Effects of agmatine on chlorpromazine toxicity in the liver of Wistar rats: the possible role of oxidant/antioxidant imbalance

Efficacy of Agmatine Treatment in Experimental Acute Pancreatitis Rat Model

BACKGROUND/AIMS

Acute pancreatitis which is characterized by pancreatic inflammation can sometimes be difficult to treat because of limited therapeutic options. The purpose of the study was to assess the effects of agmatine in the acute pancreatitis experimental rat model.

MATERIALS AND METHODS

An acute pancreatitis model was created with the administration of cerulein in 40 female Sprague-Dawley rats. Agmatine was administered as a protective agent at 5 mg/kg (low dose) and 10 mg/kg (high dose). The rats were divided into 5 groups, each with 8 rats: group 1 (acute pancreatitis); group 2 (acute pancreatitis+low-dose agmatine 5 mg/kg); group 3 (acute pancreatitis+high-dose agmatine 10 mg/kg); group 4 (placebo, acute pancreatitis+saline); and group 5 (sham and saline infusion). All rats were sacrificed 24 hours after the last injection, and the levels of superoxide dismutase, interleukin-1 beta, and tumor necrosis factor-alpha were assessed in blood samples collected via cardiac puncture. Histopathological examination was performed by a pathologist, who was blind to the groups, according to the Schoenberg's pancreatitis scoring index.

RESULTS

The amylase (16.67 and 37.89 U/L), glutathione peroxidase (13.62 and 18.44 ng/mL), tumor necrosis factor-α (39.68 and 64 ng/mL), interleukin-1 (484.73 and 561.83 pg/mL), and transforming growth factor-β (110.52 and 126.34 ng/L) levels were significantly lower and superoxide dismutase (1.29 and 0.98 ng/L) and malondialdehyde (0.99 and 0.96 nmol/mL) levels were significantly higher in group 3 compared to group 1 (P < .05). Moreover glutathione peroxidase, tumor necrosis factor-α, and transforming growth factor-β levels were lower, and malondialdehyde levels were higher in the group 3 compared to group 2 (P < .05). Although the Schoenberg's pancreatitis scoring index was not significantly different between the high- and low-dose treatment groups, rats who received high-dose treatment had significantly lower scores compared to those with acute pancreatitis group.

CONCLUSION

This is the first study that evaluated the efficacy of agmatine in an experimental model of acute pancreatitis. Agmatine, an anti-inflammatory and antioxidant agent, had a protective effect in an experimental rat model of acute pancreatitis.

Neuroprotection by agmatine: Possible involvement of the gut microbiome?

Agmatine, an endogenous polyamine derived from L-arginine, elicits tremendous multimodal neuromodulant properties. Alterations in agmatinergic signalling are closely linked to the pathogeneses of several brain disorders. Importantly, exogenous agmatine has been shown to act as a potent neuroprotectant in varied pathologies, including brain ageing and associated comorbidities. The antioxidant, anxiolytic, analgesic, antidepressant and memory-enhancing activities of agmatine may derive from its ability to regulate several cellular pathways; including cell metabolism, survival and differentiation, nitric oxide signalling, protein translation, oxidative homeostasis and neurotransmitter signalling. This review briefly discusses mammalian metabolism of agmatine and then proceeds to summarize our current understanding of neuromodulation and neuroprotection mediated by agmatine. Further, the emerging exciting bidirectional links between agmatine and the resident gut microbiome and their implications for brain pathophysiology and ageing are also discussed.

Anti-hyperprolactinemic activities of aqueous extract of Uvaria chamae (P. Beauv) roots and associated biochemical changes in chlorpromazine-induced hyperprolactinemic female Wistar rats

ETHNOPHARAMCOLOGICAL RELEVANCE

The age-long folkloric use of Uvaria chamae roots in the management of nipple discharge that is not related to pregnancy, childbirth or nursing but as a result of excessive production of prolactin (hyperprolactinemia) is yet to be substantiated with scientific data.

AIM OF THE STUDY

This study investigated the anti-hyperprolactinemic activities of aqueous extract of Uvaria chamae roots (AEUCR) and associated biochemical changes in chlorpromazine (CPZ)-induced hyperprolactinemic female Wistar rats.

MATERIALS AND METHODS

A total of sixty female rats (207.40 ± 2.69 g) were assigned into 6 groups: A-F. Animals in Group A received 0.5 ml of distilled water only whilst the 7 days CPZ-treated female rats (to induce hyperprolactinemia) in groups B, C, D, E, and F also received distilled water, 2.5 mg/kg body weight of bromocriptine (reference drug), 0.71, 1.41 2.83 mg/kg body weight of AEUCR for 28 days.

