The malian medicinal plant Trichilia emetica; studies on polysaccharides with complement fixing ability

Structure-function relationships of pectic polysaccharides from broccoli by-products with in vitro B lymphocyte stimulatory activity

To study structure-function relationships of pectic polysaccharides with their immunostimulatory activity, broccoli by-products were used. Pectic polysaccharides composed by 64 mol% uronic acids, 18 mol% Ara, and 10 mol% Gal, obtained by hot water extraction, activated B lymphocytes in vitro (25-250 μg/mL). To disclose active structural features, combinations of ethanol and chromatographic fractionation and modification of the polysaccharides were performed. Polysaccharides insoluble in 80 % ethanol (Et80) showed higher immunostimulatory activity than the pristine mixture, which was independent of molecular weight range (12-400 kDa) and removal of terminal or short Ara side chains. Chemical sulfation did not promote B lymphocyte activation. However, the action of pectin methylesterase and endo-polygalacturonase on hot water extracted polysaccharides produced an acidic fraction with a high immunostimulatory activity. The de-esterified homogalacturonan region seem to be an important core to confer pectic polysaccharides immunostimulatory activity. Therefore, agri-food by-products are a source of pectic polysaccharide functional food ingredients.

Structure characterization of an arabinogalactan from Cynanchum atratum and its immune stimulatory activity on RAW264.7 cells

In the present study, a water-soluble neutral polysaccharide (CAPW-1) with an average molecular weight of 64 kDa was purified from the root of Cynanchum atratum Bunge (Apocynaceae). The monosaccharide residue analysis revealed that CAPW-1 was composed of arabinose and galactose with a relative molar ratio of 7: 3. The backbone of CAPW-1 was consisted of 1,3-Galp and 1,3,6-Galp, the branches were attached to the O-6 of 1,3-Galp, and the side chains contained 1,6-Galp, 1,3,6-Galp, 1,5-linked, 1,3-linked, 1,3,5-linked, and terminal-Araf, which was attached to the O-3 of side 1,6-Galp. The bioactivity study indicated CAPW-1 could stimulate the proliferation of RAW264.7 cells and promote the secretion of nitric oxide (NO), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) with no cytotoxicity. The results suggested a potential application of CAPW-1 as an immunostimulant for the treatment of diseases such as infection and tumor.

Toxicity studies of Acacia nilotica (L.): A review of the published scientific literature

Introduction: Acacia nilotica is a valuable plant with medicinal properties that increasinglyincites the curiosity of many researchers. Its pharmacological properties are reported in manystudies, but the fact remains that the plant can be just as toxic as any modern pharmaceuticaldrug. It is very important to dispose sufficient knowledge on what are reported concerning itstoxicity profile. This review is aimed to provide comprehensive summary (all-in-one) of whathave been reported about the toxicity of A. nilotica and to determine the necessity or not toconduct more toxicological studies in a further step toward rationalizing its medicinal use.Methods: Scientific information about the toxicity and or safety of A. nilotica reported elsewherewere reviewed. Search engines such as Google, Bing and Baidu and databases of scientificjournals such as PubMed, Scopus, CAS, CABI, HINARI and AJOL were used to retrieve studiesfrom 1999 to 2017.Results: Few studies have reported the toxicity potential of A. nilotica and most with very limitedinformation. Three of them have reported serious deleterious toxic effects of certain parts of theplant on major organ systems such as kidney and liver. Stem bark as part of A. nilotica appearedto be the most cited to cause observable clinical signs of toxicity and organs lesions.Conclusion: Overall, this review provided comprehensive information on what is known aboutthe toxicity of A. nilotica and showed the necessity to conduct more advanced long-term-basedtoxicological studies.

