Effects of steroidal glycoalkaloids from potatoes (Solanum tuberosum) on in vitro bovine embryo development

alpha-Solanine and alpha-chaconine are two naturally occurring steroidal glycoalkaloids in potatoes (Solanum tuberosum), and solanidine-N-oxide is a corresponding steroidal aglycone. The objective of this research was to screen potential cyto-toxicity of these potato glycoalkaloids using bovine oocyte maturation, in vitro fertilization techniques and subsequent embryonic development as the in vitro model. A randomized complete block design with four in vitro oocyte maturation (IVM) treatments (Experiment 1) and four in vitro embryo culture (IVC) treatments (Experiment 2) was used. In Experiment 1, bovine oocytes (n=2506) were matured in vitro in medium supplemented with 6 microM of alpha-solanine, alpha-chaconine, solanidine-N-oxide or IVM medium only. The in vitro matured oocytes were then subject to routine IVF and IVC procedures. Results indicated that exposure of bovine oocytes to the steroidal glycoalkaloids during in vitro maturation inhibited subsequent pre-implantation embryo development. Potency of the embryo-toxicity varied between these steroidal glycoalkaloids. In Experiment 2, IVM/IVF derived bovine embryos (n=2370) were cultured in vitro in medium supplemented with 6 microM of alpha-solanine, alpha-chaconine, solanidine-N-oxide or IVC medium only. The results showed that the pre-implantation embryo development is inhibited by exposure to these glycoalkaloids. This effect is significant during the later pre-implantation embryo development period as indicated by fewer numbers of expanded and hatched blastocysts produced in the media containing these alkaloids. Therefore, we conclude that in vitro exposure of oocytes and fertilized ova to the steroidal glycoalkaloids from potatoes inhibits pre-implantation embryo development. Furthermore, we suggest that ingestion of Solanum species containing toxic amounts of glycoalkaloids may have negative effects on pre-implantation embryonic survival.

Potato glycoalkaloids: true safety or false sense of security?

As one of the major agricultural crops, the cultivated potato is consumed each day by millions of people from diverse cultural backgrounds. A product of global importance, the potato tuber contains toxic glycoalkaloids (GAs) that cause sporadic outbreaks of poisoning in humans, as well as many livestock deaths. This article will discuss some aspects of the potato GAs, including their toxic effects and risk factors, methods of detection of GAs and biotechnological aspects of potato breeding. An attempt has been made to answer a question of vital importance - are potato GAs dangerous to humans and animals and, if so, to what extent?

Inhibitory effect of antimicrobial agents and anisodamine on the staphylococcal superantigenic toxin-induced overproduction of proinflammatory cytokines by human peripheral blood mononuclear cells

Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA), produces superantigenictoxins, such as toxic shock syndrome toxin-1 (TSST-1). TSST-1 abnormally activates T cells to overproduce inflammatory cytokines (such as tumor necrosis factor-alpha, interleukin-2, and interferon-gamma) leading to shock. In this study, we investigated the inhibitory effect of antimicrobial agents and anisodamine (a Chinese herbal extract) on TSST-1-induced cytokine production. Among the macrolides and related agents examined, azithromycin and rokitamycin showed the greatest inhibitory activity against the TSST-1-induced cytokine production. This inhibitory effect was similar to that of anisodamine, which, however, had no inhibitory activity against bacterial growth. Vancomycin, teicoplanin, arbekacin, and linezolid (anti-MRSA and related agents) had no significant inhibitory effect on cytokine production. The inhibitory effect of the drugs on cell proliferation was not significant. These data indicate that some antimicrobial agents, e.g., azithromycin and rokitamycin, manifest anti-superantigenic toxin activity through the inhibition of cytokine production, just like anisodamine.

