s-Ethyl cysteine and s-propyl cysteine alleviate beta-amyloid induced cytotoxicity in nerve growth factor differentiated PC12 cells

Identification of tryptophanase from Escherichia coli for the synthesis of S-allyl-l-cysteine and related S-substituted cysteine derivatives

A wide variety of S-substituted cysteine derivatives occur in plant metabolites. For example, S-allyl-l-cysteine (SAC), mainly contained in garlic, gathers huge interest because of its favorable bioactivities for human health. However, conventional methods for preparing SAC suffer from several drawbacks with regard to efficiency and toxicity, which highlights the need for improved processes for SAC synthesis. This study aims to develop a novel bioprocess to produce SAC by microbial enzymes from easily available substrates. We found that Escherichia coli had the ability to synthesize SAC from allyl mercaptan, pyruvic acid, and ammonium sulfate. An enzyme purification through 3-step column chromatography, followed by determination of the N-terminal amino acid sequence revealed that tryptophanase (TnaA) was the enzyme responsible for SAC formation. Although the enzyme catalyzed the reversible reaction for synthesizing and degrading SAC, the degradation proceeded significantly faster than the synthesis. Interestingly, TnaA catalyzed the synthesis of a wide range of S-substituted cysteines with alkyl chains or aromatic rings, some of which are present in Allium and Petiveria plants. Our results showed a novel substrate specificity of TnaA toward various S-substituted cysteine. TnaA is a promising biocatalyst for developing a new process to supply various valuable S-substituted cysteine derivatives for medicinal and health-promoting applications.

Solar Radiation Effects on Dry Matter Accumulations and Transfer in Maize

Solar radiation is the energy source for crop growth, as well as for the processes of accumulation, distribution, and transfer of photosynthetic products that determine maize yield. Therefore, learning the effects of different solar radiation amounts on maize growth is especially important. The present study focused on the quantitative relationships between solar radiation amounts and dry matter accumulations and transfers in maize. Over two continuous years (2017 and 2018) of field experiments, maize hybrids XY335 and ZD958 were grown at densities of 4.5 × 104 (D1), 7.5 × 104 (D2), 9 × 104 (D3), 10.5 × 104 (D4), and 12 × 104 (D5) plants/ha at Qitai Farm (89°34'E, 44°12'N), Xinjiang, China. Shading levels were 15% (S1), 30% (S2), and 50% (S3) of natural light and no shading (CK). The results showed that the yields of the commonly planted cultivars XY335 and ZD958 at S1, S2, and S3 (increasing shade treatments) were 7.3, 21.2, and 57.6% and 11.7, 31.0, and 61.8% lower than the control yields, respectively. Also, vegetative organ dry matter translocation (DMT) and its contribution to grain increased as shading levels increased under different densities. The dry matter assimilation amount after silking (AADMAS) increased as solar radiation and planting density increased. When solar radiation was <580.9 and 663.6 MJ/m2, for XY335 and ZD958, respectively, the increase in the AADMAS was primarily related to solar radiation amounts; and when solar radiation was higher than those amounts for those hybrids, an increase in the AADMAS was primarily related to planting density. Photosynthate accumulation is a key determinant of maize yield, and the contributions of the vegetative organs to the grain did not compensate for the reduced yield caused by insufficient light. Between the two cultivars, XY335 showed a better resistance to weak light than ZD958 did. To help guarantee a high maize yield under weak light conditions, it is imperative to select cultivars that have great stay-green and photosynthetic efficiency characteristics.

Beneficial consequences of probiotic on mitochondrial hippocampus in Alzheimer's disease

BACKGROUND

Alzheimer's (AD) is one of the most common neurodegenerative diseases, causing dementia and brain cells death.

OBJECTIVES

This study aimed to assess the ameliorating effect of Acidophilus probiotic against AD induced in rats by d-galactose and AlCl₃ injection via evaluating mitochondrial parameter changes in hippocampus.

METHODS

This study was carried out on rats were classified into five groups; G1 (control group), G2 (probiotic group), G3 (AD group), G4 (co-treated group) and G5 (post-treated group). By the end of the experiment, some different neurotransmitters, oxidative stress biomarkers, zinc, blood glucose, Na⁺K^-ATPase subunit alpha 1 (ATP1A1), and gene expression of mitochondrial membrane potential (MMP) were measured.

RESULTS

Significant changes in neurotransmitters, antioxidants levels and decreased ATP1A1 activity and gene expression of MMP in the hippocampus in G3 were detected if compared to control. Best improvement in G5 than G4 group was observed. These results were confirmed by histological and immunohistochemical studies in hippocampus.