Medicinal Plants Used in Mali for the Treatment of Malaria and Liver Diseases

Today, ethno-pharmacology is a very important resource in order to discover new therapies for the current diseases. Moreover, another good justification for the ethno-pharmacological approach is to obtain new, effective, less expensive and simple therapies, limiting at the same time the cost of pharmaceutical research. Two major anti-malarial drugs widely used today, i.e. quinine and artemisinin, came respectively from Peruvian and Chinese ancestral treatments reported in the traditional medicines. In this contest, there is an urgent need for the discovery of new drugs, due to the critical epidemiological situation of this disease and to the growth of resistances. In Mali, malaria and liver diseases remain one of the leading public health problems. Many medicinal plants are often used, in local traditional medicine, for the treatment at the same time of malaria and liver diseases, including hepatic syndromes, jaundice, hepatitis and other hepatic disorders. Moreover, in the local language Bamanan, the word “ Sumaya” is used both for malaria and some liver diseases. In addition, we noted that some of the improved traditional phytomedicines produced by the Department of Traditional Medicine are prescribed by modern doctors both for malaria and liver diseases. In this review, pharmacological, toxicological and phytochemical data on Argemone mexicana L. (Papaveraceae), Cochlospermum tinctorium Perr. ex A. Rich (Cochlospermaceae), Combretum micranthum G.Don (Combretaceae), Entada africana Guillet Perr. (Mimosaceae), Erythrina senegalensis A. DC (Fabaceae), Mitragyna inermis (Willd) Kuntze (Rubiaceae), Nauclea latifolia Smith syn. Sarcocephalus latifolius (Smith) Bruce (Rubiaceae), Securidaca longepedunculata Fresen (Polygalaceae), Trichilia emetica Vahl. (Meliaceae), and Vernonia colorata (Willd) Drake (Asteraceae) are reported. Some of the collected data could be used to improve the actual herbal drugs and to propose new phytomedicines for the management of malaria and liver diseases.

Medicinal plants from Mali: Chemistry and biology

ETHNOPHARMACOLOGICAL RELEVANCE

Mali is one of the countries in West Africa where the health system rely the most on traditional medicine. The healers are mainly using medicinal plants for their treatments. The studies performed being the basis for this review is of importance as they will contribute to sustaining the traditional knowledge. They contribute to evaluate and improve locally produced herbal remedies, and the review gives also an overview of the plant preparations that will have the most potential to be evaluated for new Improved Traditional Medicines.

AIM OF THE REVIEW

The aim of this review is to give an overview of the studies performed related to medicinal plants from Mali in the period 1995-2015. These studies include ethnopharmacology, chemistry and biological studies of the plants that were chosen based on our interviews with the healers in different regions of Mali, and contribute to sustainable knowledge on the medicinal plants. The Department of Traditional Medicine, Bamako, Mali, is responsible for registering the knowledge of the traditional healers on their use of medicinal plants and also identifying compounds in the plants responsible for the bioactivities claimed. The studies reported aimed at getting information from the healers on the use of medicinal plants, and study the biology and chemistry of selected plants for the purpose of verifying the traditional use of the plants. These studies should form the basis for necessary knowledge for the development of registered Improved Traditional Medicines in Mali.

MATERIALS AND METHODS

The healers were the ethnopharmacological informants. Questions asked initially were related to wound healing. This was because the immune system is involved when wounds are healed, and additionally the immune system is involved in the majority of the illnesses common in Mali. Based on the results of the interviews the plant material for studies was selected. Studies were performed on the plant parts the healers were using when treating their patients. Conventional chromatographic and spectroscopic methods were used for the isolation and structural elucidation of compounds. The compounds to study were selected based on the bioassays performed concomitant with the fractionation.

RESULTS

Our results show that plants traditionally used as wound healing agents contain polysaccharides basically of pectin nature with immunomodulating activities. These pectins all have different and new structures. Several of the plants also contain compounds with effects related to antioxidant properties. These compounds are mainly of polyphenolic nature. Three of these are new compounds from Nature, while 32 was for the first time described from the plant they were isolated from. This review gives an overview of the most important results obtained during the 20 year long collaboration between Department of Traditional Medicine, Bamako, Mali, and Department of Pharmacognosy, School of Pharmacy, University of Oslo, Norway.

CONCLUSION

Our studies showed that ethnopharmacological information is important for the determination of screening and chemical methods to be used for studies of plants used in traditional medicine.

Toxicity studies of medicinal plants used in sub-Saharan Africa

In sub-Saharan Africa, traditional medicine is widely used in rural and urban areas also. This is essentially due to the prohibitive cost of pharmaceutical-based medicine and the low incomes of a major part of the population. In addition, the efficacies of many of these traditional and plant-based medicines are proven, but the fact remains that certain plants used in traditional medicine have toxic effects. It is in this perspective that we investigated by bibliographic literature on the toxicity of plants used in traditional medicine. It is crucial to gain knowledge on these plant-based medicines prepared and prescribed by practitioners, particularly in terms of toxicity, composition, specific efficacy of disease and to advise practitioners of this alternative medicine on the protection and security of patients.

