Subchronic feeding study of grape colour extract in beagle dogs

(Poly)phenol toxicity in vivo following oral administration: A targeted narrative review of (poly)phenols from green tea, grape, and anthocyanin-rich extracts

Fruit- and vegetable-derived (poly)phenols are secondary plant metabolites that may have beneficial effects on human health when consumed regularly. Recent years have seen rapid growth in both consumer demand for and research interest in (poly)phenol-rich dietary supplements, natural colorants, and functional foods. As these products continue to enter the marketplace and (poly)phenol intake patterns change from traditional food products to these sources, attention must be paid to the potential for toxicity from consuming elevated doses of (poly)phenols. To date, much remains unknown regarding the safety of high doses of (poly)phenols, especially in vivo. In this targeted narrative review, we summarize evidence from in vivo investigations of (poly)phenol toxicity after oral administration of green tea extracts, grape-derived phenolics, and anthocyanin-rich extracts. There is limited evidence of overt toxicity from oral ingestion of these (poly)phenol-rich sources, though more research on the safety of high doses-as well as defining what constitutes a "high" dose of both individual and complex mixtures of (poly)phenols-is needed before these observations can be used to create dietary guidance for consumers.

A 90 day oral toxicity study of blueberry polyphenols in ovariectomized sprague-dawley rats

Regular consumption of polyphenol-rich fruits and vegetables is associated with beneficial health outcomes. To increase polyphenol intakes, consumers are increasingly using herbal and botanical dietary supplements containing concentrated polyphenol extracts. However, the safety of this consumption modality has not been vetted. To address this, ovariectomized Sprague-Dawley (OVX-SD) rats were orally gavaged with purified blueberry polyphenols at 0-1000 mg total polyphenols/kg bw/d for 90d. No differences in behavior, body weight, or food consumption were observed. No tumors or macroscopic changes were observed, and histopathological analyses showed no differences among groups. Although several statistically significant differences between treatment and control groups were observed in urine (color and pH) and blood (monocyte count, total cholesterol, and chloride ion concentration) analyses, these parameters were within normal ranges and not considered biologically significant. Intestinal permeability assessed via FITC-dextran showed increased intestinal permeability in the highest dose, though no morphological differences were found throughout the gastrointestinal tract. Given the lack of other systemic changes, this finding is likely of minimal physiological importance. These results indicate a NOAEL for blueberry polyphenols in OVX-SD rats is ≥ 1000 mg total polyphenols/kg bw/d, which translates to a 70 kg human consuming ~10 g polyphenols. Keywords: Blueberry, Polyphenol, Sub-chronic toxicity.

Safety assessment of Vitis vinifera (grape)-derived ingredients as used in cosmetics

The Cosmetic Ingredient Review Expert Panel (Panel) assessed the safety of 24 Vitis vinifera (grape)-derived ingredients and found them safe in the present practices of use and concentration in cosmetics. These ingredients function in cosmetics mostly as skin-conditioning agents, but some function as antioxidants, flavoring agents, and/or colorants. The Panel reviewed the available animal and clinical data to determine the safety of these ingredients. Additionally, some constituents of grapes have been assessed previously for safety as cosmetic ingredients by the Panel, and others are compounds that have been discussed in previous Panel safety assessments.

The safety and regulatory status of food, drug and cosmetics colour additives exempt from certification

Colour additives exempt from certification (also known as 'natural colour additives') are commonly used in the United States to colour foods, drugs and cosmetics. The US Food and Drug Administration established regulations governing the use of these colour additives, and the labelling of the products that contain them. The safety of these colour additives has been demonstrated by safety testing programs that have yielded a significant amount of toxicology data, and also by a long and well documented history of safe use in the United States and elsewhere. In this report we review the data supporting the safety of the colour additives that are exempt from certification and approved for use in the USA, and conclude that the safety of these colour additives is well supported by the available data. Relevant aspects of the regulation of these colour additives are also described.

Reproduction study of grape colour extract in rats

The effect of Welch's Special Grape Color Powder Type BW-AT on reproductive performance was studied through two generations of Sprague-Dawley rats and a subchronic study was carried out on the F1 animals. The grape colour powder at dietary levels of 7.5 and 15.0% (w/w) had no adverse effects on reproductive performance. Body weights for F0 and F1 generation pups at both dose levels were significantly lower (P less than 0.05) than those of control pups at 21 days after birth. During the 13-wk subchronic feeding study of F1 rats, the body-weight gain of female rats in the high-dose group was reduced compared with the controls (P less than 0.05). Food conversion data was comparable among groups, thus the decrease in body-weight gain during this phase was most likely the result of the lower calorific value (w/w) of the feed supplemented with the grape colour powder compared with the control feed. No toxic effects or pathological changes were noted in rats fed grape colour powder.