Ahmed, H. H., R. M. Essam, M. F. El-Yamany, K. A. Ahmed, and A. E. El-Sahar, "Unleashing lactoferrin's antidepressant potential through the PI3K/Akt/mTOR pathway in chronic restraint stress rats.", Food & function, 2023. Abstract

Depression is a widespread neuropsychiatric illness whose etiology is yet mysterious. Lactoferrin (LF), an iron-binding glycoprotein, is reported to promote neuroprotection through its role in the modulation of oxidative stress and inflammation. The objective of the present research was to evaluate the efficacy of LF against chronic restraint stress (CRS)-induced depressive behavior in rats. Depression was evidenced by a reduced grooming time in the splash test and an increased immobility time in the tail suspension test (TST) and forced swimming test (FST). This effect was also accompanied by reduced GSH and serotonin levels and elevated lipid peroxidation and corticosterone levels in the hippocampus. Additionally, an exaggerated hippocampal inflammatory response was also shown by a rise in NF-κB (p65) and TNF-α levels and a reduced IL-10 level. Moreover, CRS substantially reduced the BDNF content as well as the protein levels of PI3K, Akt, and mTOR while boosting the GSK3β content. Interestingly, LF therapy significantly improved CRS-induced behavioral and biochemical aberrations, an effect which was suppressed upon pretreatment with LY294002 (PI3K inhibitor). This suggests that the antidepressant potential of LF may be mediated through the modulation of the PI3K/Akt/mTOR signaling pathway. Furthermore, LF succeeded in restoring 5-HT and corticosterone levels, diminishing oxidative stress and ameliorating the inflammatory cascades. Therefore, and for the first time, LF might serve as a promising antidepressant drug through targeting the PI3K/Akt/mTOR pathway.

Essam, R. M., M. A. Saadawy, M. Gamal, R. M. Abdelsalam, and A. E. El-Sahar, "Lactoferrin averts neurological and behavioral impairments of thioacetamide-induced hepatic encephalopathy in rats via modulating HGMB1/TLR-4/MyD88/Nrf2 pathway.", Neuropharmacology, vol. 236, pp. 109575, 2023. Abstract

Hepatic encephalopathy (HE) is a life-threatening disease caused by acute or chronic liver failure manifested by aberrant CNS changes. In the present study, we aimed to explore the neuroprotective effect of lactoferrin (LF) against thioacetamide (TAA)-induced HE in rats. Animals were divided into four groups, control, LF control, TAA-induced HE, and LF treatment, where LF was administered (300 mg/kg, p.o.) for 15 days in groups 2 and 4 meanwhile, TAA (200 mg/kg, i.p.) was given as two injections on days 13 and 15 for the 3rd and 4th groups. Pretreatment with LF significantly improved liver function observed as a marked decline in serum AST, ALT, and ammonia, together with lowering brain ammonia and enhancing motor coordination as well as cognitive performance. Restoration of brain oxidative status was also noted in the LF-treated group, where lipid peroxidation was hampered, and antioxidant parameters, Nrf2, HO-1, and GSH, were increased. Additionally, LF downregulated HMGB1, TLR-4, MyD88, and NF-κB signaling pathways, together with reducing inflammatory cytokine, TNF-α, and enhancing brain BDNF levels. Moreover, the histopathology of brain and liver tissues revealed that LF alleviated TAA-induced liver and brain deficits. In conclusion, the promising results of LF in attenuating HMGB1/TLR-4/MyD88 signaling highlight its neuroprotective role against HE associated with acute liver injury via ameliorating neuroinflammation, oxidative stress, and stimulating neurogenesis.

