Berry Leaves: An Alternative Source of Bioactive Natural Products of Nutritional and Medicinal Value

Abstract

Berry fruits are recognized, worldwide, as “superfoods” due to the high content of bioactive natural products and the health benefits deriving from their consumption. Berry leaves are byproducts of berry cultivation; their traditional therapeutic use against several diseases, such as the common cold, inflammation, diabetes, and ocular dysfunction, has been almost forgotten nowadays. Nevertheless, the scientific interest regarding the leaf composition and beneficial properties grows, documenting that berry leaves may be considered an alternative source of bioactives. The main bioactive compounds in berry leaves are similar as in berry fruits, i.e., phenolic acids and esters, flavonols, anthocyanins, and procyanidins. The leaves are one of the richest sources of chlorogenic acid. In various studies, these secondary metabolites have demonstrated antioxidant, anti-inflammatory, cardioprotective, and neuroprotective properties. This review focuses on the phytochemical composition of the leaves of the commonest berry species, i.e., blackcurrant, blackberry, raspberry, bilberry, blueberry, cranberry, and lingonberry leaves, and presents their traditional medicinal uses and their biological activities in vitro and in vivo.

Roots and Leaf Extracts of Dipsacus fullonum L. and Their Biological Activities

“…Despite their traditional use, leaves are rarely used nowadays, in contrast to berry and fruits [2] or other plant organs such as roots or stems, which are considered food with significant health benefits conveyed by antioxidant activity.…”

“…Plants have been globally utilized since antiquity for flavoring, coloring, and preserving foods and also for food production, cosmetic, and medicinal purposes [1]. Traditional medicine uses roots and leaves as they are rich in bioactive compounds and excellent sources of compounds such as triterpenes, iridoids, xanthones, carotenoids, and benzophenones [2][3][4]. Polyphenolic compounds such as phenolic acids and flavonoids are still among the crucial compounds exhibiting high antioxidant activity.…”

“…They are common plant secondary metabolites necessary not only in plant physiological processes but also exerting positive effects on human health as antioxidants. Biological properties of these compounds were demonstrated in vitro and in vivo and they include antioxidant [5], antifungal, antimicrobial [6], antidiabetic [7], anti-inflammatory [5,8], antipyretic, analgesic, and immunomodulatory activity [2].…”

Phenolic Antioxidants in Aerial Parts of Wild Vaccinium Species: Towards Pharmaceutical and Biological Properties

“…Human studies were also reported regarding the cardioprotective activity of bilberry leaves [68]. In a human study of 35 volunteers, Erlund [69] investigated the effects of daily consumption of mixed bilberries (100 g) and nectar containing 50 g crushed lingonberries on well-established risk factors of CVD, such as platelet function, HDL cholesterol, and blood pressure for 2 months.…”

Wild Strawberry, Blackberry, and Blueberry Leaf Extracts Alleviate Starch-Induced Hyperglycemia in Prediabetic and Diabetic Mice

“…leaves have traditionally been used in folk medicine for several purposes, including diabetes. It has been shown that water and butanol extracts of the berry leaves are active in T2DM [24]. In one experiment, different extracts exerted a hypoglycemic effect in normoglycemic and alloxan-induced diabetic animals as well [25].…”