Hongtao Bi

Anti-fatigue activity of polysaccharides from the fruits of four Tibetan plateau indigenous medicinal plants

ETHNOPHARMACOLOGICAL RELEVANCE The fruits of Hippophae rhamnoides L., Lycium barbarum L., Lycium ruthenicum Murr. and Nitraria tangutorum Bobr. are traditional medicinal food of Tibetans and used to alleviate fatigue caused by oxygen deficiency for thousands of years. The present study focused on exploiting natural polysaccharides with remarkable anti-fatigue activity from the four Qinghai-Tibet plateau characteristic berries. MATERIALS AND METHODS The fruits of Hippophae rhamnoides, Lycium barbarum, Lycium ruthenicum and Nitraria tangutorum were collected from Haixi national municipality of Mongol and Tibetan (N 36.32°, E98.11°; altitude: 3100 m), Qinghai, China. Their polysaccharides (HRWP, LBWP, LRWP and NTWP) were isolated by hot-water extraction, and purified by DEAE-Cellulose ion-exchange chromatography. The total carbohydrate, uronic acid, protein and starch contents of polysaccharides were determined by a spectrophotometric method. The molecular weight distributions of polysaccharides were determined by gel filtration chromatography. Their monosaccharide composition analysis was performed by the method of 1-phenyl-3-methyl-5-pyrazolone (PMP) pre-column derivatization and RP-HPLC analysis. HRWP, LBWP, LRWP and NTWP (50, 100 and 200 mg/kg) were orally administrated to mice once daily for 15 days, respectively. Anti-fatigue activity was assessed using the forced swim test (FST), and serum biochemical parameters were determined by an autoanalyzer and commercially available kits; the body and organs were also weighted. RESULT LBWP, LRWP and NTWP were mainly composed of glucans and some RG-I pectins, and HRWP was mainly composed of HG-type pectin and some glucans. All the four polysaccharides decreased immobility in the FST, and the effects of LBWP and NTWP were demonstrated in lower doses compared with HRWP and LRWP. There was no significant difference in liver and heart indices between non-treated and polysaccharide-treated mice, but the spleen indices were increased in LBWP and NTWP (200mg/kg) group. Moreover, the FST-induced reduction in glucose (Glc), superoxide dismutase (SOD) and glutathione peroxidase (GPx) and increase in creatine phosphokinase (CK), lactic dehydrogenase (LDH), blood urea nitrogen (BUN), triglyceride (TG) and malondialdehyde (MDA) levels, all indicators of fatigue, were inhibited by HRWP, LBWP, LRWP and NTWP to a certain extent while the effects of LBWP and NTWP were much better than that of HRWP and LRWP at the same dosage. CONCLUSION Water-soluble polysaccharides HRWP, LBWP, LRWP and NTWP, from the fruits of four Tibetan plateau indigenous berry plants, significantly exhibited anti-fatigue activities for the first time, through triglyceride (TG) (or fat) mobilization during exercise and protecting corpuscular membrane by prevention of lipid oxidation via modifying several enzyme activities. Moreover, it is demonstrated that LBWP and NTWP are more potent than HRWP and LRWP, which were proposed to be applied in functional foods for anti-fatigue and antioxidant potential.

Preparation of a glucan from the roots of Rubus crataegifolius Bge. and its immunological activity.

A water-soluble glucan (RCP-1) was prepared from the roots of Rubus crataegifolius Bge. by extraction with hot-water, deproteination by Sevag reagent, alpha-amylase treatment and ultrafiltration. RCP-1 consisted of only glucose, and its molecular weight was determined to be approximately 7KD by high performance gel permeation chromatography (HPGPC). Fourier transform infra-red spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy (NMR), methylation and periodate oxidation analyses indicated that RCP-1 was an alpha-d-glucan. Its main chains were composed of (1-->4)- and (1-->6)-linked alpha-glucopyranosyls, and side chains were single alpha-glucopyranosyl residues attached to the O-6 of glucosyls in the main chains. RCP-1 could increase both cytotoxic activity against B16 melanoma cells and the production of nitric oxide (NO) of macrophages in vitro. Furthermore, in vivo bioassay tests indicated that RCP-1 could remarkably enhance T and B lymphocyte proliferations, augment the phagocytosis of macrophages and increase the tumour necrosis factor-alpha (TNF-alpha) levels in serum.