Eitah, H. E., H. N. Attia, A. A. F. Soliman, A. A. Gamal El Din, K. Mahmoud, R. H. Sayed, Y. A. Maklad, and A. E. El-Sahar, "Vitamin D ameliorates diethylnitrosamine-induced liver preneoplasia: A pivotal role of CYP3A4/CYP2E1 via DPP-4 enzyme inhibition.", Toxicology and applied pharmacology, vol. 458, pp. 116324, 2023. Abstract

Growing evidence has indicated that vitamin D (Vit D) regulates cell proliferation and differentiation in cancer cells. Accordingly, the present study was conducted to investigate the possible beneficial effects of Vit D on diethylnitrosamine (DEN)-induced liver preneoplasia. The effect of Vit D on HepG2 cells was investigated using MTT assay. Additionally, liver preneoplasia was induced in Swiss male albino mice by giving overnight fasted animals 5 consecutive doses of DEN (75 mg/kg/week). Oral treatment with Vit D (200 IU/kg/day) was initiated either 2 weeks before DEN (first protocol) or 1 week after the first dose of DEN injection (second protocol). At the end of the experiment, tissue levels of GGT, DPP-4, TNF-α, IL-6, CYP2E1, and CYP3A4 were also estimated. Moreover, the histopathological study of liver tissue and immunohistochemical detection of GST-P, PCNA, and NF-κB were performed. Vit D exerted a significant cytotoxic effect on HepG2 cells via significantly increasing BAX, p53, and BAX/Bcl2 ratio, and significantly decreasing Bcl2 mRNA expression. In both in vivo protocols, Vit D was capable of normalizing relative liver weight, PCNA, altered hepatocellular foci, and ductular proliferation. Moreover, Vit D significantly reduced the DEN-induced elevation of AST, ALT, ALP, GGT, DDP-4, TNF-α, IL-6, CYP2E1, liver DNA damage, GST-P, NF-κB, nuclear hyperchromasia/pleomorphism, cholestasis, and inflammatory cell aggregates, but significantly increased CYP3A4 content. In conculsion, current results reflect the potential impact of Vit D in the management of early stages of liver cancer.

Mohammed, R. A., R. H. Sayed, A. E. El-Sahar, M. A. Khattab, and M. A. Saad, "Insights into the role of pERK1/2 signaling in post-cerebral ischemia reperfusion sexual dysfunction in rats.", European journal of pharmacology, vol. 933, pp. 175258, 2022. Abstract

The purpose of the present study was to investigate the effects of ERK1/2 inhibition on both the amygdala and hippocampal structures, and to investigate its role in regulating memory for sexual information. This study utilized a cerebral ischemia reperfusion (IR) model to produce a stressful brain condition that highlights the possible involvement of a hippocampal GC/pERK1/2/BDNF pathway in the resulting sexual consequences of this ailment. Male Wistar rats were divided into four groups: (1) sham; (2) IR: subjected to 45 min of ischemia followed by 48 h of reperfusion; (3) PD98059: received PD98059 at 0.3 mg/kg, i.p.; (4) IR + PD98059. This study provides new evidence for cerebral IR-induced amygdala injury and the sexual impairments that are associated with motor and cognitive deficits in rats. These findings were correlated with histopathological changes that are defined by extensive neuronal loss in both the hippocampus and the amygdala. The current study postulated that the ERK inhibitor PD98059 could reverse IR-induced injury in the amygdala as well as reversing IR-induced sexual impairments. This hypothesis is supported by the ability of PD98059 to: (1) restore luteinizing hormone and testosterone levels; (2) increase sexual arousal and copulatory performance (as evidenced by modulating mount, intromission, ejaculation latencies, and post-ejaculatory intervals); (3) improve the histological profile in the amygdala that is associated with reduced glutamate levels, c-Fos expression, and elevated gamma aminobutyric acid levels. In conclusion, the present findings introduce pERK1/2 inhibition as a possible strategy for enhancing sexual activity in survivors of IR.

