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

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.

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.

Lavandula stoechas L. subsp. stoechas, a New Herbal Source for Ursolic Acid: Quantitative Analysis, Purification and Bioactivity Studies

In this study, methanol, ethanol, methanol-dichloromethane (1 : 1, v/v), acetone, ethyl acetate, diethyl ether, and chloroform extracts of lavender (Lavandula stoechas L. subsp. stoechas) were prepared by maceration, and the ursolic acid contents in the extracts were determined quantitatively by HPLC analyses. The present results show that the methanol-dichloromethane (1 : 1, v/v) solvent system is the most efficient solvent system for the extraction of ursolic acid from the plant sample with the highest yield (2.22 g/100 g plant sample). In the present study, a new practical method for the isolation of ursolic acid from polar extracts was also demonstrated for the first time. The inhibition effects of the extracts and ursolic acid were also revealed on α-glycosidase, acetylcholinesterase, butyrylcholinesterase, and human carbonic anhydrase I and II enzymes by determining IC50 values for the first time. The extracts and ursolic acid acted as potent antidiabetic agents by strongly inhibiting the α-glycosidase activity, whereas they were found to be very weak neuroprotective agents. In view of the present results, L. stoechas and its major metabolite, ursolic acid, can be recommended as a herbal source to control postprandial blood sugar levels and prevent diabetes by delaying the digestion of starch in food.

Therapeutic Strategies to Ameliorate Neuronal Damage in Epilepsy by Regulating Oxidative Stress, Mitochondrial Dysfunction, and Neuroinflammation

Epilepsy is a central nervous system disorder involving spontaneous and recurring seizures that affects 50 million individuals globally. Because approximately one-third of patients with epilepsy do not respond to drug therapy, the development of new therapeutic strategies against epilepsy could be beneficial. Oxidative stress and mitochondrial dysfunction are frequently observed in epilepsy. Additionally, neuroinflammation is increasingly understood to contribute to the pathogenesis of epilepsy. Mitochondrial dysfunction is also recognized for its contributions to neuronal excitability and apoptosis, which can lead to neuronal loss in epilepsy. This review focuses on the roles of oxidative damage, mitochondrial dysfunction, NAPDH oxidase, the blood-brain barrier, excitotoxicity, and neuroinflammation in the development of epilepsy. We also review the therapies used to treat epilepsy and prevent seizures, including anti-seizure medications, anti-epileptic drugs, anti-inflammatory therapies, and antioxidant therapies. In addition, we review the use of neuromodulation and surgery in the treatment of epilepsy. Finally, we present the role of dietary and nutritional strategies in the management of epilepsy, including the ketogenic diet and the intake of vitamins, polyphenols, and flavonoids. By reviewing available interventions and research on the pathophysiology of epilepsy, this review points to areas of further development for therapies that can manage epilepsy.

Bioactive components, pharmacological effects, and drug development of traditional herbal medicine Rubus chingii Hu (Fu-Pen-Zi)

Rubus chingii Hu (Chinese Raspberry), known as Fu-Pen-Zi in Chinese, a woody perennial plant of the genus Rubus in the Rosaceae family, has specific nutritional and medicinal values, which is considered food-medicine herb in China for thousands of years to treat impotence, premature ejaculation, enuresis, frequent urination, and other diseases. This review aims to summarize recent advances in the bioactive components, pharmacological effects, and drug development and utilization of Rubus chingii Hu, hoping to provide useful support for its further research and clinical application. The bioactive components in Rubus chingii Hu contain mainly terpenoids, flavonoids, alkaloids, phenolic acids, polysaccharides, and steroids. The main pharmacological effects are their anti-oxidant, anti-inflammatory, and anti-tumor capacity on human health. Rubus chingii Hu is a very valuable food-medicine herb. The development of Rubus chingii Hu-related drugs is relatively single, which is limited to traditional Chinese medicine and prescriptions. Therefore, it is vital to pay interest to Rubus chingii Hu and its bioactive components in the future and extend its scientific application.

