Triterpene 3β, 6β, 16β trihidroxilup-20(29)-ene protects against excitability and oxidative damage induced by pentylenetetrazol: the role of Na(+),K(+)-ATPase activity

Treating Epilepsy with Natural Products: Nonsense or Possibility?

Epilepsy is a neurological disease characterized by recurrent seizures that can lead to uncontrollable muscle twitching, changes in sensitivity to sensory perceptions, and disorders of consciousness. Although modern medicine has effective antiepileptic drugs, the need for accessible and cost-effective medication is urgent, and products derived from plants could offer a solution. For this review, we have focused on natural compounds that have shown anticonvulsant activity in in vivo models of epilepsy at relevant doses. In some cases, the effects have been confirmed by clinical data. The results of our search are summarized in tables according to their molecular targets. We have critically evaluated the data we present, identified the most promising therapeutic candidates, and discussed these in the text. Their perspectives are supported by both pharmacokinetic properties and potential interactions. This review is intended to serve as a basis for future research into epilepsy and related disorders.

Antioxidant Therapy Reduces Oxidative Stress, Restores Na,K-ATPase Function and Induces Neuroprotection in Rodent Models of Seizure and Epilepsy: A Systematic Review and Meta-Analysis

Epilepsy is a neurological disorder characterized by epileptic seizures resulting from neuronal hyperexcitability, which may be related to failures in Na,K-ATPase activity and oxidative stress participation. We conducted this study to investigate the impact of antioxidant therapy on oxidative stress, Na,K-ATPase activity, seizure factors, and mortality in rodent seizure/epilepsy models induced by pentylenetetrazol (PTZ), pilocarpine (PILO), and kainic acid (KA). After screening 561 records in the MEDLINE, EMBASE, Web of Science, Science Direct, and Scopus databases, 22 were included in the systematic review following the PRISMA guidelines. The meta-analysis included 14 studies and showed that in epileptic animals there was an increase in the oxidizing agents nitric oxide (NO) and malondialdehyde (MDA), with a reduction in endogenous antioxidants reduced glutathione (GSH) and superoxide dismutase (SO). The Na,K-ATPase activity was reduced in all areas evaluated. Antioxidant therapy reversed all of these parameters altered by seizure or epilepsy induction. In addition, there was a percentage decrease in the number of seizures and mortality, and a meta-analysis showed a longer seizure latency in animals using antioxidant therapy. Thus, this study suggests that the use of antioxidants promotes neuroprotective effects and mitigates the effects of epilepsy. The protocol was registered in the Prospective Register of Systematic Reviews (PROSPERO) CRD42022356960.

Phytochemical screening, phenolic and flavonoid contents, antioxidant and cytogenotoxicity activities of Combretum leprosum Mart. (Combretaceae)

