Chemical and Pharmacological Screening of Rhinella icterica (Spix 1824) Toad Parotoid Secretion in Avian Preparations

Unveiling the Intricacies of Monoamine Oxidase-A (MAO-A) Inhibition in Colorectal Cancer: Computational Systems Biology, Expression Patterns, and the Anticancer Therapeutic Potential

Colorectal cancer (CRC) remains a significant health burden globally, necessitating a deeper understanding of its molecular intricacies for effective therapeutic interventions. Elevated monoamine oxidase-A (MAO-A) expression has been consistently observed in CRC tissues, correlating with advanced disease stages and a poorer prognosis. This research explores the systems biology effects of MAO-A inhibition with small molecule inhibitor clorgyline regarding CRC. The applied systems biology approach starts with a chemocentric informatics approach to derive high-confidence hypotheses regarding the antiproliferative effects of MAO-A inhibitors and ends with experimental validation. Our computational results emphasized the anticancer effects of MAO-A inhibition and the chemogenomics similarities between clorgyline and structurally diverse groups of apoptosis inducers in addition to highlighting apoptotic, DNA-damage, and microRNAs in cancer pathways. Experimental validation results revealed that MAO inhibition results in antiproliferative antimigratory activities in addition to synergistic effects with doxorubicin. Moreover, the results demonstrated a putative role of MAO-A inhibition in commencing CRC cellular death by potentially mediating the induction of apoptosis.

Interaction between Chinese medicine and digoxin: Clinical and research update

Background: Digoxin is one of the most widely and commonly used cardiac drug, which plays an irreplaceable role in treating heart failure and arrhythmia. The 2010 Edition of Pharmacopoeia of the People's Republic of China stipulates that the effective range of digoxin plasma concentration is 0.5-2.0 ng/mL and it is toxic at plasma concentration >2 ng/mL. Its effective plasma drug concentration is close to the toxic concentration, and large individual differences in the effects of the drug have been observed. It is often used in combination with other drugs, but drug interactions have a great impact on the plasma concentration of digoxin and lead to adverse reactions (ADRs), such as poisoning. Most of the reported drug interactions are with Western drugs. However, there are many combinations of traditional Chinese medicine (TCM) and Western drugs, TCM interacting with digoxin comprises monomer components, single medicines, and Chinese patent medicines. Aim of the study: We aimed i) to provide an overview of the TCM formulations affecting the pharmacology of digoxin and their mechanisms of action and ii) to provide a theoretical reference for the safe and rational use of digoxin in combination with TCM in clinical practice and to avoid ADRs. Methods: A literature search of electronic databases, including PubMed, MEDLINE, Cochrane Library, Web of Science, China National Knowledge Infrastructure, and WANFANG Data, was performed to search for articles published between 1 January 1960, and 1 August 2022. Search terms used included "digoxin," "traditional Chinese medicine," "Chinese patent medicine," and "adverse reactions" and their combinations. Results: A total of 49 articles were obtained, including clinical reports, pharmacological experiments and in vitro experiments. The mechanisms of action affecting the pharmacology of digoxin are complex. TCM formulations may affect the pharmacology of digoxin in vivo by influencing gastrointestinal motility or gastric juice pH, regulating P-glycoprotein levels, exerting cumulative pharmacological effects, and enhancing the sensitivity of the heart to digoxin. Although studies have shown that some TCM formulations interact with digoxin, they may be influenced by the complexity of the composition and the pharmacological effects of the TCM, the sensitivity of digoxin concentration determination methods, etc. The results of existing studies are controversial and further in-depth studies are required. Conclusion: Combinations of digoxin and TCM formulations are commonly used. This article serves as a reference to understand the interactions between TCM formulations and digoxin to avoid the occurrence of ADRs and improve the efficacy and safety of digoxin.

Modulation of the cholinergic pathway induced by skin secretion of Phyllomedusa iheringii Boulenger, 1885 in a vertebrate model

