and other brain disorders including ischemic stroke, epilepsy, etc, as well as the potential underlying molecular mechanisms.

Ursolic Acid against Prostate and Urogenital Cancers: A Review of In Vitro and In Vivo Studies

Prostate cancer is the second most diagnosed form of cancer in men worldwide and accounted for roughly 1.3 million cases and 359,000 deaths globally in 2018, despite all the available treatment strategies including surgery, radiotherapy, and chemotherapy. Finding novel approaches to prevent and treat prostate and other urogenital cancers effectively is of major importance. Chemicals derived from plants, such as docetaxel and paclitaxel, have been used in cancer treatment, and in recent years, research interest has focused on finding other plant-derived chemicals that can be used in the fight against cancer. Ursolic acid, found in high concentrations in cranberries, is a pentacyclic triterpenoid compound demonstrated to have anti-inflammatory, antioxidant, and anticancer properties. In the present review, we summarize the research studies examining the effects of ursolic acid and its derivatives against prostate and other urogenital cancers. Collectively, the existing data indicate that ursolic acid inhibits human prostate, renal, bladder, and testicular cancer cell proliferation and induces apoptosis. A limited number of studies have shown significant reduction in tumor volume in animals xenografted with human prostate cancer cells and treated with ursolic acid. More animal studies and human clinical studies are required to examine the potential of ursolic acid to inhibit prostate and other urogenital cancers in vivo.

Analysis of A Major Metabolite of Ursolic Acid— Ursolic Acid Sulfate, and Its Quantitative Determination on LC/MS in Human Liver Homogenate

Ursolic acid (UA) is a naturally occurring pentacyclic triterpenoid that exhibits extensive pre-systemic metabolism from in vitro studies. However, there are no available authentic metabolite standards or validated analytical methods to quantitate UA metabolites. We have identified ursolic acid sulfate (UAS) as one of the major metabolites. We were able to identify and characterize its structure via comparison to the chemically synthesized UAS. A cyano (CN, 150 × 4.6 mm, 5 µm) column along with a gradient elution of acetonitrile and 0.08% (v/v) acetic acid, pH 3.0 were employed for chromatographic separation. Negative single ion recording mode (SIR) with electron-spray ionization (ESI) source at mass-to-charge ratios of 455.3 and 535.3 were monitored for UA and UAS, respectively. UAS linearity range was 0.010-2.500 µM. The absolute values of intra-day and inter-day precision (CV, %) and accuracy (DFN, %) were all below 15%. Thus, the analytical method has been validated in the human subcellular fractions to facilitate in vitro/ in vivo DMPK and future clinical disposition studies on UA.

Ursolic acid and its isomer oleanolic acid are responsible for the anti-dementia effects of Ocimum sanctum in olfactory bulbectomized mice

This study aims to clarify the bioactive constituents responsible for the anti-dementia effects of Ocimum sanctum Linn. ethanolic extract (OS) using olfactory bulbectomized (OBX) mice, an animal model of dementia. The effects of OS or its extract further fractionated with n-hexane (OS-H), ethyl acetate (OS-E), and n-butanol (OS-B) on the spatial cognitive deficits of OBX mice were elucidated by the modified Y-maze tests. The effects of the major constituents of the most active OS fraction were also elucidated using the reference drug donepezil. The administration of OS and OS-E ameliorated the spatial cognitive deficits caused by OBX, whereas OS-H or OS-B had no effect. Two major constituents, ursolic acid (URO) and oleanolic acid (OLE), and three minor constituents were isolated from OS-E. URO (6 and 12 mg/kg) and OLE (24 mg/kg) attenuated the OBX-induced cognitive deficits. URO (6 mg/kg) and donepezil reversed the OBX-induced down-regulation of vascular endothelial growth factor (VEGF) and choline acetyltransferase expression levels in the hippocampus. URO inhibited the ex vivo activity of acetylcholinesterase with similar efficacy to donepezil. URO inhibited the in vitro activity of acetylcholinesterase (IC50 = 106.5 μM), while the effects of OS, OS-E, and other isolated compounds were negligible. These findings suggest that URO and OLE are responsible for the anti-dementia action of OS extract, whereas URO possesses a more potent anti-dementia effect than its isomer OLE. The effects of URO are, at least in part, mediated by normalizing the function of central cholinergic systems and VEGF protein expression.

A novel, differential mobility spectrometry tandem mass spectrometric method for the in vivo quantitation of ursolic acid

Ursolic acid (UA) is a naturally occurring pentacyclic triterpene widely distributed in fruits and plants. It is pharmacologically active and has the potential to be a useful therapeutic compound. To date, bioanalysis of UA has been limited by biomatrix interference and poor collision induced dissociation (CID) efficiency in tandem mass spectrometry. In this study, we developed a method based on liquid chromatography differential mobility spectrometry tandem mass spectrometry LC-DMS-MS/MS with multiple ion monitoring (MIM) for quantitation of UA in rat plasma. The method involves efficient sample preparation by solid phase extraction and requires only a limited volume of plasma (40 μL) to achieve linearity in the 1-100 ng/mL range with good accuracy and precision. The method was successfully applied to a pharmacokinetic study of orally administered UA in rat. The results indicate that LC-DMS-MS/MS with MIM is a useful strategy for the bioassay of UA suitable for high throughput analysis.

Role of heme oxygenase-1 in the antidepressant-like effect of ursolic acid in the tail suspension test

OBJECTIVES

This study investigated the involvement of heme oxygenase-1 (HO-1) in the antidepressant-like effects of ursolic acid (UA), a plant-derived compound with neuroprotective and antidepressant-like properties.