Structure-function relationships of immunostimulatory polysaccharides: A review

Immunostimulatory polysaccharides are compounds capable of interacting with the immune system and enhance specific mechanisms of the host response. Glucans, mannans, pectic polysaccharides, arabinogalactans, fucoidans, galactans, hyaluronans, fructans, and xylans are polysaccharides with reported immunostimulatory activity. The structural features that have been related with such activity are the monosaccharide and glycosidic-linkage composition, conformation, molecular weight, functional groups, and branching characteristics. However, the establishment of structure-function relationships is possible only if purified and characterized polysaccharides are used and selective structural modifications performed. Aiming at contributing to the definition of the structure-function relationships necessary to design immunostimulatory polysaccharides with potential for preventive or therapeutical purposes or to be recognized as health-improving ingredients in functional foods, this review introduces basic immunological concepts required to understand the mechanisms that rule the potential claimed immunostimulatory activity of polysaccharides and critically presents a literature survey on the structural features of the polysaccharides and reported immunostimulatory activity.

Characterisation and immunomodulating activities of exo-polysaccharides from submerged cultivation of Hypsizigus marmoreus

Exo-polysaccharides were purified and characterized from the fermentation broth of Hypsizigus marmoreus, a popular edible mushroom consumed in Asia. Among them, B-I-I and B-II-I exhibited potent complement fixating activity, meanwhile, B-N-I, B-I-I, B-II-I and B-II-II exhibited significant macrophage stimulating activity. Molecular weights of the four exo-polysaccharides were determined to be 6.3, 120, 150 and 11 kDa respectively. Molecular characterisation showed that B-N-I is basically an α-1→4 glucan, with branches on C6; B-I-I is a heavily branched α-mannan with 1→2 linked main chain. B-II-I and B-II-II, have a backbone of rhamno-galacturonan with 1→2 linked l-rhamnose interspersed with 1→4 linked galacturonic acid. Structure-activity relationship analysis indicated that monosaccharide compositions, molecular weight, certain structural units (rhamno-galacturonan type I and arabinogalactan type II) are the principal factors responsible for potent complement fixating and macrophage-stimulating activities. Their immunomodulating activities may, at least partly, explain the health benefits of the mushroom.

Are plants used for skin care in South Africa fully explored?

ETHNOPHARMACOLOGICAL RELEVANCE

South Africa is an important focal point of botanical diversity, and although many plant species have been used since ancient times in ethnomedicine, only a few species have hitherto been fully investigated scientifically. A large proportion of the South African population use traditional medicines for their physical and psychological health needs. Many medicinal plants have recently gained popularity as ingredient in cosmetic formulations based on their ethnomedicinal values and many cosmetic products sold in stores are of natural origin. The present review discusses the ethnopharmacological values, pharmacological and toxicological evidence of 117 plant species grown in South Africa, which are used traditionally for skin care purposes. Special focus was on their traditional use for many skin disorders in order to identify their therapeutic potential, the state of ethnopharmacological knowledge and special emphasis has been on areas which require further research.

MATERIALS AND METHODS

The information regarding all 117 plant species mentioned was extracted from Sci-Finder, Science direct, Medline and Google Scholar. All the available relevant data for medicinal plants was collated from literature review articles from the 19th century to early 2013.

RESULTS

The extracts from different parts of plants exhibited significant pharmacological properties, proving significant skin care potentials. Special emphasis was on those plant species which still need further exploration and these have been documented separately.

CONCLUSIONS

Despite the immense use of plants in ethnomedicine for skin care, limited research has been done on the activity of the crude extracts and very little on the active constituents. Consequently, almost 35 out of the 117 species are totally unexplored in the area of skin care. This investigation would be of interest to a broad readership including those researchers working in this field. The plant species namely: Greyia flanaganii, Sideroxylon inerme, Sclerocarya birrea, Calodendrum capense, Hyaenanche globosa, Harpephyllum caffrum, Ximenia americana, Leucosidea sericea Artemisia afra, and six Aloe species have been scientifically validated by our research group for skin hyperpigmentation problems.

