Ursolic acid reduces hepatocellular apoptosis and alleviates alcohol-induced liver injury via irreversible inhibition of CASP3 in vivo

Alcoholic liver disease (ALD) is one of the pathogenic factors of chronic liver disease with the highest clinical morbidity worldwide. Ursolic acid (UA), a pentacyclic terpenoid carboxylic acid, has shown many health benefits including antioxidative, anti-inflammatory, anticancer, and hepatoprotective activities. We previously found that UA was metabolized in vivo into epoxy-modified UA containing an epoxy electrophilic group and had the potential to react with nucleophilic groups. In this study we prepared an alkynyl-modified UA (AM-UA) probe for tracing and capturing the target protein of UA from liver in mice, then investigated the mode by which UA bound to its target in vivo. By conducting proteome identification and bioinformatics analysis, we identified caspase-3 (CASP3) as the primary target protein of UA associated with liver protection. Molecule docking analysis showed that the epoxy group of the UA metabolite reacted with Cys-163 of CASP3, forming a covalent bond with CASP3. The binding mode of the UA metabolites (UA, CM-UA, and EM-UA) was verified by biochemical evaluation, demonstrating that the epoxy group produced by metabolism played an important role in the inhibition of CASP3. In alcohol-treated HepG2 cells, pretreatment with the UA metabolite (10 μM) irreversibly inhibited CASP3 activities, and subsequently decreased the cleavage of PARP and cell apoptosis. Finally, pre-administration of UA (20-80 mg· kg-1 per day, ig, for 1 week) dose-dependently alleviated alcohol-induced liver injury in mice mainly via the inhibition of CASP3. In conclusion, this study demonstrates that UA is a valuable lead compound for the treatment of ALD.

Identification of phytochemical inhibitors against main protease of COVID-19 using molecular modeling approaches

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a novel corona virus that causes corona virus disease 2019 (COVID-19). The COVID-19 rapidly spread across the nations with high mortality rate even as very little is known to contain the virus at present. In the current study, we report novel natural metabolites namely, ursolic acid, carvacrol and oleanolic acid as the potential inhibitors against main protease (Mpro) of COVID-19 by using integrated molecular modeling approaches. From a combination of molecular docking and molecular dynamic (MD) simulations, we found three ligands bound to protease during 50 ns of MD simulations. Furthermore, the molecular mechanic/generalized/Born/Poisson-Boltzmann surface area (MM/G/P/BSA) free energy calculations showed that these chemical molecules have stable and favourable energies causing strong binding with binding site of Mpro protein. All these three molecules, namely, ursolic acid, carvacrol and oleanolic acid, have passed the ADME (Absorption, Distribution, Metabolism, and Excretion) property as well as Lipinski's rule of five. The study provides a basic foundation and suggests that the three phytochemicals, viz. ursolic acid, carvacrol and oleanolic acid could serve as potential inhibitors in regulating the Mpro protein's function and controlling viral replication. Communicated by Ramaswamy H. Sarma.

Dietary Ursolic Acid Prevents Alcohol-Induced Liver Injury via Gut-Liver Axis Homeostasis Modulation: The Key Role of Microbiome Manipulation

Ursolic acid (UA), a natural triterpenoid widely distributed within fruits and edible plants, has been proven to relieve alcoholic liver disease (ALD). However, the mechanisms involved largely remain unclear. This study investigated whether the beneficial effects of UA on ALD could be related to gut-liver axis (GLA) modulation. Special attention was paid to the contribution of gut microbiome manipulation. UA ameliorated intestinal oxidative stress and barrier dysfunction induced by alcohol. As a consequence of gut leakiness amelioration, the related endotoxemia-mediated liver toll-like receptor 4 pathway induction and the subsequent reactive oxygen species overproduction were reverted. UA also counteracted alcohol-induced gut dysbiosis. A fecal microbiota transplantation study indicated that liver injury as well as ileum oxidative stress and gut barrier dysfunction of recipient mice were partly ameliorated as a result of microbiome remodeling. These results suggest that dietary UA alleviates ALD through GLA homeostasis modulation. Gut microbiome manipulation contributes to the hepatoprotective activity and GLA modulating effect of UA.

Preclinical Assessment of Ursolic Acid Loaded into Nanostructured Lipid Carriers in Experimental Visceral Leishmaniasis

Ursolic acid, a triterpene produced by plants, displayed leishmanicidal activity in vitro and in vivo; however, the low solubility of this triterpene limits its efficacy. To increase the activity of ursolic acid (UA), this triterpene was entrapped in nanostructured lipid carriers (UA-NLC), physical-chemical parameters were estimated, the toxicity was assayed in healthy golden hamsters, and the efficacy of UA-NLC was studied in experimental visceral leishmanisis. UA-NLC exhibited a spherical shape with a smooth surface with a size of 266 nm. UA-NLC displayed low polydispersity (PDI = 0.18) and good colloidal stability (-29.26 mV). Hamsters treated with UA-NLC did not present morphological changes in visceral organs, and the levels of AST, ALT, urea and creatinine were normal. Animals infected with Leishmania (Leishmania) infantum and treated with UA-NLC showed lower parasitism than the infected controls, animals treated with UA or Amphotericin B (AmB). The therapeutic activity of UA-NLC was associated with the increase in a protective immune response, and it was associated with a high degree of spleen and liver preservation, and the normalization of hepatic and renal functions. These data indicate that the use of lipid nanoparticles as UA carriers can be an interesting strategy for the treatment of leishmaniasis.