METHODS

Mice received intracerebroventricular injections of zinc protoporphyrin IX (ZnPP) or cobalt protoporphyrin IX (CoPP) to inhibit or induce HO-1, respectively, together with effective (0.1 mg/kg, p.o.) or sub-effective (0.01 mg/kg, p.o.) doses of UA or fluoxetine (10 mg/kg, p.o.). Immobility time was assessed using the tail suspension test (TST) and the ambulatory behaviour with the open field test. HO-1 immunocontent was evaluated in mice hippocampus and prefrontal cortex.

KEY FINDINGS

ZnPP prevented the anti-immobility effects of UA and fluoxetine. Combined treatment with a sub-effective dose of CoPP and UA synergistically exerted antidepressant-like effects in the TST. Acute administration of UA or CoPP, but not fluoxetine, increased the HO-1 immunocontent in the hippocampus. None of the treatments altered the HO-1 immunocontent in the prefrontal cortex.

CONCLUSIONS

In conclusion, this work shows that increased hippocampal HO-1 content and activity mediate the antidepressant-like effect of UA in the TST.

Ursolic acid ameliorates amyloid β-induced pathological symptoms in Caenorhabditis elegans by activating the proteasome

BACKGROUND

Amyloid β induces pathological symptoms in various neurodegenerative disorders. It is the hallmark of these neurodegenerative disorders, such as Alzheimer's disease, and is reported to induce neurotoxicity leading to neuronal impairment. The continuous development of neurodegenerative disease accompanies pathological changes in amyloid β deposition in the brain. After amyloid β accumulates, the inadequate clearance of amyloid β further accelerates the development of events in the pathological cascade. In eukaryotes, the proteasome is responsible for the degradation of misfolded and damaged proteins to maintain proteostasis. Therefore, screening candidates that preserve proteasomal activity may promote amyloid β homeostasis, which is expected to provide new therapeutic opportunities for these neurodegenerative diseases. Ursolic acid, a natural triterpenoid, has prominent pharmacological antioxidant, anti-inflammatory, neuroprotective, and nontoxic activities. Here, we explored the protective effects of ursolic acid on amyloid β-induced pathological symptoms.

METHODS

This study investigated the therapeutic potential of ursolic acid and its underlying molecular mechanisms using a Caenorhabditis elegans transgenic pathological model.

RESULTS

In our study, ursolic acid successfully repressed amyloid β-induced paralysis and hypersensitivity to serotonin in Caenorhabditis elegans. The levels of amyloid β monomers, oligomers, and deposits were decreased after treatment with ursolic acid in transgenic nematodes overexpressing human amyloid β; however, ursolic acid did not affect exogenous transgene transcription and expression levels. Ursolic acid transcriptionally enhanced the ubiquitin-proteasome system and augmented proteasome activity in vivo. However, the proteasome inhibitor MG132 abolished the therapeutic effect of ursolic acid on behavioral paralysis, and Parkinson's disease-related-1 was required for the therapeutic effect of ursolic acid.

CONCLUSIONS

Our study revealed that ursolic acid prevented amyloid β-induced proteotoxic stress, specifically by reducing the amount of amyloid β and increasing proteasome activity in vivo. Furthermore, the therapeutic effect of ursolic acid on transgenic nematodes expressing amyloid β depended on the increased activity of the proteasome. This work provides an essential supplement to the information on the pharmacological mechanism of ursolic acid.

Ursolic acid does not change the cytokine levels following resistance training in healthy men: A pilot balanced, double-blind and placebo-controlled clinical trial

Ursolic acid (UA) is a natural compound that shows anti-inflammatory actions. However, no human studies have investigated the cytokine profile during the RT and UA consumption. The purpose of this study was to verify if UA is able to potentiate the anti-inflammatory activity after RT, reflecting in the reduction of blood inflammatory markers in healthy men. Twenty-seven participants were allocated to two groups: control (CON) (n = 13) and UA (n = 14). For 8weeks, each group performed RT and consumed capsules containing a placebo (400 mg/day) or UA (400 mg/day). Serum cytokine concentrations were evaluated before and after the training period. There was no difference in the serum cytokine concentrations of TNF-α, IL-10 and IL-6 (p > 0.05). In conclusion, UA supplementation for 8weeks was not able to change the blood TNF-α, IL-10, and IL-6 concentrations in healthy men undergoing RT. However, further studies are warranted to investigate other inflammatory markers.

Therapeutic Potential of Ursolic Acid in Cancer and Diabetic Neuropathy Diseases

Ursolic acid (UA) is a pentacyclic triterpenoid frequently found in medicinal herbs and plants, having numerous pharmacological effects. UA and its analogs treat multiple diseases, including cancer, diabetic neuropathy, and inflammatory diseases. UA inhibits cancer proliferation, metastasis, angiogenesis, and induced cell death, scavenging free radicals and triggering numerous anti- and pro-apoptotic proteins. The biochemistry of UA has been examined broadly based on the literature, with alterations frequently having been prepared on positions C-3 (hydroxyl), C12-C13 (double bonds), and C-28 (carboxylic acid), leading to several UA derivatives with increased potency, bioavailability and water solubility. UA could be used as a protective agent to counter neural dysfunction via anti-oxidant and anti-inflammatory effects. It is a potential therapeutic drug implicated in the treatment of cancer and diabetic complications diseases provide novel machinery to the anti-inflammatory properties of UA. The pharmacological efficiency of UA is exhibited by the therapeutic theory of one-drug → several targets → one/multiple diseases. Hence, UA shows promising therapeutic potential for cancer and diabetic neuropathy diseases. This review aims to discuss mechanistic insights into promising beneficial effects of UA. We further explained the pharmacological aspects, clinical trials, and potential limitations of UA for the management of cancer and diabetic neuropathy diseases.

