α­Solanine inhibits growth and metastatic potential of human colorectal cancer cells.

Solanum nigrum L. (Longkui) is one the most widely used anticancer herbs in traditional Chinese medicine. α­Solanine is an important ingredient of S. nigrum L. and has demonstrated anticancer properties in various types of cancer. However, the effects of α­solanine on colorectal cancer remain elusive. The aim of the present study was to assess the effects of α­solanine on human colorectal cancer cells. The results demonstrated that α­solanine inhibited the proliferation of RKO cells in a dose­ and time­dependent manner. In addition, α­solanine arrested the cell cycle at the G0/G1 phase and suppressed the expression levels of cyclin D1 and cyclin­dependent kinase 2 in RKO cells. α­Solanine induced apoptosis of RKO cells, as indicated by morphological changes and positive Annexin­FITC/propidium iodide staining. Additionally, α­solanine activated caspase­3, ­8 and ­9 in RKO cells, which contributed to α­solanine­induced apoptosis. α­Solanine also increased the generation of reactive oxygen species, which contributed to caspase activation and induction of apoptosis. α­Solanine inhibited the migration, invasion and adhesion of RKO cells, as well as the expression levels and activity of matrix metalloproteinase (MMP)­2 and MMP­9. In addition, α­solanine inhibited cell proliferation, activated caspase­3, ­8 and ­9, induced apoptosis, and inhibited the migration and invasion of HCT­116 cells. Furthermore, α­solanine inhibited tumor growth and induced apoptosis in vivo. These findings demonstrated that α­solanine effectively suppressed the growth and metastatic potential of human colorectal cancer.

Maternal periconceptional consumption of sprouted potato and risks of neural tube defects and orofacial clefts.

BACKGROUND: The association between maternal consumption of sprouted potato during periconceptional period on the development of neural tube defects (NTDs) or orofacial clefts (OFCs) remains unclear. We aimed to examine the association between maternal consumption of sprouted potatoes during periconceptional period and risks of NTDs or OFCs. METHODS: Subjects included 622 NTD cases, 135 OFC cases and 858 nonmalformed controls, were recruited from a case-control study in Shanxi Province of northern China between 2002 and 2007. Information on demographics, maternal sprouted potato consumption, lifestyle behaviors and folic acid supplementation was collected. RESULTS: Consumption of sprouted potatoes was associated with elevated odds of total NTDs (OR = 2.20; 95% CI, 1.12-4.32) and anencephaly (OR = 2.48; 95% CI, 1.10-5.58); no association for spina bifida or encephalocele. Sprouted potato consumption increased the risk of total OFCs (OR = 3.49; 95% CI, 1.29-9.49) and cleft lip with or without cleft palate (CL ± P) (OR = 4.03; 95% CI, 1.44-11.28). CONCLUSION: Maternal consumption of sprouted potatoes during periconceptional period may increase the risks of NTDs and OFCs. Given that potato is commonly consumed around the world, improper preservation and use should be a matter of concern in respect of the potential teratogenicity.

Glycoalkaloids (α-chaconine and α-solanine) contents of selected Pakistani potato cultivars and their dietary intake assessment.

Glycoalkaloids (α-solanine and α-chaconine) are naturally occurring toxic compounds in potato tuber (Solanum tuberosum L.) that cause acute intoxication in humans after their consumption. Present research was conducted to evaluate α-chaconine, α-solanine, and total glycoalkaloids (TGAs) contents in the peel and flesh portions by high-performance liquid chromatography method in selected Pakistani potato cultivars. The α-solanine content varies 45.98 ± 1.63 to 2742.60 ± 92.97 mg/100 g of dry weight (DW) in peel and from 4.01 ± 0.14 to 2466.56 ± 87.21 mg/100 g of DW in flesh. Similarly, α-chaconine content varied from 4.42 ± 0.16 to 6818.40 ± 211.07 mg/100 g of DW in potato peel and from 3.94 ± 0.14 to 475.33 ± 16.81 mg/100 g DW in flesh portion. The TGA concentration varied from 177.20 ± 6.26 to 5449.90 ± 192.68 mg/100 g of DW in peel and from 3.08 ± 0.11 to 14.69 ± 0.52 mg/100 g of DW in flesh portion of all the potato cultivars tested. All the potato cultivars contained lower concentration of TGA than the limits recommended as safe, except 2 cultivars, that is FD8-3 (2539.18 ± 89.77 mg/100 g of DW) and Cardinal (506.16 ± 17.90 mg/kg). The dietary intake assessment of potato cultivars revealed that Cardinal, FD 35-36, FD 8-3, and FD 3-9 contained higher amount of TGA in whole potato, although FD 8-3 only possessed higher content of TGA (154.93 ± 7.75) in its flesh portion rendering it unfit for human consumption. Practical Application: This paper was based on the research conducted on toxic compounds present in all possible potato cultivars in Pakistan. Actually, we quantify the toxic compounds (glycoalkaloids) of potato cultivars through HPLC and their dietary assessment. This paper revealed safety assessment and their application in food industries especially potato processing.

