Effects of maslinic acid on the proliferation and apoptosis of A549 lung cancer cells

Structure-Activity Relationship of Oleanane-Type Pentacyclic Triterpenoids on Nuclear Factor κB Activation and Intracellular Trafficking and N-Linked Glycosylation of Intercellular Adhesion Molecule-1

In our previous study, two oleanane-type pentacyclic triterpenoids (oleanolic acid and maslinic acid) were reported to affect the N-glycosylation and intracellular trafficking of intercellular adhesion molecule-1 (ICAM-1). The present study was aimed at investigating the structure-activity relationship of 13 oleanane-type natural triterpenoids with respect to the nuclear factor κB (NF-κB) signaling pathway and the expression, intracellular trafficking, and N-glycosylation of the ICAM-1 protein in human lung adenocarcinoma A549 cells. Hederagenin, echinocystic acid, erythrodiol, and maslinic acid, which all possess two hydroxyl groups, decreased the viability of A549 cells. Celastrol and pristimerin, both of which possess an α,β-unsaturated carbonyl group, decreased cell viability but more strongly inhibited the interleukin-1α-induced NF-κB signaling pathway. Oleanolic acid, moronic acid, and glycyrrhetinic acid interfered with N-glycosylation without affecting the cell surface expression of the ICAM-1 protein. In contrast, α-boswellic acid and maslinic acid interfered with the N-glycosylation of the ICAM-1 protein, which resulted in the accumulation of high-mannose-type N-glycans. Among the oleanane-type triterpenoids tested, α-boswellic acid and maslinic acid uniquely interfered with the intracellular trafficking and N-glycosylation of glycoproteins.

Bioactivities and Structure-Activity Relationships of Maslinic Acid Derivatives: A Review

Maslinic acid has a variety of biological activities, such as anti-tumor, hypoglycemic, anti-inflammatory, and anti-parasitic. In order to enhance the biological activity of maslinic acid, scholars have carried out a lot of structural modifications, and found some more valuable maslinic acid derivatives. In this paper, the structural modification, biological activity, and structure-activity relationship of maslinic acid were reviewed, providing references for the development of maslinic acid.

Improved antitumor activity through a tyramidyl maslinic acid derivative. Design and validation as drug-loaded electrospun polymeric nanofibers

Among the most harmful tumors detected in the human body, such as breast, colon, brain or pancreas, breast (BC) and colorectal cancer (CRC) are the first and third most frequent cancer worldwide, respectively. The current existing chemotherapeutic treatments present serious side effects due to their intravenous administration can induce cytotoxicity in healthy cells. Thus, new treatment methods based on drug-loaded polymeric nanofibers (NFs) have gained significant potential for their use in localized cancer chemotherapy. Here, a deep in vitro comparative analysis between maslinic acid (MA) and a tyramine-maslinic acid (TMA) derivative is initially performed. This analysis includes a proliferation, and a cell cycle assay, and a genotoxicity, antiangiogenic and apoptosis study. Then, the TMA derivative has been incorporated into electrospun polymeric NFs obtaining an implantable dressing material with antitumor activity. Two types of patches containing TMA-loaded polymeric NFs of poly(caprolactone) (PCL), and a mixture of polylactic acid/poly(4-vinylpyridine) (PLA/PVP) were fabricated by the electrospinning technique. The characterization of the drug-loaded NFs showed an encapsulation capacity of 0.027 mg TMA/mg PCL and 0.024 mg TMA/mg PLA/PVP. Then, the cytotoxic activity of both polymeric systems was tested in CRC (T84), BC (MCF-7) and a no tumor (L929) cell lines exposed to TMA-loaded NFs and blank NFs for 48 h. Moreover, cell cycle assay, genotoxicity, angiogenesis and apoptosis tests were carried out to study the mechanism of action of TMA. Blank NFs showed no-toxicity in all cell lines tested and both drug-loaded NFs significantly reduced cell proliferation (relative proliferation of ≈44 % and ≈25 % respectively). Therefore, TMA was less genotoxic than maslinic acid (MA), and reduced VEGFA expression in MCF-7 cells (1.32 and 2.12-fold for MA and TMA respectively). These results showed that TMA-loaded NFs could constitute a promising biocompatible and biodegradable nanoplatform for the local treatment of solid tumors such as CRC or BC.