Ursolic acid restores sensitivity to gemcitabine through the RAGE/NF-κB/MDR1 axis in pancreatic cancer cells and in a mouse xenograft model

Gemcitabine (GEM) is a first-line drug for pancreatic cancer therapy, but GEM resistance is easily developed in patients. Growing evidence suggests that cancer chemoprevention and suppression are highly associated with dietary phytochemical and microbiota composition. Ursolic acid (UA) has anti-inflammatory and anticancer effects; however, its role in improving cancer drug resistance in vivo remains unclear. In this study, the aim was to explore the role of UA in managing drug resistance-associated molecular mechanisms and the influence of gut microbiota. The in vitro results showed that receptor for advanced glycation end products (RAGE), nuclear factor kappa B p65 (NF-κB/p65), and multidrug resistance protein 1 (MDR1) protein levels were significantly increased in GEM-resistant pancreatic cancer cells (named MIA PaCa-2 GEMR) compared to MIA PaCa-2 cells. Downregulation of RAGE, pP65, and MDR1 protein expression not only was observed following UA treatment but also was seen in MIA PaCa-2 GEMR cells after transfection with a RAGE siRNA. Remarkably, the enhanced effects of UA coupled with GEM administration dramatically suppressed the RAGE/NF-κB/MDR1 cascade and consequently inhibited subcutaneous tumor growth. Moreover, UA could increase alpha diversity and regulate the composition of gut microbiota, especially in Ruminiclostridium 6. Taken together, these results provide the first direct evidence of MDR1 attenuation and chemosensitivity enhancement through inhibition of the RAGE/NF-κB signaling pathway in vitro and in vivo, implying that UA may be used as an adjuvant for the treatment of pancreatic cancer in the future.

Effects of Ursolic Acid on Intestinal Health and Gut Bacteria Antibiotic Resistance in Mice

Ursolic acid (UA), a natural pentacyclic triterpenoid, has been widely reported to exert anti-oxidant and anti-inflammatory properties. However, the effects of UA on the intestinal homeostasis and gut microbiota were rarely explored. The aim of the present study was to investigate the effects of UA on intestinal health and gut microflora antibiotic-resistance in antibiotic-exposed mice. Kunming mice (n = 80) were randomly allocated into three groups and fed with one of the following diets, respectively: Cont group (n = 20), the basal diet; UA group (n = 20), the basal diet supplemented with 150 mg/kg UA; Tet group (n = 40), the basal diet supplemented with 659 mg/kg chlortetracycline. After 14 days, 10 mice in each group were euthanatized and the remaining 30 mice in the Tet group were randomly allocated into three sub-groups (n = 10 per group) as follows: the Tet group which were kept feeding a Tet diet for 14 days; the Natural Restoration (NatR) group which received a basal diet for 14 days; and the UA therapy (UaT) group which fed a basal diet supplemented with 150 mg/kg UA for 14 days. Throughout the experiment, the weight and the food intake of each mouse were recorded once weekly. Serum LPS and diamine oxidase (DAO), jejunal morphology, jejunal tight junction proteins and nutrient transporters, colonic inflammatory cytokines, gut microbiota and its antibiotic resistance gene (ARG) were examined at euthanasia. The results showed that UA treatment significantly increased average daily food intake (ADFI) of mice. Notably, UA increased the jejunal villi height, decreased the jejunal crypt depth and promoted the expression of jejunum nutrient transporters. UaT group had higher villi height, lower crypt depth and higher nutrient transporter mRNA expression in jejunum than NatR group. Besides, UA decreased serum DAO content, upregulated mRNA expression of ZO-1, claudin-1 and occludin and downregulated TNF-α and IL-6. The mRNA abundances of ZO-1, claudin-1 and occludin and TNF-α and IL-6 in UaT group were, respectively upregulated and downregulated than NatR group. Furthermore, an analysis of 16S rDNA sequences demonstrated that UA increased the abundance of beneficial bacteria in the gut. And the results of ARG test showed that UA downregulated the expression of antibiotic-induced resistance genes. The UaT group inhibited the increase of harmful bacteria abundance and suppressed the mRNA abundances of ARG compared to the NatR group. In conclusion, considering the positive effects of UA on the growth performance and intestinal mucosal barrier, we anticipate that these findings could be a stepping stone for developing UA as a novel substitute of antibiotics.

