Effects of Watermelon Powder and l-arginine Supplementation on Azoxymethane-Induced Colon Carcinogenesis in Rats.

Diets high in fruits and vegetables may help prevent colorectal cancer (CRC). Watermelon consumption may reduce CRC risk due to its concentration of l-citrulline and its role in endothelial nitric oxide (NO) production. Research suggests that increased NO levels have tumoricidal effects. The purpose of this study was to determine the effects of watermelon powder supplementation on aberrant crypt foci (ACF) formation, precancerous lesions, and expression of genes associated with colon carcinogenesis. Thirty-two male Sprague-Dawley rats were assigned into three groups: control, 0.36% l-arginine, or 0.5% watermelon powder and injected with azoxymethane (15 mg/kg body weight). Both l-arginine and watermelon powder groups exhibited lower total numbers of ACF and high multiplicity ACF (P < 0.01). The watermelon powder group exhibited higher NO levels and lower 8-hydroxyguanosine DNA damage (P < 0.05). Watermelon powder and l-arginine downregulated 8-oxoguanine DNA glycosylase gene expression and upregulated O6-methylguanine DNA methyltransferase gene expression (P < 0.05). Cyclooxgenase-2 gene expression was lower for rats fed with watermelon powder (P < 0.05). These results suggest that watermelon powder or l-arginine supplementation may reduce the risk of colon cancer by suppressing ACF formation through lowering oxidative DNA damage and inflammation, modulating DNA repair enzyme expression, and/or enhancing NO production.

Case Report: A Case of Recurrent Strongyloides stercoralis Colitis in a Patient with Multiple Myeloma.

Strongyloides stercoralis chronic infection is frequently subclinical and thus under-recognized, although its increasing prevalence in nonendemic regions has implications for immunocompromised hosts. We present a 75-year-old male with stage II multiple myeloma who presented with relapse of Strongyloides infection after initial treatment, negative surveillance testing, and subsequent resumption of chemotherapy for his multiple myeloma. The optimal regimen for secondary prophylaxis against recurrent infections is unknown. Secondary prophylaxis should be considered for patients who recur and/or remain at high risk of recurrence because of ongoing immunosuppression. We implemented a prophylactic regimen of ivermectin 200 mcg/kg once monthly. In addition, improved laboratory assays for strongyloidiasis are needed to aid with diagnosis, monitoring of treatment response, and early detection of relapse.