Natural product-derived therapies for treating drug-resistant epilepsies: From ethnopharmacology to evidence-based medicine

ETHNOPHARMACOLOGICAL RELEVANCE

Epilepsy is one of the most prevalent neurological human diseases, affecting 1% of the population in all age groups. Despite the availability of over 25 anti-seizure medications (ASMs), which are approved in most industrialized countries, approximately 30% of epilepsy patients still experience seizures that are resistant to these drugs. Since ASMs target only limited number of neurochemical mechanisms, drug-resistant epilepsy (DRE) is not only an unmet medical need, but also a formidable challenge in drug discovery.

AIM

In this review, we examine recently approved epilepsy drugs based on natural product (NP) such as cannabidiol (CBD) and rapamycin, as well as NP-based epilepsy drug candidates still in clinical development, such as huperzine A. We also critically evaluate the therapeutic potential of botanical drugs as polytherapy or adjunct therapy specifically for DRE.

METHODS

Articles related to ethnopharmacological anti-epileptic medicines and NPs in treating all forms of epilepsy were collected from PubMed and Scopus using keywords related to epilepsy, DRE, herbal medicines, and NPs. The database clinicaltrials.gov was used to find ongoing, terminated and planned clinical trials using herbal medicines or NPs in epilepsy treatment.

RESULTS

A comprehensive review on anti-epileptic herbal drugs and natural products from the ethnomedical literature is provided. We discuss the ethnomedical context of recently approved drugs and drug candidates derived from NPs, including CBD, rapamycin, and huperzine A. Recently published studies on natural products with preclinical efficacy in animal models of DRE are summarized. Moreover, we highlight that natural products capable of pharmacologically activating the vagus nerve (VN), such as CBD, may be therapeutically useful to treat DRE.

CONCLUSIONS

The review highlights that herbal drugs utilized in traditional medicine offer a valuable source of potential anti-epileptic drug candidates with novel mechanisms of action, and with clinical promise for the treatment of drug-resistant epilepsy (DRE). Moreover, recently developed NP-based anti-seizure medications (ASMs) indicate the translational potential of metabolites of plant, microbial, fungal and animal origin.

OP0120-HPR IMPACT OF DIFFERENT TYPES OF PHYSICAL ACTIVITY PROGRAMS ON ANKYLOSING SPONDYLITIS: A SYSTEMATIC REVIEW AND META-ANALYSIS

Background

Ankylosing spondylitis (AS) is a chronic inflammatory rheumatic disease characterized by inflammation and ankylosis of the spine. Spinal ankylosis is responsible for significant morbidity and disability. Despite public health campaigns supporting the benefits of physical activity (PA) the average level of PA in patients with AS is low.

Objectives

This systematic review and meta-analysis of controlled studies aimed to assess the efficacy of different types of physical activity (PA) programs on ankylosing spondylitis (AS) activity, function and mobility.

Methods

We searched PubMed/Medline, Cochrane Library and Embase databases for reports of controlled trials of patients with AS with at least one activity or function outcome published up to August 2020. The studies were classified by intervention into categories defined by the 4 dimensions of PA established by the World Health Organization: aerobic, muscle strength, flexibility and neuromotor performance. We performed both overall (including any kind of PA) and sub-group analysis by type of PA program.

Results

Forty-three studies were included in qualitative synthesis and 27 in meta-analysis. The overall analysis showed a moderate effect of PA on BASDAI (-0.57, 95% CI -0.92,-0.21, p=0.002), BASFI (-0.63, 95% CI -0.85,-0.42, p<0.0001) and BASMI (-0.58, 95% CI -1.02,-0.14, p=0.01). The effect of “flexibility+muscle strength exercises” PA was large for BASMI (-1.03, 95% CI -1.64,-0.42, p=0.0009), moderate for BASDAI (-0.56, 95% CI -1.07,-0.05, p=0.03) and BASFI (-0.63, 95% CI -0.88,-0.39, p<0.005). Home-based unsupervised “flexibility+muscle strength exercises” programs improved the BASFI but not BASDAI. The effect of “flexibility+muscle strength+aerobic exercises” PA was large for BASFI (-1.26, 95% CI -1.70,-0.81, p<0.005), moderate for BASDAI (-0.77, 95% CI -1.40,-0.14, p=0.02).

