Sida tuberculata extract reduces the nociceptive response by chemical noxious stimuli in mice: Implications for mechanism of action, relation to chemical composition and molecular docking.

Sida tuberculata R.E.Fr. (Malvaceae) is a medicinal plant widely found in Southern Brazil, and popularly used for inflammatory disorders and to pain relief. A phytochemical analysis followed by an investigation about antinociceptive potential and mechanism of action were performed with leaves and roots extracts. Methanolic extracts, designated as S. tuberculata leaves extract (STLE) and S. tuberculata roots extract, were analyzed both by UHPLC­MS. The in vivo antinociceptive potential of STLE (10­300 mg kg−1) was assessed in mice subjected to the acetic acid­induced abdominal writhes and formalin model. Agonist/antagonist tests and computational docking suggest the involvement of opioid and adenosinergic systems. The main chemical class detected on extracts was the ecdysteroids, and 20­hydoxyecdysone (20HE) was confirmed as the major phytoconstituent. The pretreatment with STLE (100 mg kg−1) reduced more than 70% abdominal contortions induced by acetic acid model and produced significant inhibition on formalin­induced licking response. The mechanism of action study revealed STLE might act through opioid and adenosine systems. Molecular docking suggested kaempferol derivative and 20HE might interacting with µ­opioid receptor. Thus, the results suggest the existence of antinociceptive potential from S. tuberculata extracts being in accordance to the traditional use.

Predictive antidiabetic activities of plants used by persons with Diabetes mellitus.

BACKGROUND: There are several ways to identify medicinal power of phytoconstituents, such as in silico evaluations. Furthermore, ethnopharmacological researches are important alternatives for the identification of plants with medicinal potential. Significantly, medicinal plants are widely used by persons with Diabetes mellitus (DM) to treat manifestations of this syndrome. OBJECTIVES: i) to investigate the use of medicinal plants for individuals with DM and their health profile; ii) to evaluate in silico possible antidiabetic activities for main phytoconstituents of the commonly used plants. METHODS: A questionnaire was used to measure consumption of medicinal plants. The Prediction of Activity Spectra for Substances (PASS) platform was employed to perform in silico evaluations. In silico predictions for antidiabetic activities were performed with the main compounds identified in a literature review which focused on the more utilized plants. RESULTS: We interviewed 105 persons with DM, most them women (73.34%). Overall mean age was 59.35 years, and 97.14% of them were diagnosed with type 2 DM. An evaluation of the routine exams of the interviewees showed that they have a poor metabolic control. Among the interviewees, 67.62% confirmed the use medicinal plants. Main forms of consumed plant preparation were infusion of leaves and in association with mate (a typical beverage of southern Brazil). Most interviewees consume five or more cups of infusion per day, and when consumed with the mate, 1.73 liters per day. Forty-six medicinal plants were mentioned, and cow's paw (Bauhinia) and jambolan (Syzygium cumini) were the most used. The main informed objective for the plant use was blood glucose control (69.01%). The PASS analysis presented six phytoconstituents with high antidiabetic prediction, especially, vicenin-2, the main phytochemical identified in Passiflora genus (Pa = 0.822). CONCLUSION: Our data show that persons with DM use many plants as a complementary treatment to the traditional medicine. Moreover, part of these plants presented phytoconstituents with antidiabetic potential. These data can serve as a basis for future investigations, with the objective of exploring in vitro and in vivo antidiabetic effects of these plants and its compounds.

Extraction optimization and UHPLC method development for determination of the 20-hydroxyecdysone in Sida tuberculata leaves.

Sida tuberculata (ST) is a Malvaceae species widely distributed in Southern Brazil. In traditional medicine, ST has been employed as hypoglycemic, hypocholesterolemic, anti-inflammatory and antimicrobial. Additionally, this species is chemically characterized by flavonoids, alkaloids and phytoecdysteroids mainly. The present work aimed to optimize the extractive technique and to validate an UHPLC method for the determination of 20-hydroxyecdsone (20HE) in the ST leaves. Box-Behnken Design (BBD) was used in method optimization. The extractive methods tested were: static and dynamic maceration, ultrasound, ultra-turrax and reflux. In the Box-Behnken three parameters were evaluated in three levels (-1, 0, +1), particle size, time and plant:solvent ratio. In validation method, the parameters of selectivity, specificity, linearity, limits of detection and quantification (LOD, LOQ), precision, accuracy and robustness were evaluated. The results indicate static maceration as better technique to obtain 20HE peak area in ST extract. The optimal extraction from surface response methodology was achieved with the parameters granulometry of 710 nm, 9 days of maceration and plant:solvent ratio 1:54 (w/v). The UHPLC-PDA analytical developed method showed full viability of performance, proving to be selective, linear, precise, accurate and robust for 20HE detection in ST leaves. The average content of 20HE was 0.56% per dry extract. Thus, the optimization of extractive method in ST leaves increased the concentration of 20HE in crude extract, and a reliable method was successfully developed according to validation requirements and in agreement with current legislation.

In vitro and in silico antioxidant and toxicological activities of Achyrocline satureioides.

ETHNOPHARMACOLOGICAL RELEVANCE: Achyrocline satureioides ("macela or marcela") is a medicinal plant, traditionally collected in "Good Friday" before sunrise. In traditional medicine, dried flowers of A. satureioides are used as anti-dyspeptic, antispasmodic and anti-inflammatory. AIM OF THE STUDY: To evaluate the phytochemical profile and to present an in vitro and in silico approach about toxicity and antioxidant potential of A. satureioides flowers extract and its major phytoconstituents. MATERIALS AND METHODS: Plant were collected according to the popular tradition. Extract were obtained by infusion and analyzed from high-performance liquid chromatography. Toxicity was evaluated in Artemia salina and human lymphocytes. Extract antioxidant activity was determined with total antioxidant capacity, DPPH• and ABTS+• scavenging, ferric reducing antioxidant power, deoxyribose degradation assay, and thiobarbituric acid reactive substances (TBA-RS) assay. TBA-RS inhibitions were evaluated in brain of rats for A. satureioides extract and its major phytoconstituents. Predictions of activity spectra for substances and in silico toxicity evaluation from major phytoconstituents were performed via computer simulation. RESULTS: Chromatographic data indicated isoquercitrin, quercetin and caffeic acid as main compounds in flowers extract. Toxicity tests demonstrated a very low toxic potential of A. satureioides. Extract exhibited antioxidant activities in low concentrations. Both extract and major phytochemicals standards showed protection against lipid peroxidation in brain of rats. Computer simulations pointed some biological activities in agreement with traditional use, as well as some experimental results found in this work. Moreover, in silico toxic predictions showed that the A. satureioides major compounds had low probability for toxic risk. CONCLUSION: Our results indicate that A. satureioides infusion possesses low toxicological potential and an effective antioxidant activity. These findings confirm the traditional use of this plant in the folk medicine.