Maslinic acid solid lipid nanoparticles as hydrophobic anticancer drug carriers: Formulation, in vitro activity and in vivo biodistribution

Maslinic acid (MA) is a natural pentacyclic triterpenoid with inherent antitumor activity which has a very low solubility in water. MA solid lipid nanoparticles (SLNs) were prepared using Poloxamer 407 and Dicarboxylic acid-Poloxamer 407 as surfactants. Both MA SLNs are monodisperse, with sizes around 130 nm, and stable. Curcumin has been encapsulated in both types of nanoparticles without altering their colloidal properties. Moreover, SLNs greatly improve the solubility of MA and Curcumin. The cytotoxicity of MA and SLNs has been evaluated in BxPC3 human pancreatic cancer cells, MCF7 human breast cancer cells, and in a human fibroblast primary cell line. MA shows higher cytotoxic effect in BxPC3 and MCF7 cancer cells than in human primary fibroblasts. Nile Red loaded MA SLNs are quickly uptaken by BxPC3 and MCF7 cells, and show different cytoplasmic distributions depending on the cellular line. The oral or intravenous administration of MA SLNs in mice does not report any toxic effect, and the intravenous administration of fluorescent MA SLNs shows a homogeneous distribution in mice, without site-specific accumulation. Results suggest the great potential of MA SLNs as nanocarriers of anticancer drugs and as promising targeted theranostic nanodevices.

Maslinic acid exerts anticancer effects by targeting cancer hallmarks

BACKGROUND

Natural products have long been regarded as a source of anticancer compounds with low toxicity. Evidence revealed that maslinic acid (MA), a widely distributed pentacyclic triterpene in common foodstuffs, exhibited pronounced inhibitory effects against various cancer cell lines. Most cancer cells thrive by acquiring cancer hallmarks, as coined by Hanahan and Weinberg in 2000 and 2011.

PURPOSE

This represents the first systematic review concerning the anticancer properties of MA as these cancer hallmarks are targeted. It aims to summarize the antineoplastic activities of MA, discuss the diverse mechanisms of action based on the effects of MA exerted on each hallmark.

METHODS

A comprehensive literature search was conducted using the search terms "maslinic," "cancer," "tumor," and "neoplasm," to retrieve articles from the databases MEDLINE, EMBASE, Web of Science, and Scopus published up to September 2022. Study selection was conducted by three reviewers independently from title and abstract screening until full-text evaluation. Data extraction was done by one reviewer and counterchecked by the second reviewer.

RESULTS

Of the 330 articles assessed, 40 papers met the inclusion criteria and revealed that MA inhibited 16 different cancer cell types. MA impacted every cancer hallmark by targeting multiple pathways.

CONCLUSION

This review provides insights regarding the inhibitory effects of MA against various cancers and its remarkable biological properties as a pleiotropic bioactive compound, which encourage further investigations.

Maslinic Acid: A New Compound for the Treatment of Multiple Organ Diseases

Maslinic acid (MA) is a pentacyclic triterpene acid, which exists in many plants, including olive, and is highly safe for human beings. In recent years, it has been reported that MA has anti-inflammatory, antioxidant, anti-tumor, hypoglycemic, neuroprotective and other biological activities. More and more experimental data has shown that MA has a good therapeutic effect on multiple organ diseases, indicating that it has great clinical application potential. In this paper, the extraction, purification, identification and analysis, biological activity, pharmacokinetics in vivo and molecular mechanism of MA in treating various organ diseases are reviewed. It is hoped to provide a new idea for MA to treat various organ diseases.

