Highly selective microbial transformation of major ginsenoside Rb1 to gypenoside LXXV by Esteya vermicola CNU120806.

AIMS: This study examined the biotransformation pathway of ginsenoside Rb(1) by the fungus Esteya vermicola CNU 120806. METHODS AND RESULTS: Ginsenosides Rb(1) and Rd were extracted from the root of Panax ginseng. Liquid fermentation and purified enzyme hydrolysis were employed to investigate the biotransformation of ginsenoside Rb(1) . The metabolites were identified and confirmed using NMR analysis as gypenoside XVII and gypenoside LXXV. A mole yield of 95·4% gypenoside LXXV was obtained by enzymatic conversion (pH 5·0, temperature 50°C). Ginsenoside Rd was used to verify the transformation pathway under the same reaction condition. The product Compound K (mole yield 49·6%) proved a consecutive hydrolyses occurred at the C-3 position of ginsenoside Rb(1) . CONCLUSIONS: Strain CNU 120806 showed a high degree of specific ß-glucosidase activity to convert ginsenosides Rb(1) and Rd to gypenoside LXXV and Compound K, respectively. The maximal activity of the purified glucosidase for ginsenosides transformation occurred at 50°C and pH 5·0. Compared with its activity against pNPG (100%), the ß-glucosidase exhibited quite lower level of activity against other aryl-glycosides. Enzymatic hydrolysate, gypenoside LXXV and Compound K were produced by consecutive hydrolyses of the terminal and inner glucopyranosyl moieties at the C-3 carbon of ginsenoside Rb(1) and Rd, giving the pathway: ginsenoside Rb(1) → gypenoside XVII → gypenoside LXXV; ginsenoside Rd→F(2) →Compound K, but did not hydrolyse the 20-C, ß-(1-6)-glucoside of ginsenoside Rb(1) and Rd. SIGNIFICANCE AND IMPACT OF THE STUDY: The results showed an important practical application on the preparation of gypenoside LXXV. Additionally, this study for the first time provided a high efficient preparation method for gypenoside LXXV without further conversion, which also gives rise to a potential commercial enzyme application.

Natural medicines for alcoholism treatment: a review.

Alcoholism is a serious problem throughout the world. The development of alcoholism remedies have medical, social and economical significance. In view of the pitfalls of psychological dependence and adverse behavioural effects of synthetic drugs, the development of low toxicity and high efficiency medicines derived from natural products exhibits expansive market prospects. Based on these considerations, we summarize briefly folk application of traditional hangover remedies and clinical application of herbal complex and patent medicines for alcoholism treatment. We have reviewed the effects of natural medicines on intake, absorption and metabolism of alcohol, as well as the protective effects on alcohol-induced acute and chronic tissue injury.

ELISA for the determination of saikosaponin a, an active component of Bupleuri Radix.

In order to quantify saikosaponin a (SSA), one of the major active components of Bupleuri Radix, a competitive and indirect ELISA method was developed. High titer rabbit polyclonal antibodies (pAbs) were raised against a conjugate of SSA and bovine serum albumin, coupled with a periodate oxidation method. SSA competitively inhibited the binding of rabbit anti-SSA pAbs to SSA-ovalbumin on the solid phase, a coated antigen on the well. The quantity of pAbs bound to the well was monitored using a peroxidase-conjugated anti-rabbit IgG as a secondary antibody, and tetramethylbenzidine solution as a substrate. The measuring range extended from 50 pg/ml to 20 ng/ml of SSA, with a detection limit of 40 pg/ml (5.13 pM). Antibodies showed some cross-reactivity with saikosaponin c (12.74%). However, the antibodies showed only slight cross-reactivities with saikosaponin d (0.3%), which differs from SSA only in the stereochemistry of the 16-hydroxyl group, and the artificial saikosaponins, saikosaponin b1 (2.1%) and saikosaponin g (0.53%). The specific and sensitive ELISA is especially suited for determination of SSA in samples when only small quantities of materials can be extracted for analysis.

Production of antibody against saikosaponin a, an active component of bupleuri radix.

High titer rabbit polyclonal antibodies (pAbs) which show a specificity for saikosaponin a (SSA), have been generated. The immunogen used was a conjugate of SSA linked through its glucose moiety to bovine serum albumin by periodate oxidation method. The antibody titers obtained from two rabbits, inoculated with the immunogen, reached a plateau after the fourth and third booster injection, respectively. The specificity of the pAbs was determined by hapten inhibition assays using several SSA-like structures. SSA competitively inhibited the binding of the rabbit anti-SSA pAbs to SSA-ovalbumin on solid phase, a coated antigen on the well. The antibodies showed high specificity to SSA, exhibiting no significant cross-reactivity with any of SSA analogues tested.

In vitro angiogenic activity of Aloe vera gel on calf pulmonary artery endothelial (CPAE) cells.

Angiogenic activity of Aloe vera gel was investigated by in vitro assay. We obtained the most active fraction from dichloromethane extract of Aloe vera gel by partitioning between hexane and 90% aqueous methanol. The most active fraction (F3) increased the proliferation of calf pulmonary artery endothelial (CPAE) cells. In addition, F3 fraction induced CPAE cells to invade type 1 collagen gel and form capillary-like tube through in vitro angiogenesis assay, and increased the invasion of CPAE cells into matrigel through in vitro invasion assay. Furthermore, the effect on the mRNA expression of proteolytic enzymes which are key participants in the regulation of extracellular matrix degradation was investigated by northern blot analysis. F3 fraction enhanced mRNA expression of urokinase-type plasminogen activator (u-PA), matrix metalloproteinase-2 (MMP-2), and membrane-type MMP (MT-MMP) in CPAE cells whereas the expression of plasminogen activator inhibitor-1 (PAI-1) mRNA was not changed.