Ursolic Acid and Related Analogues: Triterpenoids with Broad Health Benefits

Ursolic acid (UA) is a well-studied natural pentacyclic triterpenoid found in herbs, fruit and a number of traditional Chinese medicinal plants. UA has a broad range of biological activities and numerous potential health benefits. In this review, we summarize the current data on the bioavailability and pharmacokinetics of UA and review the literature on the biological activities of UA and its closest analogues in the context of inflammation, metabolic diseases, including liver and kidney diseases, obesity and diabetes, cardiovascular diseases, cancer, and neurological disorders. We end with a brief overview of UA’s main analogues with a special focus on a newly discovered naturally occurring analogue with intriguing biological properties and potential health benefits, 23-hydroxy ursolic acid.

Nanoformulations of Ursolic Acid: A Modern Natural Anticancer Molecule

Background: Ursolic acid (UA) is a natural pentacyclic triterpene derived from fruit, herb, and other plants. UA can act on molecular targets of various signaling pathways, inhibit the growth of cancer cells, promote cycle stagnation, and induce apoptosis, thereby exerting anticancer activity. However, its poor water-solubility, low intestinal mucosal absorption, and low bioavailability restrict its clinical application. In order to overcome these deficiencies, nanotechnology, has been applied to the pharmacological study of UA.

Objective: In this review, we focused on the absorption, distribution, and elimination pharmacokinetics of UA in vivo, as well as on the research progress in various UA nanoformulations, in the hope of providing reference information for the research on the anticancer activity of UA.

Methods: Relevant research articles on Pubmed and Web of Science in recent years were searched selectively by using the keywords and subheadings, and were summarized systematically.

Key finding: The improvement of the antitumor ability of the UA nanoformulations is mainly due to the improvement of the bioavailability and the enhancement of the targeting ability of the UA molecules. UA nanoformulations can even be combined with computational imaging technology for monitoring or diagnosis.

Conclusion: Currently, a variety of UA nanoformulations, such as micelles, liposomes, and nanoparticles, which can increase the solubility and bioactivity of UA, while promoting the accumulation of UA in tumor tissues, have been prepared. Although the research of UA in the nanofield has made great progress, there is still a long way to go before the clinical application of UA nanoformulations.

Ursolic and Oleanolic Acids: Plant Metabolites with Neuroprotective Potential

Ursolic and oleanolic acids are secondary plant metabolites that are known to be involved in the plant defence system against water loss and pathogens. Nowadays these triterpenoids are also regarded as potential pharmaceutical compounds and there is mounting experimental data that either purified compounds or triterpenoid-enriched plant extracts exert various beneficial effects, including anti-oxidative, anti-inflammatory and anticancer, on model systems of both human or animal origin. Some of those effects have been linked to the ability of ursolic and oleanolic acids to modulate intracellular antioxidant systems and also inflammation and cell death-related pathways. Therefore, our aim was to review current studies on the distribution of ursolic and oleanolic acids in plants, bioavailability and pharmacokinetic properties of these triterpenoids and their derivatives, and to discuss their neuroprotective effects in vitro and in vivo.

Ursolic acid abrogates depressive-like behavior and hippocampal pro-apoptotic imbalance induced by chronic unpredictable stress

Emerging evidence has shown that ursolic acid exerts antidepressant-like effects, however, its ability to elicit an antidepressant-like response in rodents subjected to stress model that mimics behavioral and neurochemical alterations found in depression remains to be determined. Thus, this study investigated the possible antidepressant-like effect of ursolic acid in mice subjected to chronic unpredictable stress (CUS) for 14 days, and whether this effect could be associated with the modulation of serum corticosterone levels and hippocampal Bcl-2/Bax mRNA expression. Our results indicated that CUS induced a depressive-like behavior, as demonstrated by an increase in the immobility time and latency to first grooming in the tail suspension test and splash test, respectively. Conversely, the repeated administration of ursolic acid (0.1 mg/kg, p.o.) or fluoxetine (10 mg/kg, p.o.) in the last 7 days of CUS completely prevented CUS-induced behavioral alterations, suggesting an antidepressant-like effect. Additionally, CUS significantly increased the mRNA expression of Bax (pro-apoptosis marker), but not Bcl-2 (anti-apoptosis marker) in the hippocampus. Moreover, reduced hippocampal mRNA expression of Bcl-2/Bax ratio was detected in CUS-exposed mice. Ursolic acid, but not fluoxetine, prevented CUS-induced increase in the expression of Bax, but both ursolic acid and fluoxetine prevented CUS-induced reduction on Bcl-2/Bax ratio. Furthermore, neither CUS nor treatments with ursolic acid or fluoxetine altered serum corticosterone levels. Our study unveils the ability of ursolic acid to prevent the depressive-like behavior induced by stress and the modulation of Bcl-2/Bax expression could be associated with this response.

Ursolic acid has no additional effect on muscle strength and mass in active men undergoing a high-protein diet and resistance training: A double-blind and placebo-controlled trial

BACKGROUND

Ursolic acid (UA) is thought to have an anabolic effect on muscle mass in humans. This study sought to compare the effects of UA and a placebo on muscle strength and mass in young men undergoing resistance training (RT) and consuming a high-protein diet.

METHODS

A clinical, double-blind, placebo-controlled trial was conducted for 8 weeks. The Control + RT group (CON n = 12) received 400 mg/d of placebo, and the UA + RT group (UA n = 10) received 400 mg/d of UA. Both groups ingested ~1.6 g/kg of protein and performed the same RT program. Pre- and post-intervention, both groups were evaluated for anthropometric measures, body composition, food intake and muscle strength.