Conclusion

PA has a moderate effect on AS activity and function. Programs including flexibility and muscle strength exercises may have a large effect, especially for spinal mobility. Programs including aerobic exercise showed significant efficacy for function.

Disclosure of Interests

None declared

Rational and Efficient Preparative Isolation of Natural Products by MPLC-UV-ELSD based on HPLC to MPLC Gradient Transfer

In natural product research, the isolation of biomarkers or bioactive compounds from complex natural extracts represents an essential step for de novo identification and bioactivity assessment. When pure natural products have to be obtained in milligram quantities, the chromatographic steps are generally labourious and time-consuming. In this respect, an efficient method has been developed for the reversed-phase gradient transfer from high-performance liquid chromatography to medium-performance liquid chromatography for the isolation of pure natural products at the level of tens of milligrams from complex crude natural extracts. The proposed method provides a rational way to predict retention behaviour and resolution at the analytical scale prior to medium-performance liquid chromatography, and guarantees similar performances at both analytical and preparative scales. The optimisation of the high-performance liquid chromatography separation and system characterisation allows for the prediction of the gradient at the medium-performance liquid chromatography scale by using identical stationary phase chemistries. The samples were introduced in medium-performance liquid chromatography using a pressure-resistant aluminium dry load cell especially designed for this study to allow high sample loading while maintaining a maximum achievable flow rate for the separation. The method has been validated with a mixture of eight natural product standards. Ultraviolet and evaporative light scattering detections were used in parallel for a comprehensive monitoring. In addition, post-chromatographic mass spectrometry detection was provided by high-throughput ultrahigh-performance liquid chromatography time-of-flight mass spectrometry analyses of all fractions. The processing of all liquid chromatography-mass spectrometry data in the form of an medium-performance liquid chromatography x ultra high-performance liquid chromatography time-of-flight mass spectrometry matrix enabled an efficient localisation of the compounds of interest in the generated fractions. The methodology was successfully applied for the separation of three different plant extracts that contain many diverse secondary metabolites. The advantages and limitations of this approach and the theoretical chromatographic background that rules such as liquid chromatography gradient transfer are presented from a practical viewpoint.

Biomimetic synthesis of Tramadol

The key step in the proposed biosynthesis of tramadol was achieved using mild biomimetic conditions.

Zebrafish bioassay-guided microfractionation identifies anticonvulsant steroid glycosides from the Philippine medicinal plant Solanum torvum

Medicinal plants used for the treatment of epilepsy are potentially a valuable source of novel antiepileptic small molecules. To identify anticonvulsant secondary metabolites, we performed an in vivo, zebrafish-based screen of medicinal plants used in Southeast Asia for the treatment of seizures. Solanum torvum Sw. (Solanaceae) was identified as having significant anticonvulsant activity in zebrafish larvae with seizures induced by the GABAA antagonist pentylenetetrazol (PTZ). This finding correlates well with the ethnomedical use of this plant in the Philippines, where a water decoction of S. torvum leaves is used to treat epileptic seizures. HPLC microfractionation of the bioactive crude extract, in combination with the in vivo zebrafish seizure assay, enabled the rapid localization of several bioactive compounds that were partially identified online by UHPLC-TOF-MS as steroid glycosides. Targeted isolation of the active constituents from the methanolic extract enabled the complete de novo structure identification of the six main bioactive compounds that were also present in the traditional preparation. To partially mimic the in vivo metabolism of these triterpene glycosides, their common aglycone was generated by acid hydrolysis. The isolated molecules exhibited significant anticonvulsant activity in zebrafish seizure assays. These results underscore the potential of zebrafish bioassay-guided microfractionation to rapidly identify novel bioactive small molecules of natural origin.

[Intravenous glucose tolerance test in the functional exploration of segmental pancreatic autografts in the dog]

The aim of the present study is based on the comparison of intravenous tolerance testing before and after segmental pancreas autotransplantation in the dog. The results show that such testing must take in account the "glucose diffusion space", using the same glucose load in order to avoid the bias related to the post-operative loss of body weight.