Effects of nine active ingredients in Chinese herbal medicine sho-saiko-to on 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide mutagenicity

Panax ginseng and Panax quinquefolius: From pharmacology to toxicology

The use of Panax ginseng and Panax quinquefolius in traditional Chinese medicine dates back to about 5000 years ago thanks to its several beneficial and healing properties. Over the past few years, extensive preclinical and clinical evidence in the scientific literature worldwide has supported the beneficial effects of P. ginseng and P. quinquefolius in significant central nervous system, metabolic, infectious and neoplastic diseases. There has been growing research on ginseng because of its favorable pharmacokinetics, including the intestinal biotransformation which is responsible for the processing of ginsenosides - contained in the roots or extracts of ginseng - into metabolites with high pharmacological activity and how such principles act on numerous cell targets. The aim of this review is to provide a simple and extensive overview of the pharmacokinetics and pharmacodynamics of P. ginseng and P. quinquefolius, focusing on the clinical evidence which has shown particular effectiveness in specific diseases, such as dementia, diabetes mellitus, respiratory infections, and cancer. Furthermore, the review will also provide data on toxicological factors to support the favorable safety profile of these medicinal plants.

A high-performance liquid chromatographic method for saikosaponin a quantification in rat plasma

A high-performance liquid chromatographic method with UV detection has been developed for the determination of saikosaponin a in rat plasma. Saikosaponin a and internal standard jujuboside A were isolated from plasma samples by solid-phase extraction. The chromatographic separation was achieved on a reversed-phase C(18) column with the mobile phase of acetonitrile-water (35:65, v/v) at a flow rate of 1 mL/min and UV detection was set at 205 nm. The standard curve for saikosaponin a was linear over the concentration range 0.25-10 microg/mL and the limit of detection was 0.05 microg/mL. The absolute recovery was greater than 82%. The precision and accuracy ranged from 3.05 to 9.59% and 95.61 to 110.00%, respectively. The validated method was used to determine saikosaponin a in plasma samples in a pharmacokinetic study of saikosaponin a administered to Sprague-Dawley rats.

Antioxidative andIn Vitro hepatoprotective activity ofBupleurum kaoi leaf infusion

The roots of Bupleurus spp. have been used in traditional Chinese herbal medicine for curing liver diseases. Although bioactive saikosaponins have been detected in the leaves as well as in the roots, the aerial parts of the plants are discarded as waste. In the present study, a leaf infusion of B. kaoi Liu, Chao et Chuang, an indigenous Bupleurus species in Taiwan, was prepared and the antioxidant properties and in vitro hepatoprotective activity were demonstrated. The results show that the leaf infusion exerted DPPH free radical scavenging activity, inhibitory capacity on superoxide anion formation and superoxide anion scavenging activity. The hepatotoxicity of acetaminophen (APAP) and carbon tetrachloride (CCl4) on the rat liver cells were also decreased by the leaf infusion.

High performance liquid chromatographic assay of saikosaponins from radix Bupleuri in China

In this study, the quantitative analysis of saikosaponins from Radix Bupleuri in China was performed by high performance liquid chromatography. Saikosaponin-a and -d were converted completely into saikosaponin-b1 and -b2 by mild acid treatment. Distinctive measuring of these converted diene-saponins provided a rapid and selective method for the determination of saikosaponin-a and -d in commercial samples of Radix Bupleuri. The conditions of extraction and conversion of saikosaponins were optimized using orthogonal design L9(3(4)). The HPLC analysis was performed on ODS-C18 column with a flow rate of 1.0 ml/min and detection wavelength of 250 nm. Well resolved chromatograms of saikosaponin-b1 and -b2 were obtained with an isocratic elution of acetonitrile : 1% formic acid water (37.5 : 62.5). Calibration curves of saikosaponin-b1 and -b2 were linear in the range of 4.9-98.0 microg/ml and 3.5-71.0 microg/ml, respectively. The average recovery of saikosaponin-b1 and -b2 were 98.3% (RSD = 3.1%) and 96.4% (RSD = 1.8%), respectively. Seventeen samples of different species and habitats of Radix Bupleuri were analyzed by the developed HPLC method.

Ultrasound-assisted extraction methodology as a tool to improve the antioxidant properties of herbal drug Xiao-chia-hu-tang

Xiao-chai-hu-tang (XCHT) is an important Chinese herbal prescription for curing many types of liver diseases. The contents of bioactive constituents (saikosaponins a, c and d, baicalin, baicalein, and glycyrrhizic acid), and antioxidant properties of XCHT extracts prepared with ultrasound-assisted (US) extraction in combination with ethanol (up to 95%) as extraction modifier were studied. The results showed that the US extraction significantly increased the bioactive constituents concentrations and antioxidant properties of XCHT extracts when compared with the XCHT prepared with traditional boiling-water extraction. Among the XCHT extracts made with US extraction, the sample prepared with 95% ethanol showed the highest bioactive constituent concentrations and the best antioxidant functionalities. The results suggest that US extraction of XCHT is feasible to replace the traditional time-consuming and low efficiency preparation procedure in the future modernized and commercialized manufacture of this highly valuable Chinese herbal medicine.

