Antidiabetic, Antioxidative and Antihyperlipidemic Effects of Strawberry Fruit Extract in Alloxan-Induced Diabetic Rats

Comparative Analysis of Nutritional Properties, Phytochemical Profile, and Antioxidant Activities between Red and Green Water Chestnut (Trapa natans) Fruits

The present study explored the nutritional composition, phytochemicals analysis, and antioxidant capacity of two indigenous varieties of red and green water chestnut (WCN) fruit grown in Pakistan. Accordingly, this study was designed to investigate the proximate composition (moisture, ash, fiber, proteins, fat, and energy), physicochemical properties (pH, °Brix, and glycemic index), minerals, and vitamins. The methanolic extracts of WCN fruits were explored for phytochemicals (total phenolic and flavonoid content), and antioxidant potential was examined in vitro by 1,1-diphenyl-2-picrylhydrazyl radical scavenging capacity (DPPH) and Ferric reducing antioxidant power (FRAP). Quantitative determination of mineral (sodium, potassium, calcium, phosphorus, iron, manganese, copper, and zinc) and vitamin (vitamin C, vitamin B6, vitamin B2, vitamin B3, vitamin A, and β-Carotene) composition was also assessed. Based on the findings, the proximate compositions of WCN green and red varieties varied greatly as WCN green contained significantly higher protein (1.72%), fat (0.65%), dietary fiber (2.21%), moisture (70.23%), ash (1.16%), and energy content (112.8 Kcal) than WCN red. In WCN green, the macro-micromineral concentrations were significantly higher than WCN red. Among the minerals analyzed, potassium was the most abundant mineral found in both varieties. Levels of vitamin C, B6, A, and β-Carotene were significantly higher in WCN green. In this study, methanolic extract showed higher extraction efficiency than acetone, ethanol, and distilled water. WCN green had a significantly higher quantum of total phenolic (91.13 mg GAE/g) and total flavonoid (36.6 mg QE/g) and presented significantly higher antioxidant activity than the WCN red. This study showed that, among both varieties, WCN green extract has therapeutic potential against free radical mediated health conditions and suggested the potential use of this fruit as a source of natural antioxidants in nutraceuticals.

An extract of Hibiscus sabdariffa improves short-term memory in rats with experimental diabetic hyperglycemia

BACKGROUND

Calyxes of Hibiscus sabdariffa (Hs) contain anthocyanins, that normalize blood glucose levels (BGL) in diabetic patients. Diabetes also causes memory alterations, which could hypothetically decrease with the consumption of Hs.

OBJECTIVES

To investigate the effect of dietary supplementation with a Hs extract on working memory and BGL in rats.

METHODS

Diabetic hyperglycemia (DHG) was induced with streptozotocin (STZ, 55 mg/kg i.p.) in Wistar rats. After 72 h DHG was confirmed, and the consumption of Hs extract began (50 mg/Kg/day). BGL and body weight (BW) were measured at 10, 20 and 30 days after DHG induction in controls and treated animals. Learning and short-term memory were evaluated after 30 days with Novel Object Recognition Test (NOR) and Barnes Maze (BM). The gross hippocampal structure was histologically analyzed.

RESULTS

STZ-treated animals presented low BW and persistent DHG (BGL <300 mg/dL). Diabetic animals consuming the Hs extract had a dual response: some showed BGL comparable to controls, while others had levels comparable to diabetic animals not consuming extract. Diabetic animals that consumed the Hs extract had a better performance in NOR and BM than the diabetic animals not consuming the extract. At the histological level, hippocampal morphological differences were observed between diabetic animals that consumed the extract and those that did not.

DISCUSSION

The Hs extract used here could be a good co-adjuvant in the treatment of DHG, aimed at mitigating memory deficits and high BGL. These beneficial effects could be attributed to the anthocyanin content in the extract.