Bioactive alkaloids from the venom of Dendrobatoidea Cope, 1865: a scoping review.

Bioactive compounds derived from secondary metabolism in animals have refined selectivity and potency for certain biological targets. The superfamily Dendrobatoidea is adapted to the dietary sequestration and secretion of toxic alkaloids, which play a role in several biological activities, and thus serve as a potential source for pharmacological and biotechnological applications. This article constitutes a scoping review to understand the trends in experimental research involving bioactive alkaloids derived from Dendrobatoidea based upon scientometric approaches. Forty-eight (48) publications were found in 30 journals in the period of 60 years, between 1962 and 2022. More than 23 structural classes of alkaloids were cited, with 27.63% for batrachotoxins, 13.64% for pyridinics, with an emphasis on epibatidine, 16.36% for pumiliotoxins, and 11.82% for histrionicotoxins. These tests included in vivo (54.9%), in vitro (39.4%), and in silico simulations (5.6%). Most compounds (54.8%) were isolated from skin extracts, whereas the remainder were obtained through molecular synthesis. Thirteen main biological activities were identified, including acetylcholinesterase inhibitors (27.59%), sodium channel inhibitors (12.07%), cardiac (12.07%), analgesic (8.62%), and neuromuscular effects (8.62%). The substances were cited as being of natural origin in the "Dendrobatidae" family, genus "Phyllobates," "Dendrobates," and seven species: Epipedobates tricolor, Phyllobates aurotaenia, Oophaga histrionica, Oophaga pumilio, Phyllobates terribilis, Epipedobates anthonyi, and Ameerega flavopicta. To date, only a few biological activities have been experimentally tested; hence, further studies on the bioprospecting of animal compounds and ecological approaches are needed.

Magnetic resonance imaging texture analysis for quantitative evaluation of the mandibular condyle in juvenile idiopathic arthritis.

OBJECTIVES: Juvenile idiopathic arthritis (JIA) is a chronic inflammatory disease that affects the joints and other organs, including the development of the former in a growing child. This study aimed to evaluate the feasibility of texture analysis (TA) based on magnetic resonance imaging (MRI) to provide biomarkers that serve to identify patients likely to progress to temporomandibular joint damage by associating JIA with age, gender and disease onset age. METHODS: The radiological database was retrospectively reviewed. A total of 45 patients were first divided into control group (23) and JIA group (22). TA was performed using grey-level co-occurrence matrix (GLCM) parameters, in which 11 textural parameters were calculated using MaZda software. These 11 parameters were ranked based on the p value obtained with ANOVA and then correlated with age, gender and disease onset age. RESULTS: Significant differences in texture parameters of condyle were demonstrated between JIA group and control group (p < 0.05). There was a progressive loss of uniformity in the grayscale pixels of MRI with an increasing age in JIA group. CONCLUSIONS: MRI TA of the condyle can make it possible to detect the alterations in bone marrow of patients with JIA and promising tool which may help the image analysis.

Antinociceptive effects of a chloroform extract and the alkaloid dicentrine isolated from fruits of Ocotea puberula.

The present work describes the chemical characterization of a chloroform fraction (CF) obtained from an extract of Ocotea puberula (Lauraceae) fruits, and preliminary antinociceptive analysis of CF and the alkaloid dicentrine, isolated from this fraction. CF (30-300 mg/kg, p. o.) caused dose-related inhibition of abdominal constrictions caused by acetic acid and also inhibited both phases of formalin-induced nociception. However, hexane or ethyl acetate fractions did not produce any effect. Antinociception caused by CF (100 mg/kg, p. o.) in the acetic acid test was not affected either by caffeine, an adenosine receptor antagonist, or by naloxone, an opioid receptor antagonist, and neither was associated with nonspecific effects such as muscle relaxation or sedation. Furthermore, dicentrine (30-300 mg/kg, p. o.) produced dose-related inhibition of acetic acid-induced pain without causing changes in the motor performance of mice. The results show, for the first time, that CF from Ocotea puberula fruits produced marked antinociception in different models of chemical pain, and this effect appears to be, at least in part, due to the presence of dicentrine. The mechanism by which CF and the alkaloid produced antinociception still remains unclear, but the adenosinergic or opioid system seems unlikely to be involved in this action.

Effects of honey from Mimosa quadrivalvis L. (malícia) produced by the Melipona subnitida D. (jandaíra) stingless bee on dyslipidaemic rats.

This study assessed the effects of supplementation with honey from Mimosa quadrivalvis L. (malícia) (MH) produced by jandaíra stingless bees (Melipona subnitida D.) on the lipid metabolism, antioxidant status and some intestinal health parameters of rats with diet-induced dyslipidaemia. Rats were randomly divided into four groups: healthy control (HC), dyslipidaemic control (DC), healthy experimental (EHH) and dyslipidaemic experimental (EDH). Malícia honey (MH) was administered (1000 mL kg-1) via orogastric feeding for 35 days. Dyslipidaemic rats supplemented with MH showed lower food consumption, increased glucose tolerance and superoxide dismutase (SOD) activity, and decreased total cholesterol, LDL and AST blood levels. Counts of Bifidobacterium spp. and Lactobacillus spp. and excretion of organic acids in faeces increased in dyslipidaemic rats supplemented with MH. MH supplementation protected the colon and liver from tissue damage induced by the dyslipidaemic diet. These results show the beneficial effects of MH on the lipid metabolism, antioxidant status and intestinal health of rats with diet-induced dyslipidaemia.