Androstanes and pregnanes from Trichilia emetica ssp. suberosa J.J. de Wilde

Four pregnanes: 1-methoxy-pregnan-17(R)-1,4-dien-3,16-dione (1), 1-methoxy-pregnan-17(S)-1,4-dien-3,16-dione (2), 2,3-seco-pregnan-17(S)-2,3-dioic acid-16-oxo-dimethyl ester (4), 2α,3α,16α-trihydroxy-5α-pregnan-17(R)-20-yl acetate (7), three androstanes: 1-methoxy-androstan-1,4-dien-3,16-dione (3), 2,3-seco-androstan-2,3-dioic acid-16-oxo-dimethyl ester (5), 3-methoxycarbonyl-2,3-seco-androstan-3-oic acid-16-oxo-2,19-lactone (6), together with three known pregnane derivatives, were isolated from the roots of Trichilia emetica ssp. suberosa. Their structures were determined by means of 1D and 2D NMR spectroscopy, mass spectrometry analysis, as well as by quantum chemical calculations.

Phytochemical screening and cytotoxicity studies of Chrysophyllum pruniforme Pierre ex Engl. barks

Background:

Chrysophyllum pruniforme of family sapotaceae is a plant used in traditional medicine in Gabon.

Materials and Methods:

In this study, C. pruniforme barks were subjected to phytochemical screening and cytotoxicity investigations. Different concentrations of aqueous and total phenolic extract were tested on mice and on human erythrocytes.

Results:

Phytochemical screening of C. pruniforme barks revealed the presence of flavonoids, saponins, and tannins, reducing sugars, polyphenols and traces of anthraquinones. When tested in vitro, aqueous and the phenolic extracts showed hemolytic activities on human erythrocytes with phenolic compounds being more cytotoxic than aqueous extracts. In vivo study of toxicity, allowed to determine the LD₅₀ at 90 mg/kg for the doses of 50, 150 and 250 mg/kg of body weight.

Conclusion:

These data indicate in one hand that C. pruniforme is rich in phenolic compounds and that the aqueous and total phenolic extracts could be considered as toxic for mice and maybe potentially toxic to humans in the other hand.

Complement activation and inhibition in wound healing

Complement activation is needed to restore tissue injury; however, inappropriate activation of complement, as seen in chronic wounds can cause cell death and enhance inflammation, thus contributing to further injury and impaired wound healing. Therefore, attenuation of complement activation by specific inhibitors is considered as an innovative wound care strategy. Currently, the effects of several complement inhibitors, for example, the C3 inhibitor compstatin and several C1 and C5 inhibitors, are under investigation in patients with complement-mediated diseases. Although (pre)clinical research into the effects of these complement inhibitors on wound healing is limited, available data indicate that reduction of complement activation can improve wound healing. Moreover, medicine may take advantage of safe and effective agents that are produced by various microorganisms, symbionts, for example, medicinal maggots, and plants to attenuate complement activation. To conclude, for the development of new wound care strategies, (pre)clinical studies into the roles of complement and the effects of application of complement inhibitors in wound healing are required.

Medicinal plants traditionally used in Mali for dysmenorrhea

Dysmenorrhea is painful menstrual cramps, which negatively impacts the quality of life of a large percentage of the world's female population in reproductive age. The paper reviews the plants used in the Malian traditional medicine for the treatment of dysmenorrhea. Some medicinal plants were effective for treatments of dysmenorrhea with minimal side effects. Conventional therapy for dysmenorrhea, which usually includes non-steroidal anti-inflammatory drugs (NSAIDs), provides symptomatic relief, but presents increasing adverse effects with long-term use. This article is in the framework of a study supported by International Foundation for Science (IFS) on three medicinal plants used in the treatment of dysmenorrhea in Mali: Maytenus senegalensis Stereospermum kunthianum and Trichilia emetica.

In vitro screening on β-amyloid peptide production of plants used in traditional medicine for cognitive disorders

AIM OF THE STUDY

The aim of the study was to investigate the activity on β-amyloid peptide production of crude extracts of 9 plant species traditionally used in Benin or in Madagascar for the treatment of cognitive disorders, in order to select candidates for Alzheimer's disease treatment.

MATERIALS AND METHODS

For each species, hexane, dichloromethane, ethyl-acetate and water extracts were tested, at non-toxic concentrations, on CHO cells overexpressing the human neuronal β-amyloid peptide precursor (APP695) to measure variations of APP processing (by Western-blotting) and, for the most active, of Aβ-amyloid production (by ECLIA).