Structural elucidation and antioxidant activity of a water-soluble polysaccharide from the fruit bodies of Bulgaria inquinans (Fries)

The non-lichenized ascomycete Bulgaria inquinans (Fries), growing in the Changbai Mountain of China, has been used as medicinal diet for many years. In a previous study, we have reported that a heteropolysaccharide BIWS-4b from the fruit bodies of B. inquinans (Fries) exhibited markedly antimalarial and immunostimulating activities. In this paper, the structural features and antioxidant activity of BIWS-4b were investigated. The results showed that BIWS-4b contains an α-(1→2), (1→6)-mannan core to which the glucogalactan chains are attached. The glucogalactan chains were composed of (1→6)-, (1→5)- and (1→5,6)-linked β-Galf, (1→4)-linked and non-reducing terminal β-Glcp units, and might be attached to the mannan core at the O-2 positions of α-Manp units. The antioxidant assays showed that BIWS-4b exhibited good activities, including free radicals scavenging effects, ferrous ion-chelating ability and reducing power. Thus, BIWS-4b could be used as a natural antioxidant agent for food and pharmaceutical industries.

Structure elucidation and antioxidant activity of a novel α-(1 → 3),(1 → 4)-d-glucan from Aconitum kusnezoffii Reichb.

Aconitum kusnezoffii Reichb. has been used as traditional Chinese medicine over the last 2500 years, but its polysaccharides have been paid little attention by now. In the present study, a hot alkali extracted polysaccharide (AKP) from A. kusnezoffii Reichb. was characterized to be an alpha-(1-->3),(1-->4)-D-glucan with Mw 1.4 x 10(5) Da, of which (1-->3)-linked and (1-->4)-linked alpha-Glcp residues were in a ratio of 1:7. In vitro antioxidant testing indicated that AKP had significant ferrous ion-chelating ability, reducing power and scavenging effects on DPPH radical, hydroxyl radical, superoxide anion, H2O2 and self-oxidation of 1,2,3-phentriol, suggesting that it should be explored as a novel natural antioxidant.

A novel water-soluble β-(1->6)-D-glucan isolated from the fruit bodies of Bulgaria inquinans (Fries).

A low molecular-weight polysaccharide named BIWP2 was purified from the fruit bodies of Bulgaria Inquinans (Fries) via hot-water extraction, followed by freeze-thawing and gel filtration chromatography on Sephadex G-75. Monosaccharide composition analysis revealed that BIWP2 contained exclusively glucose. High performance size exclusion chromatography (HPSEC) showed that it was a homogeneous polysaccharide fraction. Its molecular weight was estimated to be 2.6 KD and the polydispersity index (M(w)/M(n)) was calculated to be 1.4. Periodate oxidation, methylation, and NMR analyses indicated that BIWP2 was a linear beta-(1-->6)-D-glucan without side chains. This is the first time to report a linear beta-(1-->6)-D-glucan with low molecular weight in non-lichenized ascomycete.

Antioxidant and immunological activities of water-soluble polysaccharides from Aconitum kusnezoffii Reichb.

Aconitum kusnezoffii Reichb., one of the earliest recorded toxic species of genus Aconitum, has been used as traditional Chinese medicine and medicinal diet over the last 2500 years to treat heart failure congestion, neuralgia, rheumatism and gout, etc. In the present paper, four water-soluble polysaccharide fractions isolated from the tubers of A. kusnezoffii Reichb. were studied the antioxidant and immunological activities for the first time. In vitro antioxidant assays indicated that fraction WKCP-A had noticeable scavenging activities on DPPH radical, hydroxyl radical, superoxide anion, H(2)O(2) and self-oxidation of 1,2,3-phentriol, ferrous ion-chelating ability and reducing power. Moreover, the in vivo immunological assay exhibited that fractions WKCP-A and WKHP could more significantly enhance splenic lymphocyte proliferation and macrophage phagocytosis than other fractions. Therefore, the water-soluble polysaccharides from A. kusnezoffii Reichb., especially WKCP-A, have the potential to be explored as novel natural antioxidants and immunostimulating agents for using in functional foods or medicine.

Anticancer and immunostimulating activities of a novel homogalacturonan from Hippophae rhamnoides L. berry

Our previous study isolated an anti-fatigue polysaccharide (HRWP) from the Hippophae rhamnoides berry. In this study, using ion-exchange chromatography and gel filtration chromatography in turn, a water-soluble homogenous polysaccharide HRWP-A was isolated from HRWP. Structural analysis determined that HRWP-A was a polysaccharide with repeating units of (1→4)-β-d-galactopyranosyluronic residues, of which 85.16% were esterified with methyl groups. An antitumor activity assay showed that HRWP-A could significantly inhibit the Lewis lung carcinoma (LLC) growth in tumor-bearing mice. Further experiments suggested that the antitumor effect of HRWP-A might be mediated through immunostimulating activity, as it enhances the lymphocyte proliferation, augments the macrophage activities, as well as promoting NK cell activity and CTL cytotoxicity in tumor-bearing mice. To our knowledge, this is the first report on a natural antitumor high-methoxyl homogalacturonan pectin from the H. rhamnoides berry-a compound that acts as a potential immunostimulant and anticancer adjuvant.

