Identification of a peptide derived from a Bothrops moojeni metalloprotease with in vitro inhibitory action on the Plasmodium falciparum purine nucleoside phosphorylase enzyme (PfPNP).

There is a growing need for research on new antimalarial agents against Plasmodium falciparum infection, especially in regards to planning molecular architecture for specific molecular targets of the parasite. Thus, a metalloprotease from Bothrops moojeni, known as BmooMPα-I, was explored in this study, through in silico assays, aiming at the development of a peptide generated from this molecule with potential inhibitory action on PfPNP, an enzyme necessary for the survival of the parasite. In order to isolate BmooMPα-I, cation exchange and reverse phase chromatographies were performed, followed by in vitro assays of antiparasitic activity against the W2 strain of P. falciparum. The interactions between BmooMPα-I and PfPNP were evaluated via docking, and the resulting peptide, described as Pep1 BM, was selected according to the BmooMPα-I region demonstrating the best interaction score with the target of interest. The values for the specific activities of the PfPNP reaction were measured using the inorganic phosphate substrate and MESG. The fraction corresponding to BmooMPα-I was identified as fraction 4 in the cation exchange chromatography step, due to proteolytic activity on casein and the presence of a major band at ≅ 23 kDa. BmooMPα-I was able to inhibit in vitro growth of W2 P. falciparum, with an IC50 value of 16.14 µg/mL. Virtual screening with Pep1 BM demonstrated two PfPNP target binding regions, with ΔG values at the interaction interface of -10.75 kcal/mol and -11.74 kcal/mol. A significant reduction in the enzymatic activity of PfPNP was observed in the presence of Pep 1 BM when compared to the assay in the absence of this possible inhibitor. BmooMPα-I showed activity in vitro against W2 P. falciparum. By means of in silico techniques, the Pep 1 BM was identified as having potential binding affinity to the catalytic site of PfPNP and of inhibiting its catalytic activity in vitro.

Hydroethanolic extract of Baccharis trimera ameliorates alcoholic fatty liver disease in mice.

Ethanol abuse is a serious public health problem that is associated with several stages of alcoholic liver disease (ALD) and a high incidence of morbidity and mortality. Alcoholic fatty liver disease (AFLD), the earliest stage of ALD, is a multifactorial injury that involves oxidative stress and disruptions of lipid metabolism. Although benign and reversible, no pharmacological treatments are available for this condition. In the present study, we induced AFLD in mice with 10% ethanol and a low-protein diet and then orally treated them with a hydroethanolic extract of Baccharis trimera (HEBT; 30 mg kg-1). HEBT reversed ethanol-induced oxidative stress in the liver, reduced lipoperoxidation, normalized GPx, GST, SOD and Cat activity, and GSH and total ROS levels. The reverser effect of HEBT was observed upon ethanol-induced increases in the levels of plasma and hepatic triglycerides, plasma cholesterol, plasma high-density lipoprotein, and plasma and hepatic low-density lipoprotein. Moreover, HEBT increased fecal triglycerides and reduced the histological ethanol-induced lesions in the liver. HEBT also altered the expression of genes that are involved in ethanol metabolism, antioxidant systems, and lipogenesis (i.e., CypE1, Nrf2, and Scd1, respectively). No signs of toxicity were observed in HEBT-treated mice. We propose that HEBT may be a promising pharmacological treatment for AFLD.

Sydnone 1: A Mesoionic Compound with Antitumoral and Haematological Effects In Vivo.

This study evaluated the antitumour activity of the mesoionic compound sydnone 1 (Syd-1) against Walker-256 carcinosarcoma. Tumour cells were subcutaneously inoculated in the hind limb in male Wistar rats. The animals were orally treated for 12 days with Syd-1 (75 mg/kg) or vehicle. At the end of treatment, considerable decreases in tumour volume and tumour weight were observed in treated animals. Samples of these tumours presented increases in apoptotic bodies and pro-apoptotic protein expression (Bax and p53), while the expression of the anti-apoptotic protein Bcl-2 was reduced. A decrease in reduced glutathione levels and an increase in glutathione peroxidase activity were observed in tumour after Syd-1 treatment. However, significant splenomegaly was evident in animals that received Syd-1, most likely attributable to the induction of haemolysis. This study demonstrated the antitumour activity of Syd-1 against Walker-256 carcinosarcoma. Its mechanism of action is linked to the activation of apoptotic pathways that lead to tumour cell death.

Sesquiterpene lactones of Moquiniastrum polymorphum subsp. floccosum have antineoplastic effects in Walker-256 tumor-bearing rats.

BACKGROUND AND AIM: This study aimed to evaluate the in vivo antitumor actions and toxicity of the dichloromethane fraction (F1B) of Moquiniastrum polymorphum subsp. floccosum (formerly Gochnatia polymorpha ssp. floccosa), composed of sesquiterpene lactones, against Walker-256 carcinosarcoma in rats. METHODS: Male Wistar rats received 100 mg kg(-1) F1B per day orally for 16 days after subcutaneous inoculation of Walker-256 cells in the pelvic limb. The tumor progression was monitored, and after treatment, tumor weight, oxidative stress, plasma biochemistry, inflammatory parameters, gene expression and histology of tumor and/or liver were evaluated. The toxicity of F1B was analyzed through the relative weight of organs. Additionally, an LD50 test was performed in mice. RESULTS: F1B treatment significantly reduced tumor volume and weight. There was no difference in oxidative stress in tumor tissue after treatment. F1B treatment modified hepatic glutathione and superoxide dismutase, and normalized plasma glucose, alkaline phosphatase, and amylase. F1B did not affect the activity of myeloperoxidase and N-acetylglucosaminidase or the nitric oxide levels in tumor tissue. However, F1B decreased the tumor necrosis factor (TNF)-α levels. Additionally, F1B increased apoptosis in the tumor, mediated by up-regulation of the p53 and Bax gene expression. No clinical signs of toxicity or death were observed in the rats treated with F1B. The LD50 calculated for mice was 1209 mg kg(-1). CONCLUSIONS: F1B, which is rich in sesquiterpene lactones, showed antitumor activity against Walker-256 carcinosarcoma. This effect may be, at least in part, related to the induction of apoptosis and inhibition of TNF-α signaling.