Peripheral mechanisms involved in Tityus bahiensis venom-induced pain

Anti-arthritic potential and antioxidant properties of infusion, fractions and flavonoid glycosides from Dipteryx alata (baru) leaves

ETHNOPHARMACOLOGICAL RELEVANCE

Dipteryx alata Vogel., popularly known as "baru", is a native species of Brazilian cerrado used by "Ribeirinhos" in the North Araguaia microregion. In the traditional medicine, maceration of barks or leaves infusion are used to treat back and muscle pain, osteoporosis and rheumatism. However, few studies have demonstrated the pharmacological effects of this species.

AIM OF THE STUDY

The goal of this study was to perform phytochemicals studies of lyophilized infusion of D. alata leaves (LI-DA), as well as obtaining ethyl acetate fraction (EAF-DA) and hydromethanolic fraction (HMF-DA), and isolated flavonoids. The antioxidant of LI-DA, EAF-DA and HMF-DA, anti-inflammatory effects of LI-DA and quercetin-3-O-β-glucoside-7-O-α-rhamnoside (DA-1) and quercetin-7-O-α-rhamnoside (DA-2) were performed while in silico tests were used for absorption, distribution, metabolism, excretion and toxicity predictions of DA-1 and DA-2.

MATERIALS AND METHODS

LI-DA, EAF-DA and HMF-DA were evaluated in antioxidant assays (2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid - ABTS; 2,2-diphenyl-1-picrylhydrazyl - DPPH; hydrogen peroxide - H2O2; reducing power and oxidation of β-carotene). The DA-1 and DA-2 were isolated from EAF-DA using chromatographic methods and characterized by Nuclear Magnetic Resonance (NMR) spectrometer. The Programs ProTox 3.0 and ADMETlab 2.0 were used for the prediction studies of DA-1 and DA-2. Mice received a single dose of LI-DA (3, 30, and 100 mg/kg), DA-1 (3 mg/kg) and DA-2 (3 mg/kg) and were subjected to inflammation induced by Complete Freund's Adjuvant (CFA) and in the zymosan-induced articular inflammation model.

RESULTS

DA-1 and DA-2 have been identified for the first time in the leaves of D. alata. LI-DA, EAF-DA and HMF-DA demonstrated a high level of antioxidant activity as measured by ABTS (IC50 ≤ 5.62 μg/mL) and DPPH (IC50 ≤ 11.45 μg/mL). Oral administration of LI-DA (3, 30 and 100 mg/kg), DA-1 (3 mg/kg) and DA-2 (3 mg/kg) showed significantly reduced edema, cold and mechanical allodynia in the CFA-induced inflammation model (24 h). LI-DA (3, 30, and 100 mg/kg) and DA-1 (3 mg/kg) reduced leukocytes migration into the joint cavity, mechanical allodynia, edema and NO production in mice (24 h) in the zymosan-induced articular inflammation model. Additionally, DA-2 (3 mg/kg) reduced leukocyte migration and LI-DA (30 mg/kg) reduced protein exudation (24 h) in zymosan model. DA-1 and DA-2 showed good oral bioavailability and low toxicity predicted by the ProTox model.

CONCLUSION

This is the first chemical and biological study performed of D. alata infusion and two quercetin glycoside derivatives. The results indicated promising potential for the treatment of inflammation, pain, and rheumatism, supporting the traditional use of the infusion obtained from the leaves of D. alata.

Lisdexamfetamine dimesylate-exposition in male rats during the peripubertal period impairs inflammatory mechanisms, antioxidant activity, and apoptosis process in kidneys of male pubertal rats

Lisdexamfetamine dimesylate (LDX) is a prodrug of dextroamphetamine, which has been widely recommended for the treatment of Attention-Deficit/Hyperactivity Disorder (ADHD). There are still no data in the literature relating the possible toxic effects of LDX in the kidney. Therefore, the present study aims to evaluate the effects of LDX exposure on morphological, oxidative stress, cell death and inflammation parameters in the kidneys of male pubertal Wistar rats, since the kidneys are organs related to the excretion of most drugs. For this, twenty male Wistar rats were distributed randomly into two experimental groups: LDX group-received 11,3 mg/kg/day of LDX; and Control group-received tap water. Animals were treated by gavage from postnatal day (PND) 25 to 65. At PND 66, plasma was collected to the biochemical dosage, and the kidneys were collected for determinations of the inflammatory profile, oxidative status, cell death, and for histochemical, and morphometric analyses. Our results show that there was an increase in the number of cells marked for cell death, and a reduction of proximal and distal convoluted tubules mean diameter in the group that received LDX. In addition, our results also showed an increase in MPO and NAG activity, indicating an inflammatory response. The oxidative status showed that the antioxidant system is working undisrupted and avoiding oxidative stress. Therefore, LDX-exposition in male rats during the peripubertal period causes renal changes in pubertal age involving inflammatory mechanisms, antioxidant activity and apoptosis process.

The complex repertoire of Tityus spp. venoms: Advances on their composition and pharmacological potential of their toxins

Animal venoms are a rich and complex source of components, including peptides (such as neurotoxins, anionic peptides and hypotensins), lipids, proteins (such as proteases, hyaluronidases and phospholipases) and inorganic compounds, which affect all biological systems of the envenoming victim. Their action may result in a wide range of clinical manifestations, including tachy/bradycardia, hyper/hypotension, disorders in blood coagulation, pain, edema, inflammation, fever, muscle paralysis, coma and even death. Scorpions are one of the most studied venomous animals in the world and interesting bioactive molecules have been isolated and identified from their venoms over the years. Tityus spp. are among the scorpions with high number of accidents reported in the Americas, especially in Brazil. Their venoms have demonstrated interesting results in the search for novel agents with antimicrobial, anti-viral, anti-parasitic, hypotensive, immunomodulation, anti-insect, antitumor and/or antinociceptive activities. Furthermore, other recent activities still under investigation include drug delivery action, design of anti-epileptic drugs, investigation of sodium channel function, treatment of erectile disfunction and priapism, improvement of scorpion antivenom and chelating molecules activity. In this scenario, this paper focuses on reviewing advances on Tityus venom components mainly through the modern omics technologies as well as addressing potential therapeutic agents from their venoms and highlighting this abundant source of pharmacologically active molecules with biotechnological application.

The Versatility in the Applications of Dithiocarbamates

Dithiocarbamate ligands have the ability to form stable complexes with transition metals, and this chelating ability has been utilized in numerous applications. The complexes have also been used to synthesize other useful compounds. Here, the up-to-date applications of dithiocarbamate ligands and complexes are extensively discussed. Some of these are their use as enzyme inhibitor and treatment of HIV and other diseases. The application as anticancer, antimicrobial, medical imaging and anti-inflammatory agents is examined. Moreover, the application in the industry as vulcanization accelerator, froth flotation collector, antifouling, coatings, lubricant additives and sensors is discussed. The various ways in which they have been employed in synthesis of other compounds are highlighted. Finally, the agricultural uses and remediation of heavy metals via dithiocarbamate compounds are comprehensively discussed.