Solid lipid nanoparticles to improve bioaccessibility and permeability of orally administered maslinic acid

Maslinic acid (MA) is a plant-derived, low water-soluble compound with antitumor activity. We have formulated MA in the form of solid lipid nanoparticles (SLNs) with three different shell compositions: Poloxamer 407 (PMA), dicarboxylic acid-Poloxamer 407 (PCMA), and HA-coated PCMA (PCMA-HA). These SLNs improved the solubility of MA up to 7.5 mg/mL, are stable in a wide range of pH, and increase the bioaccessibility of MA after in vitro gastrointestinal (GI) digestion. Gastrointestinal digested SLNs afforded MA delivery across in vitro gut barrier models (21 days old Caco-2 and mucus-producing Caco-2/HT29-MTX co-cultures). The cellular fraction of Caco-2/HT29-MTX co-cultures retained more MA from GI digested PCMA-HA than the Caco-2 monolayers. The concentration of MA reached in the basolateral chamber inhibited growth of pancreatic cancer cells, BxPC3. Finally, confocal microscopy images provided evidence that Nile Red incorporated in MA SLNs was capable of crossing Caco-2 monolayers to be taken up by basolaterally located BxPC3 cells. We have demonstrated that SLNs can be used as nanocarriers of hydrophobic antitumor compounds and that these SLNs are suitable for oral consumption and delivery of the bioactive across the gut barrier.

Maslinic Acid Inhibits the Growth of Malignant Gliomas by Inducing Apoptosis via MAPK Signaling

Background

Gliomas are primary malignant brain tumors. Despite recent advances in surgery and clinical neuro-oncology, the prognosis of patients with glioma is still poor. Therefore, there is an urgent need to find new therapeutic drugs.

Methods

Here, we have studied the anticancer effect of maslinic acid in glioma and explored its potential molecular mechanism. CCK-8, Ki67 immunofluorescence, and colony formation tests are used to detect the proliferation of glioma cells. Transwell and migration experiments are used to detect the function of cell invasion and migration, and RNA-seq was performed to identify differentially expressed genes. Western blot analysis helps us identify important signaling pathways. Finally, the anticancer effect of maslinic acid was confirmed in vivo through tumor xenografting experiments.

Results

Our experiments obtained high-throughput data on the treatment of maslinic acid in glioma. We found that maslinic acid significantly inhibits the proliferation, invasion, and migration of glioma cells and promotes the apoptosis of glioma cells via suppressing MAPK signaling.

Conclusions

This is the first time to analyze the mechanism of maslinic acid against glioma based on transcription. Our experiments show that maslinic acid may be a useful natural product for the treatment of glioma.

Protective effects of maslinic acid on high fat diet-induced liver injury in mice

AIMS

Due to the prevalence of high-fat diets and lack of exercise, diseases related to nutrient metabolism such as nonalcoholic fatty liver disease (NAFLD) have become one of the reasons causes endangering human liver health. Maslinic acid (MA) is a pentacyclic triterpenoid acid that is abundant in fruits such as hawthorn and jujube. In this study, we investigated the effect of MA on NAFLD to inform the development of dietary supplements for the treatment and prevention of NAFLD.

MATERIALS AND METHODS

The NAFLD model was established by feeding mice a high-fat diet (HFD). HEPG2 cells were treated with oleic acid and used as a cell culture model. Testing kits, haematoxylin and eosin staining, oil red O staining, western blotting, and immunofluorescence were performed with in vivo and in vitro experiments.

KEY FINDINGS

The current study revealed that MA significantly reduced liver weight, body weight and serum lipid levels, and protected against liver steatosis and injury induced by a HFD. MA increased the expression of Beclin1, ATG1, and Bcl-2 mRNA and protein while decreasing the expression of TNF-α and IL-1β, caspase-3 and Bax mRNA and protein. Beclin1, and ATG1 were obviously increased, and the mRNA and protein expression of TNF-α and IL-1β were obviously reduced, the mRNA and protein expression of Caspase-3 and Bax were obviously reduced, and the mRNA and protein expression of Bax were obviously increased by MA.

