NATURAL HONEY AND GASTROINTESTINAL CANCERS
There are many research studies support the use of natural honey for cancer prevention and treatment, especially cancers of the gastrointestinal tract. Nutritional studies have indicated that consumption of honey modulates the risk of the development of gastric cancer, and also honey induced apoptosis in gastric mucosa[77]. It was postulated that CAPE may be a promising adjuvant treatment in gastric cancer[78]. The chemopreventive actions of honey and its components have been also studied in various colon cancer models. Gelam and Nenas honeys suppressed the growth of HT 29 colon cancer cells by inducing DNA damage and apoptosis and suppressing inflammation[79]. Jaganathan also demonstrated the anti-proliferative effect of Caffeic acid, one of the phenolic constituents of honey, inhibited in the colon cancer cells HCT15 and HT29[80]. Honey induced apoptosis by causing the depletion of intracellular non-protein thiols and reduced the mitochondrial membrane potential and increased generation of reactive oxygen species. Furthermore, honey constituents induced apoptosis in colon cancer cells[81]. Orsolić et al[82] showed that honey exerted anti-metastatic effect in a murine tumor model with colon carcinoma. Supplementation of diet with honey and Nigella sativa had a protective effect against methylnitrosourea-induced oxidative stress, inflammatory response and carcinogenesis in Sprague Dawely rats[83]. Caffeic acid esters derivatives inhibited azoxymethane-induced colonic colonie preneoplastic lesions, ornithine decarboxylase, tyrosine protein kinase, and lipoxygenase activities and aberrant crypt foci formation, which are relevant to colon carcinogenesis in rat colon[50]. Caffeic acid and its ester are potent inhibitors of human colon adenocarcinoma cell growth[84]. Dietary administration of phenylethyl-3-methylcaffeate significantly inhibited the incidence and multiplicity of invasive, noninvasive adenocarcinomas of the colon, and also suppressed the colon tumor volume by 43% compared to the control diet, and also inhibited the formation in colonic tumors by 15%-30% in the animals[48]. Gribel’ et al[85] indicated that honey possessed moderate antitumor effect and pronounced antitumor activity of 5-flurouracil and cyclophosphamide against five different strains of rat and mouse tumors. Furthermore, honey potentiated the antitumor activity of the chemotherapeutic drugs 5-fluorouracil and cyclophosphamide in colorectal cancer cells[86,87]. The anticancer effects of natural honey and its components on liver cancer cells have been investigated in a number of studies[88-90]. Treatment of hepatocellular carcinoma HepG2 cells with bee honey and Nigella sativa led to a significant decrease in both the number of viable HepG2 cells and the levels of nitric oxide and improved the total antioxidant status and caspase-3 activity, especially in HepG2 cells treated with higher doses of bee honey Nigella sativa (20% and 5000 μg/mL)[88]. It has been reported that Spanish honeys were most effective in protecting against food mutagen-induced DNA damage in HepG2 cells, which was attributed to its antioxidant and free radical scavenging properties[89]. Gelam honey was selectively cytotoxic to liver cancer cells and found that the IC50 value of gelam honey towards HepG2 was 25% whereas it was 70% for normal human hepatocytes (WRL-68)[90]. Abdel Aziz et al[91] reported that honey extracts exerted cytotoxic, antimetastatic and anti-angiogenic effects in HepG2 cells. Treatment with diethylnitrosamine induced hepatic cancer in rats and the neoplastic hepatic cells were reduced in the liver of honey-treated DEN-induced rats[92]. These studies indicate that honey has an anticancer effect on various types of cancer cells and exerts its protective effect against the development of cancer by modulating the molecular and cellular mechanisms of carcinogenesis stages. Some of the mechanisms by which honey may exert its anticancer effects are cell cycle arrest, activation of mitochondrial pathway, induction of mitochondrial outer membrane permeabilization, induction of apoptosis, modulation of oxidative stress, amelioration of inflammation, modulation of insulin signaling, and inhibition of angiogenesis[37]. The effect of honey was also investigated in pancreatic cancer. Caffeic acid phenethyl ester induced apoptosis in human pancreatic cancer cells by activation of caspase-3/caspase-7 and mitochondrial dysfunction[93]. Treatment with CAPE slightly restored the expression of E-cadherin and markedly reversed the transforming growth factor-β-induced overexpression of vimentin at 24 h in Human pancreatic cancer cells (PANC-1) cells. CAPE suppressed the expression of Twist 2 and growth of PANC-1 xenografts without significant toxicity in an orthotopic pancreatic cancer model. These data suggest that CAPE could suppress the epithelial-mesenchymal transition in pancreatic cancer[94].
Abdel-Latif MM. Chemoprevention of gastrointestinal cancers by natural honey.
World J Pharmacol 2015; 4(1): 160-167 [DOI:
10.5497/wjp.v4.i1.160]