Effect of solanine on the membrane potential of mitochondria in HepG_2 cells and [Ca^(2+)]i in the cells

AIM： To observe the effect of solanine on the membrane potential of mitochondria in HepG2 cells and [Ca^2＋]i in the cells, and to uncover the mechanism by which solanine induces apoptosis.METHODS： HepG2 cells were double stained with AO/EB, and morphological changes of the cells were observed using laser confocal scanning microscopy （LCSM）. HepG2 cells were stained with TMRE, and change in the membrane potential of mitochondria in the cells were observed using LCSM. HepG2 cells were double stained with Fluo-3/AM, and change of [Ca^2＋]i in the cells were observed using LCSM. HepG2 cells were double stained with TMRE and Fluo-3/AM, and both the change in membrane potential of mitochondria and that of [Ca^2＋]i in the cells were observed using LCSM.RESULTS： Cells in treated groups showed typical signs of apoptosis. Staining with TMRE showed that solanine could lower membrane potential; staining with Fluo-3/AM showed that solanine could increase the concentration of Ca^2＋ in tumor cells; and those of double staining with TMRE and Fluo-3/AM showed that solanine could increase the concentration of Ca^2＋ in the cells at the same time as it lowered the membrane potential of mitochondria.CONCLUSION： Solanine opens up the PT channels in the membrane by lowering the membrane potential, leading to Ca^2＋ being transported down its concentration gradient, which in turn leads to the rise of the concentration of Ca^2＋ in the cell, turning on the mechanism for apoptosis.

6-O-Sulfated Modification of Natural Glycoalkaloids Chaconine and Solanine

Glycoalkaloids（GAS） have important biological and pharmaceutical activities, in order to study the relationship between the structures and the activities of carbohydrate chains, two natural glycoalkaloids, chaconine （compound 1 ） and solanine（ compound 2） , were isolated from potato stems and leaves（ Solanum tuberosum L. ）. The selective sulfation to the 6-hydroxy groups of chaeonine and solanine was carried out in a strategy by the use of protective groups. The 6-hydroxyl groups of the sugar chains in chaconine and solanine were protected with 4,4＇-dimethoxytrityl（DMT） while the other hydroxyl groups were acetylated. The protective group DMT was removed by using 0. 5% TFA in dichloromethane, The free 6-hydroxyl groups were sulfated by chlorosulfonic acid pyridine to give 6-O-sulfated products. After the acetyl groups were removed, the final products obtained were sulfated chaconine and sulfated solanine.^ 13C NMR spectra confirmed that chaconine and solanine were sulfated at O6 of the carbohydrate moiety.

Solanine Interferes with AKT/p-AKT and PI3K/p-PI3K Pathway to Inhibit HIF and Destroy Cell Energy Metabolism

The purpose of this study was to explore the mechanism of Solanine disrupting energy metabolism in human renal cancer ACHN cells and to clarify its target. The specific method was to culture human renal cancer ACHN cell lines, and to intervene with Solanine of high, medium and low concentrations. The content of ATP in cells was measured by ELISA method. The expression of HIF-1α protein and the expression of PI3K, AKT, p-PI3K, p-AKT in PI3K/AKT pathway were detected by Western blotting. The results showed that compared with the control group, the relative expression of p-PI3K and p-AKT showed a downward trend with the increase of Solanine concentration (P < 0.05), while the relative expression of PI3K and AKT showed no significant change (P > 0.05). In addition, the relative expression of HIF-1α also showed a downward trend (P < 0.05). According to the above results, it is suggested that Solanine can significantly inhibit the energy metabolism of renal cancer cells, the main mechanism of which is the down-regulation of HI-1αf downstream of the PI3K/Akt pathway by inhibiting the phosphorylation process of PI3K/p-PI3K and Akt/p-Akt.

Antihepatocarcinoma Effect of Solanine and Its Mechanisms

Objective To explore the antitumor effect of solanine and its mechanisms.Methods The in vivo antitumor effect of solanine was observed using models developed through in vivo transplantation of tumor cells;In vitro lines of sensitive antitumor cells were selected from the digestive system using MTT assay;The effect of solanine on cell morphology was observed using transmission electronic microscopy;The morphology of apoptotic cells was observed using Annexin V/PI double staining and laser confocal scanning microscopy(LCSM);The rate of cell apoptosis was measured using Annexin V/PI double staining and flow cytometry;The concentration of intracellular Ca 2+ ([Ca 2+ ]i)was determined using Fluo-3/AM staining and LCSM;The membrane potential of cellular mitochondria was determined using TMRE staining and LCSM;The protein expression of Bcl-2 and Bax was measured using immunological marking and LCSM;And the activity of caspase-3 was measured using the colorimetric method.Results Solanine could inhibit the growth of tumor weight in S180 tumor-bearing mice and prolong the survival time of H22 tumor-bearing mice.MTT assay revealed that HepG2 cells were quite sensitive to solanine because solanine could induce morphological changes in HepG2 cells,with the rate of early apoptosis being 4%,8.5%,and 20.1%,for HepG2 cells treated for 24 h with solanine at concentration of 0.4,2,and 10μg/mL, respectively.Solanine could raise the[Ca 2+ ]i and lower the membrane potential.It could reduce the protein expression of Bcl-2 while increase that of Bax,thus increasing the activity of caspase-3.Conclusion The obvious antitumor activity of solanine in human hepatocarcinoma is demonstrated.This inhibitory effect is achieved through solanine decreasing the Bcl-2/Bax ratio,thus increasing[Ca 2+ ]i,which could enhance the enzymatic activity of the caspase family,thus inducing the apoptosis of HepG2 cells.