El-Sahar, A. E., N. Bekhit, N. M. Eissa, R. M. Abdelsalam, and R. M. Essam, "Targeting HMGB1/PI3K/Akt and NF-κB/Nrf-2 signaling pathways by vildagliptin mitigates testosterone-induced benign prostate hyperplasia in rats.", Life sciences, vol. 322, pp. 121645, 2023. Abstract

Benign prostatic hyperplasia (BPH) is a prevalent illness in older adults. It is well-recognized that testosterone is essential in the onset of BPH. Vildagliptin (Vilda), a dipeptidyl peptidase-IV inhibitor, has been shown to have anti-inflammatory and antioxidant effects. In this study, we studied the effects of vildagliptin on testosterone-induced BPH in rats and its underlying mechanisms. Forty male Wistar rats were allocated into four groups (n = 10): CTRL, Vilda, BPH, and BPH + Vilda groups. Our results revealed that vildagliptin treatment considerably lessened the prostate weight, prostate index, serum levels of prostate-specific antigen, 5α-reductase activity, and DHT levels compared to the testosterone group. Furthermore, vildagliptin treatment inhibited the expression of HMGB1, PI3K/Akt/NF-κB, and TNF-α signaling pathways in the prostate tissue of diseased rats. Additionally, vildagliptin treatment increased the expression of Nrf-2 and HO-1, reduced GSH levels, and lowered MDA levels. Besides, vildagliptin noticeably scaled up the level of cleaved caspase-3 enzyme and, conversely, the protein expression of proliferating cell nuclear antigen (PCNA). Correspondingly, vildagliptin counteracts testosterone-induced histological irregularities in rats' prostates. These findings suggest that vildagliptin may be a potential prophylactic approach to avoid BPH.

El-Sahar, A. E., N. Bekhit, N. M. Eissa, R. M. Abdelsalam, and R. M. Essam, "Targeting HMGB1/PI3K/Akt and NF-κB/Nrf-2 signaling pathways by vildagliptin mitigates testosterone-induced benign prostate hyperplasia in rats.", Life sciences, vol. 322, pp. 121645, 2023. Abstract

Benign prostatic hyperplasia (BPH) is a prevalent illness in older adults. It is well-recognized that testosterone is essential in the onset of BPH. Vildagliptin (Vilda), a dipeptidyl peptidase-IV inhibitor, has been shown to have anti-inflammatory and antioxidant effects. In this study, we studied the effects of vildagliptin on testosterone-induced BPH in rats and its underlying mechanisms. Forty male Wistar rats were allocated into four groups (n = 10): CTRL, Vilda, BPH, and BPH + Vilda groups. Our results revealed that vildagliptin treatment considerably lessened the prostate weight, prostate index, serum levels of prostate-specific antigen, 5α-reductase activity, and DHT levels compared to the testosterone group. Furthermore, vildagliptin treatment inhibited the expression of HMGB1, PI3K/Akt/NF-κB, and TNF-α signaling pathways in the prostate tissue of diseased rats. Additionally, vildagliptin treatment increased the expression of Nrf-2 and HO-1, reduced GSH levels, and lowered MDA levels. Besides, vildagliptin noticeably scaled up the level of cleaved caspase-3 enzyme and, conversely, the protein expression of proliferating cell nuclear antigen (PCNA). Correspondingly, vildagliptin counteracts testosterone-induced histological irregularities in rats' prostates. These findings suggest that vildagliptin may be a potential prophylactic approach to avoid BPH.

Mansour, R. M., N. S. El Sayed, M. A. E. Ahmed, and A. E. El-Sahar, "Addressing Peroxisome Proliferator-Activated Receptor-gamma in 3-Nitropropionic Acid-Induced Striatal Neurotoxicity in Rats.", Molecular neurobiology, vol. 59, issue 7, pp. 4368-4383, 2022. Abstract