Action of solamargine on TNFs and cisplatin-resistant human lung cancer cells

A loss of TNF receptors expression has been found in advanced lung cancers, and human A549 lung adenocarcinoma cells are resistant to the cytotoxic effects of TNF-alpha and cisplatin. Here, the mechanisms of the drug resistance of A549 were extensively studied by gene modulation of the cells by solamargine (SM) which was isolated from Solanum incanum herb. SM induced morphological changes of chromatin condensation, DNA fragmentation, and sub-G(1) peak in a DNA histogram of A549 cells, indicating cell death by apoptosis. SM elevated the expressions of TNF-R1 and -R2 and overcame the resistance of A549 cells to TNF-alpha and -beta. The recruitment of TRADD, FADD, and activation of caspase-8 and -3 in SM-treated A549 cells evidenced the activation of TNFRs signal transduction. In addition, release of cytochrome c from mitochondria, down-expression of Bcl-2 and Bcl-x(L), up-regulation of Bax, and caspase-9 activities were observed in SM-treated A549 cells. Combinational treatment of SM and cisplatin synergistically enhanced caspase-8, -9, and -3 activities in A549 cells. Thus, SM sensitizes A549 cells through TNFRs and mitochondria-mediated pathways and may have anticancer potential against TNFs- and cisplatin-resistance lung cancer cells.

[Study on effect of anisodamine on expressions of tissue factor and plasminogen activator-1 inhibitor in vascular endothelial cells and its mechanisms]

OBJECTIVE

To explore the mechanism of anisodamine in treating infectious shock through studying effect of anisodamine on endotoxin lipopolysaccharide (LPS) induced expression of tissue factor (TF) and plasminogen activator inhibitor type 1 (PAI-1) in vascular endothelial cells (EC).

METHODS

Human umbilical vein endothelial cells (HUVEC) were cultured by trypsin digestion method. PAI-1 was measured in the conditioned medium of HUVEC by a specific enzyme-linked immunosorbent assay (ELISA), whereas TF activity was measured in the lysates of these cells by using a single step clotting assay. Specific mRNA expressions were determined by Northern blotting. In order to evaluate a possible contribution of the nuclear factor-kappa B (NF-kappa B) pathway on the transductive effects observed, electrophoretic mobility shift assays (EMSA) were performed using nuclear extracts from HUVEC and NF-kappa B binding oligonucleotides.

RESULTS

LPS could significantly strengthen the expression of HUVEC PAI-1 protein and TF activity and its mRNA, this effect of LPS could be markedly weakened after adding Anisodamine dose-dependently. Anisodamine could also completely block the LPS induced NF-kappa B DNA binding activity in nuclear extracts from HUVEC.

CONCLUSION

The possible mechanism of anisodamine in treating infectious shock may be through antagonizing LPS induced HUVEC TF and PAI-1 expression, and the antagonism might be, at least partially, transduced by path of NF-kappa B.

Arudonine, an allelopathic steroidal glycoalkaloid from the root bark of Solanum arundo Mattei

Bioassay-guided fractionation of the methanol extract of the root bark of Solanum arundo Mattei led to the isolation of a steroidal glycoalkaloid, designated arudonine, which was elucidated to be solasodine O-alpha-l-rhamnopyranosyl-(1-->2)-[beta-D-xylopyranosyl-(1-->3)], [alpha-l-rhamnopyranosyl-(1-->4)]-beta-D-glucopyranoside. This steroidal glycoalkaloid inhibited the growth of lettuce seedlings (Lactuca sativa).

Differentiating effects of anisodamine on cognitive amelioration and peripheral muscarinic side effects induced by pilocarpine in mice

Based on the cholinergic hypothesis of Alzheimer's disease (AD), many cholinomimetics have been tested for the treatment of AD. Although some of them have beneficial effects, peripheral muscarinic side effects limit their utility. Our present experiments showed that muscarinic agonist pilocarpine (pilo) could significantly improve memory deficits induced by scopolamine in step-through task, but be accompanied by pronounced peripheral cholinergic side effects such as hypersalivation, bradycardia, diarrhea and so on. Anisodamine (aniso) is a peripheral muscarinic blocker isolated from a Chinese herb Anisodus tanguticus and is widely used in China. When combined with aniso, pilo preserved its central efficacy with very minor peripheral side effects. Cholinomimetics combined with peripheral muscarinic blockers may provide alternative therapeutic strategies for AD.

