Relaxant effect of xanthomicrol and 3alpha-angeloyloxy-2alpha-hydroxy-13,14z-dehydrocativic acid from Brickellia paniculata on rat uterus

Identification of Potential Human Ryanodine Receptor 1 Agonists and Molecular Mechanisms of Natural Small-Molecule Phenols as Anxiolytics

Natural small-molecule phenols (NSMPs) possess certain ubiquitous bioactivities including the anxiolytic effect. Ryanodine receptor 1 (RyR1) may be one of the potentially critical pharmacological targets for studying the anxiolytic activity of NSMPs. However, detailed molecular mechanisms of NSMPs have not been fully clarified. This research was intended to identify potent hRyR1 agonists from NSMPs and investigate whether RyR1 plays a role in their anxiolytic effect. Homology modeling and molecular docking analysis were performed using Accelrys Discovery Studio 2.5. The most appropriate concentrations of NSMPs to activate RyR1 were measured using the MTT assay. Fluorescence analyses of the intracellular calcium levels and western blotting analysis were carried out to validate whether NSMPs could regulate the calcium flux to some extent by activating RyR1. The results demonstrated that xanthotoxol and 5-hydroxy-1,4-naphthalenedione can be screened as hit compounds for potential agonists of hRyR1 to exert the anxiolytic effect. In conclusion, NSMPs might be a kind of pharmacological signal carrier, acting on RyR1 as an agonist and resulting in calcium ion mobilization from intracellular calcium ion store.

Mexican Plants and Derivates Compounds as Alternative for Inflammatory and Neuropathic Pain Treatment-A Review

Despite the availability of many anti-pain drugs, in the form of NSAIDs, steroids, gabapentinoids, opioids, and antidepressants, in this study we address the natural compounds belonging to the group of Mexican medicinal plants or "Mexican folk medicine", used for pain management in Mexico. Our interest in this subject is due to the growing idea that "natural is harmless" and to the large number of side effects exhibited in pharmacotherapy. The objective of this review was to document the scientific evidence about Mexican medicinal plants and their derivatives used for inflammatory and neuropathic pain treatment, as well as the mechanisms of action implicated in their antinociceptive effects, their possible adverse effects, and the main pharmacological aspects of each plant or compound. Our data review suggested that most studies on Mexican medicinal plants have used inflammatory experimental models for testing. The anti-pain properties exerted by medicinal plants lack adverse effects, and their toxicological assays report that they are safe to consume; therefore, more studies should be performed on preclinical neuropathic pain models. Moreover, there is no convincing evidence about the possible mechanisms of action involved in the anti-pain properties exerted by Mexican plants. Therefore, the isolation and pharmacological characterization of these plant derivatives' compounds will be important in the design of future preclinical studies.

Chemistry and Biology of Selected Mexican Medicinal Plants

Herbal medicines are an integral element of alternative medical care in Mexico, and the best testimony to their efficacy and cultural value is their persistence in contemporary Mexican marketplaces where the highest percentages of medicinal and aromatic plants are sold. This chapter summarizes current trends in research on medicinal plants in Mexico, with emphasis on work carried out at the authors' laboratories. The most relevant phytochemical and pharmacological profiles of a selected group of plants used widely for treating major national health problems are described.From this contribution, it is evident that in the last five decades a significant amount of research on medicinal plants has been performed by Mexican scientists. Such efforts have led to the publication of many research papers in noted peer-reviewed journals and technical books. The isolation and structural characterization of hundreds of bioactive secondary metabolites have been accomplished, and most importantly, these studies have tended to support the ethnomedical uses of many different species. A multidisciplinary approach for investigating these plants has led to an increased emphasis on areas such as phytopharmacology, phytotoxicology, quality control, regulation, and conservation issues for these valuable resources. The medicinal plants analyzed so far have shown a very broad chemical diversity of their constituents, which have a high potential for exhibiting novel mechanistic effects biologically. The chapter shows also that there is need to conduct additional clinical studies on herbal drugs, in particular because the longstanding traditional evidence for their safety is not always sufficient to assure their rational use. There is also need to move to "omics" approaches for investigating the holistic effect and the influence of groups of phytochemicals on the whole organism. Mexican scientists may be expected to have bright prospects in this regard, which will imbue medicinal plant research with a new dynamism in the future.

Natural Antispasmodics: Source, Stereochemical Configuration, and Biological Activity

Natural products with antispasmodic activity have been used in traditional medicine to alleviate different illnesses since the remote past. We searched the literature and compiled the antispasmodic activity of 248 natural compounds isolated from terrestrial plants. In this review, we summarized all the natural products reported with antispasmodic activity until the end of 2017. We also provided chemical information about their extraction as well as the model used to test their activities. Results showed that members of the Lamiaceae and Asteraceae families had the highest number of isolated compounds with antispasmodic activity. Moreover, monoterpenoids, flavonoids, triterpenes, and alkaloids were the chemical groups with the highest number of antispasmodic compounds. Lastly, a structural comparison of natural versus synthetic compounds was discussed.

Juice of Bryophyllum pinnatum (Lam.) inhibits oxytocin-induced increase of the intracellular calcium concentration in human myometrial cells

The use of preparations from Bryophyllum pinnatum in tocolysis is supported by both clinical (retrospective comparative studies) and experimental (using uterus strips) evidence. We studied here the effect of B. pinnatum juice on the response of cultured human myometrial cells to stimulation by oxytocin, a hormone known to be involved in the control of uterine contractions by increasing the intracellular free calcium concentration ([Ca2+]i). In this work, [Ca2+]i was measured online during stimulation of human myometrial cells (hTERT-C3 and M11) with oxytocin, which had been pre-incubated in the absence or in the presence of B. pinnatum juice. Since no functional voltage-gated Ca2+ channels could be detected in these myometrial cells, the effect of B. pinnatum juice was as well studied in SH-SY5Y neuroblastoma cells, which are known to have such channels and can be depolarised with KCl. B. pinnatum juice prevented the oxytocin-induced increase in [Ca2+]i in hTERT-C3 human myometrial cells in a dose-dependent manner, achieving a ca. 80% inhibition at a 2% concentration. Comparable results were obtained with M11 human primary myometrial cells. In hTERT-C3 cells, prevention of the oxytocin-induced increase in [Ca2+]i was independent of the extracellular Ca2+ concentration and of voltage-dependent Ca2+-channels. B. pinnatum juice delayed, but did not prevent the depolarization-induced increase in [Ca2+]i in SH-SY5Y cells. Taken together, the data suggest a specific and concentration-dependent effect of B. pinnatum juice on the oxytocin signalling pathway, which seems to corroborate its use in tocolysis. Such a specific mechanism would explain the rare and minor side-effects in tocolysis with B. pinnatum as well as its high therapeutic index.