A new class of peptides from wasp venom: a pathway to antiepileptic/neuroprotective drugs

Animal-derived peptides from Traditional Chinese medicines: medicinal potential, mechanisms, and prospects

ETHNOPHARMACOLOGICAL RELEVANCE

Animal-derived traditional Chinese medicines have a long-standing history in Chinese medicine, which exhibit unique efficacy due to similar structure and function with human tissue. As the major types of constituents that accounted for a relatively high proportion of animal-derived TCMs, peptides with molecular weight between 100 Da and hundreds of thousands of kDa have caught wide attention due to their outstanding bioavailability and excellent specificity.

AIM OF THE STUDY

This review aims to comprehensively delve into the up-to-date research progress in their pharmacology, mechanism, sequence composition, and therapeutic application, laying a solid foundation for future clinical treatment and scientific research.

MATERIALS AND METHODS

Relevant information on the peptides from animal-derived TCMs was collected from scientific literature databases including PubMed, CNKI, literature sources (Ph.D. and M.Sc. dissertations), and Web of Science by using the keywords "Peptides", "Animal", and "TCMs" for gradual screening in the past 30 years.

RESULTS

To date, the peptides from 27 kinds of animal-derived TCMs have been systematically combed. Their pharmacological activity and underlying mechanisms on multiple systems (nervous, circulatory, skeletal, and immune), as well as anti-tumor, antioxidative, and antimicrobial effects, have been sorted out. Besides, the potential safety issues and deficiencies (low bioavailability, imperfect quality management, and toxicity of raw materials) have also been pointed out.

CONCLUSIONS

Comprehensive analysis showed that low development and resource waste accompanied by the inadequate report about the pharmacological activity of most peptides from animal-derived TCMs make it have good research prospects. Although a breakthrough in the field of healthcare products has been made, the development potential for clinical products that bring surprising turnaround will be obtained if the above-mentioned confusions and current needs (improve identification technology and design reasonable dosage forms) are implemented.

Antiepileptic profile of Parawixin-11, purified from Parawixia bistriata spider venom (Araneae, Araneidae), in Wistar rats

The pharmacological treatment of epilepsy is often complex due to the lack of efficacy in many patients and profound side effects from current drugs, including sedation, motor impairment, and teratogenesis. In the quest for new antiepileptic drugs, animal venoms offer a valuable source of neuroactive molecules targeting ion channels and neurotransmitter receptors. This study investigates the antiepileptic potential of compounds isolated from the venom of the Parawixia bistriata spider. One compound, designated Parawixin-11, demonstrated significant anticonvulsant effects when injected into the cerebral ventricle in a dose-response manner. It effectively countered seizures induced by bicuculline (ED50 0.16 µg/animal), pentylenetetrazole (ED50 0.08 µg/animal), strychnine (ED50 0.05 µg/animal), pilocarpine (ED50 0.10 µg/animal), and NMDA (ED50 0.008 µg/animal). We also assessed whether intracerebroventricular administration of Parawixin-11 caused motor or cognitive impairments in rats using the open field, rotarod, and Morris water maze tests. No differences in exploration or movement were observed with doses of 0.3, 0.2, or 0.1 µg of Parawixin-11. Although there was an increased latency to find the platform during the acquisition phase of the Morris water maze test, no differences in spatial memory retention were noted. Given Parawixin-11's potency against NMDA-induced seizures, we hypothesize that it may modulate the glutamatergic system, aligning with the mechanisms of several spider-derived polyamines.

Evaluating a Venom-Bioinspired Peptide, NOR-1202, as an Antiepileptic Treatment in Male Mice Models

Epilepsy, a neurological disorder characterized by excessive neuronal activity and synchronized electrical discharges, ranks among the most prevalent global neurological conditions. Despite common use, antiepileptic drugs often result in adverse effects and lack effectiveness in controlling seizures in temporal lobe epilepsy (TLE) patients. Recent research explored the potential of occidentalin-1202, a peptide inspired by Polybia occidentalis venom, in safeguarding Wistar rats from chemically induced seizures. The present study evaluated the new analog from occidentalin-1202 named NOR-1202 using acute and chronic pilocarpine-induced models and an acute kainic acid (KA) male mice model. NOR-1202 was administered through the intracerebroventricular (i.c.v.), subcutaneous, or intraperitoneal routes, with stereotaxic procedures for the i.c.v. injection. In the acute pilocarpine-induced model, NOR-1202 (i.c.v.) protected against generalized seizures and mortality but lacked systemic antiepileptic activity. In the KA model, it did not prevent generalized seizures but improved survival. In the chronic TLE model, NOR-1202's ED50 did not differ significantly from the epileptic or healthy groups regarding time spent in spontaneous recurrent seizures during the five-day treatment. However, the NOR-1202 group exhibited more seizures than the healthy group on the second day of treatment. In summary, NOR-1202 exhibits antiepileptic effects against chemoconvulsant-induced seizures, but no effect was observed when administered systemically.

Cognitive comorbidities in the rat pilocarpine model of epilepsy

Patients with epilepsy are prone to cognitive decline, depression, anxiety and other behavioral disorders. Cognitive comorbidities are particularly common and well-characterized in people with temporal lobe epilepsy, while inconsistently addressed in epileptic animals. Therefore, the aim of this study was to ascertain whether there is good evidence of cognitive comorbidities in animal models of epilepsy, in particular in the rat pilocarpine model of temporal lobe epilepsy. We searched the literature published between 1990 and 2023. The association of spontaneous recurrent seizures induced by pilocarpine with cognitive alterations has been evaluated by using various tests: contextual fear conditioning (CFC), novel object recognition (NOR), radial and T-maze, Morris water maze (MWM) and their variants. Combination of results was difficult because of differences in methodological standards, in number of animals employed, and in outcome measures. Taken together, however, the analysis confirmed that pilocarpine-induced epilepsy has an effect on cognition in rats, and supports the notion that this is a valid model for assessment of cognitive temporal lobe epilepsy comorbidities in preclinical research.

Animal Venoms as Potential Source of Anticonvulsants

Epilepsy affects millions of people worldwide, and there is an urgent need to develop safe and effective therapeutic agents. Animal venoms contain diverse bioactive compounds like proteins, peptides, and small molecules, which may possess medicinal properties against epilepsy. In recent years, research has shown that venoms from various organisms such as spiders, ants, bees, wasps, and conus snails have anticonvulsant and antiepileptic effects by targeting specific receptors and ion channels. This review underscores the significance of purified proteins and toxins from these sources as potential therapeutic agents for epilepsy. In conclusion, this review emphasizes the valuable role of animal venoms as a natural resource for further exploration in epilepsy treatment research.