RESULTS

AEUCR contained a total of 15 (75%) amino acids with seven (46.67%) being essential amino acids and eight (53.33%) as non-essential amino acids. Administration of CPZ increased (p < 0.05) the levels of prolactin and testosterone, and reduced (p < 0.05) the levels of estradiol, progesterone, follicle stimulating hormone (FSH), luteinizing hormone (LH), dopamine, triiodothyronine (T3) and tetraiodothyroxine (T4). Chlorpromazine also increased the levels of serum urea, creatinine, total protein, albumin, globulin, bilirubin, alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) of the animals. In contrast, AEUCR significantly (p < 0.05) reduced the CPZ-induced increases in the levels of prolactin and testosterone, and increased the levels of CPZ-induced reduction in the progesterone, estradiol, FSH, LH, dopamine, T3 and T4. The AEUCR also reversed (p < 0.05) the CPZ-induced related increases in the levels of urea, creatinine, total protein, albumin, globulin, bilirubin, ALT, AST and ALP similar to the trends in the distilled water- and bromocriptine-treated controls. The CPZ-induced remarkable increase in the size of lactating alveolus and lactiferous duct distribution in the mammary gland were restored to normal tubule-alveolar female pattern mammary glands, composed of branching ducts and small alveoli budding off the ducts.

CONCLUSION

The study concluded that aqueous extract of Uvaria chamae root exhibited anti-hyperprolactinemic activity by restoring prolactin and dopamine levels and tubule-alveolar female pattern in female rats. It also ameliorated CPZ-induced changes in the liver and kidney function indices. This study justifies the folkloric use of Uvaria chamae root in the management of abnormal discharge by the nipples that is unrelated to pregnancy, childbirth and nursing.

Antidepressants- and antipsychotics-induced hepatotoxicity

Drug-induced liver injury (DILI) is a serious health burden. It has diverse clinical presentations that can escalate to acute liver failure. The worldwide increase in the use of psychotropic drugs, their long-term use on a daily basis, common comorbidities of psychiatric and metabolic disorders, and polypharmacy in psychiatric patients increase the incidence of psychotropics-induced DILI. During the last 2 decades, hepatotoxicity of various antidepressants (ADs) and antipsychotics (APs) received much attention. Comprehensive review and discussion of accumulated literature data concerning this issue are performed in this study, as hepatotoxic effects of most commonly prescribed ADs and APs are classified, described, and discussed. The review focuses on ADs and APs characterized by the risk of causing liver damage and highlights the ones found to cause life-threatening or severe DILI cases. In parallel, an overview of hepatic oxidative stress, inflammation, and steatosis underlying DILI is provided, followed by extensive review and discussion of the pathophysiology of AD- and AP-induced DILI revealed in case reports, and animal and in vitro studies. The consequences of some ADs and APs ability to affect drug-metabolizing enzymes and therefore provoke drug–drug interactions are also addressed. Continuous collecting of data on drugs, mechanisms, and risk factors for DILI, as well as critical data reviewing, is crucial for easier DILI diagnosis and more efficient risk assessment of AD- and AP-induced DILI. Higher awareness of ADs and APs hepatotoxicity is the prerequisite for their safe use and optimal dosing.

Metabolite profiles of Pulicaria crispa and P. incisa in relation to their in-vitro/ in-vivo antioxidant activity and hepatoprotective effect: A comparative mass spectrometry-based metabolomics

Plants of the genus Pulicaria (family: Asteraceae) are widely used in central Asia and the Middle East for treatment of different human diseases. Ultra performance liquid chromatography coupled to high resolution mass spectrometry (UPLC/MS) was utilized to establish the metabolic profiles of two Pulicaria species: P. crispa and P. incisa. 122 metabolites were identified including flavonoids (37), phenolic acids (22), sesquiterpenes (17), diterpenes (7), and fatty acids (27), with enrichment in methoxylated flavonoids (20), caffeoylquinic acid conjugates (14) xanthane sesquiterpenes (9) and hydroxylated fatty acids (20) in both Pulicaria species. The metabolite profile of P. incisa was characterized by the presence of tri- and tetra-methoxylated flavonoids while xanthane sesquiterpenes were the main chemical markers of P. crispa. Additionally, a novel sesquiterpene acid (dihydropulicaric acid) was annotated in both species based on its MS fragments. Antioxidant activity for P. crispa and P. incisa methanol extracts was assessed in vitro based on DPPH and ABTS assays and further in vivo using chlorpromazine intoxicated rat model. Results revealed that P. incisa extract was more effective in inhibiting both DPPH and ABTS free radicals (IC₅₀ 0.36 and 0.52 mg/mL, respectively) than P. crispa (IC₅₀ 0.51 and 0.73 mg/mL). In the animal model, antioxidant activity of P. incisa (20 mg/kg/day) was also slightly higher causing a 55 % reduction in MDA levels and 65 % increase in GSH activity compared to untreated animals. Furthermore, both extracts showed a hepatoprotective effect as revealed by improvement in levels of serum biomarkers of liver functions: total bilirubin, alanine transaminase (ALT) and aspartate transaminase (AST) comparable to silymarin at 25 mg/kg/day. These findings were also supported by the preserved integrity of the hepatic tissues of animals receiving either extracts at a dose of 20 mg/kg b.wt. The present study reveals for the potential antioxidant and hepatoprotective effects for Pulicaria in relation to its bioactive metabolites.