Medicinal Plant Leaf Extract From Sage and Lemon Verbena Promotes Intestinal Immunity and Barrier Function in Gilthead Seabream (Sparus aurata)

The inclusion of a medicinal plant leaf extract (MPLE) from sage (Salvia officinalis) and lemon verbena (Lippia citriodora), rich in verbascoside and triterpenic compounds like ursolic acid, was evaluated in gilthead seabream (Sparus aurata) fed a low fishmeal-based diet (48% crude protein, 17% crude fat, 21.7 MJ kg-1, 7% fishmeal, 15% fish oil) for 92 days. In particular, the study focused on the effect of these phytogenic compounds on the gut condition by analyzing the transcriptomic profiling (microarray analysis) and histological structure of the intestinal mucosa, as well as the histochemical properties of mucins stored in goblet cells. A total number of 506 differentially expressed genes (285 up- and 221 down-regulated) were found when comparing the transcriptomic profiling of the intestine from fish fed the control and MPLE diets. The gut transcripteractome revealed an expression profile that favored biological mechanisms associated to the 1) immune system, particularly involving T cell activation and differentiation, 2) gut integrity (i.e., adherens and tight junctions) and cellular proliferation, and 3) cellular proteolytic pathways. The histological analysis showed that the MPLE dietary supplementation promoted an increase in the number of intestinal goblet cells and modified the composition of mucins' glycoproteins stored in goblet cells, with an increase in the staining intensity of neutral mucins, as well as in mucins rich in carboxylated and weakly sulfated glycoconjugates, particularly those rich in sialic acid residues. The integration of transcriptomic and histological results showed that the evaluated MPLE from sage and lemon verbena is responsible for the maintenance of intestinal health, supporting gut homeostasis and increasing the integrity of the intestinal epithelium, which suggests that this phytogenic may be considered as a promising sustainable functional additive for aquafeeds.

Glutaminase inhibitory activities of pentacyclic triterpenes isolated from Thymus vulgaris L

Glutaminase is an important target that is often over expressed in neurodegenerative and　lifestyle related diseases but few effective inhibitors of this enzyme have yet reached clinical trials. Ursolic acid (1), betulinic acid (2) and oleanolic acid (3), three pentacyclic triterpene acids, have been isolated from the leaves of Thymus vulgaris L. Enzyme inhibition experiments demonstrated their inhibitory effects against glutaminase activity. Compound 2 significantly inhibited the glutaminase activity with IC₅₀ of 0.31 mM, stronger than the positive control 6-diazo-5-oxo-L-norleucine (DON) with IC₅₀ of 0.57 mM. Compound 2 may serve as a potential lead compound for the prevention and treatment of neurodegenerative diseases and lifestyle related diseases by targeting glutaminase. This is the first report on glutaminase inhibitory activities of 1-3 isolated from T. vulgaris L.

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.

Anti-Inflammatory and Anti-Arthritic Potential of Standardized Extract of Clerodendrum serratum (L.) Moon

Aims: Scientific biological evaluation of standardized extracts is becoming one of the central needs for the globalization of customary medication in current times. And to validate the presence of active constituents in crude medicinal extracts, analytical techniques like HPLC and HPTLC are the most suitable authentication systems. In the current study we aimed to standardize and evaluate Clerodendrum serratum (L.) Moon (Verbenaceae). For its unique anti-inflammatory and anti-arthritic properties. Evaluation and analysis of the plant, therefore, offers a new platform for the development of the herbal drug and could prove to be a safe and cost effective treatment for arthritis management.

Methods: The aqueous extract of C. serratum, a common plant in the Southeastern Asian region, was used for phytochemical investigation and standardization by HPTLC and HPLC. The standardized HPLC method was further validated by using ICH guidelines. The standardized extract was investigated for anti-inflammatory and anti-arthritic activity. Complete Freund’s adjuvant (CFA) model was performed to evaluate the activity. Paw diameter, joint diameter, arthritic score, and body weight was accepted as a parameter for the evaluation of biological activity.

Results: HPTLC method revealed the presence of ursolic acid with an R_f value of 0.38 and the amount quantified was 0.03% w/w. The presence of the bioactive phytochemical was further analyzed and confirmed by HPLC for which the validation was done successfully in accordance with ICH guidelines. The assay content for ursolic acid was found to be 0.059% with relative standard deviation (RSD) <2.5% for specificity and precision with spike recovery between 95–110%. The anti-arthritic activity of aqueous extract exhibited COX-2 and TNF-α inhibition as observed in various parameters like paw edema, arthritic index, and joint diameter. Plant extract showed reclamation of arthritis in regard to body weight, arthritic score, paw edema, and joint diameter. The extract showed significant results for TNF-α and COX-2(p < 0.0001). The plant extract also exhibited in-vitro anti-inflammatory activity.