A Water-Soluble Polysaccharide from the Fruit Bodies of Bulgaria inquinans (Fries) and Its Anti-Malarial Activity

A water-soluble polysaccharide (BIWS-4b) was purified from the fruit bodies of Bulgaria inquinans (Fries). It is composed of mannose (27.2%), glucose (15.5%) and galactose (57.3%). Its molecular weight was estimated to be 7.4 kDa (polydispersity index, Mw/Mn: 1.35). Structural analyses indicated that BIWS-4b mainly contains (1 → 6)-linked, (1 → 5)-linked and (1 → 5,6)-linked β-Galf units; (1 → 4)-linked and non-reducing terminal β-Glcp units; and (1 → 2)-linked, (1 → 6)-linked, (1 → 2,6)-linked and non-reducing terminal α-Manp units. When examined by the 4-day method and in a prophylactic assay in mice, BIWS-4b exhibited markedly suppressive activity against malaria while enhancing the activity of artesunate. Immunological tests indicated that BIWS-4b significantly enhanced macrophage phagocytosis and splenic lymphocyte proliferation in malaria-bearing mice and normal mice. The anti-malarial activity of BIWS-4b might be intermediated by enhancing immune competence and restoring artesunate-suppressed immune function. Thus, BIWS-4b is a potential adjuvant of anti-malaria drugs.

The photocytotoxicity of different lights on mammalian cells in interior lighting system

In the present paper, two light sources commonly used in interior lighting system: incandescent light and light emitting diode (LED) were chosen to evaluate their influences on three kinds of mammalian cells, together with UVA and UVB, and the mechanism of the photocytotoxicity was investigated in terms of intracellular ROS production, lipid peroxidation, SOD activity and GSH level assays. The results showed that LED and incandescent light both had some photocytotoxicities. In the interior lighting condition (100lx-250lx), the cytotoxicities of LED and incandescent lamp on RF/6A cells (rhesus retinal pigment epithelium cell line) were stronger than that on two fibroblast cell lines, while the cytotoxicity of UVA and UVB on HS68 cells (fibroblast cell line) was highest in the tests. The mechanism analysis revealed that the photocytotoxicities of LED and incandescent lamp were both caused by cell lipid peroxidation. LED and incandescent light could promote the production of ROS, raise lipid peroxidation level and lower the activity of the antioxidant key enzymes in mammalian cells, and finally cause a number of cells death. However, the negative function of LED was significantly smaller than incandescent light and ultraviolet in daily interior lighting condition. And the significantly lower photocytotoxicity of LED might be due to the less existence of ultraviolet. Therefore, LED is an efficient and relative safe light source in interior lighting system, which should be widely used instead of traditional light source.

In vivo antimalarial activity of ginseng extracts

Context: Novel antimalarial agents are in demand due to the emergence of multidrug resistant strains. Ginseng, a medicinal plant with antiparasitic activity, contains components that can be used to treat the tropical disease malaria. Objective: Ginsenosides and polysaccharides are active components of ginseng. This study aimed to elucidate the ability of these compounds to inhibit the replication of Plasmodium yoelii in an attempt to determine whether the medicinal uses of ginseng are supported by pharmacological effects. New antimalarial compounds may be developed from ginsenosides and water-soluble ginseng polysaccharides (WGP). Materials and methods: Ginsenosides and ginseng polysaccharides were prepared from ginseng. Antimalarial activities were examined by 4-day tests and repository tests. Macrophage phagocytosis was tested in normal and malaria-bearing mice. Results: Ginseng polysaccharides could inhibit residual malaria infection. After a 6-day treatment, the parasitemia reductions of WGP and acidic ginseng polysaccharide (WGPA) were 55.66% and 64.73% at 200 mg/kg/day, respectively. Ginsenosides showed significant antimalarial activity on early infection. Protopanaxadiol-type ginsenosides caused 70.97% chemosuppression at 50 mg/kg/day, higher than 52.8% of total ginsenosides at the same dose. Discussion and conclusion: Protopanaxadiol-type ginsenosides have remarkably suppressive activity during early infection, while acidic ginseng polysaccharides have significant prophylactic activity against malaria by stimulating the immune system. We propose that the activity of ginsenosides is dependent upon non-specific carbohydrate interactions and that the activity of ginseng polysaccharides is due to immunological modulation. Ginsenosides and ginseng polysaccharides might have a potential application in antimalarial treatments.