SIGNIFICANCE

MA reduces the content of fat in the liver cells of NAFLD mice through lipophagy activitiy and reduces inflammation and apoptosis injury.

The Anticancer Potential of Maslinic Acid and Its Derivatives: A Review

Cancer is still an insurmountable problem for humans and critically attacking human health. In recent years, natural products have gained increasing attention in the field of anti-tumor due to their extensive sources and minimal side effects. Maslinic acid (MA), a pentacyclic triterpene acid mainly derived from the olive tree (Olea europaea L.) has been confirmed to possess great anti-cancer effects. This paper reviewed the inhibitory effect of MA and its derivatives on lung cancer, colon cancer, ovarian cancer, gastric cancer, lymphatic, leukemia, breast cancer, pancreatic cancer, melanoma, prostate cancer, renal cell carcinoma, gallbladder cancer, and bladder cancer, among others. MA inhibited the proliferation of various tumor cells and showed lower IC50 values in melanoma 518A2 cells and gastric cancer MKN28 cells compared with other cell lines. A series of semi-synthetic derivatives obtained by modifying MA chemical structure have been shown to have high cytotoxicity to human tumor cell lines, but low cytotoxicity to non-malignant cells, which is conducive to developing its potential as a chemotherapeutic agent. These studies suggest that MA derivatives have broad prospects in the development of antitumor therapeutics in the future and warrant further study.

Advances in Research on the Preparation and Biological Activity of Maslinic Acid

Maslinic acid, a pentacyclic triterpene acid, is mainly isolated from olives. Maslinic acid and its derivatives exhibit a broad range of biological properties, such as anti-inflammatory, anticancer, anti-diabetic, antimicrobial, neuroprotective and hepatoprotective activities. In this minireview, the progress of research on maslinic acid with regard to its bioactivities, extraction, semisynthetic preparation and patents is reported. The relationships between the structure and the activity of maslinic acid and its derivatives are also discussed.

Survivin expression and localization in different organs of yaks (Bos grunniens)

Yaks (Bos grunniens) have special physiological structures that help them adapt to high-altitude environments. Survivin is actively studied in cancer tissues, but less in normal tissues. Therefore, the aim of the present study was to analysis the relationship between survivin expression and apoptosis rate in yaks. A partial gene sequence of survivin was cloned and characterized using bioinformatics. The expression of survivin was investigated using real-time quantitative PCR (RT-qPCR) and western blot (WB) analysis and localized using immunohistochemistry (IHC). The results revealed that in normal physiological organs, survivin is mainly expressed in cytoplasm and its expression was up-regulated with age. Its expression in heart and liver was higher than in other organs, such as spleen, lung, brain, kidney, and testis. It is noteworthy that the expression of survivin in spleen is differed from that in other organs. Therefore, we selected immune organs (lymph node, thymus and spleen) to investigate the relationship between survivin expression and apoptosis. Caspase-3 was used as a reference. Within the same age group, the expression of survivin was the highest in the spleen, but that of caspase-3 was the highest in the lymph node (P < 0.01). Furthermore, the IHC analysis revealed that survivin and caspase-3 are expressed in the same location (mainly in the cytoplasm, Hassall's corpuscles, the medulla of the lymph node, the red pulp and marginal zone of the spleen. More importantly, survivin expression was down-regulated with age in immune organs, and the opposite trend was observed for caspase-3 expression (P < 0.01). The results proved that the expression of survivin and caspase-3 is down- and up-regulated with age, respectively, suggesting that survivin and caspase-3 might coordinating and participating in slowing down the rate of apoptosis rate in immune organs of healthy yak.