Conclusion: The current study established the scientific basis of ethnomedicinal use of the plant for anti-inflammatory purposes and the management of arthritis and can also be used for quality control purposes.

Ursolic acid disturbs ROS homeostasis and regulates survival-associated gene expression to induce apoptosis in intestinal cancer cells

Ursolic acid is a natural compound possessing several therapeutic properties including anticancer potential. In present study, cytotoxic and antimetastatic properties of ursolic acid were investigated in intestinal cancer cell lines INT-407 and HCT-116. The cells growth and number were decreased in a dose- and time-dependent manner in both the cell lines. It also increases reactive oxygen species levels in the cells in order to induce apoptosis. Ursolic acid was found to be a significant inhibitor of cancer cells migration and gene expression of migration markers FN1, CDH2, CTNNB1 and TWIST was also downregulated. Ursolic acid treatment downregulated the gene expression of survival factors BCL-2, SURVIVIN, NFKB and SP1, while upregulated the growth-restricting genes BAX, P21 and P53. These results indicate that ursolic acid has anticancer and antimetastatic properties against intestinal cancer. These properties could be beneficial in cancer treatment and could be used as complementary medicine.

Combined Cornus Officinalis and Paeonia Lactiflora Pall Therapy Alleviates Rheumatoid Arthritis by Regulating Synovial Apoptosis via AMPK-Mediated Mitochondrial Fission

Rheumatoid arthritis (RA) is a chronic autoimmune disease that leads to cartilage destruction and bone erosion. In-depth exploration of the pathogenesis of RA and the development of effective therapeutic drugs are of important clinical and social value. Herein, we explored the medicinal value of Cornus officinalis Sieb. and Paeonia lactiflora Pall. in RA treatment using a rat model of collagen-induced arthritis (CIA). We compared the therapeutic effect of Cornus officinalis and Paeonia lactiflora with that of their main active compounds, ursolic acid and paeoniflorin, respectively. We demonstrated that the combination of Cornus officinalis and Paeonia lactiflora effectively inhibited the release of factors associated with oxidative stress and inflammation during RA, therein ameliorating the symptoms and suppressing the progression of RA. We further showed that the underlying mechanisms may be related to the regulation of apoptosis in synovial tissues, and we investigated the potential involvement of AMPK-mediated mitochondrial dynamics in the therapeutic action of the two drugs and their active components.

The Presence of a Cyclohexyldiamine Moiety Confers Cytotoxicity to Pentacyclic Triterpenoids

Pentacyclic triterpenoids oleanolic acid, ursolic acid, betulinic acid, and platanic acid were acetylated and converted into several amides 9-31; the cytotoxicity of which has been determined in sulforhodamine B assays employing seral human tumor cell lines and nonmalignant fibroblasts. Thereby, a betulinic acid/trans-1,4-cyclohexyldiamine amide showed excellent cytotoxicity (for example, EC₅₀ = 0.6 μM for HT29 colon adenocarcinoma cells).

A novel oral nutritional supplement improves gait speed and mitochondrial functioning compared to standard care in older adults with (or at risk of) undernutrition: results from a randomized controlled trial

Undernutrition in older adults is mainly addressed by oral nutritional supplements, which do not affect physical functioning. In this study, we tested a novel oral nutritional supplement that included whey and casein protein, ursolic acid, free branch-chained amino acids and vitamin D against a standard supplement. We included older adults (>65y) with (or at risk of) undernutrition (n=82) and randomized them to 12 weeks of novel or standard supplement.

Both groups showed significant increases in body mass. No within or between-group differences in lean body mass were observed. Fat mass increased significantly more in the standard than the novel supplement group (time*treatment effect P=0.045). The novel supplement group showed a larger improvement in walking performance on distances of 4m (treatment x time interaction P=0.048) and 400m (treatment x time interaction P=0.038) than the standard treatment group. Gene sets related to mitochondrial functioning and oxidative phosphorylation were upregulated in the novel supplement group and downregulated in the standard supplement group.

We conclude that a 12-week intervention with the novel supplement improved walking performance both during short and long distance as compared to a standard supplement, which can largely be explained by increased mitochondrial functioning in the group receiving the novel supplement.

