The anti-tumor effects of alkaloids from the seeds of Strychnos nux-vomica on HepG2 cells and its possible mechanism

To screen the anti-tumor effects of the four alkaloids: brucine, strychnine, brucine N-oxide and isostrychnine from the seed of Strychnos nux-vomica, MTT assay was used to examine the growth inhibitory effects of these alkaloids on human hepatoma cell line (HepG2). Brucine, strychnine and isostrychnine revealed significant inhibitory effects against HepG2 cell proliferation, whereas brucine N-oxide didn't have such an effect. In addition, brucine caused HepG2 cell shrinkage, membrane blebbing, apoptotic body formation, all of which are typical characteristics of apoptotic programmed cell death. The results of flow cytometric analysis demonstrated that brucine caused dose-dependent apoptosis of HepG2 cells through cell cycle arrest at G0/G1 phase, thus preventing cells entering S or G2/M phase. Immunoblot results revealed that brucine significantly decreased the protein expression level of cyclooxygenase-2, whereas increased the expression caspase-3 as well as the caspase-3-like protease activity in HepG2 cells, suggesting the involvement of cyclooxygenase-2 and caspase-3 in the pro-apoptotic effects exerted by brucine. Therefore, this paper indicate that the major alkaloids present in the seed of Strychnos nux-vomica are effective against HepG2 cells proliferation, among which brucine proceed HepG2 cells death via apoptosis, probably through the participation of caspase-3 and cyclooxygenase-2.

Analgesic and anti-inflammatory properties of brucine and brucine N-oxide extracted from seeds of Strychnos nux-vomica

To further understand the purpose of the traditional processing method of the seeds of Strychnos nux-vomica L. (Loganiaceae) as well as analgesic and anti-inflammatory activities of brucine and brucine N-oxide extracted from this medicinal plant, various pain and inflammatory models were employed in the present study to investigate their pharmacological profiles. Both brucine and brucine N-oxide revealed significant protective effects against thermic and chemical stimuli in hot-plate test and writhing test. However, on different phases they exerted analgesic activities in formalin test. Brucine N-oxide showed stronger inhibitory effect than brucine in carrageenan-induced rat paw edema, both of them significantly inhibited the release of prostaglandin E2 in inflammatory tissue, reduced acetic acid-induced vascular permeability and the content of 6-keto-PGF1a in Freund's complete adjuvant (FCA) induced arthritis rat's blood plasma. In addition, brucine and brucine N-oxide were shown to reduce the content of 5-hydroxytryptamine (5-HT) in FCA-induced arthritis rat's blood plasma, while increase the content of 5-hydroxytryindole-3-acetic acid (5-HIAA) accordingly. These results suggest that central and peripheral mechanism are involved in the pain modulation and anti-inflammation effects of brucine and brucine N-oxide, biochemical mechanisms of brucine and brucine N-oxide are different even though they are similar in chemical structure.

Role of transferrin in the stimulation of Na,K-ATPase induced by low K+ in Madin Darby canine kidney cells

The presence of serum in a culture medium makes it impossible to identify whether changed cellular functions are directly caused by a manipulation itself or mediated by a component in serum. Madin Darby canine kidney cells can survive in a serum-free medium for about 48 h. We took this advantage to examine whether low K(+)-induced up-regulation of Na,K-ATPase requires serum. We found that serum was essential for low K(+) to induce an increase in Na,K-ATPase binding sites as quantified by ouabain factor binding assays. In an attempt to identify which component was critical, we screened EGF, IGF1, PGE1 and transferrin to identify which one can replace serum. We discovered that transferrin was the single most important factor that mimicked about 80% to 90% of the effect of serum. Transferrin potentiated the effect of low K(+) on the Na,K-ATPase binding sites in a time- and dose-dependent manner. Furthermore, transferrin was also required for low K(+)-induced increase in alpha(1)-promoter activity, alpha(1)- and beta(1)-subunit protein abundance of the Na,K-ATPase. In the presence of transferrin, low K(+) enhanced cellular uptake of iron approximately by 70%. Inhibition of intracellular iron activity by deferoxamine (30 micromol/L) abrogated the effect of low K(+). We conclude that stimulation of the Na,K-ATPase by low K(+) is critically dependent on transferrin. The effect of transferrin is mediated by increased iron transport.