Clinical significance and biological function of fucosyltransferase 2 in lung adenocarcinoma

Fucosylation, which is catalyzed by fucosyltransferases (FUTs), is one of the most important glycosylation events involved in cancer. Studies have shown that fucosyltransferase 8 (FUT8) is overexpressed in NSCLC and promotes lung cancer progression. However, there are no reports about the pathological role of fucosyltransferase 2 (FUT2) in lung cancer. To identify FUT2 associated with lung cancer, the expression and clinical significance of FUT2 in lung cancer was investigated by Real-Time PCR, Immunohistochemistry and Western Blot. In addition, we investigated the effect of knockdown FUT2 in lung adenocarcinoma cells. The results showed that the expression of FUT2 in lung adenocarcinoma is higher than that in adjacent noncancerous tissues. Knocking down FUT2 in A549 and H1299 cells decreased cell proliferation, migration and invasion, and increased cell apoptosis compared to corresponding control cells. Furthermore, Western Blot showed that knockdown FUT2 can impact the expression of migration-associated and apoptosis-associated proteins in A549 cells. Our results suggest that FUT2 may be associated with lung adenocarcinoma development and thus is a potential biomarker or/and therapeutic target in lung adenocarcinoma.

Maslinic acid promotes autophagy by disrupting the interaction between Bcl2 and Beclin1 in rat pheochromocytoma PC12 cells

Maslinic acid (2α, 3β-dihydroxyolean-12-en-28-oic acid, MA) was isolated from natural plants and showed anti-cancer activity in rat Pheochromocytoma PC12 cells in our previous studies. We now discover that MA disrupts the interaction between Bcl2 and autophagy scaffold protein Beclin1 in the above cell line, leading to the up-regulation of autophagy. We investigated the effect of MA on the interaction between Bcl2 and Beclin1 by biochemical and biophysical methods in combination with autophagy characterization in the above cell line. Our results suggest that MA may serve as an autophagy activator by directly blocking the Bcl2-Beclin1 interaction to release free Beclin1 required for the recruitment of autophagy positive regulators, implying MA may exert its anti-cancer activity by regulating autophagy.

Maslinic Acid Inhibits Proliferation of Renal Cell Carcinoma Cell Lines and Suppresses Angiogenesis of Endothelial Cells

Despite the introduction of many novel therapeutics in clinical practice, metastatic renal cell carcinoma (RCC) remains a treatment-resistant cancer. As red and processed meat are considered risk factors for RCC, and a vegetable-rich diet is thought to reduce this risk, research into plant-based therapeutics may provide valuable complementary or alternative therapeutics for the management of RCC. Herein, we present the antiproliferative and antiangiogenic effects of maslinic acid, which occurs naturally in edible plants, particularly in olive fruits, and also in a variety of medicinal plants. Human RCC cell lines (ACHN, Caki-1, and SN12K1), endothelial cells (human umbilical vein endothelial cell line [HUVEC]), and primary cultures of kidney proximal tubular epithelial cells (PTEC) were treated with maslinic acid. Maslinic acid was relatively less toxic to PTEC when compared with RCC under similar experimental conditions. In RCC cell lines, maslinic acid induced a significant reduction in proliferation, proliferating cell nuclear antigen, and colony formation. In HUVEC, maslinic acid induced a significant reduction in capillary tube formation in vitro and vascular endothelial growth factor. This study provides a rationale for incorporating a maslinic acid–rich diet either to reduce the risk of developing kidney cancer or as an adjunct to existing antiangiogenic therapy to improve efficacy.