Therapeutic effect of ursolic acid on fetal development in pregnant rats with gestational diabetes mellitus via AGEs-RAGE signaling pathway

To investigate the effect of ursolic acid on the fetal development of gestational diabetes mellitus (GDM) caused by streptozotocin (STZ) and explore the potential mechanism for it. For the current experimental research, SD rats (pregnant animal) were used. STZ has been used to cause the diabetes mellitus in pregnant rats. Rats with evolved GDM were randomly divided and ursolic acid was given to pregnant rats in the experimental period up to 19 days in a dose-dependent manner. Blood samples and fetal rats of all group rats were collected at 19 days (pregnant rats), fetal rats and placental rats were weighted and the blood glucose, plasma insulin, C-peptide, and lipid parameters of pregnant women were estimated prior to delivery. Advanced serum glycation end-products (AGEs) were estimated at regular intervals in the heart and brain of pregnant rats. Monocyte Chemoattractant Protein-1 (MCP-1), NADPH oxidase 2 (Nox2), Role of advanced glycation end product (RAGE), Vascular endothelial growth factor (VEGF), p65, and vascular cell adhesion molecule 1 (VCAM-1) mRNA expression were estimated in the placenta. STZ-induced GDM pregnant rats showed significantly decreased placental weight and weight of fetal rats and dose-dependent ursolic acid treatment (p < .001) improved placental weight and weight of fetal rats at dose-dependent levels. After the ursolic acid treatment, serum blood glucose and lipid level were improved especially fasting blood glucose (FBG), high density lipoprotein (HDL), hepatic glycogen, fasting insulin (FINS), and serum insulin level and reached near to the normal control group rats. The antioxidant level of pancreas and liver were significantly (p < .001) reduced by the dose-dependent treatment of ursolic acid. Treatment with Ursolic acid moderately but not significantly decreases the risk of fetal development defects relative to the GDM group. The potential effect on fetal development in Pregnant Rats with Gestational Diabetes Mellitus via AGEs-RAGE signaling pathway was shown by Ursolic acid. PRACTICAL APPLICATIONS: As we know that the gestational diabetes mellitus increases worldwide day by day. In the current experimental study, we try to examine the gestational diabetic effect of ursolic acid. The finding of the current study showed the gestational diabetic protective effect in the female rats via AGEs-RAGE signaling pathway. The result showed the antioxidant, anti-inflammatory, and biochemical parameters. On the basis of the result, we can say that the ursolic acid can be the protective drug for treatment of gestational diabetes mellitus.

Antitumor Effects of Ursolic Acid through Mediating the Inhibition of STAT3/PD-L1 Signaling in Non-Small Cell Lung Cancer Cells

Targeted therapy based on natural compounds is one of the best approaches against non-small cell lung cancer. Ursolic acid (UA), a pentacyclic triterpenoid derived from medicinal herbs, has anticancer activity. Studies on the molecular mechanism underlying UA’s anticancer activity are ongoing. Here, we demonstrated UA’s anticancer activity and the underlying signaling mechanisms. We used Western blotting and real-time quantitative polymerase chain reaction for molecular signaling analysis. We also used in vitro angiogenesis, wound healing, and invasion assays to study UA’s anticancer activity. In addition, we used tumorsphere formation and chromatin immunoprecipitation assays for binding studies. The results showed that UA inhibited the proliferation of A549 and H460 cells in a concentration-dependent manner. UA exerted anticancer effects by inducing G0/G1 cell cycle arrest and apoptosis. It also inhibited tumor angiogenesis, migration, invasion, and tumorsphere formation. The molecular mechanism underlying UA activity involves UA’s binding to epidermal growth factor receptor (EGFR), reducing the level of phospho-EGFR, and thus inhibiting the downstream JAK2/STAT3 pathway. Furthermore, UA reduced the expressions of vascular endothelial growth factor (VEGF), metalloproteinases (MMPs) and programmed death ligand-1 (PD-L1), as well as the formation of STAT3/MMP2 and STAT3/PD-L1 complexes. Altogether, UA exhibits anticancer activities by inhibiting MMP2 and PD-L1 expression through EGFR/JAK2/STAT3 signaling.

Cyclodextrins, Natural Compounds, and Plant Bioactives-A Nutritional Perspective

Cyclodextrins (CDs) are a group of cyclic oligosaccharides produced from starch or starch derivatives. They contain six (αCD), seven (βCD), eight (γCD), or more glucopyranose monomers linked via α-1,4-glycosidic bonds. CDs have a truncated cone shape with a hydrophilic outer wall and a less hydrophilic inner wall, the latter forming a more apolar internal cavity. Because of this special architecture, CDs are soluble in water and can simultaneously host lipophilic guest molecules. The major advantage of inclusion into CDs is increased aqueous solubility of such lipophilic substances. Accordingly, we present studies where the complexation of natural compounds such as propolis and dietary plant bioactives (e.g., tocotrienol, pentacyclic triterpenoids, curcumin) with γCD resulted in improved stability, bioavailability, and bioactivity in various laboratory model organisms and in humans. We also address safety aspects that may arise from increased bioavailability of plant extracts or natural compounds owing to CD complexation. When orally administered, α- and βCD—which are inert to intestinal digestion—are fermented by the human intestinal flora, while γCD is almost completely degraded to glucose units by α-amylase. Hence, recent reports indicate that empty γCD supplementation exhibits metabolic activity on its own, which may provide opportunities for new applications.