[Effect and significance of anisodamine on IkappaB kinase-beta in Kupffer cells following hemorrhagic shock]

OBJECTIVE

To investigate the possible role of IkappaB kinase-beta (IKK-beta), the pathogenesis of hepatic injury induced by resuscitation of hemorrhagic shock and endotoxin, and to evaluate the preventive effect of anisodamine (654-2).

METHODS

Twenty-seven rabbits were randomly divided into the normal group, hemorrhagic shock plus endotoxin group and 654-2 treatment group. The expression of IKK-beta, activity of the nuclear factor-kappaB (NF-kappaB) in Kupffer cells (KC) and the concentration of tumor necrosis factor-alpha (TNF-alpha) in the culture supernatant were measured by in situ hybridization (ISH), electrophoretic mobility shift assay (EMSA) and enzyme linked immunoadsorbent analysis (ELISA), respectively. The pathological changes in the hepatic tissue were examined with light microscope.

RESULTS

Compared with the normal group, the expression of IKK-beta (0.21+/-0.03), the activity of NF-kappaB (2.29+/-0.25) in KC, and the level of TNF-alpha[(560.21+/-31.04) ng/L] in the culture supernatant of KC were obviously increased after hemorrhagic shock and endotoxin(all P<0.01 ). 654-2 treatment could significantly inhibit the expression of IKK-beta (0.14+/-0.03) and the activity of NF-kappaB (1.35+/-0.17) in KC, decrease the content of TNF-alpha [(300.79+/-23.47) ng/L] in the culture supernatant of KC in rabbits with hemorrhagic shock plus endotoxin challenge (all P<0.01 ),and alleviate hepatic injury as observed by histological examination.

CONCLUSION

IKK-beta expression in KC could be enhanced after hemorrhagic shock and endotoxin, and it might play an important role in the development and progression of hepatic injury following hemorrhagic shock and endotoxin. 654-2 could inhibit IKK-beta expression, decrease NF-kappaB activation and cytokine secretion in KC after hemorrhagic shock followed by resuscitation and endotoxin. The inhibition of IKK-beta expression might be a protective mechanism for hepatic injury.

Effect of morphine and M-cholinoceptor blocking drugs on human sphincter of Oddi during choledochofiberscopy manometry

OBJECTIVE

To evaluate the effects of morphine on the human sphincter of Oddi pressure and the antagonism of anticholinergic agents against morphine.

METHODS

The action of these drugs on the sphincter of Oddi (SO) was evaluated by means of choledochofiberscopy manometry in 40 operated patients with T-tube. The patients were divided randomly into 4 groups: anisodamine, atropine, buscopan, and control. The following data were recorded: duodenal pressure (DP), basal pressure of the sphincter of Oddi (BPSO), contractive amplitude of the sphincter of Oddi (CASO), contractive frequency of the sphincter of Oddi (CFSO), contractive duration of the sphincter of Oddi (CDSO), and pressure of the common bile duct (PCBD). Both morphine and anticholinergic agents were given intramuscularly.

RESULTS

After injection of 10 mg morphine, BPSO, CASO, CFSO, and PCBD increased significantly. After injection of 15 mg anisodamine or 0.75 mg atropine, CASO, BPSO declined obviously, and after injection of 20 mg buscopan, CASO, BPSO, CFSO declined obviously, but in anisodamine, atropine and buscopan groups, they differed insignificantly.

CONCLUSIONS

The results illustrate that SO manometry via choledochofiberscopy is a new method for SO dynamic study. Morphine can increase DP, BPSO, CASO, PCBD, but anisodamine atropine and buscopan can antagonize the effect of morphine.

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.