Ursolic acid: a natural modulator of signaling networks in different cancers

Incidence rate of cancer is estimated to increase by 40% in 2030. Furthermore, the development of resistance against currently available treatment strategies has contributed to the cancer-associated mortality. Scientists are now looking for the solutions that could help prevent the disease occurrence and could provide a pain-free treatment alternative for cancers. Therefore, efforts are now put to find a potent natural compound that could sever this purpose. Ursolic acid (UA), a triterpene acid, has potential to inhibit the tumor progression and induce sensitization to conventional treatment drugs has been documented. Though, UA is a hydrophobic compound therefore it is usually chemically modified to increase its bioavailability prior to administration. However, a thorough literature indicating its mechanism of action and limitations for its use at clinical level was not reviewed. Therefore, the current study was designed to highlight the potential mechanism of UA, its anti-cancer properties, and potential applications as therapeutic compound. This endeavour is a valuable contribution in understanding the hurdles preventing the translation of its potential at clinical level and provides foundations to design new studies that could help enhance its bioavailability and anti-cancer potential for various cancers.

Exploring the potential anti-Alzheimer disease mechanisms of Alpiniae Oxyphyliae Fructus by network pharmacology study and molecular docking

Alpiniae Oxyphyliae Fructus (AOF) (yizhi) is a frequently medicated Chinese herb for Alzheimer disease (AD) treatment. The present study investigated the components and potential mechanisms of AOF through network pharmacology analysis and molecular docking. The results showed that AOF contains at least 20 active ingredients and involves 184 target genes. A total of 301 AD-related genes were obtained from the DisGeNET, GeneCards, GEO, OMIM, and Alzheimer Disease: Genes databases. A total of 41 key targets were identified from the topology analysis of the AOF-AD target network. These key targets are involved in 105 signal pathways, such as the PI3K-Akt, HIF-1, and MAPK pathways, and can regulate gene transcription, cell death, cell proliferation, drug response, and protein phosphorylation. AOF's active ingredients, Chrysin, Isocyperol, Izalpinin, Linolenic acid, CHEMBL489541, Oxyphyllenone A, Oxyphyllenone B, and Oxyphyllol C, show high affinity to targets, including PPARG, ESR1, and AKT1. These findings provide a new basis for AOF application and anti-AD study.

Ursolic Acid Enhances Myelin Repair in Adult Mice Brains and Stimulates Exhausted Oligodendrocyte Progenitors to Remyelinate

In multiple sclerosis patients, long-term inflammation makes the oligodendrocyte progenitor cells (OPCs) exhausted; therefore, a new therapy that makes them responsive to insults to participate in remyelination is highly in demand. Here, we investigated the effect of ursolic acid (UA) on myelin repair after mid-term and long-term demyelination periods induced by 6 or 12 weeks of cuprizone treatment followed by 2 weeks of recovery with or without UA. Immunohistochemistry studies and myelin genes expression assessment were used to evaluate the myelination status of mouse corpora callosa and the cellular mechanisms of myelin repair. Results showed that UA significantly promoted recovery from myelin loss after discontinuing 6 or 12 weeks of cuprizone feeding, as measured by luxol fast blue (LFB), fluoroMyelin (FM), anti-myelin basic protein (MBP) staining, and oligodendrocyte progenitor cell counts. It led to reduced inflammation and gliosis as evaluated by glial fibrillary acidic protein (GFAP), Iba1, or other marker gene transcripts. Following long-term demyelination, gliosis and TNF-α were observed as potential players in lesion pathology, which were restored by UA. An increased IL-10 may contribute to UA anti-inflammatory effect and making responsive the exhausted OPCs. UA increased the number of new oligodendrocyte lineage cells and myelination. Our findings indicated that UA can enhance myelin repair after cuprizone challenge through the prevention of gliosis and increasing the newly generated myelin.

Development, Physical-Chemical Characterization, and Molecular Docking Simulations of Ursolic Acid-Sodium Alginate Complexes

The aim of this study was to fabricate ursolic acid (UA)-sodium alginate (SA) complexes to improve the dissolution rate and antioxidant abilities. The antioxidant activity was evaluated by the DPPH (1,1-diphenyl-2-trinitrophenylhydrazine) assay and the pyrogallol auto-oxidation method. For the optimal composition ratio of UA:SA (1:5, w/w), the cumulative release of UA was about 101.22 ± 1.50% for 180 min. Powder X-ray diffractometry (PXRD), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM) analyses confirmed that the crystallinity of UA was significantly reduced by forming complexes with SA. By Fourier transform infrared spectroscopy (FTIR) and molecular docking simulations, it was observed that the hydroxyl group in UA formed hydrogen bonding with the carbonyl group in SA. The DPPH scavenger activities of the complexes were also increased compared with free UA. The results indicated that SA could serve as a promising carrier for lipophilic functional food ingredients due to improved solubility and antioxidant activity.

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.