A Carrier-Free Folate Receptor-Targeted Ursolic Acid/Methotrexate Nanodelivery System for Synergetic Anticancer Therapy

PURPOSE

To avoid undefined metabolic mechanisms and to eliminate potential side effects of traditional nanocarriers, new green carriers are urgently needed in cancer treatment. Carrier-free nanoparticles (NPs) based on ursolic acid (UA) have attracted significant attention, but the UA NPs targeting the folate receptor have never been explored. We designed a novel self-assembled UA-Methotrexate (MTX) NPs targeting the folate-receptor and its synergetic anticancer activity was studied in vitro and in vivo.

METHODS

UA-MTX NPs were prepared using the solvent precipitation method. Characterization of the UA-MTX NPs preparation was performed using a size analyzer, transmission electron microscopy, and UV-vis spectrophotometry. The in vitro pH-responsive drug release capability of UA-MTX NPs was tested at different pH values. The UA-MTX NPs targeting of folates was determined by comparing the endocytosis rates of cell lines with low or overexpression of the folate receptor (A549 and MCF-7 cells). The cytotoxicity and cell apoptosis of UA-MTX NPs were also studied to determine the in vitro synergistic effects. Combination chemotherapy of UA-MTX NPs in vivo was evaluated using MCF-7 xenografted tumor models.

RESULTS

Compared with free UA or MTX, the water solubility of UA-MTX NPs improved significantly. Drug-release from the UA-MTX NPs was faster at pH 5.0 than pH 7.4, suggesting MTX-UA NPs could rapidly release MTX in the acidic conditions of the tumor microenvironment. Confocal laser scanning microscopy revealed the excellent folate receptor targeting of UA-MTX NPs in MCF-7 cells. Cytotoxicity and cell apoptosis results demonstrated greater antiproliferative capacity of UA-MTX NPs than that of free drug in folate receptor overexpressing MCF-7 cells. Anticancer effects in vivo suggested MTX-UA NPs exhibited good biological safety and could enhance antitumor efficacy due to the combination therapy.

CONCLUSION

Our findings indicate that the UA-MTX NPs targeting folate-receptors is an efficient strategy for combination chemotherapy.

[Mechanism of ursolic acid in regulating colorectal cancer cell HCT116 autophagy through hedgehog signaling pathway]

To prove that ursolic acid(UA)could activate the autophagy of colorectal cancer HCT116 cells by inhibiting hedgehog signaling pathway. The effect of UA on the viability of HCT116 cells was determined by MTT assay. The effect of UA on the proliferation and migration of HCT116 cells was detected by crystal violet staining and scratch test. In the study on autophagy, the time points were screened out first: the autophagy fluorescence intensity of UA acting on HCT116 at different time points were detected by Cell Meter~(TM) Autophagy Assay Kit; Western blot was used to detect the expression of autophagy protein P62 at different time points. Then, Cell Meter~(TM) Autophagy Assay Kit was used to detect the effect of UA on autophagy fluorescence intensity of HCT116 cells. The effect of different doses of UA on the expressions of LC3Ⅱ and P62 proteins in HCT116 cells were detected by Western blot. Further, AdPlus-mCherry-GFP-LC3 B adenovirus transfection was used to detect the effects of UA on autophagy flux of HCT116 cells; UA combined with autophagy inhibitor chloroquine(CQ) was used to detect the expression of LC3Ⅱ by Western blot. In terms of mechanism, the effect of UA on hedgehog signaling pathway-related proteins in HCT116 cells was detected by Western blot. The results showed that UA inhibited the activity, proliferation and migration of HCT116 cells. UA enhanced the fluorescence intensity of autophagy in HCT116 cells, while promoting the expression of LC3Ⅱ and inhibiting the expression of P62, in a time and dose dependent manner. UA activated the autophagy in HCT116 cells, which manifested that UA resulted in the accumulation of fluorescence spots and strengthened the fluorescence intensity of autophagosomes; compared with UA alone, UA combined with autophagy inhibitor CQ promoted the expression of LC3Ⅱ. UA reduced the expressions of PTCH1, GLI1, SMO, SHH and c-Myc in hedgehog signaling pathway, while increased the expression of Sufu. In conclusion, our study showed that UA activated autophagy in colorectal cancer HCT116 cells, which was related to the mechanism in inhibiting hedgehog signaling pathway activity.