Telmisartan (TEL) is an angiotensin II type 1 receptor blocker and a partial activator of peroxisome proliferator-activated receptor-gamma (PPARγ), which regulates inflammatory and apoptotic pathways. Increasing evidence has demonstrated the PPARγ agonistic property of TEL in several brain disorders. This study aims to explore the neuroprotective impact of TEL in 3-nitropropionic acid (3-NP)-induced neurotoxicity in rats. The PPARγ effect of TEL was affirmed by using the PPARγ agonist pioglitazone (PIO), and the antagonist GW9662. 3-NP led to a significant reduction in body weight alongside motor and cognitive functioning. The striata of the 3-NP-treated rats showed energy-deficit, microglia-mediated inflammatory reactions, apoptotic damage as well as histopathological lesions. PIO and TEL improved motor and cognitive perturbations induced by 3-NP, as confirmed by striatal histopathological examination, energy restoration, and neuronal preservation. Both drugs improved mitochondrial biogenesis evidenced by elevated mRNA expression of PPARγ, PGC-1α, and TFAM, alongside increased striatal ATP and SDH. The mitochondrial effect of TEL was beyond PPARγ activation. As well, their anti-inflammatory effect was attributed to suppression of microglial activation, and protein expression of pS536 p65 NF-κB with marked attenuation of striatal inflammatory mediator's release. Anti-inflammatory cytokine IL-10 expression was concurrently increased. TEL effectively participated in neuronal survival as it promoted phosphorylation of Akt/GSK-3β, further increased Bcl-2 expression, and inhibited cleavage of caspase-3. Interestingly, co-treatment with GW9662 partially revoked the beneficial effects of TEL. These findings recommend that TEL improves motor and cognitive performance, while reducing neuronal inflammation and apoptosis in 3-NP-induced neurotoxicity via a PPARγ-dependent mechanism.

El-Shamarka, M. E. - S., A. E. El-Sahar, M. A. Saad, N. A. G. L. A. A. ASSAF, and R. H. Sayed, "Inosine attenuates 3-nitropropionic acid-induced Huntington's disease-like symptoms in rats via the activation of the A2AR/BDNF/TrKB/ERK/CREB signaling pathway.", Life sciences, vol. 300, pp. 120569, 2022. Abstract

Huntington's disease (HD) is an autosomal dominant inherited neurodegenerative disease characterized by involuntary bizarre movements, psychiatric symptoms, dementia, and early death. Several studies suggested neuroprotective activities of inosine; however its role in HD is yet to be elucidated. The current study aimed to demonstrate the neuroprotective effect of inosine in 3-nitropropionic acid (3-NP)-induced neurotoxicity in rats while investigating possible underlying mechanisms. Rats were randomly divided into five groups; group 1 received i.p. injections of 1% DMSO, whereas groups 2, 3, 4, and 5 received 3-NP (10 mg/kg, i.p.) for 14 days, concomitantly with inosine (200 mg/kg., i.p.) in groups 3, 4, and 5, SCH58261, a selective adenosine 2A receptor (A2AR) antagonist, (0.05 mg/kg, i.p.) in group 4, and PD98059, an extracellular signal-regulated kinase (ERK) inhibitor, (0.3 mg/kg, i.p.) in group 5. Treatment with inosine mitigated 3-NP-induced motor abnormalities and body weight loss. Moreover, inosine boosted the striatal brain-derived neurotrophic factor (BDNF) level, p-tropomyosin receptor kinase B (TrKB), p-ERK, and p-cAMP response element-binding protein (CREB) expression, which subsequently suppressed oxidative stress biomarkers (malondialdehyde and nitric oxide) and pro-inflammatory cytokines (tumor necrosis factor alpha and interleukin-1β) and replenished the glutathione content. Similarly, histopathological analyses revealed decreased striatal injury score, the expression of the glial fibrillary acidic protein, and neuronal loss after inosine treatment. These effects were attenuated by the pre-administration of SCH58261 or PD98059. In conclusion, inosine attenuated 3-NP-induced HD-like symptoms in rats, at least in part, via the activation of the A2AR/BDNF/TrKB/ERK/CREB signaling pathway.