RESULTS

Food intake remained unchanged throughout the study. Both groups showed significant increases in body weight (CON Δ: 2.12 ± 0.47 kg, p = 0.001 vs. UA Δ: 2.24 ± 0.67 kg, p = 0.009), body mass index (BMI) (CON Δ: 0.69 ± 0.15 kg/m2, p = 0.001 vs. UA Δ: 0.75 ± 0.23, p = 0.011) and thigh circumference (CON Δ: 1.50 ± 0.36, p = 0.002 vs. UA Δ: 2.46 ± 0.50 cm, p = 0.003 vs. UA 1.84 ± 0.82 cm, p = 0.001), with differences between them. There was no difference in the arm, waist and hip circumferences. Both groups showed increases in muscle mass (CON Δ: 1.12 ± 0.26, p = 0.001 vs. UA Δ: 1.08 ± 0.28 kg, p = 0.004), but there was no significant difference between them. Additionally, there were significant increases in the one repetition maximum test in the bench press and in the 10-repetition maximum test in the knee extension (CON Δ: 5.00 ± 2.09, p = 0.036 vs. UA Δ: 7.8 ± 1.87, p = 0.340 and CON Δ: 3.58 ± 1.15, p = 0.010 vs. UA Δ: 1.20 ± 0.72, p = 0.133), respectively, with no difference between them.

CONCLUSIONS

Ursolic acid had no synergic effect on muscle strength and mass in response to RT in physically active men consuming a high-protein diet.

BRAZILIAN CLINICAL TRIALS REGISTRY (REBEC)

RBR-76tbqs.

Identification of the Myogenetic Oligodeoxynucleotides (myoDNs) That Promote Differentiation of Skeletal Muscle Myoblasts by Targeting Nucleolin

Herein we report that the 18-base telomeric oligodeoxynucleotides (ODNs) designed from the Lactobacillus rhamnosus GG genome promote differentiation of skeletal muscle myoblasts which are myogenic precursor cells. We termed these myogenetic ODNs (myoDNs). The activity of one of the myoDNs, iSN04, was independent of Toll-like receptors, but dependent on its conformational state. Molecular simulation and iSN04 mutants revealed stacking of the 13-15th guanines as a core structure for iSN04. The alkaloid berberine bound to the guanine stack and enhanced iSN04 activity, probably by stabilizing and optimizing iSN04 conformation. We further identified nucleolin as an iSN04-binding protein. Results showed that iSN04 antagonizes nucleolin, increases the levels of p53 protein translationally suppressed by nucleolin, and eventually induces myotube formation by modulating the expression of genes involved in myogenic differentiation and cell cycle arrest. This study shows that bacterial-derived myoDNs serve as aptamers and are potential nucleic acid drugs directly targeting myoblasts.

Phytochemicals with Added Value from Morella and Myrica Species

Terrestrial plants, due to their sessile nature, are highly exposed to environmental pressure and therefore need to produce very effective molecules that enable them to survive all the threats. Myrica and Morella (Myricaceae) are taxonomically close genera, which include species of trees or shrubs with edible fruits that exhibit relevant uses in traditional medicine. For instance, in Chinese or Japanese folk medicine, they are used to treat diarrhea, digestive problems, headache, burns, and skin diseases. A wide array of compounds isolated from different parts of Myrica and/or Morella species possess several biological activities, like anticancer, antidiabetic, anti-obesity, and cardio-/neuro-/hepatoprotective activities, both in vitro and in vivo, with myricanol, myricitrin, quercitrin, and betulin being the most promising. There are still many other compounds isolated from both genera whose biological activities have not been evaluated, which represents an excellent opportunity to discover new applications for those compounds and valorize Morella/Myrica species.

Intranasal administration of perillyl alcohol-loaded nanoemulsion and pharmacokinetic study of its metabolite perillic acid in plasma and brain of rats using ultra-performance liquid chromatography/tandem mass spectrometry

Perillyl alcohol (POH) is a monocyclic terpene that has strong antitumor activity. Brain tumors are particularly difficult to treat with therapeutic agents, and clinical trials have shown their low tolerance through oral administration. We proposed the entrapment of POH into an oil-in-water chitosan nanoemulsion aiming its intranasal administration for brain targeting. An ultra-performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for the quantitation of total metabolite perillic acid (PA) in plasma and brain of rats. The rat samples containing the metabolite were treated by liquid-liquid extraction with acetonitrile. The mobile phase was 0.1% formic acid in water (solvent A) and 0.1% formic acid in methanol (solvent B), at a flow rate of 0.3 mL min^-1 in gradient elution. The chromatography was run for 10 min, and analytical curves were built in acetonitrile, plasma, and brain. The PA was detected in positive ion mode with multiple reaction monitoring. The method has shown high selectivity, sensitivity, and throughput. The low quantification limits of 162, 178, and 121 ng mL^-1 for acetonitrile, brain, and plasma, respectively, indicate a good detectability of the method. The repeatability and precision observed were within the limits recommended in the literature. The accuracy of the method was verified through high recovery rates (106-118%). The validated method was successfully applied to the pharmacokinetic study of the metabolite PA after the intranasal administration of free or POH-loaded nanoemulsion in rats. The results showed that chitosan nanoemulsion improved the plasma and brain bioavailability of POH, representing a promising alternative to free POH treatment.

Ursolic acid: A systematic review of its pharmacology, toxicity and rethink on its pharmacokinetics based on PK-PD model

Ursolic acid (UA) is a natural pentacyclic triterpenoid compound existing in various traditional Chinese medicinal herbs, and it possesses diverse pharmacological actions and some undesirable adverse effects, even toxicological activities. Due to UA's low solubility and poor bioavailability, and its interaction with gut microbiota after oral administration, the pharmacokinetics of UA remain elusive, leading to obscurity in the pharmacokinetics-pharmacodynamics (PK-PD) profile and relationship for UA. Based on literatures from PubMed, Google Scholar, ResearchGate, Web of Science and Wiley Online Library, with keywords of "pharmacology", "toxicology", "pharmacokinetics", "PK-PD" and "ursolic acid", herein we systematically review the pharmacology and toxicity of UA, and rethink on its pharmacokinetics on the basis of PK-PD model, and seek to delineate the underlying mechanisms for the characteristics of pharmacology and toxicology of UA, and for the pharmacokinetic features of UA particularly from the organ tropism and the interactions between UA and gut microbiota, and lay a solid foundation for development of UA-derived therapeutic agents in clinical settings.

