Attenuating effect of Prosopis cineraria against paraquat-induced toxicity in prepubertal mice, Mus musculus

Pharmacological evaluations of amide carboxylates as potential anti-Alzheimer agents: anti-radicals, enzyme inhibition, simulation and behavioral studies in animal models

Alzheimer's disease (AD) is a neurological disorder that progresses gradually but irreversibly leading to dementia and is difficult to prevent and treat. There is a considerable time window in which the progression of the disease can be intervened. Scientific advances were required to help the researchers to identify the effective methods for the prevention and treatment of disease. This research was designed to investigate potential mediators for the remedy of AD, five new carboxylate amide zinc complexes (AAZ9-AAZ13) were synthesized and characterized by spectroscopic and physicochemical techniques. The biological evaluation was carried out based on the cholinesterase inhibitory mechanism. The preparation methodology provided the effective synthesis of targeted moieties. The in vitro pharmacological activities were evaluated involving AChE/BChE inhibition and antioxidant potential. All synthesized compounds displayed activity against both enzymes in higher or comparable to the standard drug Galantamine, a reversible inhibitor but the results displayed by compound AAZ10 indicated IC50 of 0.0013 µM (AChE) and 0.061 µM (BChE) as high values for dual AChE/BChE inhibition with potent anti-oxidant results. Structure activity relationship (SAR) indicated that the potent activity of compound AAZ10 appeared due to the presence of nitro clusters at the ortho position of an aromatic ring. The potent synthesized compound AAZ10 was also explored for the in-vivo Anti-Alzheimer activity and anti-oxidant activity. Binding approaches of all synthesized compounds were revealed through molecular docking studies concerning binding pockets of enzymes that analyzed the best posture interaction with amino acid (AA) residues providing an appreciable understanding of enzyme inhibitory mechanisms. Results indicate that synthesized zinc (II) amide carboxylates can behave as an effective remedy in the treatment of Alzheimer's disease.Communicated by Ramaswamy H. Sarma.

Neuroprotective potentials of Lead phytochemicals against Alzheimer's disease with focus on oxidative stress-mediated signaling pathways: Pharmacokinetic challenges, target specificity, clinical trials and future perspectives

BACKGROUND

Alzheimer's diseases (AD) and dementia are among the highly prevalent neurological disorders characterized by deposition of beta amyloid (Aβ) plaques, dense deposits of highly phosphorylated tau proteins, insufficiency of acetylcholine (ACh) and imbalance in glutamatergic system. Patients typically experience cognitive, behavioral alterations and are unable to perform their routine activities. Evidence also suggests that inflammatory processes including excessive microglia activation, high expression of inflammatory cytokines and release of free radicals. Thus, targeting inflammatory pathways beside other targets might be the key factors to control- disease symptoms and progression.

PURPOSE

This review is aimed to highlight the mechanisms and pathways involved in the neuroprotective potentials of lead phytochemicals. Further to provide updates regarding challenges associated with their use and their progress into clinical trials as potential lead compounds.

METHODS

Most recent scientific literature on pre-clinical and clinical data published in quality journals especially on the lead phytochemicals including curcumin, catechins, quercetin, resveratrol, genistein and apigenin was collected using SciFinder, PubMed, Google Scholar, Web of Science, JSTOR, EBSCO, Scopus and other related web sources.

RESULTS

Literature review indicated that the drug discovery against AD is insufficient and only few drugs are clinically approved which have limited efficacy. Among the therapeutic options, natural products have got tremendous attraction owing to their molecular diversity, their safety and efficacy. Research suggest that natural products can delay the disease onset, reduce its progression and regenerate the damage via their anti-amyloid, anti-inflammatory and antioxidant potentials. These agents regulate the pathways involved in the release of neurotrophins which are implicated in neuronal survival and function. Highly potential lead phytochemicals including curcumin, catechins, quercetin, resveratrol, genistein and apigenin regulate neuroprotective signaling pathways implicated in neurotrophins-mediated activation of tropomyosin receptor kinase (Trk) and p75 neurotrophins receptor (p75NTR) family receptors.