CONCLUSIONS

Acidophilus probiotic was able to alleviate learning and memory associated injuries in AD by reducing mitochondrial dysfunction induced by d-galactose and AlCl₃. This may be associated with its antioxidant properties.

Enhancing and Complementary Mechanisms of Synergistic Action of Acori Tatarinowii Rhizoma and Codonopsis Radix for Alzheimer's Disease Based on Systems Pharmacology

Materials and Methods

In this study, a systems pharmacology-based strategy was used to elucidate the synergistic mechanism of Acori Tatarinowii Rhizoma and Codonopsis Radix for the treatment of AD. This novel systems pharmacology model consisted of component information, pharmacokinetic analysis, and pharmacological data. Additionally, the related pathways were compressed using the Kyoto Encyclopedia of Genes and Genomes (KEGG) database, and the organ distributions were determined in the BioGPS bank.

Results

Sixty-eight active ingredients with suitable pharmacokinetic profiles and biological activities were selected through ADME screening in silico. Based on 62 AD-related targets, such as APP, CHRM1, and PTGS1, systematic analysis showed that these two herbs were mainly involved in the PI3K-Akt signaling pathway, MAPK signaling pathway, neuroactive ligand-receptor interaction, and fluid shear stress and atherosclerosis, indicating that they had a synergistic effect on AD. However, ATR acted on the KDR gene, while CR acted on IGF1R, MET, IL1B, and CHUK, showing that they also had complementary effects on AD. The ingredient contribution score involved 29 ingredients contributing 90.14% of the total contribution score of this formula for AD treatment, which emphasized that the effective therapeutic effects of these herbs for AD were derived from both ATR and CR, not a single herb. Organ distribution showed that the targets of the active ingredients were mainly located in the whole blood, the brain, and the muscle, which are associated with AD.

Conclusions

In sum, our findings suggest that the systems pharmacology methods successfully revealed the synergistic and complementary mechanisms of ATR and CR for the treatment of AD.

Effects of Lignans from Schisandra chinensis Rattan Stems against Aβ1-42-Induced Memory Impairment in Rats and Neurotoxicity in Primary Neuronal Cells

Oxidative stress, which is caused by Amyloid-β deposition in brain, plays an important role in Alzheimer’s disease. In this study, we found that lignans from Schisandra chinensis rattan stems (rsSCH-L) could reduce the escape latency and the distance travelled by the Aβ_1–42 injected rats while the crossing platform time was enhanced in the Morris water maze test. Further research demonstrated that lignans from rsSCH-L attenuated Aβ_1-42-induced neuronal cell injury by increasing the content of SOD and GSH-Px and decreasing the levels of LDH, ROS, and MDA. Moreover, rsSCH-L also inhibited the apoptosis of primary neuronal cells. The mechanisms of the apoptosis were related with the downregulation of caspase-3, caspase-8, Bax, and upregulation of Bcl-2. Taken together, the results show that rsSCH-L can improve cognitive ability in vivo. Meanwhile rsSCH-L exhibit a neuroprotective environment against oxidative stress and apoptosis in vitro. Therefore, rsSCH-L may be a potential therapeutic agent for this neurodegenerative disease.

Role of Lactobacillus plantarum MTCC1325 in membrane-bound transport ATPases system in Alzheimer's disease-induced rat brain

Introduction: Alzheimer’s disease (AD) is a neurodegenerative disorder, clinically characterized by memory dysfunction and progressive loss of cognition. No curative therapeutic or drug is available for the complete cure of this disease. The present study was aimed to evaluate the efficacy of Lactobacillus plantarum MTCC1325 in ATPases activity in the selected brain regions of rats induced with Alzheimer’s.

Methods: For the study, 48 healthy Wistar rats were divided into four groups: group I as control group, group II as AD model (AD induced by intraperitoneal injection of D-Galactose, 120 mg/kg body weight for 6 weeks), group III as normal control rats which were orally administered only with L. plantarum MTCC1325 for 60 days, and group IV where the AD-induced rats simultaneously received oral treatment of L. plantarum MTCC1325 (10ml/kg body weight, 12×10⁸ CFU/mL) for 60 days. The well known membrane bound transport enzymes including Na⁺, K⁺-ATPases, Ca²⁺-ATPases, and Mg²⁺-ATPases were assayed in the selected brain regions of hippocampus and cerebral cortex in all four groups of rats at selected time intervals.