Combretum leprosum Mart. (Combretaceae), a shrub popularly known as mofumbo, is used in folk medicine for treatment of uterine bleeding, pertussis, gastric pain, and as a sedative. The aim of this study was to (1) determine the phytochemical profile,(2) identify chemical constituents and (3) examine antioxidant and cytogenotoxic activity of ethanolic extracts and fractions of stem bark and leaves. The plant material (leaf and stem bark) was submitted to extraction with ethanol, followed by partition using hexane, chloroform, and ethyl acetate. It was possible to identify and quantify the epicatechin in the ethanolic stem bark extract (0.065 mg/g extract) and rutin in the leaf extract (3.33 mg/g extract). Based upon in vitro tests a significant relationship was noted between findings from antioxidant tests and levels of total phenolic and flavonoid. Comparing all samples (extracts and fractions), the ethyl acetate fractions of stem bark (411.40 ± 15.38 GAE/g) and leaves (225.49 ± 9.47 GAE/g) exhibited higher phenolic content, whereas hexanic fraction of stem bark (124.28 ± 56 mg/g sample) and ethyl acetate fraction of leaves (238.91 ± 1.73 mg/g sample) demonstrated a higher content of flavonoids. Among the antioxidant tests, the intermediate fraction of stem bark (28.5 ± 0.60 μg/ml) and ethyl acetate fraction of leaves (40 ± 0.56 μg/ml) displayed a higher % inhibition of free radical DPPH activity, whereas intermediate fraction of stem bark (27.5 ± 0.9 μg/ml) and hydromethanol fraction of leaves (81 ± 1.4 μg/ml) demonstrated inhibition of the free radical ABTS. In biological tests (Allium cepa and micronucleus in peripheral blood), data showed that none of the tested concentrations of ethanolic extracts of leaves and stem bark produced significant cytotoxicity, genotoxicity, and mutagenic activity.Abbreviations AA%: percentage of antioxidant activity; ABTS: 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid); CEUA: Ethics Committee in the Use of Animals; TLC: Thin Layer Chromatography; DNA: deoxyribonucleic acid; DPPH: 1,1-diphenyl-2-picrylhydrazyl; ROS: Reactive oxygen species; EEB: ethanol extract of the stem bark; HFB: Hexanic fraction of stem bark; IFB: Intermediate fraction of stem bark; CFB: Chloroform fraction of stem bark; EAFB: Ethyl acetate fraction of stem bark; HMFB: Hydromethanol fraction of the stem bark; EEL: Ethanol extract from leaves; HFL: Hexane fraction of leaves; CFL: Chloroform fraction of leaves; EAFL: Ethyl acetate fraction of leaves; HMFL: Hydromethanol fraction of leaves; GAE: Gallic Acid Equivalent; IC₅₀: 50% inhibition concentration; HCOOH: Formic acid; HCl: hydrochloric acid; HPLC: High-performance liquid chromatography; MN: micronucleus; WHO: World Health Organization; UFLC: Ultra-Fast Liquid Chromatography; UESPI: State University of Piauí.

Pharmacological modulation of Na+, K+-ATPase as a potential target for OXA-induced neurotoxicity: Correlation between anxiety and cognitive decline and beneficial effects of 7-chloro-4-(phenylselanyl) quinoline

Growing evidence demonstrates that Oxaliplatin (OXA) is commonly associated with neurotoxicity that leads to emotional and cognitive impairments. The aim of the present study was to evaluate the OXA and Na⁺, K⁺-ATPase interaction and to correlate anxious behavior and cognitive impairment induced by this chemotherapeutic in Swiss mice. Also, considering the pharmacological modulation of Na⁺, K⁺-ATPase as a potential target for OXA-induced neurotoxicity, the therapeutic potential of 7-chloro-4-(phenylselanyl) quinoline (4-PSQ) was evaluated. Mice received OXA (10 mg kg^-1) or vehicle by intraperitoneal route (days 0 and 2). Oral administration of 4-PSQ (1 mg kg^-1) or vehicle was performed from days 2-14. Behavioral tasks started from day 12 onwards. On day 15, the animals were sacrificed, and the tissues collected. The effects of OXA and 4-PSQ on activity and expression level of Na⁺, K⁺-ATPase in the hippocampus and cerebral cortex, and the plasmatic corticosterone levels were determined. The findings demonstrated a significant positive correlation between anxious behavior and cognitive impairment induced by OXA. OXA caused an increase on the plasmatic corticosterone levels and reduced activity and expression level of Na⁺, K⁺-ATPase. 4-PSQ reduced both anxious behavior and cognitive impairment induced by OXA. 4-PSQ effect seems to be due to the modulation of Na⁺, K⁺-ATPase and reduction of corticosterone levels. Our results helped to expand knowledge about the mechanisms involved in the physiopathology of the OXA-induced neurotoxicity and strongly indicated that 4-PSQ may be a good prototype for the treatment of anxious behavior and cognitive impairment induced by OXA exposure.