Sonic hedgehog activates mesenchymal Gli1 expression during prostate ductal bud formation

Ductal budding in the developing prostate is a testosterone-dependent event that involves signaling between the urogenital sinus epithelium (UGE) and urogenital sinus mesenchyme (UGM). We show here that ductal bud formation is associated with focused expression of Sonic hedgehog (Shh) in the epithelium of nascent prostate buds and in the growing tips of elongating prostate ducts. This pattern of localized Shh expression occurs in response to testosterone stimulation. The gene for the Shh receptor, Ptc1, is expressed in the UGM, as are the members of the Gli gene family of transcriptional regulators (Gli1, Gli2, and Gli3). Expression of Ptc1, Gli1, and Gli2 is localized primarily to mesenchyme surrounding prostate buds, whereas Gli3 is expressed diffusely throughout the UGM. A strong dependence of Gli1 (and Ptc1) expression on Shh signaling is demonstrated by induction of expression in both the intact urogenital sinus and the isolated UGM by exogenous SHH peptide. A similar dependence of Gli2 and Gli3 expression on Shh is not observed. Nonetheless, the chemical inhibitor of Shh signaling, cyclopamine, produced a graded inhibition of Gli gene expression (Gli1>Gli2>Gli3) in urogenital sinus explants that was paralleled by a severe inhibition of ductal budding.

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.

The effects of anisodamine and dobutamine on gut mucosal blood flow during gut ischemia/reperfusion

AIM: To determine if anisodamine is able to augment mucosal perfusion during gut I/R ischemia-reperfusion.

METHODS: A jejunal sac was formed in Sprague Dawley rat. A Laser Doppler probe and a tonometer were inserted into the sac which was filled with saline. The superior mesenteric artery was occluded (SMAO) for 60 minutes followed by 90 minutes of reperfusion. At the end of 60 minutes of SMAO, either 0.2 mg/kg of anisodmine or dobutamine was injected into the jejunal sac. Laser Doppler mucosal blood flow and regional PCO₂ (PrCO₂) measurements were made.

RESULTS: Mucosal blood flow was significantly increased at 30, 60 and 90 minutes of reperfusion (R₃₀, R₆₀, R₉₀) when intraluminal anisodamine or dobutamine was present compared to intraluminal saline only (44 ± 3.3% or 48 ± 4.1% vs 37 ± 2.6% at R₃₀, 57 ± 5.0% or 56 ± 4.7% vs 45 ± 2.7% at R₆₀, 64 ± 3.3% or 56 ± 4.2% vs 48 ± 3.4% at R₉₀, respectively P < 0.05). Blood flow changes were also reflected by lowering of jejunal PrCO₂ measurements after intraluminal anisodamine or dobutamine compared with that of the saline controls (41 ± 3.1 mmHg or 44 ± 3.0 mmHg vs 49 ± 3.7 mmHg at R₃₀, 38 ± 3.7 mmHg or 40 ± 2.1 mmHg vs 47 ± 3.8 mmHg at R₆₀, 34 ± 2.1 mmHg or 39 ± 3.0 mmHg vs 46 ± 3.4 mmHg at R₉₀, respectively, P < 0.05). Most interesting finding was that there were significantly higher mucosal blood flow and lower jejunal PrCO₂ in anisodamine group than those in dobutamine group at 90 minutes of reperfusion (64 ± 3.3% vs 56 ± 4.2% for blood flow or 34 ± 2.1 mmHg vs 39 ± 3.0 mmHg for PrCO₂, respectively, P < 0.05), suggesting that anisodamine had a more lasting effect on mucosal perfusion than dobutamine.

CONCLUSION: Intraluminal anisodamine and dobutamine can augment mucosal blood flow during gut I/R and alleviate mucosal acidosis. The results provided benificial effects on the treatment of splanchnic hypoperfusion following traumatic or burn shock.