A 28-day repeat dose toxicity study of steroidal glycoalkaloids, alpha-solanine and alpha-chaconine in the Syrian Golden hamster.

Glycoalkaloids alpha-solanine and alpha-chaconine are naturally present toxicants in the potato plant (Solanumtuberosum). Human intake of high doses of glycoalkaloids has led to acute intoxication, in severe cases coma and death. Previous studies have indicated that the ratio of alpha-solanine to alpha-chaconine may determine the degree and nature of the glycoalkaloid toxicity in potatoes, as the toxicity of the two alkaloids act synergistically. The aim of the present study was to investigate whether an altered ratio of alpha-solanine and alpha-chaconine would reduce the toxicity of the glycoalkaloids. The Syrian Golden hamster was given daily doses of alpha-solanine and alpha-chaconine by gavage for 28 days. Doses of up to 33.3 mg total glycoalkaloids/kg body weight were applied in ratios of 1:3.7 and 1:70 (alpha-solanine:alpha-chaconine). Administration of the highest doses of both ratios resulted in distended and fluid filled small intestines and stomach. Animals receiving the ratio with the reduced content of alpha-solanine were less affected compared to those receiving the other ratio. Gene expression profiling experiments were conducted using RNA from epithelial scrapings from the small intestines of the hamsters administered the highest doses of the glycoalkaloid treatments. In general, more differential gene expression was observed in the epithelial scrapings of the hamsters fed the ratio of 1:3.7. Mostly, pathways involved in lipid and energy metabolism were affected by the ratio of 1:3.7.

Induction of apoptosis in HepG2 cells by solanine and Bcl-2 protein.

The nightshade (Solanum nigrum Linn.) has been widely used in Chinese traditional medicine as a remedy for the treatment of digestive system cancer. The anti-tumor activity of solanine, a steroid alkaloid isolated from the nightshade has been demonstrated. To observe the effect of anti-tumor and mechanism of solanine. The MTT assay was used to evaluate the IC(50) on the three digestive system tumor cell lines. The effect on the morphology was observed with a laser confocal microscopy; the rate of apoptosis and the cell cycle were measured using flow cytometry (FCM); the expression of Bcl-2 protein was measured by Western blot. The results show that the IC(50) for HepG(2), SGC-7901, and LS-174 were 14.47, >50, and >50 microg/ml, respectively; the morphology of cells in the negative control was normal; for the treated groups, typical signs for apoptosis were found. The rate of apoptosis in HepG(2) cells induced by solanine was found to be 6.0, 14.4, 17.3, 18.9, and 32.2%, respectively. Observation of the cell cycle showed that cells in the G(2)/M phases disappeared while the number of cells in the S phase increased significantly for treated groups. Western blot showed that solanine decreased the expression of Bcl-2 protein. Therefore, the target of solanine in inducing apoptosis in HepG(2) cells seems to be mediated by the inhibition in the expression of Bcl-2 protein.

Anticarcinogenic effects of glycoalkaloids from potatoes against human cervical, liver, lymphoma, and stomach cancer cells.