Ursolic acid alleviates lipid accumulation by activating the AMPK signaling pathway in vivo and in vitro

The mechanism underlying the effect of ursolic acid (UA) on lipid metabolism remains unclear. This study aimed to explore the mechanisms of UA in reducing lipid accumulation in free fatty acids-cultured HepG2 cells and in high-fat-diet-fed C57BL/6J mice. In vivo, UA effectively alleviated liver steatosis and decreased the size of adipocytes in the epididymis. It also significantly decreased the total cholesterol (TC) and triglyceride (TG) contents in the liver and plasma in C57BL/6 mice. In vitro, UA (20 µM) significantly reduced lipid accumulation; the intracellular TC contents decreased from 0.078 ± 0.0047 to 0.049 ± 0.0064 µmol/mg protein, and TG contents from 0.133 ± 0.005 to 0.066 ± 0.0047 µmol/mg protein, in HepG2 cells. Furthermore, UA reduced the mRNA expression related to fat synthesis, enhanced the mRNA expression related to adipose decomposition, and dramatically upregulated the protein expression of P-AMPK in vivo and in vitro. Of note, these protective effects of UA on a high-fat environment were blocked by the AMPK inhibitor (compound C) in vitro. In addition, the molecular docking results suggested that UA could be docked to the AMPK protein as an AMPK activator. These results indicated that UA lowered the lipid content probably via activating the AMPK signaling pathway, thereby inhibiting lipid synthesis and promoting fat decomposition. PRACTICAL APPLICATION: Ursolic acid (UA) widely exists in vegetables and fruits. This study highlighted a lipid-lowing mechanism of UA in HepG2 cells and C57BL/6J mice. The data indicated that UA might be used in lipid-lowering functional foods.

A systematic review on phytochemicals for the treatment of dengue

Dengue fever is prevalent in subtopic regions, producing mortality and morbidity worldwide, which have been of major concern to different governments and World Health Organization. The search of new anti-dengue agents from phytochemicals was assumed to be highly emergent in past. The phytochemicals have been used in wide distribution of vector ailments such as malaria. The demand of the phytochemicals is based on the medicines which are mostly considered to be safer, less harmful than synthetic drugs and nontoxic. This review mentions majorly about the phytochemicals potentially inhibiting dengue fever around the world. The phytochemicals have been isolated from different species, have potential for the treatment of dengue. Different crude extracts and essential oils obtained from different species showed a broad activity against different phytochemicals. The current studies showed that natural products represent a rich source of medicines toward the dengue fever. Furthermore, ethnobotanical surveys and laboratory investigation established identified natural plants species in the development of drug discovery to control the dengue fever.

Epigenetics/epigenomics of triterpenoids in cancer prevention and in health

Triterpenoids are a powerful group of phytochemicals derived from plant foods and herbs. Many reports have shown that they possess chemopreventive and chemotherapeutic effects not only in cell lines and animal models but also in clinical trials. Because epigenetic changes could potentially occur in the early stages of carcinogenesis preceding genetic mutations, epigenetics are considered promising targets in early interventions against cancer using epigenetic bioactive substances. The biological properties of triterpenoids in cancer prevention and in health have multiple mechanisms, including antioxidant and anti-inflammatory activities, cell cycle regulation, as well as epigenetic/epigenomic regulation. In this review, we will discuss and summarize the latest advances in the study of the pharmacological effects of triterpenoids in cancer chemoprevention and in health, including the epigenetic machinery.

Evolution from small molecule to nano-drug delivery systems: An emerging approach for cancer therapy of ursolic acid

Ursolic acid (UA), a natural pentacyclic triterpenoid, possesses widespread biological and pharmacological activities. However, drawbacks such as low bioavailability, poor targeting and rapid metabolism greatly hinder its further clinical application. Recently, with the development of nanotechnology, various UA nanosystems have emerged as promising strategies for effective cancer therapy. This article reviews various types of UA-based nano-delivery systems, primarily with emphasis placed on novel UA-based carrier-free nano-drugs, which are considered to be innovative methods for cancer therapy. Moreover, this review presents carrier-free nano-drugs that co-assembled of UA and photosensitizers that displayed synergistic antitumor performance. Finally, the article also describes the development and challenges of UA nanosystems for future research in this field. Overall, the information presented in this review will provide new insight into the rational utilization of nano-drugs in cancer therapy.

Recent Trends in Fast Liquid Chromatography for Pharmaceutical Analysis

Background:

Liquid chromatography is the workhorse of analytical laboratories of pharmaceutical companies for analysis of bulk drug materials, intermediates, drug products, impurities and degradation products. This efficient technique is impeded by its long and tedious analysis procedures. Continuous efforts of scientists to reduce the analysis time resulted in the development of three different approaches namely, HTLC, chromatography using monolithic columns and UHPLC.

Methods:

Modern column technology and advances in chromatographic stationary phase including silica-based monolithic columns and reduction in particle and column size (UHPLC) have not only revolutionized the separation power of chromatographic analysis but also have remarkably reduced the analysis time. Automated ultra high-performance chromatographic systems equipped with state-ofthe- art software and detection systems have now spawned a new field of analysis, termed as Fast Liquid Chromatography (FLC). The chromatographic approaches that can be included in FLC are hightemperature liquid chromatography, chromatography using monolithic column, and ultrahigh performance liquid chromatography.

Results:

This review summarizes the progress of FLC in pharmaceutical analysis during the period from year 2008 to 2017 focusing on detecting pharmaceutical drugs in various matrices, characterizing active compounds of natural products, and drug metabolites. High temperature, change in the mobile phase, use of monolithic columns, new non-porous, semi-porous and fully porous reduced particle size of/less than 3μm packed columns technology with high-pressure pumps have been extensively studied and successively applied to real samples. These factors revolutionized the fast high-performance separations.