CONCLUSIONS

Phytochemicals especially phenolic compounds were identified as highly potential molecules which ameliorate oxidative stress induced neurodegeneration, reduce Aβ load and inhibit vital enzymes. Yet their clinical efficacy and bioavailability are the major challenges which need further interventions for more effective therapeutic outcomes.

Ultrasensitive quantitation of Paraquat based on a small molecule-induced dual-cycle amplification strategy

Paraquat (PQ) is a typical biotoxic small molecule. Knowledge of how to directly introduce it into cyclic amplification rather than transform it into a secondary target is lacking in current analytical methods. Considering the urgent need for trace pesticide residue detection and the inherent defects of small molecule analysis, a CRISPR/Cas12a-driven small molecule-induced dual-cycle strategy was developed based on the immune competition method. The key to signal amplification is the mutual activation and acceleration between Cycle 1 triggered by the small molecule and Cycle 2 driven by CRISPR/Cas12a. Impressively, small molecules have been successfully incorporated into the dual-cycle strategy, which achieves a low detection limit (3.1 pg/mL) and a wide linear range (from 10 pg/mL to 50 μg/mL). Moreover, the designed biosensor was successfully employed to evaluate the PQ residual level in real samples and showed effective implementation for the bioanalysis of small molecule targets and pesticide residue-related food safety.

Toxicity profiling of Burgmansia aurea Lagerh. Leaves using acute and sub-acute toxicity studies in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Toxicity studies in appropriate animal models are an integral and very important component of pre-clinical studies in drug development. Brugmansia aurea lagerh. is used for both medicinal and non-medical purposes, including treating skin infections, different types of physical discomfort, inflammation, cough, hallucinations, and evil protection.

AIM OF THE STUDY

This study was designed to detect any hazardous effects of B. aurea on animals and find out its LD₅₀.

MATERIALS & METHODS

An acute toxicity study was performed to find out the LD₅₀ value and sub-acute toxicity study was performed to find out the toxicity on repeated dose administration till 28 days. Both studies were performed according to the organization of economic cooperation and development (OECD) 425 and 407 respectively. For the acute oral toxicity study, animals were divided into two groups, group I normal control (NC) and group II received a 2000mg/kg dose of B.aurea leaves extract. In the sub-acute toxicity study, male and female animals were divided into eight groups, I-IV for males and V-VIII for females received control, 100, 200 & 400mg/kg B. aurea leaves extract respectively. Hematological and biochemical markers were estimated at the end of each study.

RESULTS

Results revealed that no mortality and morbidity were observed in acute oral as well as sub-acute toxicity studies. Oxidative stress markers were increased significantly in all organs of the treatment groups in both studies. Animals significantly decreased their food and water intake in an acute oral toxicity study. A slight difference in renal function tests was observed in the acute oral toxicity study when compared with the normal control group. No significant change in histopathology was observed in both studies on selected organs.

CONCLUSION

This study concluded that B. aurea can be safely used for pharmacological purposes.

Ellagic acid activates the Keap1-Nrf2-ARE signaling pathway in improving Parkinson's disease: A review

Parkinson's disease (PD) is a familiar neurodegenerative disease, accompanied by motor retardation, static tremor, memory decline and dementia. Heredity, environment, age and oxidative stress have been suggested as key factors in the instigation of PD. The Keap1-Nrf2-ARE signaling is one of the most significant anti- oxidative stress (OS) pathways. The Keap1 is a negative regulator of the Nrf2. The Keap1-Nrf2-ARE pathway can induce cell oxidation resistance and reduce nerve injury to treat neurodegenerative diseases. Ellagic acid (EA) can inhibit the Keap1 to accumulate the Nrf2 in the nucleus, and act on the ARE to produce target proteins, which in turn may alleviate the impact of OS on neuronal cells of PD. This review analyzes the structure and physiological role of EA, along with the structure, composition and functions of the Keap1-Nrf2-ARE signaling pathway. We further expound on the mechanism of ellagic acid in its activation of the Keap1-Nrf2-ARE signaling pathway, as well as the relationship between EA in impairing the TLR4/Myd88/NF-κB and Nrf2 pathways. Ellagic acid has the potentiality of improving PD by activating the Keap1-Nrf2-ARE signaling pathway and scavenging free radicals.