Cytotoxic Potential of a-Azepano- and 3-Amino-3,4-SeCo-Triterpenoids

Semi-synthetic triterpenoids, holding an amino substituted seven-membered A-ring (azepano-ring), which could be synthesized from triterpenic oximes through a Beckmann type rearrangement followed by a reduction of lactame fragment, are considered to be novel promising agents exhibiting anti-microbial, alpha-glucosidase, and butyrylcholinesterase inhibitory activities. In this study, in an attempt to develop new antitumor candidates, a series of A-ring azepano- and 3-amino-3,4-seco-derivatives of betulin, oleanolic, ursolic, and glycyrrhetinic acids were evaluated for their cytotoxic activity against five human cancer cell lines and non-malignant mouse fibroblasts by means of a colorimetric sulforhodamine assay. Azepanoallobetulinic acid amide derivative 11 was the most cytotoxic compound of this series but showed little selectivity between the different human tumor cell lines. Flow cytometry experiments showed compound 11 to act mainly by apoptosis (44.3%) and late apoptosis (21.4%). The compounds were further screened at the National Cancer Institute towards a panel of 60 cancer cell lines. It was found that compounds 3, 4, 7, 8, 9, 11, 15, 16, 19, and 20 showed growth inhibitory (GI₅₀) against the most sensitive cell lines at submicromolar concentrations (0.20–0.94 μM), and their cytotoxic activity (LC₅₀) was also high (1–6 μM). Derivatives 3, 8, 11, 15, and 16 demonstrated a certain selectivity profile at GI₅₀ level from 5.16 to 9.56 towards K-562, CCRF-CEM, HL-60(TB), and RPMI-8226 (Leukemia), HT29 (Colon cancer), and OVCAR-4 (Ovarian cancer) cell lines. Selectivity indexes of azepanoerythrodiol 3 at TGI level ranged from 5.93 (CNS cancer cell lines SF-539, SNB-19 and SNB-75) to 14.89 for HCT-116 (colon cancer) with SI 9.56 at GI₅₀ level for the leukemia cell line K-562. The present study highlighted the importance of A-azepano-ring in the triterpenic core for the development of novel antitumor agents, and a future aim to increase the selectivity profile will thus lie in the area of modifications of azepano-triterpenic acids at their carboxyl group.

Modulatory effect of ursolic acid on neurodegenerative activities in oxidative brain injury: An ex vivo study

Natural products-based antioxidants have been well reported for their therapeutic benefits in the treatment and management of neurodegenerative diseases. The neuroprotective effect of ursolic acid (UA) against oxidative injury was investigated in isolated rat brain. Induction of oxidative injury in isolated rat brains with 0.1 mM FeSO4 led to depleted levels of glutathione, superoxide dismutase, catalase, and ENTPDase activities, with concomitant exacerbation of malondialdehyde and nitric oxide levels, α-chymotrypsin, ATPase, and acetylcholinesterase activities. These levels and activities were significantly reversed following treatment of the brain tissues with UA. Molecular docking studies revealed strong molecular interactions between UA, catalase, and ATPase. Overall, these results indicate the neuroprotective effect of UA against oxidative injury in isolated rat brains as depicted by their ability to mitigate oxidative stress, purinergic, and cholinergic dysfunctions, with concomitant suppression of proteolytic activity. PRACTICAL APPLICATIONS: Neurodegenerative diseases are among the common diseases associated with aging and has been implicated as oxidative mediated. Natural products have received increasing recognition in their use as treatment remedy for various oxidative-mediated diseases including neurodegeneration. These natural products include plant secondary metabolites commonly known as phytochemicals. Ursolic acid is a phytochemical usually present in leafy vegetables and fruits. The present study describes the possible therapeutic mechanism of ursolic acid in the amelioration of complications linked to neurodegeneration in oxidative-mediated brain injury. These findings thus give insights into the use of natural products of plant origin in treating and managing neurodegenerative diseases, which may have little or no side effects.

Ursolic acid reduces Adriamycin resistance of human ovarian cancer cells through promoting the HuR translocation from cytoplasm to nucleus

Ursolic acid (UA) has been shown to suppress various tumor progression, however, its roles in Adriamycin resistance of human ovarian cancer (OC) cells are still unclear. This work aims to investigate the effects of UA on the Adriamycin resistance of human OC cells. Here, we constructed Adriamycin-resistant OC SKOV3-Adr cells and found that UA attenuated Adriamycin resistance in SKOV3-Adr cells. Additionally, UA enhanced Adriamycin sensitivity in the parental SKOV3 and another OC cell line A2780 cells. Mechanistic studies showed that HuR mRNA level was similar between SKOV3 and SKOV3-Adr cells, but the cytoplasmic expression of HuR protein was increased in SKOV3-Adr cells compared with that in SKOV3 cells, and subsequently enhancing the mRNA stability of multidrug resistance gene 1 (MDR1). Moreover, UA had no effects on HuR expression, but promoted the cytoplasm-nucleus translocation of HuR protein, decreased MDR1 mRNA stability and thus reduced MDR1 expression. Furthermore, overexpression of MDR1 rescued the effects of UA on Adriamycin resistance and sensitivity. This work reveals a novel HuR/MDR1 axis responsible for UA-mediated attenuation on Adriamycin resistance in OC cells.