Conclusion:

Taking into account the recent development in fast liquid chromatography approaches, future trends can be clearly predicated. UHPLC must be the most popular approach followed by the use of monolithic columns. Use of high temperatures during analysis is not a feasible approach especially for pharmaceutical analysis due to thermosensitive nature of analytes.

Ursolic acid: Pharmacokinetics process in vitro and in vivo, a mini review

Ursolic acid (UA) is a natural triterpene compound found in various fruits and vegetables. UA has a widespread pharmacologic effect, including antitumor, anti-inflammatory, anti-oxidant, anti-apoptotic, anti-allergy, and anti-carcinogenic effects. UA can be used as an alternative medicine for the treatment and prevention of many diseases. However, the bioavailability of UA by oral administration is low since it is absorbed by the intestine through passive diffusion. Therefore, some novel technologies are used to produce UA preparations that can change the pharmacokinetics process and increase its solubility and bioavailability. At present, pharmacokinetic studies on UA are few. In this paper, we will review the pharmacokinetics features of free UA and some novel UA preparations in vitro and in vivo, in order to provide a reference for rational utilization and drug design of UA.

Liquid chromatography-tandem mass spectrometry based method development and validation of S016-1271 (LR8P), a novel cationic antimicrobial peptide for its application to pharmacokinetic studies

S016-1271 (LR8P) is a broad spectrum novel cationic antimicrobial peptide. The objective of the present study was to develop a selective liquid chromatography-tandem mass spectrometry (LC-MS/MS) based bioanalytical method of S016-1271 peptide in mice and human plasma in order to uncover its pharmacokinetic aspects. The chromatographic separation of S016-1271 (FR8P as internal standard) was achieved on a Waters™ X select CSH-C18 column (75 × 3.0 mm, 2.5 μ) using mixture of acetonitrile and triple distilled water (TDW) both containing 0.05% formic acid as mobile phase. A seven minute linear gradient method was designed to separate analytes from ion suppression at a flow rate of 0.3 mL/min. The extraction of analytes from mice and human plasma was performed through solid phase extraction technique using mixed mode weak cation exchange cartridge (Thermo SOLA WCX 10 mg 1CC) with an extraction recovery of analytes about 75%. Mass spectrometric detection of S016-1271 and FR8P was performed with optimized multiple reaction monitoring (MRM) transitions (Q1/Q3) at 658.8 [M+3H] ³⁺/653.2 [M+3H-NH₃] ³⁺ and 443.4 [M+5H]⁵⁺ /434.7 [y₁₂-NH₃]⁴⁺,respectively in positive electrospray ionization (ESI) mode. The linearity in mice and human plasma was established over a concentration range of 7.81-250 ng/mL with regression coefficient (r² > 0.99). The currently developed method was validated as per US-FDA guidelines and found to be within the acceptable limits. The method was successfully applied to intravenous (IV) pharmacokinetic study in mice wherein the levels were detected upto 24 h. The peptide demonstrated poor distribution characteristics which were demonstrated through volume of distribution at steady state (202.71 ± 47.02 mL/kg less than total body water of mice; 580 mL/kg). The clearance of the peptide predominantly occurred through central compartment (central clearance is 25 fold greater than peripheral clearance). Also, the in vitro pharmacokinetic studies demonstrated the stability of S016-1271 in plasma and high plasma protein binding in mice and humans.

Rapid and Sensitive Quantification of Ursolic Acid and Oleanolic Acid in Human Plasma Using Ultra-performance Liquid Chromatography-Mass Spectrometry

Ultra-performance liquid chromatography (UPLC) interfaced with atmospheric pressure chemical ionization mass-spectrometry was used to separate and quantify ursolic acid (UA) and oleanolic acid (OA) in human plasma. UA and OA were extracted from 0.5 mL human plasma using supported liquid extraction and separated utilizing an Acquity UPLC HSS column. The method has been validated for both UA and OA quantitation with a limit of detection of 0.5 ng/mL. The UPLC separations are carried out with isocratic elution with methanol and 5 mM ammonium acetate in water (85:15) as a mobile phase at a flow rate of 0.4 mL/min. The assay was linear from 1 ng/mL to 100 ng/mL for both analytes. The total analysis time was 7 min with the retention times of 3.25 (internal standard), 3.65 (UA) and 3.85 min (OA). Recovery of drug from plasma ranged from 70% to 115%. Analysis of quality control samples at 3, 30 and 80 ng/mL (n = 14) had an intra-day coefficient of variation of 9.9%, 4.3% and 5.5%, respectively. A proof-of-concept study in human patients who consumed apple peels indicates that this analytical method could be applied to clinical studies of UA and/or OA in human subjects.

Ursolic acid, a potential anticancer compound for breast cancer therapy

There are growing interests in the health benefits associated with consumption of fruits and vegetables, especially for the prevention of cancer, cardiovascular, or other chronic diseases. Epidemiological studies and clinical trials suggest that these health benefits are strongly associated with phytochemicals found in fruits and vegetables. Ursolic acid is a naturally synthesized pentacyclic triterpenoid, widely distributed in different fruits and vegetables. Current research suggested that ursolic acid and its derivatives exhibited anticancer activity, anti-inflammatory effects, and induction of apoptosis in several human cancer cells. In particular, ursolic acid inhibited breast cancer proliferation by inducing cell G1/G2 arrest and regulating the expression of key proteins in signal transduction pathways. In addition, ursolic acid induced apoptosis in human breast cancer cells through intrinsic and extrinsic apoptotic pathways. Ursolic acid was also determined to scavenge free radicals and have potent anti-inflammation activity. The purpose of this paper is to review recent literature on anticancer activity of ursolic acid and focus on its mechanisms of action.

