Andean Prumnopitys Andina (Podocarpacae) Fruit Extracts: Characterization of Secondary Metabolites and Potential Cytoprotective Effect

The fruits from the Chilean Podocarpaceae Prumnopitys andina have been consumed since pre-Hispanic times. Little is known about the composition and biological properties of this fruit. The aim of this work was to identify the secondary metabolites of the edible part of P. andina fruits and to assess their antioxidant activity by means of chemical and cell-based assays. Methanol extracts from P. andina fruits were fractionated on a XAD7 resin and the main compounds were isolated by chromatographic means. Antioxidant activity was determined by means of 2,2-diphenyl-1-picrylhydrazyl radical (DPPH), ferric reducing power (FRAP), trolox equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) assays. The cytoprotective activity of the extract against oxidative and dicarbonyl stress was evaluated in human gastric epithelial cells (AGS). The total intracellular antioxidant activity (TAA) of the extract was determined in AGS cells. The inhibition of meat lipoperoxidation was evaluated under simulated gastric digestion conditions. Rutin, caffeic acid β-glucoside and 20-hydroxyecdysone were identified as major components of the fruit extract. Additional compounds were identified by high-performance liquid chromatography diode-array detector mass spectrometry (HPLC-DAD-MSⁿ) and/or co-injection with standards. Extracts showed dose-dependent cytoprotective effects against oxidative and dicarbonyl-induced damage in AGS cells. The TAA increased with the pre-incubation of AGS cells with the extract. This is the first report on the composition and biological activity of this Andean fruit.

Erythrocytes and cell line-based assays to evaluate the cytoprotective activity of antioxidant components obtained from natural sources

Oxidative stress can damage cellular components including DNA, proteins or lipids, and may cause several skin diseases. To protect from this damage and addressing consumer's appeal to natural products, antioxidants obtained from algal and vegetal extracts are being proposed as antioxidants to be incorporated into formulations. Thus, the development of reliable, quick and economic in vitro methods to study the cytoactivity of these products is a meaningful requirement. A combination of erythrocyte and cell line-based assays was performed on two extracts from Sargassum muticum, one from Ulva lactuca, and one from Castanea sativa. Antioxidant properties were assessed in erythrocytes by the TBARS and AAPH assays, and cytotoxicity and antioxidant cytoprotection were assessed in HaCaT and 3T3 cells by the MTT assay. The extracts showed no antioxidant activity on the TBARS assay, whereas their antioxidant capacity in the AAPH assay was demonstrated. On the cytotoxicity assays, extracts showed low toxicity, with IC50 values higher than 200μg/mL. C. sativa extract showed the most favourable antioxidant properties on the antioxidant cytoprotection assays; while S. muticum and U. lactuca extracts showed a slight antioxidant activity. This battery of methods was useful to characterise the biological antioxidant properties of these natural extracts.

Omega-3 prevents behavior response and brain oxidative damage in the ketamine model of schizophrenia

Supplementation with omega-3 has been identified as an adjunctive alternative for the treatment of psychiatric disorders, in order to minimize symptoms. Considering the lack of understanding concerning the pathophysiology of schizophrenia, the present study hypothesized that omega 3 prevents the onset of symptoms similar to schizophrenia in young Wistar rats submitted to ketamine treatment. Moreover, the role of oxidative stress in this model was assessed. Omega-3 (0.8g/kg) or vehicle was given by orogastric gavage once daily. Both treatments were performed during 21days, starting at the 30th day of life in young rats. After 14days of treatment with omega-3 or vehicle, a concomitant treatment with saline or ketamine (25mg/kg ip daily) was started and maintained until the last day of the experiment. We evaluated the pre-pulse inhibition of the startle reflex, activity of antioxidant systems and damage to proteins and lipids. Our results demonstrate that supplementation of omega-3 prevented: decreased inhibition of startle reflex, damage to lipids in the hippocampus and striatum and damage to proteins in the prefrontal cortex. Furthermore, these changes are associated with decreased GPx in brain tissues evaluated. Together, our results suggest the prophylactic role of omega-3 against the outcome of symptoms associated with schizophrenia.

