Solasodine Research Articles

Exceptional stability of the sugammadex-solasodine complex: Insights from experimental and theoretical studies

Sugammadex (SGM) is the first cyclodextrin (CD)-based selective relaxant binding agent. We investigated its ability to capture natural aminosteroid phytotoxins, and assessed its potential as an antidote for intoxication. Solasodine (SS), a toxic alkaloid from the Solanaceae family, was chosen as the model compound. Complexation was studied using nuclear magnetic resonance (NMR) spectroscopy, molecular modelling, and isothermal titration calorimetry (ITC). NMR in various D2O/DMSO‑d6 media revealed a particularly stable inclusion-type complex, identifying a slow exchange process between the CD and the aminosteroid along with a less significant fast exchange between DMSO and SGM. Using various NMR techniques, the structure and kinetic/thermodynamic parameters of the inclusion complex were explored. Theoretical calculations showed the secondary amino head of SS near the carboxylate ends of the SGM sidechains, facilitating intermolecular ionic interactions. ITC experiments in an aqueous environment provided Ka stability constants of 7.03 × 106 M−1 and 4.17 × 106 M−1 at 25 °C and 37 °C, respectively, similar to previously reported SGM complexes with aminosteroid neuromuscular blockers. Finally, SGM significantly increased cell survival and reduced SS toxicity in mHippoE-14 mouse hippocampal embryonic cells, supporting the hypothesis that SGM could act as an antidote to SS's toxic effects.

Role of solasodine hydrochloride in AS2O3 induced HeLa cells apoptosis as well as its effect on cell telomerase activity in vitro

Objective To study whether solasodine hydrochloride (SBHL) could enhance the effect of arsenic trioxide in inducing apoptosis and affecting telomerase activity in cervical cancer HeLa cells. Methods Using cell culture methods, cervical cancer HeLa cells were cultured in vitro. The optimal concentration of SBHL was determined by MTT method from 0, 10, 20, 40, 80, 160, to 320 μmol/L. HeLa cells were grown in improved RPMI1640 supplemented respectively with arsenic trioxide(5 μmol/L As2O3), As2O3(5 μmol/L)+ SBHL( 40 μmol/L) and none (control group). The growth morphology of HeLa cells was observed under phase contrast microscopy after culture for 24, 48, and 72 h. Apoptosis of HeLa cells was determined under transmission electronic microscopy. The method of MTT was used to study the cell survival percentage. The technique of flow cytometry was used to measure cell cycle and cell apoptosis percentage. The method of tartrate-resistant acid phosphatase-enzyme linked immunosorbent assay (TRAP-ELISA) was used to determine telomerase activity of HeLa cells. Results Under phase contrast microscopy, in control group HeLa cells were round, densely packed; in As2O3 group the numbers of the cells were less, cell spacing increased; in As2O3 + SBHL group the cells shrinked significantly, nuclear fragmented as a petal-like, gap became larger. Under transmission electronic microscopy, there were rich microvillus on the cell surface in control group, cell intervals clear, immature connections, and the intervals did not close. The structure of the mitochondria in the cytoplasm was integrated. Most of the chromatin in the nucleus were, euchromatin and characteristics of apoptosis with heterochromatin increased and the chromatin condensed into masses, on the boundary of nuclear membrane. The microvillud on the cell surface were ruptured and decreased in As2O3 + SBHL group. The chromatin condensed into masses. The formation of apoptotic bodies was observed. The difference was statistically significant between groups in cell survival percentage at 24, 48, 72h(x2 = 10.39 , 13.88 , 17.21,respectively, all P < 0.05). Cell survival percentage in SBHL + As2O3 group (52.80%) was significantly less than that of As2O3 group(77.51%, x2 = 9.29, P < 0.05) at 72 h. In cell cycles, the difference was statistically significant between groups in C1 phase and S phase(F = 7.46,22.14, all P < 0.05), respectively. Compared with , control group[ (41.57 ± 1.56)%, (50.45 ± 2.37)%], cell percentages in S phase in As2O3 + SBHL group[(20.06 ± 4.98)%] and As2O3 group[(27.10 ± 5.32)%] were decreased(P< 0.05 or < 0.01), while cell percentage in C1 phase was increased[(58.70 ± 5.18)%, (69.67 ± 4.17)%, P< 0.05 or < 0.01]. The difference was statistically significant between groups in apoptotic percentage of HeLa cells (F = 4.01, P < 0.05). Compared with control group[ (1.18 ± 1.40)%], apoptosis percentage was significantly increased in As2O3 + SBHL group and As2O3 group [(21.08± 1.22)%, (6.04±2.53)%, P< 0.05 or < 0.01], respectively, and As2O3 + SBHL group was higher than As2O3 group(P < 0.01). The difference was statistically significant between groups in telomerase activity (F = 21.28, P< 0.05). Telomerase activity was inhibited in As2O3 group(1.214 ± 0.621) and As2O3A + SBHL group(0.865 ± 0.284) compared to control group (2.107 ± 0.057, all P < 0.05), and telomerase activity in As2O3 + SBHL group was lower than that of As2O3 group (P < 0.05). Conclusions SBHL enhances the effect of As2O3 in inducing apoptosis in HeLa cells, which is related to its inhibiting telomerase activity in HeLa cells. Key words: Solasodine hydrochloride; As2O3; HeLa cells; Apoptosis; Telomerase

Evidence for essential histidine and dicarboxylic amino-acid residues in the active site of UDP-glucose : solasodine glucosyltransferase from eggplant leaves.

Effects of several chemical probes selectively modifying various amino-acid residues on the activity of UDP-glucose : solasodine glucosyltransferase from eggplant leaves was studied. It was shown that diethylpyrocarbonate (DEPC), a specific modifier of histidine residues, was strongly inhibitory. However, in the presence of excessive amounts of the enzyme substrates, i.e. either UDP-glucose or solasodine, the inhibitory effect of DEPC was much weaker indicating that histidine (or histidines) are present in the active site of the enzyme. Our results suggest also that unmodified residues of glutamic (or aspartic) acid, lysine, cysteine, tyrosine and tryptophan are necessary for full activity of the enzyme. Reagents modifying serine and arginine residues have no effect on the enzyme activity.

Solanum alkaloids, 128. Steroid alkaloid glycosides from Solanum robustum

Abstractβ1‐Solamargine and three new glycoalkaloids, robustine, N‐hydroxyrobustine, and 25‐acetoxyrobustine, have been isolated from the roots of Solanum robustum, the structures of which have been elucidated as 3‐O‐{O‐α‐L‐arabinopyranosyl‐(1→3)‐O‐[α‐L‐rhamnopyranosyl‐(1→2)]‐ O‐[α‐L‐rhamnopyranosyl‐(1→4)]‐(β‐D‐glucopyranosyl}solasodine (3)), its N‐hydroxy, and its 25‐acetoxy derivative. These compounds have characteristic structures in comparison with the hitherto known Solanum glycoalkaloids. magnified image