RESULTS

We observed, at non-toxic concentrations, a significant increase in CTF/APP ratio with Oldenlandia affinis cyclotide-enriched fraction, Prosopis africana EtOAc extract, Pterocarpus erinaceus aqueous extract and Trichilia emetica hexane extract. We also showed that the Pterocarpus erinaceus extract significantly decreased Aβ production, displaying effects similar to those of DAPT (γ-secretase inhibitor) on APP processing, but may act on another inhibition site.

CONCLUSION

These active extracts are worth further studies to isolate the compounds responsible for the observed activities, to analyze their mode of action and determine their clinical potentials.

Complement-fixing activity of fulvic acid from Shilajit and other natural sources

Shilajit has been used traditionally in folk medicine for the treatment of a variety of disorders, including syndromes involving excessive complement activation. Extracts of Shilajit contain significant amounts of fulvic acid (FA), and it has been suggested that FA is responsible for many therapeutic properties of Shilajit. However, little is known regarding the physical and chemical properties of Shilajit extracts, and nothing is known about their effects on the complement system. To address this issue, extracts of commercial Shilajit were fractionated using anion exchange and size-exclusion chromatography. One neutral (S-I) and two acidic (S-II and S-III) fractions were isolated, characterized and compared with standardized FA samples. The most abundant fraction (S-II) was further fractionated into three sub-fractions (S-II-1 to S-II-3). The van Krevelen diagram showed that the Shilajit fractions are the products of polysaccharide degradation, and all fractions, except S-II-3, contained type II arabinogalactan. All Shilajit fractions exhibited dose-dependent complement-fixing activity in vitro with high potency. Furthermore, a strong correlation was found between the complement-fixing activity and carboxylic group content in the Shilajit fractions and other FA sources. These data provide a molecular basis to explain at least part of the beneficial therapeutic properties of Shilajit and other humic extracts.

Polysaccharides with complement fixing and macrophage stimulation activity from Opilia celtidifolia, isolation and partial characterisation

AIM OF THE STUDY

The present study is aimed to determine the bioactivity and structure of polysaccharides present in the leaves from the Malian medicinal plant Opilia celtidifolia [Guill. & Perr. Endl. ex Walp (Opiliaceae)].

MATERIALS AND METHODS

The polysaccharides from the leaves of Opilia celtidifolia were isolated from water extracts of the leaves using gelfiltration and anion exchange chromatography giving the fractions Oc50A1 and Oc50A2. Monosaccharide composition was determined by gas chromatography of the derived TMS-derivatives of the methyl-glycosides. Linkages were determined of the partly methylated, partly acetylated alditol acetates obtained after a process including reduction, methylation, hydrolysis, reduction and acetylation followed by GC-MS. Effects on the complement system and the macrophages were determined using specific methods aimed for studying those activities.

RESULTS

The polysaccharide fractions isolated from the leaves of Opilia celtidifolia has high complement fixing activity and induce nitrite oxide release from macrophages in a dose dependent manner. The fractions had an ICH50 of 0.5 and 0.9 microg/ml respectively in the complement fixing assay. They induced the release of 7.2 and 7.3 microM of nitrite oxide from macrophages respectively at a dose of 100 microg/ml. The monosaccharide composition in Oc50A1 and Oc50A2, analysed, showed the presence of arabinose (26.7 and 13.2%), galactose (31.5 and 28%) and galacturonic acid (5.3 and 7.8%) respectively. The Yariv test confirmed the presence of arabinogalactan type II in both fractions. Structural analyses did also show the presence of terminal and 1-4 linked galacturonic acid and terminal and 1-2 linked rhamnose. Endo-polygalacturonanase treatment was performed to isolate the heavily substituted parts of the polysaccharides. These parts contained the same monosaccharides in similar proportion, and showed stronger dose dependent complement fixing activity and also stimulated macrophages to release nitrite oxide.

CONCLUSIONS

The leaves of Opilia celtidifola contains polysaccharides of pectic type that have both complement fixing and macrophage stimulating activity.

Cytotoxic kurubasch aldehyde from Trichilia emetica

Kurubasch aldehyde, a sesquiterpenoid with an hydroxylated humulene skeleton, was isolated as free alcohol from Trichilia emetica Vahl. (Meliaceae), belonging to the order Sapindales. Related substances have been previously found in plants as esters of aromatic acids, and these plants were species belonging to the distant order Apiales. This is the first report of humulenes found in the genus Trichilia and only the second of humulenes in the order Sapindales. The aldehyde is a modest inhibitor of the growth of Plasmodium falciparum (IC50 76 microM) and slow-proliferating breast cancer cells MCF7 (78 microM), but a potent inhibitor of proliferation of S180 cancer cells (IC50 7.4 microM).