Results: Chronic injection of D-Galactose caused lipid peroxidation, oxidative stress, and mitochondrial dysfunction leading to the damage of neurons in the brain, finally bringing a significant decrease (-20%) in the brain total membrane bound ATPases over the controls. Contrary to this, treatment of AD-induced rats with L. plantarum MTCC1325 reverted all the constituents of ATPase enzymes to near normal levels within 30 days.

Conclusion: Lactobacillus plantarum MTCC1325 exerted a beneficial action on the entire ATPases system in AD-induced rat brain by delaying neurodegeneration.

The Pharmacological Effects of S-Propargyl-Cysteine, a Novel Endogenous H2S-Producing Compound

S-propargyl-cysteine (SPRC), also named as ZYZ-802, is a structural analog of S-allylcysteine (SAC), the most abundant constituent of aged garlic extract. SPRC becomes a derivative of the amino acid cysteine, which contains sulfur atom, by changing allyl group in SAC to propargyl group in SPRC. Another analog of SPRC and SAC is S-propyl cysteine (SPC), which has propyl group instead in its cysteine structure. Drug formulation of SPRC has been investigated in the mixture of extenders, such as lactose, microcrystalline cellulose, and cross-linked povidone, showing good fluidity and scale-up production possibility. Controlled release formulation of SPRC (CR-SPRC) and leonurine-SPRC were invented and shown the decent pharmacological effects in heart failure and hypoxia injury, respectively. The pharmacological effects of SPRC have been shown that cardioprotection and proangiogenesis in several ischemic heart models, neuroprotection in Alzheimer's disease, proapoptosis in gastric cancer and anti-inflammation in acute pancreatitis. Moreover, CR-SPRC reduced infarct size and recovered partial cardiac function in heart failure rat model. Leonurine-SPRC protected hypoxic neonatal rat ventricular myocytes in much lower dose. Interestingly, since the propagyl group in SPRC has the stronger chemical bond in the cysteine structure than allyl group in SAC and propyl group in SPC, SPRC showed more extensive cardioprotection in ischemic rat hearts model compared to SAC and SPC. The mechanisms of pharmacological effects of SPRC have been unveiled that SPRC reduced Ca2+ accumulation, activated antioxidants, inhibited STAT3, decreased inflammatory cytokines, and elevated p53 and Bax. More pharmacological effects and mechanisms of SPRC will be discovered in atherosclerosis, hypertension, and other diseases.

p-Coumaric acid and ursolic acid from Corni fructus attenuated β-amyloid(25-35)-induced toxicity through regulation of the NF-κB signaling pathway in PC12 cells

Neuroinflammatory responses induced by amyloid-beta peptide (Aβ) are important causes in the pathogenesis of Alzheimer's disease (AD). Blockade of Aβ has emerged as a possible therapeutic approach to control the onset of AD. This study investigated the neuroprotective effects and molecular mechanisms of p-coumaric acid (p-CA) and ursolic acid (UA) from Corni fructus against Aβ(25-35)-induced toxicity in PC12 cells. p-CA and UA significantly inhibited the expression of iNOS and COX-2 in Aβ(25-35)-injured PC12 cells. Blockade of nuclear translocation of the p65 subunit of nuclear factor κB (NF-κB) and phosphorylation of IκB-α was also observed after p-CA and UA treatment. For the upstream kinases, UA exclusively reduced ERK1/2, p-38, and JNK phosphorylation, but p-CA suppressed ERK1/2 and JNK phosphorylation. Both compounds comprehensively inhibited NF-κB activity, but possibly with different upstream pathways. The results provide new insight into the pharmacological modes of p-CA and UA and their potential therapeutic application to AD.

ETAS, an Enzyme-treated Asparagus Extract, Attenuates Amyloid β-Induced Cellular Disorder in PC 12 Cells

One of the pathological characterizations of Alzheimer's disease (AD) is the deposition of amyloid beta peptide (Aβ) in cerebral cortical cells. The deposition of Aβ in neuronal cells leads to an increase in the production of free radicals that are typified by reactive oxygen species (ROS), thereby inducing cell death. A growing body of evidence now suggests that several plant-derived food ingredients are capable of scavenging ROS in mammalian cells. The purpose of the present study was to investigate whether enzyme-treated asparagus extract (ETAS), which is rich in antioxidants, is one of these ingredients. The pre-incubation of differentiated PC 12 cells with ETAS significantly recovered Aβ-induced reduction of cell viability, which was accompanied by reduced levels of ROS. These results suggest that ETAS may be one of the functional food ingredients with anti-oxidative capacity to help prevent AD.

s-Methyl cysteine enhanced survival of nerve growth factor differentiated PC12 cells under hypoxic conditions

A nerve growth factor-differentiated PC12 cell line was used to investigate the protective effects ofs-methyl cysteine (SMC) at 1, 2, 4, and 8 μM under oxygen–glucose deprivation (OGD) conditions.