Effects of Diets on Adipose Tissue

BACKGROUND

Obesity is a major health problem that has become a global epidemic. Overweight and obesity are commonly associated with the development of several pathologies, such as insulin resistance, cardiovascular diseases, sleep apnea and several types of cancer, which can lead to further morbidity and mortality. An increased abdominal adiposity renders overweight and obese individuals more prone to metabolic and cardiovascular problems.

OBJECTIVE

This Review aims to describe the dietary strategies to deal with excess adiposity given the medical, social and economic consequences of obesity.

METHODS

One hundred and eighty-five papers were included in the present Review.

RESULTS

Excess adiposity leads to several changes in the biology, morphology and function of the adipose tissue, such as adipocyte hypertrophy and hyperplasia, adipose tissue inflammation and fibrosis and an impaired secretion of adipokines, contributing to the onset of obesity- related comorbidities. The first approach for obesity management and prevention is the implementation of a diet combined with physical activity. The present review summarizes the compelling evidence showing body composition changes, impact on cardiometabolism and potential adverse effects of very-low calorie, low- and high-carbohydrate, high-protein or low-fat diets. The use of macronutrients during the preprandial and postprandial state has been also reviewed to better understand the metabolic changes induced by different dietary interventions.

CONCLUSION

Dietary changes should be individualised, tailored to food preferences and allow for flexible approaches to reducing calorie intake in order to increase the motivation and compliance of overweight and obese patients.

Galangin Prevents Increased Susceptibility to Pentylenetetrazol-Stimulated Seizures by Prostaglandin E2

Epilepsy is one of the most common chronic neurological diseases. It is characterized by recurrent epileptic seizures, where one-third of patients are refractory to existing treatments. Evidence revealed the association between neuroinflammation and increased susceptibility to seizures since there is a pronounced increase in the expression of key inflammatory mediators, such as prostaglandin E₂ (PGE₂), during seizures. The purpose of this study was to investigate whether PGE₂ increases susceptibility to pentylenetetrazol-induced (PTZ) seizures. Subsequently, we evaluated if the flavonoid isolated from the plant Piper aleyreanum (galangin) presented any anticonvulsive effects. Our results demonstrated that the group treated with PGE₂ increased susceptibility to PTZ and caused myoclonic and generalized seizures, which increased seizure duration and electroencephalographic wave amplitudes. Furthermore, treatment with PGE₂ and PTZ increased IBA-1 (microglial marker), GFAP (astrocytic marker), 4-HNE (lipid peroxidation marker), VCAM-1 (vascular cell adhesion molecule 1), and p-PKAIIα (phosphorylated cAMP-dependent protein kinase) immunocontent. Indeed, galangin prevented behavioral and electroencephalographic seizures, reactive species production, decreased microglial and astrocytic immunocontent, as well as decreased VCAM-1 immunocontent and p-PKA/PKA ratio induced by PGE₂/PTZ. Therefore, this study suggests galangin may have an antagonizing role on PGE₂-induced effects, reducing cerebral inflammation and protecting from excitatory effects evidenced by administrating PGE₂ and PTZ. However, further studies are needed to investigate the clinical implications of the findings and their underlying mechanisms.

Modulation of Na+/K+- ATPase activity by triterpene 3β, 6β, 16β-trihidroxilup-20 (29)-ene (TTHL) limits the long-term secondary degeneration after traumatic brain injury in mice