El-Safty, H., A. Ismail, R. M. Abdelsalam, A. E. El-Sahar, and M. A. Saad, "Dapagliflozin diminishes memory and cognition impairment in Streptozotocin induced diabetes through its effect on Wnt/β-Catenin and CREB pathway.", Brain research bulletin, vol. 181, pp. 109-120, 2022. Abstract

Diabetic neuropathy is a chronic condition that affects a significant number of individuals with diabetes. Streptozotocin injection intraperitoneally to rodents produces pancreatic islet β-cell destruction causing hyperglycemia, which affect the brain leading to memory and cognition impairment. Dapagliflozin may be able to reverse beta-cell injury and alleviate this impairment. This effect may be via neuroprotective effect or possible involvement of the antioxidant, and anti-apoptotic properties. Forty rats were divided into four groups as follows: The normal control group, STZ-induced diabetes group, STZ-induced diabetic rats followed by treatment with oral dapagliflozin group and normal rats treated with oral dapagliflozin. Behavioral tests (Object location memory task and Morris water maze) were performed. Serum biomarkers (blood glucose and insulin) were measured and then the homeostatic model assessment for insulin resistance (HOMA-IR) was calculated. In the hippocampus the followings were determined; calmodulin, ca-calmodulin kinase Ⅳ (CaMKIV), protein kinase A (PKA) and cAMP-responsive element-binding protein to determine the transcription factor CREB and its signaling pathway also Wnt signaling pathway and related parameters (WnT, B-catenin, lymphoid enhancer binding factor LEF, glycogen synthase kinase 3β). Moreover, nuclear receptor-related protein-1, acetylcholine and its hydrolyzing enzyme acetylcholine esterase, oxidative stress parameter malondialdehyde (MDA) and apoptotic parameter caspase-3 were determined. STZ was able to cause destruction to pancreatic β-cells which was reflected on glucose levels causing diabetes. Diabetic neuropathy was clear in the rats performing the behavioral tests. Memory and cognition parameters in the hippocampus were negatively affected. Oxidative stress and apoptotic parameter were elevated while the electrical activity was declined. Dapagliflozin was able to reverse the previously mentioned parameters and behavior. Thus, to say dapagliflozin significantly showed neuroprotective action along with antioxidant, and anti-apoptotic properties.

El-Saiy, K. A., R. H. Sayed, A. E. El-Sahar, and E. S. R. A. A. A. KANDIL, "Modulation of histone deacetylase, the ubiquitin proteasome system, and autophagy underlies the neuroprotective effects of venlafaxine in a rotenone-induced Parkinson's disease model in rats.", Chemico-biological interactions, vol. 354, pp. 109841, 2022. Abstract

Parkinson's disease (PD) is a neurodegenerative disease characterized by motor and non-motor symptoms. Impairment of the ubiquitin proteasome system (UPS) and autophagy has been suggested to contribute to α-synuclein accumulation, which is identified as the pathological hallmark of PD. Recently, alteration in histone-3 acetylation has also been found to be correlated to PD. Interestingly, the histone deacetylase 6 (HDAC6) enzyme, which regulates the acetylation of histone-3, was shown to be involved in autophagy. Venlafaxine is an antidepressant that was proposed to inhibit HDAC expression in depressive rats' hippocampi. In this study, we aimed to examine the ability of venlafaxine to inhibit striatal HDAC6 and to enhance α-synuclein clearance through the activation of the UPS and autophagy, in addition to treating depression, which is the most debilitating non-motor symptom, in a rotenone model of PD. Venlafaxine administration was noted to decrease α-synuclein accumulation and preserve dopaminergic neurons along with restoration of striatal dopamine levels and motor recovery. Its administration augmented the UPS and autophagic markers (beclin-1, p62, and LC3) with consequent modulation of apoptotic indicators (Bax/Bcl-2 ratio, cytochrome c, and caspase-3). Additionally, venlafaxine inhibited HDAC6 with further enhancement of autophagy and restoration of histone-3 acetylation with subsequent increases in survival gene expressions (Bcl-2 and brain-derived neurotrophic factor). Chloroquine (autophagy inhibitor) was used to indicate the proposed pathway. Moreover, venlafaxine hampered depressive symptoms and improved hippocampal noradrenaline and serotonin levels. Collectively, venlafaxine is suggested to display neuroprotective effects with improvement of motor and non-motor PD symptoms.