Attenuated JNK signaling in multidrug-resistant leukemic cells. Dual role of MAPK in cell survival

Having found previously that leukemic cells with multidrug resistant (MDR) phenotype, but not their sensitive counterparts, exhibit collateral sensitivity to cold stress in a P-gp-dependent manner, our aim was to study the signaling pathways involved in this phenomenon in sensitive (L1210) and resistant cells (L1210R and CBMC-6). It was observed that the acquisition of MDR phenotype by leukemic cells or their transfection with the extrussion pump, P-gp, modifies the activation profile and regulation of Mitogen-Activated Protein Kinases (MAPK) in cells exposed to low temperatures. More specifically, cold stress provoked the activation of c-Jun N-terminal kinase (JNK) in sensitive cells, while attenuated JNK signaling was observed in MDR cells. This effect was also observed, although with less intensity, in P-gp-transfected cells. Using pharmacological inhibitors to determine the role of MAPK in leukemic cell survival in physiological conditions or under cold stress, a dual temperature-dependent role was observed for JNK in MDR cell survival. At 37°C JNK is necessary for the survival of parental, resistant and P-gp-transfected cells; however, the use of inhibitors of either extracellular signal-regulated protein kinase (ERK) or JNK significantly counteracts cold-induced death of resistant and P-gp-transfected cells, supporting a role for ERK and JNK in cold-stress induced cell death. Finally, a connectivity model concerning MAPK is proposed, summarizing how cold stress and MDR-1 might trigger apoptosis in resistant cell lines. These findings on MDR cells may assist in the design of specific therapeutic strategies to complement current chemotherapy.

LRRK2 knockdown in zebrafish causes developmental defects, neuronal loss, and synuclein aggregation

Although mutations in the leucine-rich repeat kinase 2 (LRRK2) gene are the most common cause of genetic Parkinson's disease, their function is largely unknown. LRRK2 is pleiotropic in nature, shown to be involved in neurodegeneration and in more peripheral processes, including kidney functions, in rats and mice. Recent studies in zebrafish have shown conflicting evidence that removal of the LRRK2 WD40 domain may or may not affect dopaminergic neurons and/or locomotion. This study shows that ∼50% LRRK2 knockdown in zebrafish causes not only neuronal loss but also developmental perturbations such as axis curvature defects, ocular abnormalities, and edema in the eyes, lens, and otic vesicles. We further show that LRRK2 knockdown results in significant neuronal loss, including a reduction of dopaminergic neurons. Immunofluorescence demonstrates that endogenous LRRK2 is expressed in the lens, brain, heart, spinal cord, and kidney (pronephros), which mirror the LRRK2 morphant phenotypes observed. LRRK2 knockdown results further in the concomitant upregulation of β-synuclein, PARK13, and SOD1 and causes β-synuclein aggregation in the diencephalon, midbrain, hindbrain, and postoptic commissure. LRRK2 knockdown causes mislocalization of the Na(+) /K(+) ATPase protein in the pronephric ducts, suggesting that the edema might be linked to renal malfunction and that LRRK2 might be associated with pronephric duct epithelial cell differentiation. Combined, our study shows that LRRK2 has multifaceted roles in zebrafish and that zebrafish represent a complementary model to further our understanding of this central protein. © 2016 Wiley Periodicals, Inc.

CaMKII prevents spontaneous acrosomal exocytosis in sperm through induction of actin polymerization

In order to interact with the egg and undergo acrosomal exocytosis or the acrosome reaction (AR), mammalian spermatozoa must undergo a series of biochemical changes in the female reproductive tract, collectively called capacitation. We showed that F-actin is formed during sperm capacitation and fast depolymerization occurs prior to the AR. We hypothesized that F-actin protects the sperm from undergoing spontaneous-AR (sAR) which decreases fertilization rate. We show that activation of the actin-severing protein gelsolin induces a significant increase in sAR. Moreover, inhibition of CaMKII or PLD during sperm capacitation, caused an increase in sAR and inhibition of F-actin formation. Spermine, which leads to PLD activation, was able to reverse the effects of CaMKII inhibition on sAR-increase and F-actin-decrease. Furthermore, the increase in sAR and the decrease in F-actin caused by the inactivation of the PLD-pathway, were reversed by activation of CaMKII using H2O2 or by inhibiting protein phosphatase 1 which enhance the phosphorylation and oxidation states of CaMKII. These results indicate that two distinct pathways lead to F-actin formation in the sperm capacitation process which prevents the occurrence of sAR.