Interactions of betulinic acid with xenobiotic metabolizing and antioxidative enzymes in DMBA-treated Sprague Dawley female rats

Cancer chemoprevention is related to classical epidemiology and involves the use of agents that inhibit, delay, or reverse the carcinogenesis that occurs as a result of accumulation of mutations and increased proliferation. Betulinic acid is known for its cytotoxic effects against a panel of cancer cell lines. In the present study, interactions of betulinic acid (BA) with xenobiotic metabolizing enzymes including mixed function oxidases (cytochrome b5, P420, P450, NADPH cytochrome P450 reductase, and NADH cytochrome b5 reductase), phase II enzymes (GST, DT-diaphorase, γ-glutamyl transpeptidase), LDH, antioxidative enzymes (glutathione reductase, SOD, catalase, ascorbate peroxidase, and guaiacol peroxidase), and lipid peroxidation are studied alone as well as in the presence of 7,12 dimethylbenzanthracene (DMBA)--a potent carcinogen using Sprague Dawley female rats. The effect of BA on reduced glutathione content and protein content is also taken into consideration. It has been found that administration of BA decreased the level of mixed function oxidases that are involved in the conversion of carcinogen to electrophile, elevated the level of phase II enzymes which participated in the removal of electrophiles by sulfation, conjugation etc. It has been found that BA effectively removed or neutralized the reactive species by the action of phase II enzymes and such an effect was reflected from the specific activities of antioxidative enzymes which were found to be lower as compared to positive control (DMBA-treated group) and in some cases even that of untreated control. BA was also found to have a pronounced effect in protecting the animals from lipid peroxidation as evident from the reduced levels of TBARS, conjugated diene, and lipid hydroperoxide formation. This study highlights the role of BA in modulating the activities of xenobiotic and antioxidative enzymes that have putative roles in cancer initiation and proliferation.

Bioactivity assessment and toxicity of crocin: a comprehensive review

Since ancient times, saffron, the dried stigma of the plant Crocus sativus L. has been extensively used as a spice and food colorant; in folk medicine it has been reputed to be efficacious for the alleviation and treatment of ailments. In addition to the three founded major constituents including crocin, picrocrocin and safranal, presence of carotenoids, carbohydrates, proteins, anthocyanins, vitamins and minerals provide valuable insights into the health benefits and nutritional value of saffron. Of the carotenoids present in saffron, highly water-soluble crocin (mono and diglycosyl esters of a polyene dicarboxylic acid, named crocetin) is responsible for the majority of its color, and appears to possess various health-promoting properties, as an antioxidant, antitumor, memory enhancer, antidepressant, anxiolytic and aphrodisiac. It is also worth noting that the crocin principle of saffron exhibited high efficacy along with no major toxicity in experimental models. We would be remiss to not consider the great potential of saffron and crocin, which benefits the cuisine and health of human life throughout the world. The present study provides a comprehensive and updated report of empirical investigations on bioactivities and biological characteristics of crocin.

Diphenyl diselenide prevents hepatic alterations induced by paraquat in rats

This study aimed to investigate the beneficial effect of diphenyl diselenide (PhSe)₂ on paraquat (PQ) induced alterations in rats liver. Adult male Wistar rats received (PhSe)₂ at 10 mg kg(-1), by oral administration (p.o.), during five consecutive days. Twenty-four hours after the last (PhSe)₂ dose, rats received PQ at 15 mg kg(-1), in a single intraperitoneally injection (i.p.). Seventy-two hours after PQ exposure, animals were sacrificed by decapitation for blood and liver samples obtainment. Histological alterations induced by PQ exposure, such as inflammatory cells infiltration and edema, were prevented by (PhSe)₂ administration. Moreover, (PhSe)₂ prevented hepatic lipid peroxidation (LPO) induced by PQ and was effective in reducing the myeloperoxidase (MPO) activity in liver, which was enhanced by PQ exposure. (PhSe)₂ also was effective in protecting against the reduction in ascorbic acid and non-protein thiols (NPSH) levels induced by PQ. The inhibition of glutathione S-transferase (GST) activity, in rats exposed to PQ, was normalized by (PhSe)₂ pre-treatment, whereas the inhibition of catalase (CAT) activity was not prevented by (PhSe)₂. The serum alkaline phosphatase (ALP) inhibition, induced by PQ administration, was also prevented by (PhSe)₂ pre-treatment. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities were not modified by PQ and/or (PhSe)₂ administration. Therefore, (PhSe)₂ pre-treatment was effective in protecting against the hepatic alterations induced by PQ in rats. This protective effect can involve the antioxidant and anti-inflammatory properties of (PhSe)₂.

L-carnitine supplementation as a potential antioxidant therapy for inherited neurometabolic disorders

In recent years increasing evidence has emerged suggesting that oxidative stress is involved in the pathophysiology of a number of inherited metabolic disorders. However the clinical use of classical antioxidants in these diseases has been poorly evaluated and so far no benefit has been demonstrated. l-Carnitine is an endogenous substance that acts as a carrier for fatty acids across the inner mitochondrial membrane necessary for subsequent beta-oxidation and ATP production. Besides its important role in the metabolism of lipids, l-carnitine is also a potent antioxidant (free radical scavenger) and thus may protect tissues from oxidative damage. This review addresses recent findings obtained from patients with some inherited neurometabolic diseases showing that l-carnitine may be involved in the reduction of oxidative damage observed in these disorders. For some of these diseases, reduced concentrations of l-carnitine may occur due to the combination of this compound to the accumulating toxic metabolites, especially organic acids, or as a result of protein restricted diets. Thus, l-carnitine supplementation may be useful not only to prevent tissue deficiency of this element, but also to avoid oxidative damage secondary to increased production of reactive species in these diseases. Considering the ability of l-carnitine to easily cross the blood-brain barrier, l-carnitine supplementation may also be beneficial in preventing neurological damage derived from oxidative injury. However further studies are required to better explore this potential.

