Phytochemical Evaluation and Anti-Inflammatory Potential of Miconia albicans (Sw.) Triana Extracts.

The plant Miconia albicans (Sw.) Triana has been popularly used in Brazil to treat chronic inflammatory disturbances, such as osteoarthritis. This disease affects 250 million people worldwide, and is associated with intense pain and loss of articular function. There is a lack of information about the phytochemistry and bioactivity of M. albicans. Therefore, this study determined the chemical composition of some extracts and evaluated their cytotoxicity, along with their antioxidant and anti-inflammatory, activities using in vitro models. Aqueous and ethanolic extracts were prepared. Afterwards, a liquid-liquid partition was developed using chloroform, ethyl acetate, and n-butanol. The extracts were characterized by LC-MS, and their biological activities were evaluated on epithelial cells (Vero), tumoral hepatic cells (Hep-G2), and THP-1 macrophages. LC-MS analyses identified several flavonoids in all fractions, such as quercetin, myricetin, and their glycosides. The crude extracts and n-butanol fractions did not present cytotoxicity to the cells. The non-toxic fractions presented significant antioxidant activity when evaluated in terms of DPPH scavenging activity, lipid peroxidation, and ROS inhibition. THP-1 macrophages treated with the n-butanol fraction (250 µg/mL) released fewer pro-inflammatory cytokines, even in the presence of LPS. In the future, it will be necessary to identify the phytochemicals that are responsible for anti-inflammatory effects for the discovery of new drugs. In vivo studies on M. albicans extracts are still required to confirm their possible mechanisms of action.

Effects of o,p'-DDE, a Mitotane Metabolite, in an Adrenocortical Carcinoma Cell Line.

In South Brazil, the incidence of pediatric adrenocortical carcinoma (ACC) is higher than in other regions and countries worldwide. The ACC treatment includes therapy with mitotane, the only adrenolytic drug approved by the FDA. The mitotane metabolism occurs via two main reactions: the ß-hydroxylation, which yields the final product o,p'-DDA, and the α-hydroxylation, which will give the final product o,p'-DDE. It is speculated that o,p'-DDE may be an active metabolite since it has a cytotoxic effect on adrenocortical carcinoma cells (H295R). No further studies have been conducted to confirm this hypothesis; however, it was found that mitotane and its metabolites are present at significantly different concentrations in the plasma of the patients. Our study aimed to assess the in vitro effects of o,p'-DDE and o,p'-DDD in cell death pathways, oxidative parameters, and interaction with adrenal CYP's involved in the steroidogenic process in the H295R cell line. It was found that o,p'-DDE had a different effect than the o,p'-DDD on apoptosis, inhibiting this cell death pathway, but it promotes cell necrosis at higher concentrations. In contrast to o,p'-DDD, the o,p'-DDE did not have effects on the different oxidative parameters evaluated, but exhibited stimulatory interactions with steroidogenic CYP's, at intermediate concentrations. Therefore, we demonstrated important cell effects of o,p'-DDE; its plasma levels during mitotane therapy should be monitored as an important therapeutic parameter.

Dichloroacetate and Pyruvate Metabolism: Pyruvate Dehydrogenase Kinases as Targets Worth Investigating for Effective Therapy of Toxoplasmosis.