Antiplasmodial and GABA(A)-benzodiazepine receptor binding activities of five plants used in traditional medicine in Mali, West Africa

Extracts of five medicinal plants: Boscia angustifolia, Cissus quadrangularis, Securidaca longipedunculata, Stylosanthes erecta and Trichilia emetica, used traditionally in Malian traditional medicine were screened for in vitro antiplasmodial activity and GABA(A)-benzodiazepine receptor binding activity. Four extracts showed significant antiplasmodial activities, with the dichloromethane extract of leaf of Securidaca longipedunculata being the most active (IC(50) of 7 microg/ml [95% CI: 5-9]). The dichloromethane extract of leaf of Trichilia emetica, in addition to its antiplasmodial activity (IC(50): 12 microg/ml [95% CI: 12-14]), exhibited a good binding activity to the GABA(A)-benzodiazepine receptor, while water and methanol extracts of the same plant did not show any activity. A strong GABA(A)-receptor complex binding activity was observed in the methanol extract of aerial part of Stylosanthes erecta. The results in this study justify some of the traditional indications of the plants investigated and may thus be candidates for Improved Traditional Medicines in Mali.

Insect management products from Malian traditional medicine--establishing systematic criteria for their identification

In material-resource poor countries like Mali, traditional practices incorporate the use of plants for medicinal purposes. Ethnobotanical research has documented traditional uses of plants, while concomitant studies by natural product chemists, ethnobotanists, and microbiologists have verified the efficacy of using traditional medicinal plants that have proven antimicrobial activity. These plants may also be used to protect agricultural crops pre-harvest and post-harvest from insect herbivory. In Mali, subsistence farmers, regional scientists, and extension specialists rely on local plants for many medicinal needs and are amenable to using traditional plant materials for insect pest management. The goal of this research was to develop Integrated Pest Management (IPM) strategies using Malian traditional medicine as a discovery lead. The discovery premise was based on identifying plants through a matrix approach utilizing agricultural scientists, traditional practitioners, and subsistence farmers. We hypothesized that plants used in traditional medicine with antimicrobial activity lead to potential insect pest management agents. To test our hypothesis, we developed a four-step process for selecting Malian plant species. Seven criteria were selected to create a systematic matrix to identify the most promising plant materials for practical, affordable, ecologically-sound insect management by Malian farmers. In the first step of the process, we developed a list of 294 medicinal Malian plant species which were evaluated using the matrix. Sixty-seven plant species met our main criteria. After the environmental soundness of these species was evaluated using four minor criteria, 50 species emerged from this pre-chemical, pre-bioassay process for further consideration in IPM programs in Mali.

Purification and Partial Characterization of an Acidic Polysaccharide with Complement Fixing Ability from the Stems of Avicennia Marina

An acidic polysaccharide fraction that had high anticomplementary activity was isolated from the stems of Grey Mangrove in 0.15% yield. The final fractions was designated HAM-3-IIb-II. The polysaccharide fraction appeared to be homogenous by high performance size exclusion chromatography with an estimated molecular weight of 105 kDa. The isolated polysaccharide is more effective than polysaccharide K (PSK) in its anticomplementary activity at 58 microg/ml of PSK and 23 microg/ml of HAM-3-IIb-II that inhibit 50% of complement activity in the complement fixation assay. Structural studies indicated that HAM-3-IIb-II was rich in galacturonic acid along with arabinose, galactose and rhamnose, characterizing a pectin-type polysaccharide, which was also confirmed by FT-IR spectrum. The presence of rich neutral sugar side chains of arabinogalactans may have contributed to the expression of high activity. Traditionally, this mangrove plant is used for medicinal purposes and it appears to have some scientific applications.

