Many authors of publicly available top-selling nutrition books in Canada are without clinical nutrition credentials, do not cite evidence, and promote their own services or products.

The accuracy of books as public nutrition resources varies substantially; whether authors of publicly available nutrition books possess related experience, cite scientific evidence, or have other financial incentives has not been assessed thoroughly. This study aimed to determine if publicly available top-selling nutrition books are written by authors who (1) have relevant expertise, (2) cite scientific evidence, and (3) benefit financially in other ways. Best-selling nutrition books were gathered from Amazon Canada. Differences in scientific citations and financial incentives were compared between authors with and without credentials. Authors who were Doctor of Medicine (MD), registered dietitians (RD), chiropractors, or naturopathic doctors had more in-text citations (56% versus 25%; p = 0.014) and cited more scientific articles (83% versus 50%; p = 0.0045) compared to all other authors. The majority of authors of publicly available top-selling nutrition books in Canada did not have MD/RD credentials. Many of the authors promoted their own services or products, regardless of credentials.

Apple Peel Flavonoid Fraction 4 Suppresses Breast Cancer Cell Growth by Cytostatic and Cytotoxic Mechanisms.

Many dietary flavonoids possess anti-cancer activities. Here, the effect of apple peel flavonoid fraction 4 (AF4) on the growth of triple-negative (MDA-MB-231, MDA-MB-468), estrogen receptor-positive (MCF-7), and HER2-positive (SKBR3) breast cancer cells was determined and compared with the effect of AF4 on normal mammary epithelial cells and dermal fibroblasts. AF4 inhibited breast cancer cell growth in monolayer cultures, as well as the growth of MCF-7 spheroids, without substantially affecting the viability of non-malignant cells. A sub-cytotoxic concentration of AF4 suppressed the proliferation of MDA-MB-231 cells by inhibiting passage through the G0/G1 phase of the cell cycle. AF4-treated MDA-MB-231 cells also exhibited reduced in vitro migration and invasion, and decreased Akt (protein kinase B) signaling. Higher concentrations of AF4 were selectively cytotoxic for MDA-MB-231 cells. AF4 cytotoxicity was associated with the intracellular accumulation of reactive oxygen species. Importantly, intratumoral administration of AF4 suppressed the growth of MDA-MB-231 xenografts in non-obese diabetic severe combined immunodeficient (NOD-SCID) female mice. The selective cytotoxicity of AF4 for breast cancer cells, combined with the capacity of sub-cytotoxic AF4 to inhibit breast cancer cell proliferation, migration, and invasion suggests that flavonoid-rich AF4 (and its constituents) has potential as a natural therapeutic agent for breast cancer treatment.

Retinoic acid and arsenic trioxide induce lasting differentiation and demethylation of target genes in APL cells.

Acute promyelocytic leukemia (APL) is characterized by arrested differentiation of promyelocytes. Patients treated with all-trans retinoic acid (ATRA) alone experience relapse, while patients treated with ATRA and arsenic trioxide (ATO) are often relapse-free. This suggests sustained changes have been elicited by the combination therapy. To understand the lasting effects of the combination therapy, we compared the effects of ATRA and ATO on NB4 and ATRA-resistant NB4-MR2 APL cells during treatment versus post treatment termination. After treatment termination, NB4 cells treated with ATRA or ATO reverted to non-differentiated cells, while combination-treated cells remained terminally differentiated. This effect was diminished in NB4-MR2 cells. This suggests combination treatment induced more permanent changes. Combination treatment induced higher expression of target genes (e.g., transglutaminase 2 and retinoic acid receptor beta), which in NB4 cells was sustained post treatment termination. To determine whether sustained epigenetic changes were responsible, we quantified the enrichment of histone modifications by chromatin immunoprecipitation, and CpG methylation by bisulfite-pyrosequencing. While ATRA and combination treatment induced similar histone acetylation enrichment, combination treatment induced greater demethylation of target genes, which was sustained. Therefore, sustained demethylation of target genes by ATRA and ATO combination treatment is associated with lasting differentiation and gene expression changes.