Phytochemical Analysis, Total Phenolic, Flavonoid Contents, and Anticancer Evaluations of Solvent Extracts and Saponins of H. digitata

Cancer is one of the most challenging diseases in the modern era for the researchers and investigators. Extensive research worldwide is underway to find novel therapeutics for prevention and treatment of diseases. The extracted natural sources have shown to be one of the best and effective treatments for cell proliferation and angiogenesis. Different approaches including disc potato model, brine shrimp, and chorioallantoic membrane (CAM) assay were adopted to analyze the anticancer effects. Habenaria digitata was also evaluated for MTT activity against NIH/3T3 cell line. The dexamethasone, etoposide, and vincristine sulfate were used as a positive control in these assays. All of the extracts including crude extracts (Hd.Cr), saponin (Hd.Sp), n-hexane (Hd.Hx), chloroform (Hd.Chf), ethyl acetate (Hd.EA), and aqueous fraction (Hd.Aq) were shown excellent results by using various assays. For example, saponin and chloroform have displayed decent antitumor and angiogenic activity by using potato tumor assay. The saponin fraction and chloroform were shown to be the most efficient in potato tumor experiment, demonstrating 87.5 and 93.7% tumor suppression at concentration of 1000 μg/ml, respectively, with IC50 values of 25.5 and 18.3 μg/ml. Additionally, the two samples, chloroform and saponins, outperformed the rest of the test samples in terms of antiangiogenic activity, with IC50 28.63 μg/ml and 16.20 μg/ml, respectively. In characterizing all solvent fractions, the chloroform (Hd.Chf) and saponin (Hd.Sp) appeared to display good effectiveness against tumor and angiogenesis but very minimal activity against A. tumefaciens. The Hd.Chf and Hd.Sp have been prospective candidates in the isolation of natural products with antineoplastic properties.

Development of sensitive colorimetric aptasensor based on short DNA aptamer and its application to screening for paraquat residues in agricultural soil

Paraquat is a widely used herbicide for controlling weeds and grasses in agriculture, and its contaminated residues in agricultural areas are of increasing concern. This work reports the development of the sensitive and easy-to-use colorimetric aptasensor for screening paraquat residues in agricultural soil. The short DNA fragments derived from the original aptamer were analyzed for their capability to interact with paraquat by molecular dynamic simulation. The paraquat-aptasensor was developed using the selected DNA fragment and gold nanoparticles. Its limit of detection (LOD) for paraquat is 2.76 nM, which is more sensitive than the aptasensor with long-length aptamer (LOD = 12.98 nM). The developed aptasensor shows the selectivity to paraquat, but not to other tested herbicides; ametryn, atrazine, difenzoquat, 2,4-D-dimethyl ammonium, and glufosinate. The recovery rates of paraquat detection in the spiked soil samples were in a range of 99.5%-105.1%, with relative standard deviation values of <4%. The developed aptasensor was used to screen for paraquat residues in agricultural soils, and three out of 23 soil samples were tested positive for paraquat, which was confirmed by a high-performance liquid chromatography analysis. These results suggested the potential application of the developed aptasensor to detect paraquat residues in agricultural sites.