Na⁺-K⁺-ATPase, a potent neuroprotective modulator against Alzheimer disease

Alzheimer disease (AD) is a neurodegenerative disorder clinically characterized by progressive cognitive and memory dysfunction, which is the most common form of dementia. Although the pathogenesis of neuronal injury in AD is not clear, recent evidences suggest that Na⁺-K⁺-ATPase plays an important role in AD, and may be a potent neuroprotective modulator against AD. This review aims to provide readers with an in-depth understanding of Na⁺-K⁺-ATPase in AD through these modulations of some factors that are as follows, which leads to the change of learning and memory in the process of AD. 1. The deficiency in Na⁺, K⁺-ATPase α1, α2 and α3 isoform genes induced learning and memory deficits, and α isoform was evidently changed in AD, revealing that Na⁺, K⁺-ATPase α isoform genes may play an important role in AD. 2. Some factors, such as β-amyloid, cholinergic and oxidative stress, can modulate learning and memory in AD through the mondulation of Na⁺-K⁺-ATPase activity. 3. Some substances, such as Zn, s-Ethyl cysteine, s-propyl cysteine, citicoline, rivastigmine, Vit E, memantine, tea polyphenol, curcumin, caffeine, Alpinia galanga (L.) fractions, and Bacopa monnieri could play a role in improving memory performance and exert protective effects against AD by increasing expression or activity of Na⁺, K⁺-ATPase.

s-Allyl cysteine, s-ethyl cysteine, and s-propyl cysteine alleviate β-amyloid, glycative, and oxidative injury in brain of mice treated by D-galactose

The neuroprotective effects of s-allyl cysteine, s-ethyl cysteine, and s-propyl cysteine in D-galactose (DG)-treated mice were examined. DG treatment increased the formation of Aβ(1-40) and Aβ(1-42), enhanced mRNA expression of β-amyloid precursor protein (APP) and β-site APP cleavage enzyme 1 (BACE1), and reduced neprilysin expression in brain (P < 0.05); however, the intake of three test compounds significantly decreased the production of Aβ(1-40) and Aβ(1-42) and suppressed the expression of APP and BACE1 (P < 0.05). DG treatments declined brain protein kinase C (PKC) activity and mRNA expression (P < 0.05). Intake of test compounds significantly retained PKC activity, and the expression of PKC-α and PKC-γ (P < 0.05). DG treatments elevated brain activity and mRNA expression of aldose reductase (AR) and sorbitol dehydrogenase as well as increased brain levels of carboxymethyllysine (CML), pentosidine, sorbitol, and fructose (P < 0.05). Test compounds significantly lowered AR activity, AR expression, and CML and pentosidine levels (P < 0.05). DG treatments also significantly increased the formation of reactive oxygen species (ROS) and protein carbonyl and decreased the activity of glutathione peroxidase (GPX), superoxide dismutase (SOD), and catalase (P < 0.05); however, the intake of test compounds in DG-treated mice significantly decreased ROS and protein carbonyl levels and restored brain GPX, SOD, and catalase activities (P < 0.05). These findings support that these compounds via their anti-Aβ, antiglycative, and antioxidative effects were potent agents against the progression of neurodegenerative disorders such as Alzheimer's disease.

Na(+)/K(+)-ATPase inhibition upregulates NMDA-evoked currents in rat hippocampal CA1 pyramidal neurons

Na(+)/K(+)-ATPase and N-methyl-D-aspartate (NMDA) receptor in hippocampus play very important roles in the regulation of learning and memory. Here, we showed that dihydroouabain (DHO, 10(-5)-10(-3) M), a Na(+)/K(+)-ATPase inhibitor, significantly potentiated NMDA current in rat hippocampal CA1 pyramidal neurons, which was blocked by PP2 (the selective Src tyrosine kinase inhibitor) and PD-98059 [the selective inhibitor of the mitogen-activated protein kinases (MAPK) cascade]. These findings reported here uncover that Src mediates the cross-talk between Na(+)/K(+)-ATPase and NMDA receptor to transduce the signals from Na(+)/K(+)-ATPase to the MAPK cascade and provide new insights into therapeutic target for deeper understanding of the nature of cognitive disorder.