Anisodamine inhibits cardiac contraction and intracellular Ca(2+) transients in isolated adult rat ventricular myocytes

Increased cardiac workload often leads to serious complications during cardiac surgery such as pericardiopulmonary bypass. Various agents have been applied to lower peripheral resistance and cardiac workload, one of which, anisodamine, is widely used in Asia. However, the direct action of anisodamine on cardiac contractile property is essentially unknown. This study was designed to examine the influence of anisodamine on ventricular contractile function at the single cardiac myocyte level. Ventricular myocytes from adult rat hearts were stimulated to contract at 0.5 Hz, and mechanical and intracellular Ca(2+) properties were evaluated using an IonOptix Myocam system. Contractile properties analyzed included peak shortening (PS), time-to-PS (TPS), time-to-90% relengthening (TR(90)), maximal velocity of shortening/relengthening (+/-dL/dt), intracellular Ca(2+) fluorescence intensity change (DeltaFFI) and decay (tau). Anisodamine exhibited a concentration-dependent (10(-12)-10(-6) M) inhibition in PS and DeltaFFI, with maximal inhibitions of 44.7% and 47.2%, respectively. Anisodamine inhibited +/-dL/dt, lowered resting FFI but elicited no effect on TPS/TR(90) and tau. Pretreatment with the nitric oxide synthase (NOS) inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME, 100 microM) abolished the inhibitory effect of anisodamine in cell shortening. In addition, anisodamine prevented cholinoceptor agonist carbachol-induced positive cardiac contractile response. This study demonstrated a direct cardiac depressive action of anisodamine at the myocyte level, which may be related to, at least in part, NO production and cholinoceptor antagonism.

Effects of short-term treatment of solasodine on cauda epididymis in dogs

Oral administration (80 mg/kg body wt/day for 30 days) of solasodine (extracted and isolated from the berries of the Solanum xanthocarpum) to intact dogs significantly decreased the epithelial cell height of cauda epididymides. The cells became atrophic and the lumen was devoid of spermatozoa. Castration followed by the adminstration of solasodine further reduced the epithelial cell height in comparison to castrated controls. Concurrent treatment of solasodine along with testosterone propionate was unable to restore the normal epithelial lumen parameters. Total protein, sialic acid, glycogen and acid phosphatase activities were significantly reduced in solasodine treated cauda epididymides. These result suggest antiandrogenic potency of solasodine.

Bioactive steroidal alkaloid glycosides from Solanum aculeastrum

Solanum aculeastrum Dunal was investigated for the presence of molluscicidal compounds. This led to the isolation of solaculine A, from the root bark in addition to known steroidal alkaloids; solamargine and beta-solamarine from the berries. The structures were elucidated by spectroscopic techniques. Molluscicidal activity of the aqueous extracts of the berries and root bark, and the isolated compounds were investigated.

Anisodamine inhibits endotoxin-induced tissue factor expression in human endothelial cells

By study on the effect of anisodamine on lipopolysaccharide-induced expression of tissue factor (TF) in vascular endothelial cells (EC), the mechanism of anisodamine antithrombosis, as well as in the treatment of bacteraemic shock was investigated. Human umbilical vein endothelial cells (HUVECs) were cultured by trypsin digestion method. TF activity was measured in the lysates of HUVEC by using a single step clotting assay. Specific mRNA expression was detected by Northern blotting. In order to evaluate a possible contribution of the nuclear factor (NF)-kappa B pathway on the effects observed, electrophoretic mobility shift assays (EMSA) were performed using nuclear extracts from HUVECs and NF-kappa B-binding oligonucleotides. The results showed that treatment of HUVEC with LPS resulted in a significant increase in TF activity. Anisodamine dose-dependently inhibited LPS-induced upregulation of TF. These effects was also confirmed on the level of specific TF mRNA expression by Northern blotting. Furthermore, EMSA showed that anisodamine completely abolished LPS-induced NF-kappa B DNA binding activity in nuclear extracts from HUVECs treated with LPS together with anisodamine. The results suggest that anisodamine counteracts endothelial cell activation by inhibiting LPS-induced TF expression in these cells. Its interference with the NF-kappa B pathway might--at least in part--contribute to this effect. The ability of anisodamine to counteract LPS effect on endothelial cells might be one underlying mechanism explaining its antithrombosis and efficacy in the treatment of bacteraemic shock.