Polysaccharide biological response modifiers

Biological response modifiers (BRMs) are substances which augment immune response. BRMs can be cytokines which are produced endogenously in our body by immune cells or derivatives of bacteria, fungi, brown algae, Aloe vera and photosynthetic plants. Such exogeneous derivatives (exogeneous BRMs) can be nucleic acid (CpG), lipid (lipotechoic acid), protein or polysaccharide in nature. The receptors for these exogeneous BRMs are pattern recognition receptors. The binding of exogeneous BRMs to pattern recognition receptors triggers immune response. Exogenous BRMs have been reported to have anti-viral, anti-bacterial, anti-fungal, anti-parasitic, and anti-tumor activities. Among different exogeneous BRMs, polysaccharide BRMs have the widest occurrence in nature. Some polysaccharide BRMs have been tested for their therapeutic properties in human clinical trials. An overview of current understandings of polysaccharide BRMs is summarized in this review.

A complement fixing polysaccharide from Biophytum petersianum Klotzsch, a medicinal plant from Mali, West Africa

Biophytum petersianum Klotzsch (syn. Biophytum sensitivum (L.) DC) is a medicinal plant having a traditional use, among others, as a wound healing remedy in Mali and other countries. As a water extract of the aerial parts of the plant is a frequently used preparation, we decided to look for a bioactive polysaccharide in this extract. One of the obtained polysaccharide fractions, BP100 III, isolated from a 100 degrees C water extract from the aerial parts of B. petersianum and having a monosaccharide composition typical for pectic substances, was shown to exhibit potent dose-dependent complement fixating activity. The BP100 III fraction was subjected to degradation by endo-alpha-d-(1-->4)-polygalacturonase, and three fractions were obtained by gel filtration. The highest molecular weight fraction, BP100 III.1, had a more potent activity in the complement test system than the native polymer, while the two lower molecular weight fractions were less active than the native polymer. The major part of BP100 III.1 consists of galacturonic acid and rhamnose, with branches being present on both the rhamnose and galacturonic acid residues. Arabinogalactan type II is also present in the polymer, indicating that BP100 III.1 has a structure typical of the hairy region of pectins. The major part of the two other fractions is a galacturonan, containing a strikingly high number of branch points, some to which xylose is attached. These results indicate that the pectic substance in B. petersianum contains both rhamnogalacturonan and xylogalacturonan regions.

Botanical polysaccharides: macrophage immunomodulation and therapeutic potential

Botanical polysaccharides exhibit a number of beneficial therapeutic properties, and it is thought that the mechanisms involved in these effects are due to the modulation of innate immunity and, more specifically, macrophage function. In this review, we summarize our current state of understanding of the macrophage modulatory effects of botanical polysaccharides isolated from a wide array of different species of flora, including higher plants, mushrooms, lichens and algae. Overall, the primary effect of botanical polysaccharides is to enhance and/or activate macrophage immune responses, leading to immunomodulation, anti-tumor activity, wound-healing and other therapeutic effects. Furthermore, botanical and microbial polysaccharides bind to common surface receptors and induce similar immunomodulatory responses in macrophages, suggesting that evolutionarily conserved polysaccharide structural features are shared between these organisms. Thus, the evaluation of botanical polysaccharides provides a unique opportunity for the discovery of novel therapeutic agents and adjuvants that exhibit beneficial immunomodulatory properties.

Ethnopharmacological survey of different uses of seven medicinal plants from Mali, (West Africa) in the regions Doila, Kolokani and Siby

An ethnopharmacological survey was carried out to collect information on the use of seven medicinal plants in rural areas in the nearby regions of Bamako, Mali. The plants were Opilia celtidifolia, Anthocleista djalonensis, Erythrina senegalensis, Heliotropium indicum, Trichilia emetica, Piliostigma thonningii and Cochlospermum tinctorium. About 50 medical indications were reported for the use of these plants in traditional medicine. The most frequent ailments reported were malaria, abdominal pain and dermatitis. The highest number of usages was reported for the treatment of malaria (22%). The majority of the remedies were prepared from freshly collected plant material from the wild and from a single species only. They were mainly taken orally, but some applications were prepared with a mixture of plants or ingredients such as honey, sugar, salt, ginger and pepper. Decoction of the leaves was the main form of preparation (65%) and leaf powder was mostly used for the preparation of infusions (13%). The part of the plants most frequently used was the leaves. There was a high degree of informant consensus for the species and their medicinal indications between the healers interviewed. The results of this study showed that people are still dependent on medicinal plants in these rural areas of Mali.