Traumatic brain injury (TBI) is a public health problem characterized by a combination of immediate mechanical dysfunction of the brain tissue, and secondary damage. Based on the hypothesis that selected targets, such as Na⁺ K⁺-ATPase are involved in the secondary damage after TBI and modulation of this enzyme activity by triterpene 3β, 6β, 16β-trihidroxilup-20 (29)-ene (TTHL) supports the ethnomedical applications of this plant, we decided to investigate whether previous TTHL treatment interrupts the progression of pathophysiology induced by TBI. Statistical analyses revealed that percussion fluid injury (FPI) increased Na⁺,K⁺-ATPase activity in all isoform (α₁ and α_2/3) 15 min after neuronal injury. The FPI protocol inhibited Na⁺,K⁺-ATPase activity total and α₁ isoform, increased [³H]MK-801 binding but did not alter Dichloro-dihydro-fluorescein diacetate (DCFH-DA) oxidation, carbonylated proteins and free -SH groups 60 min after injury. The increase of immunoreactivity of protein PKC and state of phosphorylation of at Ser¹⁶ of Na⁺,K⁺-ATPase 60 min after FPI suggest the involvement of PKC on Na⁺,K⁺-ATPase activity oscillations characterized by inhibition of total and α₁ isoform. Our experimental data also revealed that natural product rich in compounds such as triterpenes (TTHL; 30 mg/kg) attenuates [³H]MK-801 binding increase, phosphorylation of the PKC and the Na⁺,K⁺-ATPase alpha 1 subunit (Ser¹⁶) induced by FPI. The previous TTHL treatment had not effect on motor disability but protected against spatial memory deficit, BDNF, TrKB expression decrease, protein carbonylation and hippocampal cell death 7 days after FPI. These data suggest that TTHL-induced reduction on initial damage limits the long-term secondary degeneration and supports neural repair or behavioral compensation after neuronal injury.

Medicinal plant Combretum leprosum mart ameliorates motor, biochemical and molecular alterations in a Parkinson's disease model induced by MPTP

ETHNOPHARMACOLOGICAL RELEVANCE

Combretum leprosum is a popular medicinal plant distributed in north and northeastern regions of Brazil. Many different parts of this plant are used in traditional medicine to treat several inflammatory diseases. Parkinson's disease (PD) is a disorder associated with inflammatory toxic factors and the treatments available provide merely a delay of the neurodegeneration.

AIM OF THE STUDY

We investigated the potential neuroprotective properties of the C. leprosum ethanolic extract (C.l.EE) in a murine model of PD using the toxin 1-methyl-4 phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP).

MATERIALS AND METHODS

The mice were split into four groups: V/S (vehicle/saline), E/S (extract/saline), V/M (vehicle/MPTP) and E/M (extract/ MPTP). Mice received MPTP (30mg/kg, i.p.) or vehicle (10ml/kg, i.p.) once a day for 5 consecutive days and vehicle (10ml/kg) or C.l.EE (100mg/kg) orally by intra-gastric gavage (i.g.) during a 14-d period, starting 3 days before the first MPTP injection. All groups were assessed for behavioural impairments (amphetamine-induced locomotor activity and muscle strength), dopamine content in striatum using high performance liquid chromatography (HPLC), tyrosine hydroxylase (TH) and dopamine transporter (DAT) gene expressions using qPCR.

RESULTS

Animals were injected with d-amphetamine (2mg/kg) and the activity was recorded. Amphetamine-induced hyperlocomotion was observed in all groups; however animals treated with MPTP showed exacerbated hyperlocomotion (approximately 3 fold increase compared to control groups). By contrast, mice treated with MPTP that received C.l.EE exhibited attenuation of the hyperlocomotion and did not differ from control groups. Muscle strength test pointed that C.l.EE strongly avoided muscular deficits caused by MPTP (approximately 2 fold increase compared to V/M group). Dopamine and its metabolites were measured in the striatum. The V/M group presented a dopamine reduction of 80%. On the other hand, the E/M group exhibited an increase in dopamine and its metabolites levels (approximately 3 fold increase compared to V/M group). Tyrosine hydroxylase (TH) and dopamine transporter (DAT) gene expressions were significantly reduced in the V/M group (60%). Conversely, C.l.EE treatment was able to increase the mRNA levels of those genes in the E/M group (approximately 2 fold for TH and DAT).

CONCLUSIONS

These data show, for the first time, that C. leprosum ethanolic extract prevented motor and molecular changes induced by MPTP, and partially reverted dopamine deficit. Thus, our results demonstrate that C.l.EE has potential for the treatment and prevention of PD.