Cytotoxicities of alkaloids from processed and unprocessed seeds of Strychnos nux-vomica

AIM

To examine the cytotoxicities of 6 crude Strychnos alkaloid fractions from the seeds of Strychnos nux-vomica unprocessed or processed with various traditional processing methods and 13 pure Strychnos alkaloids from the fractions.

METHODS

Using cell culture, their inhibitory effects on Vero cell growth-inhibition assay, and host cell DNA synthesis by [3H]thymidine ([3H]TdR) uptake assay.

RESULTS

The IC50 of processed seeds were 155% and 212% of unprocessed ones in cell growth-inhibition assay and in [3H]TdR uptake assay, respectively. The IC50 of 13 compounds were 0.45-0.80 mmol.L-1 and 0.50-12 mmol.L-1, respectively. The processing method with sand bath exhibited a wide safety margin compared with other traditional processing methods or no processing. The isomers of Strychnos alkaloids and their N-oxides showed much lower cytotoxicities among these alkaloids. Isobrucine N-oxide showed the lowest cytotoxicity. The contents of isomers and N-oxides of Strychnos alkaloids were the highest in the sand processing.

CONCLUSION

Processing of nux vomica plays a critical role in its toxicity.

[Determination of alkaloids and comparison of the acute toxicity of differently processed products of the seeds of Strychnos nux-vomica L]

This paper deals with the extraction, determination and identification of the alkaloids in differently processed products of the seeds of Strychnos nux-vomica. The relationship between processing methods and toxicitys is discussed according to the comparison of acute toxicity.

[The effect of Pinellia processed by ginger juice on gastric and intestinal function of animals]

The experimental research has shown that neither pinellia processed by ginger juice and alum nor pinellia boiled by ginger juice have any marked influence on the secretion of PGE2 in rat gastric juice, or on the activity of gastric proteinase in rats. Both the processed products of pinellia can obviously inhibit the gastric and intestinal motility in mice. Raw pinellia can strongly inhibit the secretion of PGE2, gastric acidity and gastric proteinase in rats, but acts not so heavily on their gastric secretion and appears rather harmful to the gastric mucosa in rats. Raw pinellia can also obviously accelerate the gastric and intestinal motility in rats.

[Effect of processing on the alkaloids in Strychnos nux-vomica L]

The contents of strychnine, brucine, isostrychnine and isobrucine in different processed products of Strychnos nux-vomica were determined by TLC-densitometry. The relationship of the contents of strychnos alkaloids with processing methods was studied.

[Haemorrheological effects of different processed products of radix Aconiti Kusnezoffii on animal model with syndrome of "accumulation of cold and blood stasis"]

The effects of Radix Aconiti Kusnezoffii processed by moistening in combination with steaming method and by pharmacopoeial method as well as of the crude drug on haemorrheological nature and the plasma fibronogen content and platelet aggregation rate in the rat model with syndrome of "accumulation of cold and blood stasis" were studied, the result shows that the product processed by moistening in combination with steaming works best.

[The effect of stimulation and toxicity of rhizoma Pinelliae processed by ginger juice on animals]

Rhizoma Pinelliae boiled with ginger juice has less stimulation and toxicity on animals, which is similar to Rhizoma Pinelliae processed by alum solution. The effect of Rhizoma Pinelliae that has been immersed in ginger juice is not as good as that of the ginger-boiled. It was also observed that the stimulation of raw Rhizoma Pinelliae on mice could be reduced when the mice was given fresh or boiled ginger juice. The Rhizoma Pinelliae processed by ginger juice and alum has very little toxicity on mice.

[Effect of processing on the extraction of alkaloids from Strychnos]

Results of experiments showed that the contents of strychnine and brucine were about the same in decoction of Strychnos nux-vomica and S. pierriana, but the contents of vomicine, strychnine N-oxide and brucine N-oxide were greater in the former than in the latter. The contents of strychnine and brucine were greater under scalding with hot sand than deep-frying with sesame oil.

Processing of nux vomica. II. Changes in alkaloid composition of the seeds of Strychnos nux-vomica on traditional drug-processing

In the course of our study on the drug-processing of the seeds of Strychnos nux-vomica L. (Loganiaceae), the alkaloid composition of the heat-treated seeds of S. nux-vomica was compared to that of the untreated seeds. On heat treatment, the contents of the major alkaloids such as strychnine and brucine declined significantly with increases in the amounts of isostrychnine, isobrucine, strychnine N-oxide and brucine N-oxide. The cleavage of an ether linkage and the occurrence of N-oxidation were demonstrated by heat treatment of authentic strychnine and brucine.