Chemical composition and evaluation of antinociceptive activity of the essential oil of Stevia serrata Cav. from Guatemala

Chemical Analysis and Antidiabetic Potential of a Decoction from Stevia serrata Roots

A decoction of the roots (31.6-316 mg/kg) from Stevia serrata Cav. (Asteraceae) as well as the main component (5-150 mg/kg) showed hypoglycemic and antihyperglycemic effects in mice. The fractionation of the active extract led to the isolation of dammaradiene acetate (1), stevisalioside A (2), and three new chemical entities characterized by spectroscopic methods and named stevisaliosides B-D (3-5). Glycoside 2 (5 and 50 mg/kg) decreased blood glucose levels and the postprandial peak during oral glucose and insulin tolerance tests in STZ-hyperglycemic mice. Compounds 1-5 were tested also against PTP1B1-400 and showed IC50 values of 1180.9 ± 0.33, 526.8 ± 0.02, 532.1 ± 0.03, 928.2 ± 0.39, and 31.8 ± 1.09 μM, respectively. Compound 5 showed an IC50 value comparable to that of ursolic acid (IC50 = 30.7 ± 0.00 μM). Docking studies revealed that 2-5 and their aglycones bind to PTP1B1-400 in a pocket formed by the C-terminal region. The volatilome of S. serrata was characterized by a high content of (E)-longipinene, spathulenol, guaiadiene, seychellene, and aromandendrene. Finally, a UHPLC-UV method was developed and validated to quantify the content of 2 in the decoction of the plant.

UPLC-ESI-MS/MS profiling and hepatoprotective activities of Stevia leaves extract, butanol fraction and stevioside against radiation-induced toxicity in rats

Stevioside is the major component of Stevia rebaudiana (Bertoni) leaves, family Asteraceae. UPLC-ESI-MS/MS analyses of leaves total methanol extract (TEx) and standardized butanol fraction (BF, 113.5 mg stevioside/g) were performed herein, revealing steviol glycosides, caffeoylquinic acid derivatives, flavonoids, and sesquiterpenoids. Their hepatoprotective activities against radiation-induced toxicity were evaluated compared to pure stevioside. Rats pretreatment with stevioside, TEx, and BF orally for 7 days before subjection to 6.5 Gy whole-body-gamma-irradiation reversed histopathological damages; improved liver functions and restored depleted antioxidants. ALT and reduced-glutathione levels showed insignificant changes, compared to control, by (5.22%, 3.20%, 24.90%) and (-0.47%, -3.95%, -2.63%), respectively. Glutathione-S-transferase, catalase, and MDA levels were significantly ameliorated. Liver tissue molecular profiling showed reduction in elevated TNF-α by 23.83%, 29.06%, 28.34%, respectively, and in NF-kB and COX-2 expression levels via immunohistochemical study. BF showed better hepatoprotective activity than TEx which may be attributed to higher stevioside, flavonoids, and caffeoylquinic acid derivatives content.

Stevia Genus: Phytochemistry and Biological Activities Update

The Stevia genus (Asteraceae) comprises around 230 species, distributed from the southern United States to the South American Andean region. Stevia rebaudiana, a Paraguayan herb that produces an intensely sweet diterpene glycoside called stevioside, is the most relevant member of this genus. Apart from S. rebaudiana, many other species belonging to the Stevia genus are considered medicinal and have been popularly used to treat different ailments. The members from this genus produce sesquiterpene lactones, diterpenes, longipinanes, and flavonoids as the main types of phytochemicals. Many pharmacological activities have been described for Stevia extracts and isolated compounds, antioxidant, antiparasitic, antiviral, anti-inflammatory, and antiproliferative activities being the most frequently mentioned. This review aims to present an update of the Stevia genus covering ethnobotanical aspects and traditional uses, phytochemistry, and biological activities of the extracts and isolated compounds.

Phytopharmacological Possibilities of Bird Cherry Prunus padus L. and Prunus serotina L. Species and Their Bioactive Phytochemicals

Wild cherry is a plant observed in the form of trees or shrubs. This species comprises about twenty kinds of plants and the most popular are two, Prunus padus L. and Prunus serotina L., whose properties and content of phytochemical compounds are subject to studies. Wild cherry contains many active compounds, including tocopherols, vitamins, polyphenols and terpenes, which can have beneficial effects on health. On the other hand, wild cherry contains cyanogenic glycosides. Nevertheless, current research results indicate pro-health properties associated with both P. serotina and P. padus. The aim of this study was to collect and present the current state of knowledge about wild cherry and to review available in vitro and in vivo studies concerning its antioxidant, anti-inflammatory, antibacterial and antidiabetic activity. Moreover, the current work presents and characterizes phytochemical content in the leaves, bark and fruits of P. padus and P. serotina and compiles data that indicate their health-promoting and functional properties and possibilities of using them to improve health. We find that the anatomical parts of P. padus and P. serotina can be a valuable raw material used in the food, pharmaceutical and cosmetic industries as a source of bioactive compounds with multi-directional action.

Characterization of the Antinociceptive Activity from Stevia serrata Cav

Background: Stevia serrata Cav. (Asteraceae), widely found in Guatemala, is used to treat gastrointestinal problems. The aim of this study was to demonstrate the antinociceptive and anti-inflammatory effects of the essential oil (EO) and the mechanism of action. Methods: EO was tested in chemical (capsaicin- and glutamate-induced licking response) or thermal (hot plate) models of nociception at 10, 30 or 100 mg/kg doses. The mechanism of action was evaluated using two receptor antagonists (naloxone, atropine) and an enzyme inhibitor (L-NAME). The anti-hyperalgesic effect was evaluated using carrageenan-induced nociception and evaluated in the hot plate. Results: All three doses of EO reduced licking response induced by glutamate, and higher doses reduced capsaicin-induced licking. EO also increased area under the curve, similar to the morphine-treated group. The antinociceptive effect induced by EO was reversed by pretreatment of mice with naloxone (1 mg/kg, ip), atropine (1 mg/kg, ip) or L-NAME (3 mg/kg, ip). EO also demonstrated an anti-hyperalgesic effect. The 100 mg/kg dose increased the latency time, even at 1 h after oral administration and this effect has been maintained until the 96th hour, post-administration. Conclusions: Our data suggest that essential oil of S. serrata presents an antinociceptive effect mediated, at least in part, through activation of opioid, cholinergic and nitrergic pathways.