Antioxidant properties of the Lebanese plant Iris x germanica L. crude extracts and antagonism of chlorpromazine toxicity on Saccharomyces cerevisiae

Iris x germanica L., which belongs to the Iridaceae family, has been reported in the literature for its antioxidant properties in acellular chemical-antioxidant assays. Chlorpromazine (CPZ) is an antipsychotic drug known to cause adverse reactions in humans. Oxidative stress is among the main mechanisms by which CPZ exerts its toxicity in animal cell models as well as in the yeast Saccharomyces cerevisiae. In this study we investigated the protective effects of I. germanica L. crude extracts against CPZ toxicity. We demonstrated that methanolic extracts from rhizome (R-M), leaf (L-M) and flower (Fl-M) had potent antioxidant activity by scavenging the free radical DPPH, with half-maximal effective concentrations (EC₅₀) 193, 107, and 174 µg/mL, respectively. R-M, L-M and Fl-M at doses up to 1000 µg/mL, didn't affect yeast cell growth. In addition, we demonstrated for the first time that L-M at 1000 µg/mL and R-M at all tested doses counteracted CPZ toxicity, probably by promoting yeast cell antioxidant agents. The R-M capacity to counteract CPZ toxicity was lost in the yeast strain mutant in catalase-encoding gene (Cta1), while strains mutant in Sod2, Skn7 and Rap1 showed mild or full R-M-induced protective effect against CPZ toxicity. Our results demonstrated that I. germanica L. R-M extract counteracted CPZ toxicity in the yeast cell model. Further studies are planned to isolate the involved bioactive compounds and identify the involved genes and the antioxidant agents.

Neuroprotective Role of Agmatine in Neurological Diseases

Background:

Neurological diseases have always been one of the leading cause of mobility and mortality world-widely. However, it is still lacking efficient agents. Agmatine, an endogenous polyamine, exerts its diverse biological characteristics and therapeutic potential in varied aspects.

Methods:

This review would focus on the neuroprotective actions of agmatine and its potential mechanisms in the setting of neurological diseases.

Results:

Numerous studies had demonstrated the neuroprotective effect of agmatine in varied types of neurological diseases, including acute attack (stroke and trauma brain injury) and chronic neurodegenerative diseases (Parkinson's disease, Alz-heimer’s disease). The potential mechanism of agmatine induced neuroprotection includes anti-oxidation, anti-apoptosis, anti-inflammation, brain blood barrier (BBB) protection and brain edema prevention.

Conclusions:

The safety and low incidence of adverse effects indicate the vast potential therapeutic value of agmatine in the treatment of neurological diseases. However, most of the available studies relate to the agmatine are conducted in experi-mental models, more clinical trials are needed before the agmatine could be extensively clinically used

Neuroprotective effect of agmatine (decarboxylated l-arginine) against oxidative stress and neuroinflammation in rotenone model of Parkinson's disease

Parkinson's disease (PD) is the second most common age-related neurodegenerative disease after Alzheimer's disease, characterized by loss of dopaminergic neurons in substantia nigra pars compacta, accompanied by motor and nonmotor symptoms. The neuropathological hallmarks of PD are well reported, but the etiology of the disease is still undefined; several studies assume that oxidative stress, mitochondrial defects, and neuroinflammation play vital roles in the progress of the disease. The current study was established to investigate the neuroprotective effect of agmatine on a rotenone (ROT)-induced experimental model of PD. Adult male Sprague Dawley rats were subcutaneously injected with ROT at a dose of 2 mg/kg body weight for 35 days. Agmatine was injected intraperitoneally at 50 and 100 mg/kg body weight, 1 h prior to ROT administration. ROT-treated rats that received agmatine showed better performance on beam walking and an elevated number of rears within the cylinder test. In addition, agmatine reduced midbrain malondialdehyde as an indication of lipid peroxidation, pro-inflammatory cytokines including tumor necrosis factor alpha and interleukin-1β, and glial fibrillary acidic protein. Moreover, agmatine was responsible for preventing loss of tyrosine hydroxylase-positive neurons. In conclusion, our study showed that agmatine possesses a dose-dependent neuroprotective effect through its antioxidant and anti-inflammatory activities. These findings need further clinical investigations of agmatine as a promising neuroprotective agent for the future treatment of PD.