Identification and Quantification of Four Anthraquinones in Rhubarb and its Preparations by Gas Chromatography-Mass Spectrometry

A gas chromatographic-mass spectrometric (GC-MS) method was developed for the determination of four anthraquinones found in rhubarb. Chrysophanol, physcion, aloe-emodin and emodin were confirmed by GC-MS and the possible main cleavage pathways of fragment ions are discussed in this study. Rhubarb is a traditional Chinese medicinal herb which required an effective evaluation method to quantitate the four major active anthraquinone compounds described. The determinations of analytes were accomplished by GC-MS using osthole as an internal standard. MS detection was performed in selected ion monitoring mode to increase the sensitivity. The method was evaluated by a number of validation characteristics (precision, limit of detection, calibration range and recovery). The calibration ranges were all 3.2-30.0 μg/mL. This method was fully validated and showed good performances in terms of recovery (96.9-102.9%) and precision (1.4-2.9%). Finally, the method was applied to the analysis of four anthraquinones in rhubarb and its preparations in the first time.

Ursolic acid affords antidepressant-like effects in mice through the activation of PKA, PKC, CAMK-II and MEK1/2

BACKGROUND

Ursolic acid has been shown to display antidepressant-like effects in mice through the modulation of monoaminergic systems. In this study, we sought to investigate the involvement of signaling pathways on the antidepressant-like effects of ursolic acid.

METHODS

Mice were treated orally with ursolic acid (0.1mg/kg) and, 45min later they received the followings inhibitors by intracerebroventricular route: H-89 (PKA inhibitor, 1μg/mouse), KN-62 (CAMK-II inhibitor, 1μg/mouse), chelerythrine (PKC inhibitor, 1μg/mouse), U0126 (MEK1/2 inhibitor, 5μg/mouse), PD98059 (MEK1/2 inhibitor, 5μg/mouse), wortmannin (PI3K irreversible inhibitor, 0.1μg/mouse) or LY294002 (PI3K inhibitor, 10 nmol/mouse). Immobility time of mice was registered in the tail suspension test (TST).

RESULTS

The anti-immobility effect of ursolic acid in the TST was abolished by the treatment of mice with H-89, KN-62, chelerythrine, U0126 or PD98059, but not with wortmannin or LY294002.

CONCLUSIONS

These results suggest that activation of PKA, PKC, CAMK-II, MEK1/2 may underlie the antidepressant-like effects of ursolic acid.

Therapeutic Potential of Ursolic Acid to Manage Neurodegenerative and Psychiatric Diseases

Ursolic acid is a pentacyclic triterpenoid found in several plants. Despite its initial use as a pharmacologically inactive emulsifier in pharmaceutical, cosmetic and food industries, several biological activities have been reported for this compound so far, including anti-tumoural, anti-diabetic, cardioprotective and hepatoprotective properties. The biological effects of ursolic acid have been evaluated in vitro, in different cell types and against several toxic insults (i.e. 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, amyloid-β peptides, kainic acid and others); in animal models of brain-related disorders (Alzheimer disease, Parkinson disease, depression, traumatic brain injury) and ageing; and in clinical studies with cancer patients and for muscle atrophy. Most of the protective effects of ursolic acid are related to its ability to prevent oxidative damage and excessive inflammation, common mechanisms associated with multiple brain disorders. Additionally, ursolic acid is capable of modulating the monoaminergic system, an effect that might be involved in its ability to prevent mood and cognitive dysfunctions associated with neurodegenerative and psychiatric conditions. This review presents and discusses the available evidence of the possible beneficial effects of ursolic acid for the management of neurodegenerative and psychiatric disorders. We also discuss the chemical features, major sources and potential limitations of the use of ursolic acid as a pharmacological treatment for brain-related diseases.

Pharmacokinetics and Pharmacodynamics of the Triterpenoid Ursolic Acid in Regulating the Antioxidant, Anti-inflammatory, and Epigenetic Gene Responses in Rat Leukocytes

The triterpenoid ursolic acid (UA) has been proposed as a potential cancer chemopreventive agent in many preclinical and clinical studies. In the present work, we aimed to characterize the pharmacokinetics (PK) of UA and to quantitatively assess the antioxidative and anti-inflammatory effects of UA, which are potentially linked to its chemopreventive efficacy. UA was administered intravenously (i.v., 20 mg/kg) or by oral gavage (100 mg/kg) to male Sprague-Dawley rats, and blood samples were collected at a series of designated time points. The plasma concentration of UA was determined using a validated liquid chromatography-mass spectrometry (LC-MS) approach. A biexponential decline in the UA plasma concentration was observed after i.v. dosing and was fitted to a two-compartmental model. The expression levels of phase II drug metabolism (DM)/antioxidant genes and the inflammatory iNos gene in corresponding treatment arms were measured using qPCR as a pharmacodynamic (PD) marker. The expression of phase II DM/antioxidant genes increased and peaked approximately 3 h after 20 mg/kg UA treatment. In a lipopolysaccharide (LPS)-induced acute inflammation model, UA inhibited LPS-stimulated iNos expression and that of the epigenetic markers the DNA methyltransferases (DNMTs) and histone deacetylases (HDACs) in leukocytes. A PK-PD model using Jusko's indirect response model (IDR) with transition compartments (TC) was established to describe the time delay and magnitude of the gene expression elicited by UA. The PK-PD model provided reasonable fitting linking the plasma concentration of UA simultaneously with the PD response based on leukocyte mRNA expression. Overall, our results indicate that UA is effective at inducing various phase II DM/antioxidant genes and inhibiting pro-inflammatory genes in vivo. This PK-PD modeling approach may provide a conceptual framework for the future clinical evaluation of dietary chemopreventive agents in humans.

