Antioxidant action and enzyme activity modulation by bioaccessible polyphenols from jambolan (Syzygium cumini (L.) Skeels).

Jambolan is rich in antioxidant polyphenols; however, the bioactivity of these compounds remains poorly investigated. We compared changes in polyphenols and antioxidant capacity by ABTS and FRAP assays of jambolan pulp during in vitro digestion and chemical extraction and evaluated the effects of these changes on oxidative stress in wild and mutant Saccharomyces cerevisiae. Digestion and chemical extraction were performed with enzyme saline solutions, deionized water, and 50% (v/v) aqueous acetone solution. Caffeic, quinic, gallic, and ellagic acids, isomers of myricetin, catechin, and anthocyanins are bioaccessible during gastric digestion. In the duodenum, flavonoids and proanthocyanidins remained stable when the pH changed from acidic to neutral/alkaline, whereas anthocyanins were degraded when exposed to pH 7. In the colon, anthocyanins were not identified. The antioxidant activity of bioaccessible fractions is correlated with non-anthocyanin flavonoids and proanthocyanidins, reflected in the modulation of antioxidant enzymes of S. cerevisiae. The digestion process favors the release of bio-polyphenols from jambolan with preventive, scavenger, and reparative antioxidant action. They also stimulate the production and activity of Sod and Cat, strengthening the endogenous antioxidant system.

Punicic acid was metabolised and incorporated in the form of conjugated linoleic acid in different rat tissues.

The objective of this study was to evaluate the effects of a supplementation of pomegranate seed oil (PSO), being rich in punicic acid, on the biochemical parameters of healthy rats. PSO was given to the animals intragastrically for 40 days at concentrations of 1%, 2% and 4%. There were no changes in their total body weight gain, their serum biochemical markers, or in the oxidative stress in their tissues. However, the TBARS values were reduced in the brains of the animals, noting that no significant amounts of conjugated fatty acids were found in this tissue. Conjugated linoleic acid (CLA) was present in all the other tissues studied. The results obtained have demonstrated that punicic acid from PSO was metabolised and incorporated in the form of CLA in different rat tissues. It did not cause alterations in their lipid metabolism, nor did it participate in the processes of oxidation inhibition.

Bitter gourd (Momordica charantia L. ) seed oil as a naturally rich source of bioactive compounds for nutraceutical purposes

Background: Characterization of food lipids has triggered the development of applications for the food and health industries. Thus, the lipid profiles of an increasing number of fruits and their seeds have been characterized and numerous bioactive components have been isolated. The bitter gourd seed oil has aroused great interest because it contains relevant amounts of conjugated fatty acid α-eleostearic acid (C18:3 9c11t13t), a positional and geometric isomer of α-linolenic acid. The aim of this paper was to evaluate the phytochemical composition and quality parameters of the seed oil of bitter gourd grown in Brazil. Methods: Bitter gourd was purchased from CEAGESP (Brazilian company of fresh food storages and warehouses). Seeds were lyophilized, and their oil was extracted using the Soxhlet and Folch extraction methods. The profiles of fatty acids and phytosterols were analyzed by gas chromatography, and the acidity and peroxide values were evaluated by methods of the American Oil Chemists' Society (AOCS). Results: The Soxhlet extraction (40 % w / w ) resulted in a higher yield of bitter gourd seed oil than the Folch extraction (16 % w / w). For both methods, α-eleostearic acid (56 and 58 %) was the major lipid in bitter gourd seed oil, followed by stearic acid (C18:0; 32 and 27 %). The oil displayed high content of phytosterols (886 mg/100 g), mainly ß-sitosterol, and low acidity and peroxide values. Conclusions: Bitter gourd seed oil from Brazil is an oil of good quality and its high contents of α-eleostearic acid and phytosterols with potential health-beneficial properties make it an attractive plant byproduct.

Incorporation and effects of punicic acid on muscle and adipose tissues of rats.

BACKGROUND: This study evaluated the effect of pomegranate seed oil (PSO) supplementation, rich in punicic acid (55 %/C18:3-9c,11 t,13c/CLNA), on the lipid profile and on the biochemical and oxidative parameters in the gastrocnemius muscle and adipose tissues of healthy rats. Linseed oil (LO), rich in linolenic acid (52 %/C18:3-9c12c15c/LNA) was used for comparison. METHODS: Male Wistar rats (n = 56) were distributed in seven groups: control (water); LNA 1 %, 2 % and 4 % (treated with LO); CLNA 1 %, 2 % and 4 % (treated with PSO), po for 40 days. The percentages were compared to the daily feed intake. Fatty acid profile were performed by gas chromatography, antioxidant enzymes activity by spectrophotometer and the adipocytes were isolated by collagenase tissue digestion. Analysis of variance (ANOVA) was applied to check for differences between the groups (control, LNAs and CLNAs) and principal component analysis (PCA) was used to project the groups in the factor-place (PC1 vs PC2) based on the biochemical responses assessed in the study. RESULTS: The fatty acids profile of tissues showed that the LNA percentages were higher in the animals that were fed LO. However, PA was only detected in the adipose tissues. Conjugated linoleic acid (CLA) was present in all the tissues of the animals supplemented with PSO, in a dose dependent manner, and 9c11t-CLA was the predominant isomer. Nevertheless there were no changes in the total weight gain of the animals, the weights of the tissues, and the oxidative stress parameters in the muscle. In addition, there was an increase in the size of the epididymal fat cells in the groups treated with PSO. Principal component analysis (PCA) showed that the CLNAs groups were arranged separately with a cumulative variance of 68.47 %. CONCLUSIONS: The results show that PSO can be used as a source of CLAs but that it does not cause changes in body modulation and does not interfere in the antioxidant activity of healthy rats.

Metabolic effects of sulforaphane oral treatment in streptozotocin-diabetic rats.

Diabetes has reached epidemic levels in the whole world, and the use of bioactive compounds that may have the capacity to prevent and treat diabetes is of great interest. Sulforaphane (SFN) is a compound which is found in cruciferous vegetables and that acts as both a potent antioxidant and regulator of gene expression. The aim of this study was to evaluate the effect of SFN in diabetes induced by streptozotocin (STZ). Male Wistar rats were gavaged with water or 0.1, 0.25, or 0.5 mg/kg of SFN before an injection of STZ (80 mg/kg). Animals treated with SFN showed fasting glycemia, insulin sensitivity, and hepatic glycogen concentrations, similar to the control group (nondiabetic), and different from the diabetic group. Diabetic animals also presented elevated levels of serum triacylglycerols (TAG), urea, and creatinine, and all SFN doses were able to reverse these alterations. However, the same doses of SFN accentuated alterations in total cholesterol, alanine, and aspartate aminotransferase levels, and had no effect on hepatic TAG, HDL cholesterol, and uptake of 2-deoxy glucose in adipose tissue and soleum muscle. Based on the effects inferred by the present data, SFN presented some positive effects against diabetes induction, although the impairment of hepatic function and cholesterol levels were aggravated after treatment with the compound.