English and Black Walnut Phenolic Antioxidant Activity <i>in Vitro</i>and Following Human Nut Consumption

Background: Walnut consumption may reduce the risk of cardiovascular disease by providing antioxidant protection to low density lipoproteins (LDL). Aim: This study compared the phenolic profile and antioxidant activity of English ver- sus black walnuts. Methods: Nuts were extracted in methanol or acetone prior to analysis with HPLC/LC-MS-MS for phenolic identification and quantitation. The ability to prevent oxidation of LDL was examined in vitro using walnut extracts and ex vivo after walnut consumption for 28 days. Results: Flavonoids identified/quantified with HPLC/LC- MS-MS included the phenolic acids 5-caffeoylquinic acid, 3-caffeoylquinic acid (black walnut only), 4-caffeoylquinic acid, and the flavonol glycosides quercetin-3-rutinoside, quercetin-3-galactoside, quercetin-3-pentoside, quercetin-3- arabinoside, quercetin-3-rhamnoside, and the aglycone quercetin (English walnut only). Total phenolic yield of acetone extracts were 166.1 and 24.2 μg/g for English and black walnut respectively, and yield for methanol extracts were 147.6 and 4.1 μg/g for English and black walnut respectively. In vitro LDL oxidation by Cu++ with English walnut ex- tracts significantly extended oxidation lag-time (A234) in a dose dependent manner at 1.0 and 0.1 μg/ml and reduced TBARS formation (1.0 μg/ml). Black walnut extracts reduced TBARS significantly but had no effect on A234. Human consumption of English or black walnuts (30 g nuts/day) for 28 days resulted in no differences in LDL antioxidant ca- pacity (A234) between groups or within groups. Conclusion: This study suggests that the English walnuts have a pheno- lic profile and in vitro antioxidant capacity that is better than black walnuts, but that walnut consumption for 28 days does not improve LDL resistance to oxidation.

LC-MS-MS Analysis and the Antioxidant Activity of Flavonoids from Eggplant Skins Grown in Organic and Conventional Environments

Eggplant fruits are known to contain different classes of phenolic phytochemicals (flavonols, phenolic acids, and anthocyanins) that can exert beneficial effects on human health. This study developed methods for the qualitative and quantitative composition analysis of phenolic compounds in the skin of eggplant fruits harvested following conventional and certified organic farming conditions. Eggplant skin was extracted using aqueous methanol prior to phenolic profiling with UHPLC-ESI-MS-MS. Eggplant skin extracts yielded a profile of 16 phenolic acids, 4 anthocyanins, and 11 flavonols, the first report of quercetin-3-diglucoside, myricetin-3-neohesperidoside, myricetin-3-galactoside, kaempferol-3,7-diglucoside, kaempferol-diglucoside and quercetin-3-rhamnoside. Polyphenolic extracts from all sources potently delayed the cupric ion-mediated lag-time for LDL lipid oxidation and protected Apo-B100 proteins against oxidative modification. Organic growing environment positively influences eggplant skin extract phenolic profile but not antioxidant capacity. In conclusion, eggplant skin has a robust profile of phenolic phytochemicals with excellent antioxidant properties.

Glycemic Response of Type 2 Diabetics to Raisins

Background: Raisins are a nutritious fruit snack containing fiber, antioxidants, and potassium. Diabetics tend to have low fruit intakes, possibly due to concerns about glycemic response. Aim: This study sought to characterize the utility of raisins as a way to improve fruit consumption by type 2 diabetics. Methods: Fasting type 2 diabetics randomly received 100 Calorie servings of bananas (BA;103.1 g), white bread (WB;40.2 g), raisins (RA;30.3 g), or Thompson seedless grapes (TG;112.4 g) on each of four separate lab visits in single cross-over fashion. Blood glucose (n = 15) and plasma insulin (n = 7) were measured before and 30, 60, 120 minutes after snack consumption. Results: Relative to baseline, blood glucose peaked significantly at 30 minutes for TG, RA and WB at 204.6 ± 16.2, 180.5 ± 12.7, and 176.2 ± 12.2 mg/dL, respectively, the 30 minute value for BA (173.2 ± 11.6 mg/dL) approached significance (p = 0.12). At 30 minutes, the blood glucose values for BA and TG differed significantly, at all other times no significant differences were observed, and all values returned to near baseline 120 minutes after consumption. Postprandial plasma insulin increased for all treatments, though not significantly. Conclusion: The extended shelf life and portability of raisins may make them an attractive choice for improving fruit consumption in type 2 diabetics.

Pneumothorax as a predatory goal for the sabertooth cat (<i>Smilodon fatalis</i>)

Smilodon fatalis was a large extinct felid distinguished by their two impressive maxillary canines and surprisingly low canine fracture rates. Previous theories regarding their attack strategy have suggested delivering damage by a bite with their maxillary canines. It has also been previously suggested that the canines could have been used to deliver a non-biting stab with an open jaw. It has been generally hypothesized that the attack was delivered to the neck of their large herbivore prey. Smilodon fatalis could have used their canines in a non-biting stab delivered with a closed jaw for the sole purpose of creating a pneumothorax. Creation of a pneumothorax would maximize immediate attack lethality, and minimize exposure of its canines to fracture.