Methods were devised for the isolation of large amounts of pure alpha-chaconine and alpha-solanine from Dejima potatoes and for the extraction and analysis of total glycoalkaloids from five fresh potato varieties (Dejima, Jowon, Sumi, Toya, and Vora Valley). These compounds were then evaluated in experiments using a tetrazolium microculture (MTT) assay to assess the anticarcinogenic effects of (a) the isolated pure glycoalkaloids separately, (b) artificial mixtures of the two glycoalkaloids, and (c) the total glycoalkaloids isolated from each of the five potato varieties. All samples tested reduced the numbers of the following human cell lines: cervical (HeLa), liver (HepG2), lymphoma (U937), stomach (AGS and KATO III) cancer cells and normal liver (Chang) cells. The results show that (a) the effects of the glycoalkaloids were concentration dependent in the range of 0.1-10 mug/mL (0.117-11.7 nmol/mL); (b) alpha-chaconine was more active than was alpha-solanine; (c) some mixtures exhibited synergistic effects, whereas other produced additive ones; (d) the different cancer cells varied in their susceptibilities to destruction; and (e) the destruction of normal liver cells was generally lower than that of cancer liver cells. The decreases in cell populations were also observed visually by reversed-phase microscopy. The results complement related observations on the anticarcinogenic potential of food ingredients.

Potato glycoalkaloids adversely affect intestinal permeability and aggravate inflammatory bowel disease.

BACKGROUND: Disruption of epithelial barrier integrity is important in the initiation and cause of inflammatory bowel disease (IBD). Glycoalkaloids, solanine (S), and chaconine (C) are naturally present in potatoes, can permeabilize cholesterol-containing membranes, and lead to disruption of epithelial barrier integrity. Frying potatoes concentrates glycoalkaloids. Interestingly, the prevalence of IBD is highest in countries where fried potatoes consumption is highest. OBJECTIVE: To further understand the role of potato glycoalkaloids on intestinal barrier integrity, we examined the effect of varying concentrations of solanine and chaconine on intestinal permeability and function. METHODS: Solanine (0-50 microM), chaconine (0-20 microM), or a 1:1 mixture (0-20 microM) were exposed to T84 cultured epithelial monolayers for varying periods of time to determine concentration response effect on epithelial permeability. Next, a 1:1 mixture (5 microM) of solanine-to-chaconine (C:S) was exposed to sheets of normal murine small intestine, mounted in Ussing chambers, from control and interleukin-10 gene-deficient mice to determine whether glycoalkaloids affected intestine from mice with a genetic predisposition for IBD greater than controls. Finally, the effects of glycoalkaloids on colonic histologic injury were examined in mice orally fed amounts of glycoalkaloids that would normally be consumed in a human diet. RESULTS: Glycoalkaloids embedded and permeabilized the T84 monolayer epithelial membrane bilayer in a concentration-dependent fashion, with C:S > C > S. In vitro Ussing chamber experiments also illustrated a concentration-dependent disruption of intestinal barrier integrity in animals with a genetic predisposition to develop IBD, but not in control animals. Similarly, in vivo oral feeding experiments demonstrated that C:S ingestion, at physiologic concentrations, aggravated histologic colonic injury in mice genetically predisposed to developing IBD. CONCLUSION: Concentrations of glycoalkaloids normally available while eating potatoes can adversely affect the mammalian intestine and can aggravate IBD.

Absence of genotoxicity of potato alkaloids alpha-chaconine, alpha-solanine and solanidine in the Ames Salmonella and adult and foetal erythrocyte micronucleus assays.

To assess whether reported toxicities of potato-derived glycoalkaloids could be the result of interactions with cellular DNA, the genotoxic effects of alpha-solanine, alpha-chaconine and solanidine were studied, using the Ames test (Salmonella strains TA98 and TA100), the mouse peripheral blood micronucleus test and the mouse transplacental micronucleus test. The Ames test for mutagenicity with alpha-solanine was weakly positive in TA100 with S-9 activation (29 revertants per millimole per plate). However, pooled data from duplicate tests gave a negative effect. Pooled data from two experiments with alpha-chaconine gave a weak positive response in TA98 without microsomes (17 revertants per millimole per plate). The micronucleus tests for clastogenicity using male mouse and foetal blood were negative. The absence of mutagenicity and clastogenicity suggests lack of damage to intracellular DNA for potato alkaloid toxicity.