Toxoplasmosis, a protozoan infection caused by Toxoplasma gondii, is estimated to affect around 2.5 billion people worldwide. Nevertheless, the side effects of drugs combined with the long period of therapy usually result in discontinuation of the treatment. New therapies should be developed by exploring peculiarities of the parasite's metabolic pathways, similarly to what has been well described in cancer cell metabolism. An example is the switch in the metabolism of cancer that blocks the conversion of pyruvate into acetyl coenzyme A in mitochondria. In this context, dichloroacetate (DCA) is an anticancer drug that reverts the tumor proliferation by inhibiting the enzymes responsible for this switch: the pyruvate dehydrogenase kinases (PDKs). DCA has also been used in the treatment of certain symptoms of malaria; however, there is no evidence of how this drug affects apicomplexan species. In this paper, we studied the metabolism of T. gondii and demonstrate that DCA also inhibits T. gondii's in vitro infection with no toxic effects on host cells. DCA caused an increase in the activity of pyruvate dehydrogenase followed by an unbalanced mitochondrial activity. We also observed morphological alterations frequently in mitochondria and in a few apicoplasts, essential organelles for parasite survival. To date, the kinases that potentially regulate the activity of pyruvate metabolism in both organelles have never been described. Here, we confirmed the presence in the genome of two putative kinases (T. gondii PDK [TgPDK] and T. gondii branched-chain α-keto acid dehydrogenase kinase [TgBCKDK]), verified their cellular localization in the mitochondrion, and provided in silico data suggesting that they are potential targets of DCA.IMPORTANCE Currently, the drugs used for toxoplasmosis have severe toxicity to human cells, and the treatment still lacks effective and safer alternatives. The search for novel drug targets is timely. We report here that the treatment of T. gondii with an anticancer drug, dichloroacetate (DCA), was effective in decreasing in vitro infection without toxicity to human cells. It is known that PDK is the main target of DCA in mammals, and this inactivation increases the conversion of pyruvate into acetyl coenzyme A and reverts the proliferation of tumor cells. Moreover, we verified the mitochondrial localization of two kinases that possibly regulate the activity of pyruvate metabolism in T. gondii, which has never been studied. DCA increased pyruvate dehydrogenase (PDH) activity in T. gondii, followed by an unbalanced mitochondrial activity, in a manner similar to what was previously observed in cancer cells. Thus, we propose the conserved kinases as potential regulators of pyruvate metabolism and interesting targets for new therapies.

Multiple Risk Factors for Heart Disease: A Challenge to the Ethnopharmacological Use of Croton urucurana Baill.

Croton urucurana Baill. is a native Brazilian tree, popularly known as "sangra-d'água" or "sangue-de-dragão," based on the red resinous sap of the trunk. Its use has been transmitted through generations based on popular tradition that attributes analgesic, anti-inflammatory, and cardioprotective properties to the tree. However, its cardioprotective effects have not yet been scientifically investigated. Thus, the present study investigated the pharmacological response to an ethanol-soluble fraction from the leaves of C. urucurana in Wistar rats exposed to smoking and dyslipidemia, two important cardiovascular risk factors. The extract was evaluated by high-performance liquid chromatography. Wistar rats received a 0.5% cholesterol-enriched diet and were exposed to cigarette smoke (9 cigarettes/day for 10 weeks). During the last 5 weeks, the animals were orally treated with vehicle (negative control group), C. urucurana extract (30, 100, and 300 mg/kg), or simvastatin (2.5 mg/kg) + enalapril (15 mg/kg). One group of rats that was not exposed to these risk factors was also evaluated (basal group). Electrocardiograms and systolic, diastolic, and mean blood pressure were measured. Blood was collected to measure total cholesterol, triglycerides, urea, and creatinine. The heart and kidneys were collected and processed for oxidative status and histopathological evaluation. The phytochemical analysis revealed different classes of flavonoids and condensed tannins. The model induced dyslipidemia and cardiac and renal oxidative stress and increased levels of urea and creatinine in the negative control group. Treatment with the C. urucurana extract (300 mg/kg) and simvastatin + enalapril decreased cholesterol and triglyceride levels. In contrast to simvastatin + enalapril treatment, the C. urucurana extract exerted cardiac and renal antioxidant effects. No alterations of electrocardiograms, blood pressure, or histopathology were observed between groups. These findings indicate that C. urucurana exerts lipid-lowering, renal, and cardioprotective effects against oxidative stress in a preclinical model of multiple risk factors for heart disease.

Baccharis trimera (Less.) DC: An Innovative Cardioprotective Herbal Medicine Against Multiple Risk Factors for Cardiovascular Disease.

