Antioxidant Activity in Gilthead Seabream (Sparus aurata L.) Fed with Diet Supplemented with Moringa

Rosemary Extracts Improved the Antioxidant Status of Low-Fat Yoghurt Sauces Enriched with Inulin

Yoghurt sauces are considered fatty products which are quite susceptible to oxidation and must be stabilised using antioxidants. Novel formulations for yoghurt sauces often involve replacement of fat with dietary fibres and use of natural preservatives. The aim of the present research was to design healthier formulations for yoghurt sauces based on the replacement of sunflower oil (SO) with chicory inulin (IN) and the use of rosemary extracts (RE) as natural antioxidants. Different sauces were developed by adding IN at 2 and 5% w: w and/or 300 mg/kg lipo- and/or water-soluble rosemary extracts (RLE and/or RWE) containing 120 and 146 mg polyphenols per g extract, respectively. Nutritional value (proximate composition and caloric contribution), some physical properties (pH and CIELab colour) and antioxidant status (deoxyribose, DPPH radical scavenging, Rancimat, lipid peroxidation and linoleic acid assays) were assessed in the sauces. Replacement of SO with IN (5%) reduced fat content by 30%, roughly 15% low calories, thereby obtaining healthier sauces. As expected, the RLE was more effective than the RWE in improving antioxidant activity in lipidic environment. Using RLE enhanced the antioxidant capacity of lipid peroxidation by 44%. In the Rancimat test, this increased the oxidative protection of the sauce made with and without IN (5%) by around 20% or 45%, respectively. Similarly, using RLE doubled protection against linoleic acid oxidation. Application of IN in yoghurt sauce has nutritional (replacement of lipids with dietary fibre) and technological interest (foaming agent) and can be combined with RE of high polyphenol content as a potential functional ingredient capable of stabilising the sauces against oxidation.

Moringa oleifera Leaves' Extract Enhances Nonspecific Immune Responses, Resistance against Vibrio alginolyticus, and Growth in Whiteleg Shrimp (Penaeus vannamei)

Simple Summary

This study found that moringa (Moringa oleifera) leaves’ water extract triggered phenoloxidase activity, phagocytic rate, and superoxide anion production in whiteleg shrimp (Penaeus vannamei) hemocytes by an in vitro assay. By an in vivo assay, a dietary moringa extract enhanced the total hemocyte count, phenoloxidase activity, phagocytic rate, immune-related gene expressions, and growth performance of the whiteleg shrimp. The administration of dietary moringa extract increased the survival rate after challenging the whiteleg shrimp with Vibrio alginolyticus.

Abstract

Moringa is widely known as a plant with high medicinal properties. Therefore, moringa has a high potential for use as an immunostimulant in shrimp. This study investigated the effect of a moringa water extract on the immune response, resistance against V. alginolyticus, and growth performance of whiteleg shrimp. To perform the in vitro assay, hemocytes were incubated with different concentrations of the moringa extract. Furthermore, the moringa extract was incorporated at 0 (control), 1.25 g (ME1.25), 2.5 g (ME2.5), and 5.0 g (ME5.0) per kg of diet for the in vivo assay. During the rearing period, immune responses, namely the total hemocyte count (THC), phenoloxidase (PO) activity, phagocytosis activity, superoxide anion production, and immune-related gene expression were examined on days 0, 1, 2, 4, 7, 14, 21, and 28. Growth performance was measured 60 days after the feeding period. Furthermore, the shrimp were challenged with V. alginolyticus after being fed for different feeding durations. The results of the in vitro assay revealed that 100–250 ppm of the moringa extract enhanced the PO activity, phagocytic rate (PR), and superoxide anion production. The findings of the in vivo assay demonstrated that the THC, PO activity, PR, and immune-related gene expression, including alpha-2-macroglobulin, prophenoloxidase II, penaeidin2, penaeidin3, anti-lipopolysaccharide factor, crustin, lysozyme, superoxide dismutase, and clotting protein, were higher in the group of ME.25 and ME5.0 than in the control and ME1.25 at several time points. Growth performance was significantly increased (p < 0.05) in the ME2.5 group compared to the control group. Furthermore, the dietary ME2.5 resulted in a higher survival rate compared to that of the control group after challenging with V. alginolyticus, especially at ME2.5 administered for 4 and 7 days. This study indicated that the incorporation of the moringa extract at 2.5 g per kg of diet enhanced the immune response, the growth performance of the whiteleg shrimp, and the resistance against V. alginolyticus infection.