Current studies on anti-endotoxic chemical components of traditional Chinese medicine in China

Endotoxin (ET) was found to have wide bioactivities and ET antagonists have become the pop research topic in life science. The chemical components of traditional Chinese medicine (TCM) were the substance basis of its pharmacology. This review demonstrated the study state of about 18 chemical components from TCM, eg, organic acids of Radix Isatidis, anisodamine, matrine, tetramethypyrazine, colchicine, and glycine, etc, which showed anti-endotoxin effects through different routes. But now the most of them were limited to the laboratory. In the future, the trends of development should not only enlarge the range of research, but also strengthen the clinical study.

Verapamil, cyproheptadine, and anisodamine antagonized [Ca2+]i elevation induced by TNFalpha in a single endothelial cell

AIM

To study the effect of tumor necrosis factor alpha (TNFalpha) on intracellular free Ca2+ concentration ([Ca2+]i) and the effects of verapamil (Ver), cyproheptadine (Cyp), and anisodamine (Ani) on TNFalpha-induced [Ca2+]i changes in single endothelial cell, and to explore the mechanisms of TNFalpha-mediated shock and antishock actions of Cyp and Ani.

METHODS

Human umbilical vein endothelial cell strains (ECV304) were seeded in 35-mm tissue culture dish with 2 mL DMEM culture medium. The cultured cells were loaded by Fluo-3/AM. The spatial distribution and the dynamic changes of [Ca2+]i in single endothelial cell were determined by laser scanning confocal microscopy.

RESULTS

After stimulation with TNFalpha, [Ca2+]i in single endothelial cell rapidly increased in a concentration-dependent manner and arrived at the peak value within 60 s, afterwards, decreased and kept above the basal level. The confocal scanning image showed that [Ca2+]i elevation was more obvious in nuclear than in cytoplasma and decreased slowly. Ver (1, 2 micromol/L), Cyp (30, 60 micromol/L), and Ani (20, 40 micromol/L) markedly inhibited TNFalpha 1.2 nmol/L-induced [Ca2+]i elevation.

CONCLUSION

TNFalpha markedly induces elevation of [Ca2+]i in a single endothelial cell, it may be an important mechanism of TNFalpha-induced shock and tissue injury. That Cyp and Ani obviously suppress TNFalpha-induced [Ca2+]i elevation probably is one of the mechanisms of their antishock effects.

Anisodamine inhibits shiga toxin type 2-mediated tumor necrosis factor-alpha production in vitro and in vivo

Cytokines, in particular tumor necrosis factor (TNF), appear to be necessary to develop the pathological process of Shiga toxin-producing Escherichia coli (STEC) infection. In this study we examined the effect of anisodamine, a vasoactive drug, on TNF-alpha production in Shiga toxin type 2 (Stx2)-stimulated human monocytic cells in vitro and in Stx2-injected mice sera in vivo. Human monocytes and THP-1 cells were stimulated by Stx2 (1-100 ng/ml) with or without anisodamine addition (1-400 micrograms/ml). For in vivo evaluations, C57BL/6 mice were given a single intraperitoneal injection of anisodamine (6-50 mg/kg) or saline after intraperitoneal injection of Stx2 (50 ng/kg). The results showed that anisodamine suppressed Stx2-induced TNF-alpha production in a dose- and time-dependent manner. Anisodamine also suppressed Stx2-induced TNF-alpha mRNA expression. Further study showed that endogenous prostaglandin E2 may be involved in this inhibitory effect. In contrast to TNF-alpha mRNA, anisodamine at concentrations as high as 400 micrograms/ml did not decrease Stx2-induced IL-1 beta and IL-8 mRNA levels. In addition, anisodamine (> 50 micrograms/ml) increased Stx2-stimulated THP-1 cell viability. Levels of TNF-alpha in anisodamine-treated mice sera were significantly lower than those in the saline-treated group 1.5 and 24 hr after Stx2 injection. Anisodamine induced a lower percentage of death in Stx2-injected mice. Taken together, our results indicate that anisodamine has an important regulatory effect on Stx2-induced TNF-alpha production in vitro and in vivo. The present study suggested that this drug should be further investigated for its effects on Stx2-mediated diseases in humans.