High dietary protein decreases fat deposition induced by high-fat and high-sucrose diet in rats

High-protein diets are known to reduce adiposity in the context of high carbohydrate and Western diets. However, few studies have investigated the specific high-protein effect on lipogenesis induced by a high-sucrose (HS) diet or fat deposition induced by high-fat feeding. We aimed to determine the effects of high protein intake on the development of fat deposition and partitioning in response to high-fat and/or HS feeding. A total of thirty adult male Wistar rats were assigned to one of the six dietary regimens with low and high protein, sucrose and fat contents for 5 weeks. Body weight (BW) and food intake were measured weekly. Oral glucose tolerance tests and meal tolerance tests were performed after 4th and 5th weeks of the regimen, respectively. At the end of the study, the rats were killed 2 h after ingestion of a calibrated meal. Blood, tissues and organs were collected for analysis of circulating metabolites and hormones, body composition and mRNA expression in the liver and adipose tissues. No changes were observed in cumulative energy intake and BW gain after 5 weeks of dietary treatment. However, high-protein diets reduced by 20 % the adiposity gain induced by HS and high-sucrose high-fat (HS-HF) diets. Gene expression and transcriptomic analysis suggested that high protein intake reduced liver capacity for lipogenesis by reducing mRNA expressions of fatty acid synthase (fasn), acetyl-CoA carboxylase a and b (Acaca and Acacb) and sterol regulatory element binding transcription factor 1c (Srebf-1c). Moreover, ketogenesis, as indicated by plasma β-hydroxybutyrate levels, was higher in HS-HF-fed mice that were also fed high protein levels. Taken together, these results suggest that high-protein diets may reduce adiposity by inhibiting lipogenesis and stimulating ketogenesis in the liver.

The natural triterpene 3β,6β,16β-trihydroxy-lup-20(29)-ene obtained from the flowers of Combretum leprosum induces apoptosis in MCF-7 breast cancer cells

Background

The 3β, 6β, 16β-trihydroxylup-20(29)-ene (TTHL) is a pentacyclic triterpene obtained from the medicinal plant Combretum leprosum Mart. In folk medicine, this plant is popularly known as mofumbo, cipoaba or mufumbo, and is used to treat several diseases associated with inflammation and pain.

Methods

We investigated the antitumor efficacy of TTHL isolated from C. leprosum. The TTHL cytotoxic effect was investigated in MRC5, MCF-7, HepG2, T24, HCT116, HT29, and CACO-2 cells after 24, 48, 72 and 120 h of treatment. The mechanisms of cell death and DNA damage induction were investigated by flow cytometry and comet assay, respectively.

Results

The results indicated that TTHL induced a time- and concentration-dependent growth inhibition in all human cancer cell lines. The cytotoxicity was more pronounced in MCF-7 breast cancer cells, with an IC50 of 0.30 μg/mL at 120 h. We therefore evaluated the cell death mechanism induced by TTHL (IC20, IC50, and IC80) in MCF-7 cells at 24 h. We found that the treatment with IC50 and IC80 TTHL for 24 h induced apoptosis in 14% (IC50) and 52% (IC80) of MCF-7 cells. The apoptosis induced by TTHL was accompanied by increased levels of both cleaved caspase-9 and intracellular ROS. In order to further understand the biological mechanism of TTHL-induced cytotoxicity, we have also investigated its effect on different Saccharomyces cerevisiae yeast strains. The mutant strains sod1Δ, sod2Δ, and sod1Δsod2Δ, which are deficient in superoxide dismutase antioxidant defenses, were hypersensitive to TTHL, suggesting that its capacity to disturb cellular redox balance plays a role in drug toxicity. Moreover, TTHL induced mutagenicity in the yeast strain XV185-14c.

Conclusions

Taken together, the results suggest that TTHL forms covalent adducts with cellular macromolecules, potentially disrupting cellular function and triggering apoptosis.

Electronic supplementary material

The online version of this article (doi:10.1186/1472-6882-14-280) contains supplementary material, which is available to authorized users.