Structure-immunomodulating activity relationships of a pectic arabinogalactan from Vernonia kotschyana Sch. Bip. ex Walp

Structure and immunological characteristics of the pectic arabinogalactan Vk2a (previously reported as Vk100A2a) from the roots of Vernonia kotschyana Sch. Bip. ex Walp. were investigated after enzymatic digestion of the galacturonan moiety and the side chains of the rhamnogalacturonan structure of Vk2a. endo-alpha-D-(1-->4)-Polygalacturonase digestion released the high molecular weight 'hairy region' (Vk2a-HR) and oligogalacturonides. Vk2a-HR consisted of GalA (4-linked) and Rha (2- or 2,4-linked) in a 1:1 ratio, with 60% of Rha branched at C-4. The Rha located in the rhamnogalacturonan core was branched randomly by Gal units. Vk2a-HR was rich in neutral sugars such as Araf 5- (12.2%) and 3,5-substituted (12.8%) and terminally- (14.1%) linked and Gal 4- (13.0%), 3- (0.9%), 6- (2.2%) and 3,6- (1.1%) substituted. Arabinans with chain lengths up to 11 units were identified. Araf residues were attached to C-3 of alpha-L-(1-->5)-Araf chains and to C-4 of Gal residues. Single Gal units and chains of beta-D-(1-->6)-linked galacto di- to penta-saccharides were attached to a beta-D-(1-->3)-galactan core. All the enzyme resistant fractions expressed potent complement fixation and induction of B-cell mitogenic activity, and the present study indicates that there may be several and possibly structurally different active sites involved in the bioactivity of Vk2a. The bioactive sites may be located both in the more peripheral parts of the molecule but also in the inner core of the 'hairy region' or in larger enzyme-resistant chains.

Hepatoprotective and antibacterial effects of extracts from Trichilia emetica Vahl. (Meliaceae)

Trichilia emetica Vahl. (Meliaceae) is a tree widely distributed in Tropical Africa. It has been used in Mali folk medicine for the treatment of various illnesses. The aim of this work was to study the hepatoprotective and antibacterial effects of a crude aqueous extract from Trichilia emetica root. An ethyl ether fraction from the aqueous extract was also prepared and studied. We have examined the hepatoprotective activity of the extracts on CCl4-induced damage in rat hepatocytes, their toxicity using the brine shrimp bioassay and their antibacterial activity against clinical isolated bacterial strains, which are commonly responsible for respiratory infections. A preliminary phytochemical analysis showed a high polyphenolic content in the aqueous extract and the presence of limonoids in the ethyl ether fraction. These latter compounds may be considered responsible for the good activity against the bacterial strains tested. Trichilia emetica extracts exerted also a significant (P<0.05) hepatoprotective effect at a dose of 1000 microg/ml both on plasma membrane and mitochondrial function as compared to silymarin used as a positive control. These activities may be a result of the presence of either polyphenols or limonoids. Finally, both the aqueous extract and its ethyl ether fraction did not show toxicity (LC50>1000 microg/ml) in the brine shrimp bioassay.

Structural and immunological studies of a pectin and a pectic arabinogalactan from Vernonia kotschyana Sch. Bip. ex Walp. (Asteraceae)

Two polysaccharides, a pectin (Vk100A2b) and a pectic arabinogalactan (Vk100A2a) with mean Mw 2 x 10(4) and 1.15 x 10(6)Da, respectively, were isolated from the dried powdered roots of Vernonia kotschyana Sch. Bip. ex Walp. by hot water extraction followed by fractionation on DEAE-Sepharose fast flow and Sephacryl S-400 HR. The pectin showed low-complement fixation activity and no influence on proliferation of B or T cells, while the pectic arabinogalactan showed a potent, dose-dependent complement fixation activity and a T cell independent induction of B-cell proliferation. Both polysaccharides induced chemotaxis of human macrophages, T cells and NK cells. exo-alpha-L-arabinofuranosidase and exo-beta-D-galactosidase digestion followed by component sugar and methylation analysis indicated that Vk100A2a consisted of a highly branched rhamnogalacturonan core with approximately 50% of the rhamnose 1,2,4-substituted, side chains rich in terminal-, 1,5-linked and 1,3,5-branched arabinose and terminal-, 1,4-, 1,6-linked and 1,3,6-branched galactose. The enzyme resistant part of Vk100A2a still showed strong complement fixating activity, suggesting that this activity may at least in part be expressed by carbohydrate structures present in the enzyme resistant, inner portion of the polymer.