Differential neurosensory responses of adult Colorado potato beetle, Leptinotarsa decemlineata, to glycoalkaloids

Neurons from chemosensory hairs on the galeae of adult Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), were investigated for responses to glycoalkaloids of the family Solanaceae. While solanine and tomatine elicited irregular firing by multiple neurons and bursting activity at 1 mM concentration in most sensory hairs, stimulation with leptine I resulted in consistently high-frequency, slowly adapting responses with a dose-dependent effect between 0.03 and 0.3 mM concentrations. Responses to a mixture of solanine and leptine I suggested possible modification of the leptine I response by other glycoalkaloids, resulting in reduced neural activity relative to leptine I alone. These results establish a method for specifically evaluating leptine I and other glycoalkaloids for effects on feeding behavior of CPB and provide a sensory component for incorporating deterrent chemistry into biorational control methods for the CPB.

[Influence of anisodamine on guinea pig experimental nasal hypersensitivity]

OBJECTIVE

To observe the influence of anisodamine on guinea pig experimental nasal hypersensitivity.

METHOD

Experimental animals were divided into normal control group, TDI group, reserpine group and anisodamine group. The scores of symptom of nose and the cytologic changes of nasal mucosa were parameters of observing.

RESULT

The nasal symptom of reserpine group was significantly stronger than the TDI group, and the eosinophilia evidently increased (both P < 0.01). The nasal symptom of the anisodamine group reduced and the eosinophilia decreased. It is significantly difference between the TDI group and the reserpine group (both P < 0.01).

CONCLUSION

Anisodamine may play a role in therapy of the experimental nasal hypersensitivity with hyperfunction of parasympathetic nerve.

Inhibitory effect of steroidal alkaloids on drug transport and multidrug resistance in human cancer cells

Intrinsic or acquired resistance of tumor cells to multiple cytotoxic drugs (multidrug resistance MDR) is a major cause of failure of cancer chemotherapy. MDR is often caused by elevated expression of drug transporters such as P-glycoprotein (P-gp) or multidrug resistance protein (MRP). A number of compounds, termed chemosensitizers, have little or no cytotoxic action of their own, but inhibit (P-gp) or MRP-mediated drug export and are capable of sensitizing MDR cells to the cytotoxic effects of chemotherapeutic drugs. Here we examined the ability of steroidal alkaloids of plant origin, namely the Veratrum sp. alkaloid cyclopamine and the Lycopersicon sp. alkaloid tomatidine, to act as potent and effective chemosensitizers in multidrug resistant tumor cells. Drug uptake was determined by measuring accumulation of tetramethylrosamine in multidrug resistant NCI AdrR human adenocarcinoma cells. Resistance to adriamycin and vinblastine was determined by utilizing the MTT cell survival assay. Cyclopamine and tomatidine elevate tetramethylrosamine uptake by NCI AdrR cells and sensitize the cells to the cytotoxic action of adriamycin and vinblastine. In both cases these agents are comparable in patency and efficacy to verapamil, a reversal agent commonly used in MDR research. It is concluded that steroidal alkaloids of plant origin act as inhibitors of P-gp-mediated drug transport and multidrug resistance and therefore may serve as chemosensitizers in combination chemotherapy with conventional cytotoxic drugs for treating multidrug resistant cancer.

Effects of naturally occurring glucosides, solasodine glucosides, ginsenosides and parishin derivatives on multidrug resistance of lymphoma cells and leukocyte functions

Solamargine, solasonine, ginsenosides and parishin-related compounds were investigated for their effects on mdr efflux pump of lymphoma cells, and their effects on T cell proliferative assays and cell mediated immune functions, antibody-dependent cellular cytotoxicity (ADCC) and natural killer (NK) cell activity of human peripheral mononuclear cells. Solamargine and solasonine were the only drugs which inhibited all of the tested immune functions; however, ginsenoside Rc and Rd enhanced T cell proliferative assays and marginally increased the NK cell activity. The majority of the compounds were not able to reverse the multidrug resistance of mouse lymphoma cells. However, ginsenosides Rc, Rd and parishin C were able to moderately reduce the activity of the efflux pump. Parishin, parishin C and crude extract significantly enhanced the ADCC reaction.