Phytotherapeutic Approach in the Management of Cisplatin Induced Vomiting; Neurochemical Considerations in Pigeon Vomit Model

Cisplatin induced vomiting involves multiple mechanisms in its genesis and a single antiemetic agent do not cover both the phases (acute & delayed) of vomiting in clinics; necessitating the use of antiemetics in combination. Cannabis sativa and other selected plants have ethnopharmacological significance in relieving emesis. The aim of the present study was to investigate the intrinsic antiemetic profile of Cannabis sativa (CS), Bacopa monniera (BM, family Scrophulariaceae), and Zingiber officinale (ZO, family Zingiberaceae) in combinations against vomiting induced by highly emetogenic anticancer drug-cisplatin in pigeons. We have analysed the neurotransmitters which trigger the vomiting response centrally and peripherally. Electrochemical detector (ECD) was used for the quantification of neurotransmitters and their respective metabolites by high performance liquid chromatography in the brain stem (BS) and area postrema (AP) while peripherally in the small intestine. Cisplatin (7 mg/kg i.v.) induced reliable vomiting throughout the observation period (24 hrs). CS-HexFr (10 mg) + BM-MetFr (10 mg)–Combination 1, BM-ButFr (5 mg) + ZO-ActFr (25 mg)–Combination 2, ZO-ActFr (25 mg) + CS-HexFr (10 mg)–Combination 3, and CS-HexFr (10 mg) + BM-ButFr (5 mg)–Combination 4; provided ~30% (30 ± 1.1), 70% (12 ± 0.4; P < 0.01), 60% (19 ± 0.2; P < 0.05) and 90% (05 ± 0.1; P < 0.001) protection, respectively, against cisplatin induced vomiting as compared to cisplatin control. Standard MCP (30 mg) provided ~50% (23 ± 0.3) protection (P > 0.05). CS Hexane fraction (10 mg/kg), BM methanolic (10 mg/kg) and bacoside rich n-butanol fraction (5 mg/kg) and ZO acetone fraction (25 mg/kg) alone provided ~62%, 36%, 71%, and 44% protection, respectively, as compared to cisplatin control. The most effective and synergistic combination 4 was found to reduce 5HT and 5HIAA (P < 0.05–0.001) in all the brain areas area postrema (AP)+brain stem (BS) and intestine at the 3^rd hour of cisplatin administration. In continuation, at the 18^th of cisplatin administration reduction in dopamine (P < 0.001) in the AP and 5HT in the brain stem and intestine (P < 0.001) was observed. The said combination did not change the neurotransmitters basal levels and their respective metabolites any significantly. In conclusion, all the tested combinations offered protection against cisplatin induced vomiting to variable degrees, where combination 4 provided enhanced attenuation by antiserotonergic mechanism at the 3^rd hour while a blended antidopaminergic and antiserotonergic mechanism at the 18^th hour after cisplatin administration.

Green Nano-Biotechnology: A New Sustainable Paradigm to Control Dengue Infection

Dengue is a growing mosquito-borne viral disease prevalent in 128 countries, while 3.9 billion people are at high risk of acquiring the infection. With no specific treatment available, the only way to mitigate the risk of dengue infection is through controlling of vector, i.e., Aedes aegypti. Nanotechnology-based prevention strategies like biopesticides with nanoformulation are now getting popular for preventing dengue fever. Metal nanoparticles (NPs) synthesized by an eco-friendly process, through extracts of medicinal plants have indicated potential anti-dengue applications. Green synthesis of metal NPs is simple, cost-effective, and devoid of hazardous wastes. The recent progress in the phyto-synthesized multifunctional metal NPs for anti-dengue applications has encouraged us to review the available literature and mechanistic aspects of the dengue control using green-synthesized NPs. Furthermore, the molecular bases of the viral inhibition through NPs and the nontarget impacts or hazards with reference to the environmental integrity are discussed in depth. Till date, major focus has been on green synthesis of silver and gold NPs, which need further extension to other innovative composite nanomaterials. Further detailed mechanistic studies are required to critically evaluate the mechanistic insights during the synthesis of the biogenic NPs. Likewise, detailed analysis of the toxicological aspects of NPs and their long-term impact in the environment should be critically assessed.

Analagesic and Anti-Inflammatory Potentials of a Less Ulcerogenic Thiadiazinethione Derivative in Animal Models: Biochemical and Histochemical Correlates

Purpose

Gastric ulcer induced by NSAIDs is the major medical concern and researchers are utilizing several approaches to combat this medical issue. In the current study, we investigated the efficacy of thiadiazinethione derivative (2,2’(2-thioxo-1,3,5-thiadiazinane-3,5-diyl) diacetic acid, as new less ulcerogenic compound.

