Antioxidant, Gastroprotective, Cytotoxic Activities and UHPLC PDA-Q Orbitrap Mass Spectrometry Identification of Metabolites in Baccharis grisebachii Decoction.

The decoction of the local plant Baccharis grisebachii is used as a digestive, gastroprotective, external cicatrizing agent and antiseptic in Argentine. A lyophilized decoction (BLD) from the aerial parts of this plant was evaluated regarding its anti-ulcer, antioxidant and cytotoxic activities and the bioactivities were supported by UHPLC-MS metabolome fingerprinting which revealed the presence of several small bioactive compounds. The antioxidant properties were evaluated by DPPH, TEAC, FRAP and lipoperoxidation inhibition in erythrocytes methods, and the antibacterial activity was evaluated according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. The BLD showed a moderate free radical scavenging activity in the DPPH (EC50 = 106 µg/mL) and lipid peroxidation in erythrocytes assays (67%, at 250 µg/mL). However, the BLD had the highest gastroprotective effect at a dose of 750 mg/kg with a ninety-three percent inhibition of damage through a mechanism that involve NO and prostaglandins using the ethanol-induced gastric damage in a standard rat model. On the other hand, BLD does not induce cytotoxic changes on human tumor and no-tumor cell lines at the concentrations assayed. Regarding the metabolomic analysis, thirty-one compounds were detected and 30 identified based on UHPLC-OT-MS including twelve flavonoids, eleven cinnamic acid derivatives, one coumarin, one stilbene and two other different phenolic compounds. The results support that the medicinal decoction of Baccharis grisebachii is a valuable natural product with gastroprotective effects and with potential to improve human health that opens a pathway for the development of important phytomedicine products.

Role of Oxytocin in Prolactin Secretion during Late Pregnancy.

BACKGROUND/AIMS: During late pregnancy, the blockade of progesterone action by mifepristone (Mp) treatment induces a dopaminergic tone fall that enables naloxone (NAL) administration to release pituitary prolactin (PRL). We determined whether oxytocin (OT), which stimulates PRL secretion acting directly on anterior pituitary lactotrophs, mediates the stimulatory action of Mp and NAL on PRL secretion during late pregnancy. METHODS: On day 19 of pregnancy, circulating and pituitary OT and PRL levels were measured by radioimmunoassay, 10, 20, and 30 min after NAL (given at 17:30 h) in rats pretreated with Mp (at 08:00 h). Pituitary OT receptor (OTR) expression in Mp-treated rats was evaluated by RT-PCR. Activation of OT neurons in Mp-NAL-treated rats was measured counting double immunoreactive neurons for Fos and OT (Fos-OT-ir) in supraoptic nuclei (SON), and medial (PaMM) and lateral magnocellular divisions of paraventricular nuclei. RESULTS: Elevated serum OT and decreased pituitary OT were observed 10 min after NAL administration in both vehicle- and Mp-treated rats. This PRL increase was prevented by previous i.p. administration of an OTR antagonist, but intracerebroventricular OT administration was ineffective. Mp increased pituitary OTR expression at 18:00 h. Only Mp-NAL increased Fos-OT-ir neurons in the PaMM and SON. CONCLUSIONS: These findings suggest that PRL secretion induced by Mp-NAL treatment is preceded by OT release. These results, together with the activation of hypothalamic OT neurons and the higher expression of pituitary OTR, support the hypothesis that, during late pregnancy, OT may act at the pituitary level to facilitate PRL secretion if the inhibitory action of progesterone is blocked.