Protective effects of baicalein and wogonin against benzo[a]pyrene- and aflatoxin B(1)-induced genotoxicities

To evaluate the protective effects of baicalein and wogonin against benzo[a]pyrene- and aflatoxin (AF) B(1)-induced toxicities, the effects of these flavonoids on the genotoxicities and oxidation of benzo[a]pyrene and AFB(1) were studied in C57BL/6J mice. Baicalein and wogonin reduced benzo[a]pyrene and AFB(1) genotoxicities as monitored by the umuC gene expression response in Salmonella typhimurium TA1535/pSK1002. Baicalein added in vitro decreased liver microsomal benzo[a]pyrene hydroxylation (AHH) activity with an ic(50) of 33.9 +/- 1.4 microM at 100 microM benzo[a]pyrene. Baicalein also inhibited AFQ(1) and AFB(1)-epoxide formation from AFB(1) (50 microM) oxidation (AFO) with ic(50) values of 22.8 +/- 1.4 and 5.3 +/- 0.8 microM, respectively. However, the in vitro inhibitory effects of wogonin on AHH and AFO activities in liver microsomes were less than those of baicalein as inhibition by 500 microM wogonin was only about 51-65%. Treatment of mice with liquid diets containing 5 mM baicalein and wogonin resulted in 22 and 49% decreases in hepatic AHH activities, respectively. Baicalein treatment resulted in 39 and 32% decreases in AFQ(1) and AFB(1)-epoxide formation from liver microsomal AFO, respectively. Wogonin treatment resulted in 39 and 47% decreases in AFQ(1) and AFB(1)-epoxide formation, respectively. A 1-week pretreatment with wogonin significantly decreased hepatic DNA adduct formation in mice treated with 200 mg/kg of benzo[a]pyrene via gastrogavage. These in vitro and in vivo effects suggested that baicalein and wogonin might have beneficial effects against benzo[a]pyrene- and AFB(1)-induced hepatic toxicities and that wogonin had a stronger protective effect in vivo.

The bioactivity of saponins: triterpenoid and steroidal glycosides

Triterpenoid and steroidal glycosides, referred to collectively as saponins, are bioactive compounds present naturally in many plants. They have considerable potential as pharmaceutical and/or nutraceutical agents in natural or synthetic form. Saponins, from a variety of sources, have been shown to have hypocholesterolemic, anti-coagulant, anticarcinogenic, hepatoprotective, hypoglycemic, immunomodulatory, neuroprotective, anti-inflammatory and anti-oxidant activity. This paper reviews saponin research of the last decade, focussing on developments in understanding their mechanism of action and structure-activity relationships. Virtually all of this work has used animal and in vitro models. To date there are very few human data.

Characterization and antimutagenic activity of soybean saponins

An extract was prepared from a commercial soybean-processing by-product (soybean molasses) and was fractionated into purified chemical components. In previous work, this extract (phytochemical concentrate, PCC) repressed induced genomic DNA damage, whole cell clastogenicity and point mutation in cultured mammalian cells. In the current study, a chemical fraction was isolated from PCC using preparative high-performance liquid chromatography (HPLC). This fraction, PCC100, repressed 2-acetoxyacetylaminofluorene (2AAAF)-induced DNA damage in Chinese hamster ovary (CHO) cells as measured by single cell gel electrophoresis (alkaline Comet assay). Using liquid chromatography-electrospray ionization-mass spectroscopy and 1H and 13C nuclear magnetic resonance (NMR) spectroscopy, PCC100 was shown to consist of a mixture of group B soyasaponins and 2,3-dihydro-2,5-dihydroxy-6-methyl-4H-pyran-4-one (DDMP) soyasaponins. These include soyasaponins I, II, III, IV, V, Be, betag, betaa, gammag and gammaa. Purified soyasapogenol B aglycone prepared from fraction PCC100 demonstrated significant antigenotoxic activity against 2AAAF. To our knowledge, these data demonstrate for the first time the antimutagenic activity of soybean saponins in mammalian cells.

Sho-saiko-to: Japanese herbal medicine for protection against hepatic fibrosis and carcinoma

Herbal medicines, which have been used in China for thousands of years, are now being manufactured in Japan, in standardized form in terms of quality and quantities of ingredients. The Chinese herbal medicine Sho-saiko-to is a mixture of seven herbal preparations, which is widely administered in Japan to patients with chronic hepatitis and cirrhosis. In a prospective study, this herbal medicine was found to play a chemopreventive role in the development of hepatocellular carcinoma in cirrhotic patients. However, little is known about the mechanism by which Sho-saiko-to protects against hepatic fibrosis and carcinoma. Several laboratories, including ours, have clearly demonstrated the preventive and therapeutic effects of Sho-saiko-to on experimental hepatic fibrosis, as well as its inhibitory effect on the activation of hepatic stellate cells, which are the major types of collagen-producing cells. We provided evidence that Sho-saiko-to functions as a potent anti-fibrosuppressant via the inhibition of oxidative stress in hepatocytes and hepatic stellate cells and that its active components are baicalin and baicalein. In addition, Sho-saiko-to has anti-carcinogenic properties in that it inhibits chemical hepatocarcinogenesis in animals, acts as a biological response modifier and suppresses the proliferation of hepatoma cells by inducing apoptosis and arrests the cell cycle. Among the active components of Sho-saiko-to, baicalin, baicalein and saikosaponin-a have the ability to inhibit cell proliferation. It should be noted that baicalin and baicalein are flavonoids with chemical structures very similar to silybinin, which shows anti-fibrogenic activities. This may provide valuable information on the search for novel anti-fibrogenic agents.