Pharmacological mechanisms involved in the diuretic activity of the ethanol-soluble fraction of Baccharis milleflora (Less.) DC. - An ethnopharmacological investigation.

ETHNOPHARMACOLOGICAL RELEVANCE: Baccharis milleflora (Less.) DC. is a plant native to Brazil that is frequently used in traditional medicine as a diuretic and antihypertensive. However, even though it is traditionally used for these purposes, its diuretic and hypotensive effects have not been fully elucidated. AIM: Investigate the cardiorenal effects of the ethanol-soluble fraction (ESBM) of Baccharis milleflora in normotensive rats. MATERIALS AND METHODS: Cladodes of B. milleflora were analyzed using light and scanning electron microscopy to provide anatomical data to support quality control. Subsequently, the ESBM was obtained and analyzed using LC-DAD-MS, and its components were annotated. The acute toxicity of ESBM was assessed in female Wistar rats. The acute and prolonged diuretic and hypotensive effects were then studied in Wistar rats. Finally, we assessed the mechanisms responsible for the diuretic effects of ESBM, including the activity of renal Na+/K+/ATPase, angiotensin-converting enzyme, and erythrocyte carbonic anhydrase. Additionally, we also investigated the involvement of bradykinin, prostaglandins, and nitric oxide. RESULTS: From LC-DAD-MS data, thirty-three metabolites were identified from ESBM, including chlorogenic acids, glycosylated phenolic derivatives, C-glycosylated flavones, and O-glycosylated flavonols. No signs of acute toxicity were observed in female rats. The findings showed that ESBM had significant diuretic and natriuretic effects, as well as a potassium-sparing effect. The treatment with ESBM was able to significantly decrease serum levels of creatinine and malondialdehyde, and also significantly increase levels of nitrite, an indirect marker of nitric oxide bioavailability. Furthermore, pre-treatment with L-NAME abolished all diuretic effects induced by ESBM. CONCLUSION: This study presented important morpho-anatomical and phytochemical data that support the quality control of Baccharis milleflora. The ESBM exhibited a significant diuretic and natriuretic effect following acute and seven-days repeated treatment in Wistar rats, without affecting renal potassium elimination. These effects appear to be dependent on the activation of the nitric oxide-cyclic GMP pathway. This study suggests the potential use of B. milleflora preparations in clinical situations where a diuretic effect is needed.

Guettarda viburnoides Cham. & Schltdl.: Neuroprotective Activities in Mice, Molecular Docking and Microchemical and Morphoanatomical Characteristics of Leaves and Stems.

BACKGROUND: Guettarda viburnoides Cham. & Schltdl., "veludinho do campo", is used in the Brazilian Amazon for its effects on the central nervous system (CNS) as a "brain tonic"; however, scientific evidence is needed to elucidate its ethnobotanical uses. OBJECTIVE: This study evaluated the neurobehavioural effects of an ethanolic extract of G. viburnoides (EEGV). Molecular docking, microchemical and morphoanatomical features of the species were investigated. METHODS: EEGV was investigated by UHPLC‒MS/MS and dereplication and molecular network were investigated using platforms available for natural product chemistry. For the in vivo assay, EEGV was administered to mice orally (3, 30 or 100 mg/kg). The effect of EEGV on spatial memory was measured using the Morris water maze test in mice with scopolamine-induced amnesia. The depression- and anxiety-like effects were assessed by forced swimming, tail suspension, marble burying and elevated plus maze tests. The AChE inhibition was evaluated in the brains of treated mice and molecular docking simulations were carried out with the main constituents. The leaves and stems of G. viburnoides were analysed via optical microscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy. RESULTS: Secoxyloganin, grandifloroside, hyperin/or isoquercitrin, uncaric acid and ursolic acid were identified by UHPLC‒MS/MS. Molecular networking by three flavonoids, three triterpenes, two coumarins, two iridoids, and one phenolic acid. EEGV reversed these scopolamineinduced effects. In the forced swim and tail suspension test, EEGV (30 and 100 mg/kg) significantly reduced the immobility time. EEGV significantly reduced the number of buried marbles, while in the elevated plus maze test, no changes were observed compared to the Sco group. AChE activity was altered in the hippocampus. Studies of the molecular coupling of iridoid glycosides (grandifloroside and secoxyloganin) and flavonoid hyperin with AChE revealed significant interactions, corroborating the activity indicated by the inhibition assay. CONCLUSIONS: These results might be in accordance with medicinal use for neuroprotetor effects and important microchemical and micromorphological data that support the identification and quality control of G. viburnoides.

Microscopic investigations of Ocotea paranaensis-A Brazilian endemic and endangered species.

This article describes the morpho-anatomies of the leaves and stems of Ocotea paranaensis Brotto, Baitello, Cervi & Santos (Lauraceae) using light and scanning electron microscopy. The main anatomical features characterizing the species are the presence of simple non-glandular trichomes in the leaves and stems, large secretory cells in the leaves, flat-convex petioles with two small lateral ribs, brachysclereids in the stem cortex and pith, and the presence of starch grains and various types of calcium oxalate crystals in the pith. Histochemical tests indicated the presence of lignin in stone cells, fibers, and xylem. Lipophilic contents were found in the secretory cells. Phenolic compounds were detected in the epidermis, hypodermis, phloem, and xylem. The present study's findings can contribute to the taxonomy and authentication of O. paranaensis. RESEARCH HIGHLIGHTS: This article is the first morpho-anatomical study of Ocotea paranaensis. Anatomy and histochemistry of the leaves and stems were studied by light microscopy, FESEM and EDS. The findings of this study would aid in the species identification and taxonomy.

Ocotea porosa: Anatomy and Histochemistry of Leaves and Stems, Chemical Composition, Cytotoxicity and Insecticidal Activities of Essential Oil

Abstract Ocotea porosa (Nees & Mart.) Barroso, commonly known as "imbuia", "canela-imbuia" or "imbuia-amarela" in Brazil, is a tree of the Southern Atlantic Forest. The present study investigates the anatomy of leaf and stem, volatile oil chemistry, as well as cytotoxicity and insecticidal activities of the essential oil of O. porosa. Species identification was achieved by anatomy features, mainly due to paracytic and anomocytic stomata; non-glandular trichomes; biconvex midrib and petiole with a collateral open arc vascular bundle; presence of a sclerenchymatous layer, starch grains and crystal sand in the stem; and the presence of phenolic compounds in the epidermis, phloem and xylem of the midrib, petiole and stem. The main volatile components of the essential oil were α-pinene (19.71%), β-pinene (13.86%) and bicyclogermacrene (24.62%). Cytotoxicity against human cancer cell (MCF-7), mouse cancer cell (B16F10) and mouse non-tumoral cell (McCoy) was observed as well as insecticidal activity of the essential oil against susceptible 'Ft. Dix' bed bugs (Cimex lectularius L.) by topical application.