Methods

2,2’(2-thioxo-1,3,5-thiadiazinane-3,5-diyl) diacetic acid was evaluated using standard animal models including hot plate, writhing test and formalin induced nociceptive models. Anti-inflammatory activity was assessed via carrageenan-induced paw oedema model. Involvement of opioidergic nociceptive mechanism was confirmed via naloxone administration in hot plat assay. The gastro-ulcerogenic potential of test and standard compounds were evaluated via NSAID-induced pyloric ligation model followed by standard histopathological and biochemical analysis.

Results

In acetic acid-induced writhing test, our compound significantly reduced abdominal constrictions at the tested doses of 15 (p < 0.05), 30 (p < 0.01) and 45 mg kg⁻¹ (p < 0.001) as compared to control (p < 0.001). In hot plate test, after 30 min of administration, our test compound showed significant anti-nociceptive potential (p < 0.05 at 15 and 30 mg kg⁻¹ and p < 0.01 at 45 mg kg⁻¹) and tramadol (p ˂ 0.001) at 30 mg kg⁻¹ dose. After 60 min tramadol (30 kg⁻¹) and test sample (30, 45 mg kg⁻¹) exhibited significant anti-nociceptive activity p < 0.001. In Formalin-induced nociceptive response, a significant decline (p ˂ 0.001) was observed for aspirin and test compound during acute and chronic phases. Decline in the anti-nociceptive potential of tramadol and test sample via administration of naloxone indicate the involvement of opioidergic mechanism. Our compound exhibited significant anti-inflammatory activity in second phase of carrageenan induced paw oedema model. Histological and biochemical parameters exhibited less ulcerogenic potential as compared to aspirin.

Conclusion

Our findings suggests that our test compound has desirable anti-nociceptive and anti-inflammatory potentials with less propensity to cause gastric ulcer.

Hepatoprotective Effects of (-) Epicatechin in CCl4-Induced Toxicity Model Are Mediated via Modulation of Oxidative Stress Markers in Rats

Objective

(−) Epicatechin (EP) is a naturally occurring antioxidant flavonoid found in some green plants. The current study was designed to evaluate the potential role of antioxidant mechanisms in the hepatoprotective properties of EP using the carbon tetrachloride (CCl₄)-induced acute liver injury model.

Materials and Methods

Rats (n = 7 per group) were divided into five groups including control group, (−) epicatechin group (20 mg·kg⁻¹ body weight), CCl₄ group (1 mL⁻¹ body weight), CCl₄-EP treatment group, and CCl₄-silymarin (SILY) group. The levels of enzymes including hepatic malondialdehyde (MDA), glutathione (GSH), catalase (CAT), glutathione S-transferase (GST), nitric oxide synthase (NOS), glutathione peroxidase (GPx), and cytochrome P450 (CYP450) were analyzed via enzyme-linked immunosorbent assay (ELISA). Histological studies were performed on all groups to assess the regenerative effects of test sample and compare it with the control group.

Results

Test compound EP and standard drug silymarin (SILY) considerably reduced liver function enzyme levels in the blood, which were raised by CCl₄ administration, and increased serum albumin and total protein (TP) concentrations. The hepatic malondialdehyde (MDA) level was considerably declined, whereas glutathione (GSH), catalase (CAT), glutathione S-transferase (GST), nitric oxide synthase (NOS), glutathione peroxidase (GPx), and cytochrome P450 (CYP450) levels were upregulated in the EC-treated groups. The hepatoprotective results of the study were further confirmed via the histological assessments, which indicated a regeneration of the damaged hepatic tissue in treated rats.

Conclusions

The results of this study revealed a significant protective efficacy of EP against CCl₄-induced liver injury, which was potentially mediated via upregulation of antioxidant enzymes and direct scavenging effects of the compound against free radicals.