Ursolic acid ameliorates hypobaric hypoxia-induced skeletal muscle protein loss via upregulating Akt pathway: An experimental study using rat model

Hypobaric hypoxic stress leads to oxidative stress, inflammation, and disturbance in protein turnover rate. Aggregately, this imbalance in redox homeostasis is responsible for skeletal muscle protein loss and a decline in physical performance. Hence, an urgent medical need is required to ameliorate skeletal muscle protein loss. The present study investigated the efficacy of ursolic acid (UA), a pentacyclic triterpene acid to ameliorate hypobaric hypoxia (HH)-induced muscle protein loss. UA is a naturally occurring pentacyclic triterpene acid present in several edible herbs and fruits such as apples. It contains skeletal muscle hypertrophy activity; still its potential against HH-induced muscle protein loss is unexplored. To address this issue, an in vivo study was planned to examine the beneficial effect of UA supplementation on HH-induced skeletal muscle loss. Male Sprague Dawley rats were exposed to HH with and without UA supplementation (20 mg/kg; oral) for 3 continuous days. The results described the beneficial role of UA as supplementation of UA with HH exposure attenuated reactive oxygen species production and oxidative protein damage, which indicate the potent antioxidant activity. Furthermore, UA supplementation enhanced Akt, pAkt, and p70S6kinase activity (Akt pathway) and lowered the pro-inflammatory cytokines in HH exposed rats. UA has potent antioxidant and anti-inflammatory activity, and it enhanced the protein content via upregulation of Akt pathway-related proteins against HH exposure. These three biological activities of UA make it a novel candidate for amelioration of HH-induced skeletal muscle damage and protein loss.

Ursolic Acid Inhibits Collective Cell Migration and Promotes JNK-Dependent Lysosomal Associated Cell Death in Glioblastoma Multiforme Cells

Ursolic acid (UA) is a bioactive compound which has demonstrated therapeutic efficacy in a variety of cancer cell lines. UA activates various signalling pathways in Glioblastoma multiforme (GBM) and offers a promising starting point in drug discovery; however, understanding the relationship between cell death and migration has yet to be elucidated. UA induces a dose dependent cytotoxic response demonstrated by flow cytometry and biochemical cytotoxicity assays. Inhibitor and fluorescent probe studies demonstrate that UA induces a caspase independent, JNK dependent, mechanism of cell death. Migration studies established that UA inhibits GBM collective cell migration in a time dependent manner that is independent of the JNK signalling pathway. Cytotoxicity induced by UA results in the formation of acidic vesicle organelles (AVOs), speculating the activation of autophagy. However, inhibitor and spectrophotometric analysis demonstrated that autophagy was not responsible for the formation of the AVOs. Confocal microscopy and isosurface visualisation determined co-localisation of lysosomes with the previously identified AVOs, thus providing evidence that lysosomes are likely to be playing a role in UA induced cell death. Collectively, our data identify that UA rapidly induces a lysosomal associated mechanism of cell death in addition to UA acting as an inhibitor of GBM collective cell migration.

Ursolic Acid Regulates Cell Cycle and Proliferation in Colon Adenocarcinoma by Suppressing Cyclin B1

Aims: The biological functions of cyclin B1 (CCNB1) in colon adenocarcinoma (COAD) will be explored in this study. Furthermore, the therapeutic effects and potential molecular mechanisms of ursolic acid (UA) in COAD cells will also be investigated in vitro.

Methods: COAD data were obtained from Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. Differentially expressed genes (DEGs) were determined with differential analysis. The biological functions of CCNB1 were analyzed through the GeneCards, the Search Tool for the Retrieval of Interacting Genes (STRING), and the Database for Annotation, Visualization, and Integrated Discovery (DAVID) databases. Therapeutic effects of UA on COAD cell lines HCT-116 and SW-480 were analyzed by CCK-8 and high-content screening (HCS) imaging assay. Flow cytometry was utilized to detect cell cycle changes of SW-480 and HCT-116 cells. Levels of mRNA and expression proteins of HCT-116, SW-480, and normal colon epithelial cells NCM-460 were determined by qRT-PCR and western blot.

Results: CCNB1 was highly expressed and acted as an oncogene in COAD patients. CCNB1 and its interacting genes were significantly enriched in the cell cycle pathway. UA effectively inhibited the proliferation and injured COAD cells. In addition, UA arrested cell cycle of COAD cells in S phase. With regard to the molecular mechanisms of UA, we demonstrated that UA can significantly downregulate CCNB1 and its interacting genes and proteins, including CDK1, CDC20, CCND1, and CCNA2, which contributed to cell cycle blocking and COAD treatment.

Conclusion: Results from this study revealed that UA possesses therapeutic effects on COAD. The anti-COAD activities of UA are tightly related to suppression of CCNB1 and its interacting targets, which is crucial in abnormal cell cycle process.