Cardiovascular disease (CVD) is the leading cause of death worldwide and among its modifiable risk factors are dyslipidemia, diabetes, and smoking. Experimental models evaluated this risk factors singly, however, there is a lack of models that agglomerate these risk factors, resembling real patients and elucidating the pathophysiology of CVD. Moreover, few studies have investigated the cardioprotective effects of Baccharis trimera, a species with lipid-lowering effects. In this study, ethanol-soluble fraction of B. trimera was characterized by liquid chromatography-mass spectrometry. Diabetes was induced by streptozotocin in Wistar rats that also received 0.5% cholesterol-enriched chow and were exposed to the smoke of nine cigarettes, 5 days/week, for 4 weeks. During the last 2 weeks, the animals were treated with vehicle (C-), B. trimera, or simvastatin plus insulin. At the end, cholesterol, triglyceride, urea, and creatinine levels; blood pressure (BP); heart rate (HR); abdominal aortic morphometry; vascular reactivity; renal and cardiac oxidative status; and histopathological changes were evaluated. The agglomerate of risk factors promoted alterations contrary to those described in the literature for the isolated risk factors. The C- group exhibited oxidative stress, increase in biochemical parameters, and thickening of the wall of the abdominal aorta. HR, systolic, diastolic, and mean BP decreased, and vascular reactivity was altered. Cardiac and renal histopathological changes were observed. Treatment with B. trimera reversed these changes and this effect may be partially attributable to lipid-lowering action and to the inhibition of free radical generation. B. trimera has cardioprotective effects in this model, with no toxicity.

Promising therapeutic use of Baccharis trimera (less.) DC. as a natural hepatoprotective agent against hepatic lesions that are caused by multiple risk factors.

ETHNOPHARMACOLOGICAL RELEVANCE: Baccharis trimera (Less.) DC is a perennial subshrub, popularly known as "carqueja," that belongs to the Asteraceae family. Ethnobotanical studies indicate that this species is used for the treatment of diabetes and digestive and liver diseases. However, studies that sought to validate its popular use were conducted using ethanolic extracts of the plant, which does not reflect the ethnomedicinal use of this species in humans. AIM OF THE STUDY: Non-alcoholic fatty liver disease (NAFLD) is characterized by triglyceride accumulation in the liver that can progress to cirrhosis and hepatocellular carcinoma. Because of the severity of this disease, less toxic and more effective therapeutic agents need to be developed. B. trimera may be a promising therapeutic alternative, but its activity against multiple risk factors for liver disease (e.g., smoking, dyslipidemia, and diabetes mellitus) has not been studied. The present study investigated the effects of an ethnomedicinal form of a B. trimera preparation in a rat model of NAFLD that is associated with multiple risk factors. MATERIAL AND METHODS: Phytochemical analysis of the ethanolic soluble fraction of B. trimera extract was performed using ultra-performance liquid chromatography coupled to high-resolution mass spectrometry. Streptozotocin was used to induce diabetes in male Wistar rats. The rats received a 0.5% cholesterol-enriched diet and were exposed to cigarette smoke (9 cigarettes/day, 5 days/week, for 4 weeks). In the last 2 weeks, the animals were orally treated with vehicle (negative control group), B. trimera extract (30, 100, and 300 mg/kg), or insulin + simvastatin. One group of rats that was not exposed to these risk factors was also evaluated. Blood was collected for glucose, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) analysis. The liver and feces were collected for lipid quantification. The liver was additionally processed for histopathological analysis. RESULTS: The model successfully induced NAFLD and increased levels of glucose, AST, and ALT in the negative control group. Treatment with the B. trimera extract (30 and 100 mg/kg) and insulin + simvastatin decreased hepatic and fecal lipids. In contrast to insulin + simvastatin treatment, all three doses of B. trimera effectively reduced AST and ALT levels. CONCLUSION: B. trimera may be promising as a hepatoprotective agent against hepatic lesions that are caused by multiple risk factors.