Amphibians represent one of the main natural sources of bioactive molecules of interest to biotechnological research. The Phyllomedusidae family has several species occurring in Brazil and some studies demonstrate the biological potential of poisons of these species, however many still need to be characterized. Phyllomedusa iheringii is endemic in Brazilian and Uruguayan Pampa Biome and has little data in the literature regarding the action of its poison on experimental organisms. Thus, the present work evaluates the biological activity of P. iheringii secretion on the central and peripheral nervous system of a vertebrate model. The skin secretions of P. iheringii (SSPI) were collected through manual compression and electrical stimulation of the animal's bodies. The resulting content was used in neurobiological tests searching for modulatory effects on the main pathways involved in the neurotoxicity mechanism of vertebrates. SSPI affected the contraction force of the chick biventer cervicis muscle (Gallus gallus domesticus) at some concentrations used (5, 10, and 12 μg/mL). In slices from the cerebral cortex of G. gallus domesticus an increase in cell viability was observed after treatment with SSPI (10 μg/mL) and a neuroprotective effect when treated simultaneously with hydrogen peroxide (H₂O₂), Neostigmine (NEO) and Trichlorfon (TRI). The cholinergic pathway is possibly the main pathway modulated by SSPI since assays with the cerebral cortex and biventer cervicis muscle demonstrated the increased activity of the enzyme acetylcholinesterase (AChE) (SSPI 10 μg/mL and 12 μg/mL, respectively). SSPI (10 μg/mL) also prevented the modulation of NEO and TRI, two recognized anticholinesterase agents, in AChE activity in slices of the cerebral cortex. Therefore, our results have demonstrated the unpublished biotechnological potential of P. iheringii over the vertebrate model and its modulation on the nervous system, with apparent action on the cholinergic pathway.

Animal Venoms and Their Components: Molecular Mechanisms of Action

Animal venoms comprise numerous toxin families, consisting mainly of peptides and proteins [...].

Bufo viridis secretions improve anxiety and depression-like behavior following intracerebroventricular injection of amyloid β

Background and purpose:

Venenum Bufonis is a Chinese traditional medicine produced from the glandular secretions of toads that contain biogenic amines, which have anti-inflammatory properties. The present study aimed to examine the effect of Bufo viridis secretions (BVS) on anxiety and depression-like behavior and hippocampal senile plaques volume in an animal model of Alzheimer's disease (AD).

Experimental approach:

Thirty-eight male Wistar rats were used. AD was induced by amyloid-beta (Aβ_1-42) (10 μg/2 μL, intracerebroventricular injection, icv) and then BVS at 20, 40, and 80 mg/kg were injected intraperitoneally (ip) in six equal intervals over 21 days. Anxiety and depression-like behavior were assessed using behavioral tests including open field test (OFT), elevated plus maze (EPM), and forced swimming test (FST) 21 days after the surgery. The volume of senile plaques was assessed based on the Cavalieri principle.

Findings/Results:

Results of the OFT showed that the central crossing number and the time in the AD group were significantly decreased compared to the sham group (P < 0.01 and P < 0.001, respectively). Also, the values of these two parameters significantly increased in the AD + BVS80 group than the AD group (P < 0.05 and P < 0.001, respectively). The time spent in the closed arm in the EPM dramatically increased in the AD group compared to the sham group (P < 0.05) and significantly decreased in the AD + BVS80 group compared to the AD group (P < 0.05). Results of the FST indicated that immobility time had a reduction in the AD + BVS20 (P < 0.01), AD + BVS40, and AD + BVS80 groups compared to the AD group (P < 0.001). The volume of senile plaques in the hippocampus showed a reduction in the treatment groups in comparison with the AD group (P < 0.001 for all).

Conclusion and implications:

Results revealed that BVS injection could improve symptoms of anxiety and depression and decrease senile plaques in the hippocampus in an animal model of AD.

The Insecticidal Activity of Rhinella schneideri (Werner, 1894) Paratoid Secretion in Nauphoeta cinerea Cocroaches

Rhinella schneideri is a common toad found in South America, whose paratoid toxic secretion has never been explored as an insecticide. In order to evaluate its insecticidal potential, Nauphoeta cinerea cockroaches were used as an experimental model in biochemical, physiological and behavioral procedures. Lethality assays with Rhinella schneideri paratoid secretion (RSPS) determined the LD₅₀ value after 24 h (58.07µg/g) and 48 h exposure (44.07 µg/g) (R² = 0.882 and 0.954, respectively). Acetylcholinesterase activity (AChE) after RSPS at its highest dose promoted an enzyme inhibition of 40%, a similar effect observed with neostigmine administration (p < 0.001, n= 5). Insect locomotion recordings revealed that RSPS decreased the distance traveled by up to 37% with a concomitant 85% increase in immobile episodes (p < 0.001, n = 36). RSPS added to in vivo cockroach semi-isolated heart preparation promoted an irreversible and dose dependent decrease in heart rate, showing a complete failure after 30 min recording (p < 0.001, n ≥ 6). In addition, RSPS into nerve-muscle preparations induced a dose-dependent neuromuscular blockade, reaching a total blockage at 70 min at the highest dose applied (p < 0.001, n ≥ 6). The effect of RSPS on spontaneous sensorial action potentials was characterized by an increase in the number of spikes 61% (p < 0.01). Meanwhile, there was 42% decrease in the mean area of those potentials (p < 0.05, n ≥ 6). The results obtained here highlight the potential insecticidal relevance of RSPS and its potential biotechnological application.