Evaluation of Toxicological Effects of an Aqueous Extract of Shells from the Pecan Nut Carya illinoinensis (Wangenh.) K. Koch and the Possible Association with Its Inorganic Constituents and Major Phenolic Compounds

Abstract

Background. Industrial processing of the pecan nut Carya illinoinensis K. Koch generated a large amount of shells, which have been used to prepare nutritional supplements and medicinal products; however, the safe use of shells requires assessment. This study evaluated the toxic, genotoxic, and mutagenic effects of pecan shell aqueous extract (PSAE) and the possible contribution of phenolic compounds, ellagic and gallic acids, and inorganic elements present in PSAE to induce toxicity. Results. Levels of inorganic elements like K, P, Cl, and Rb quantified using the Particle-Induced X-Ray Emission method were higher in PSAE than in pecan shells, while Mg and Mn levels were higher in shells. Mice showed neurobehavioral toxicity when given high PSAE doses (200–2,000 mg kg−1). The LD50 was 1,166.3 mg kg−1. However, PSAE (50–200 mg·kg−1) and the phenolic compounds (10–100 mg·kg−1) did not induce DNA damage or mutagenicity evaluated using the comet assay and micronucleus test. Treatment with ellagic acid (10–100 mg·kg−1) decreased triglyceride and glucose levels, while treatments with PSAE and gallic acid had no effect. Conclusion. Pecan shell toxicity might be associated with high concentrations of inorganic elements such as Mn, Al, Cu, and Fe acting on the central nervous system, besides phytochemical components, suggesting that the definition of the safe dose should take into account the consumption of micronutrients.

Bioactive components and health effects of pecan nuts and their by-products: a review

“…In subacute studies, Porto et al (2013) determined that no toxic effect was observed on Wistar rats summited to doses of 100 mg/kg for 28 days, a doses that showed some beneficial effects, such as decrease in TAG and body weight. The same group (Porto et al, 2015b) observed no toxic effect of doses up to 200 mg/kg for 3 days in CF-1 mice. Authors concluded that when using nutshell extracts the high levels of inorganic elements should be considered for safety reasons.…”

“…Gad et al (2007)determined an LD50 of 8.3 g/kg for an ethanolic leave extract in Sprague Dawley rats. Porto et al (2015b) determined the acute LD50 of aqueous nutshell extracts to be higher than 2 g/ kg for Wistar rats and 1166 mg/kg for CF-1 mice. Hawary et al…”

Potential applications of pecan residual biomasses: a review

“…In this context, studies have shown that aqueous extracts of pecan shells (rich in acids such as gallic, 4-hydroxybenzoic, vanillic, chlorogenic, caelic and ellagic) have the ability to induce breast cancer cell death and increase breast cancer survival time of patients with certain tumors [18,27]. Also, shell in fresh condition has been used in nutraceutical products against obesity, hypercholesterolemia and as a source for the precaution of metabolic and inflammatory diseases, neurological disorders, gastric ulcers, and cancer [28]. These residues act as antinociceptive and antiedematogenic materials due to the high concentration of rutin, or vitamin P, in its composition [29].…”

Cytotoxicity of subcritical water extracts obtained from byproducts generated at commercial pecan shelling operations on cancer cells

“…A study by Hilbig and co-workers (2018) have shown that pecan nut shell extracts effectively reduced viability of the breast cancer tumor cells and intensi ed cell death. Another study by Porto et al (2016) reported that pecan shell extracts did not induce DNA damage or mutagenicity.…”