Alzheimer's disease treated patients showed different patterns for oxidative stress and inflammation markers

Alzheimer's disease (AD) is the most common type of dementia accounting for 60-80% of the reported cases. The aim of this study was to evaluate levels of certain parameters of oxidative stress and markers of endothelial dysfunction in the blood of 21 AD patients under standard treatment compared with 10 controls, in an attempt to elucidate the contribution of AD to the total oxidative stress status of the patients. Results indicate that IL-6, TNF-α, ADMA and homocysteine levels were significantly elevated in AD patients. Protein carbonyls levels were higher in AD group, while glutathione reductase and total antioxidant capacity were lower, depicting decreased defense ability against reactive oxygen species. Besides, a higher level of advanced glycation end-products was observed in AD patients. Depending on the treatment received, a distinct inflammatory and oxidative stress profile was observed: in Rivastigmine-treated group, IL6 levels were 47% lower than the average value of the remaining AD patients; homocysteine and glutathione reductase were statistically unchanged in the Rivastigmine and Donepezil-Memantine, respectively Donepezil group. Although the study is based on a limited population, the results could constitute the basis for further studies regarding the effect of medication and diet on AD patients.

Influence of perinatal trans fat on behavioral responses and brain oxidative status of adolescent rats acutely exposed to stress

Because consumption of processed foods has increased in the last decades and so far its potential influence on emotionality and susceptibility to stress is unknown, we studied the influence of different fatty acids (FA) on behavioral and biochemical parameters after acute restrain stress (AS) exposure. Two sequential generations of female rats were supplemented with soybean oil (control group; C-SO), fish oil (FO) and hydrogenated vegetable fat (HVF) from pregnancy and during lactation. At 41days of age, half the animals of each supplemented group were exposed to AS and observed in open field and elevated plus maze task, followed by euthanasia for biochemical assessments. The HVF-supplemented group showed higher anxiety-like symptoms per se, while the C-SO and FO groups did not show these behaviors. Among groups exposed to AS, HVF showed locomotor restlessness in the open field, while both C-SO and HVF groups showed anxiety-like symptoms in the elevated plus maze, but this was not observed in the FO group. Biochemical evaluations showed higher lipoperoxidation levels and lower cell viability in cortex in the HVF group. In addition, HVF-treated rats showed reduced catalase activity in striatum and hippocampus, as well as increased generation of reactive species in striatum, while FO was associated with increased cell viability in the hippocampus. Among groups exposed to AS, HVF increased reactive species generation in the brain, decreased cell viability in the cortex and striatum, and decreased catalase activity in the striatum and hippocampus. Taken together, our findings show that the type of FA provided during development and growth over two generations is able to modify the brain oxidative status, which was particularly adversely affected by trans fat. In addition, the harmful influence of chronic consumption of trans fats as observed in this study can enhance emotionality and anxiety parameters resulting from stressful situations of everyday life, which can trigger more severe neuropsychiatric conditions.

Antioxidant and Antidiabetic Activity of Helicteres isora (L.) Fruits

The present investigations evaluated the antioxidant and antidiabetic activity of Helicteres isora (L.) fruits belonging to the family Sterculiaceae. The hot water extract of Helicteres isora fruits was prepared and screened for its in vitro antioxidant activity using 1,1-diphenyl,2-picryl hydrazyl assay, ß-carotene-linoleate model and microsomal lipid peroxidation or thiobarbituric acid reactive species assays and the IC₅₀ values were calculated. Antidiabetic effect was studied using the in vitro glucose uptake in the isolated rat hemi-diaphragm model. The hot water extract of Helicteres isora showed maximum activity with IC₅₀ value 25.12±0.18 μg/ml for 1,1-diphenyl,2-picryl hydrazyl assay method, and low activity with IC₅₀ value 740.64±4.76 μg/ml for microsomal lipid peroxidation assay. In the ß-carotene-linoleate model, the extract showed 45.63% antioxidant activity. The extract produce a significant (P<0.05) uptake of glucose by isolated rat hemi-diaphragm but less effective to that of the reference drug, metformin. The hot water extract of fruit of Helicteres isora exhibited significant antioxidant activity and moderate antidiabetic activity and merits further investigation in animal models and isolation of its active constituents.