Inhibition of Human Kallikrein 5 Protease by Triterpenoids from Natural Sources

Stratum corneum tryptic enzyme kallikrein 5 (KLK5) is a serine protease that is involved in the cell renewal and maintenance of the skin barrier function. The excessive activation of KLK5 causes an exacerbation of dermatoses, such as rosacea and atopic dermatitis. Some triterpenoids are reported to suppress the serine proteases. We aimed to investigate whether bioactive triterpenoids modulate the KLK5 protease. Nineteen triterpenoids occurring in medicinal crude drugs were evaluated using an enzymatic assay to measure the anti-KLK5 activity. The KLK5-dependent cathelicidin peptide LL-37 production in human keratinocytes was examined using immunoprecipitation and Western blotting. Screening assays for evaluating the anti-KLK5 activity revealed that ursolic acid, oleanolic acid, saikosaponin b₁, tumulosic acid and pachymic acid suppressed the KLK5 protease activity, although critical molecular moieties contributing to anti-KLK5 activity were unclarified. Ursolic acid and tumulosic acid suppressed the proteolytic processing of LL-37 in keratinocytes at ≤10 μM; no cytotoxicity was observed. Both triterpenoids were detected in the plasma of rats administered orally with triterpenoid-rich crude drug Jumihaidokuto. Our study reveals that triterpenoids, such as ursolic acid and tumulosic acid, modulate the KLK5 protease activity and cathelicidin peptide production. Triterpenoids may affect the skin barrier function via the regulation of proteases.

Interference of ursolic acid treatment with glioma growth: An in vitro and in vivo study

Glioblastoma multiforme is the most devastating tumor in the brain. Ursolic acid (UA) is found in a variety of plants, and exhibits several pharmacological activities. In this study, we investigated the effects of UA in vitro, clarifying the mechanisms that mediate its toxicity and the long-lasting actions of UA in C6 glioma cells. We also evaluated the antitumor activity of UA in an in vivo orthotopic glioma model. Cell numbers were assessed using the Trypan blue exclusion test, and the cell cycle was characterized by flow cytometry using propidium iodide staining. Apoptosis was analyzed using an Annexin V kit and by examining caspase-3. Akt immunocontent was verified by Western blot and the long-lasting actions of UA were measured by cumulative population doubling (CPD). In vivo experiments were performed in rats to measure the effects on tumor size, malignant features and toxicological parameters. In vitro results showed that UA decreased glioma cell numbers, increased the sub-G1 fraction and induced apoptotic death, accompanied by increased active caspase-3 protein levels. Akt phosphorylation/activation in cells was also diminished by UA. With regard to CPD, cell proliferation was almost completely restored upon single UA treatments, but when the UA was added again, the majority of cells died, demonstrating the importance of re-treatment cycles with chemotherapeutic agents for abolishing tumor growth. In vivo, ursolic acid slightly reduced glioma tumor size but did not decrease malignant features. Ursolic acid may be a potential candidate as an adjuvant for glioblastoma therapy.

Therapeutic effect of ursolic acid in experimental visceral leishmaniasis

Leishmaniasis is an important neglected tropical disease, affecting more than 12 million people worldwide. The available treatments are not well tolerated and present diverse side effects in patients, justifying the search for new therapeutic compounds. In the present study, the therapeutic potential and toxicity of ursolic acid (UA), isolated from the leaves of Baccharis uncinella C. DC. (Asteraceae), were evaluated in experimental visceral leishmaniasis. To evaluate the therapeutic potential of UA, hamsters infected with L. (L.) infantum were treated daily during 15 days with 1.0 or 2.0 mg UA/kg body weight, or with 5.0 mg amphotericin B/kg body weight by intraperitoneal route. Fifteen days after the last dose, the parasitism of the spleen and liver was stimated and the main histopathological alterations were recorded. The proliferation of splenic mononuclear cells was evaluated and IFN-γ, IL-4, and IL-10 gene expressions were analyzed in spleen fragments. The toxicity of UA and amphotericin B were evaluated in healthy golden hamsters by histological analysis and biochemical parameters. Animals treated with UA had less parasites in the spleen and liver when compared with the infected control group, and they also showed preservation of white and red pulps, which correlate with a high rate of proliferation of splenic mononuclear cells, IFN-γ mRNA and iNOS production. Moreover, animals treated with UA did not present alterations in the levels of AST, ALT, creatinine and urea. Taken together, these findings indicate that UA is an interesting natural compound that should be considered for the development of prototype drugs against visceral leishmaniasis.

Potential use of nanocarriers with pentacyclic triterpenes in cancer treatments

Ursolic, oleanolic and betulinic acids are representative pentacyclic triterpenoids found in various plants and fruits. Despite having marked antitumor potentials, the very poor water solubility of these triterpenes hinders treatment development. Nanotechnology can enhance solubility, stability, bioavailability and phytochemical delivery, improving the therapeutic efficiency of triterpenes. This review focuses on the formulation, characterization and in vitro/in vivo evaluation of several delivery nanosystems used to enhance the physicochemical properties of ursolic, oleanolic and betulinic acids.

Discovery of ursolic acid prodrug (NX-201): Pharmacokinetics and in vivo antitumor effects in PANC-1 pancreatic cancer

The aim of our study was to develop ursolic acid (UA) prodrugs in order to overcome UA's weakness, which has an extremely low bioavailability. UA-medoxomil (NX-201), one of our UA prodrugs, showed an improved bioavailability about 200times better than UA in rodent model. According to in vivo test performed with PANC-1 xenograft SCID mouse model, tumor growth rate decreased dose-dependently and 100mg/kg dose of NX-201 had an anticancer effect comparable to gemcitabine. Most of all the combination of NX-201 (50mg/kg, po, daily) and gemcitabine (40mg/kg, iv, 2timesperweek) even reduced tumor size after three weeks.