Natural products and synthetic compounds as immunomodulators

Immunotherapies inducing immunogenic cell death in cancer: insight of the innate immune system

Cancer immunotherapies include monoclonal antibodies, cytokines, oncolytic viruses, cellular therapies, and other biological and synthetic immunomodulators. These are traditionally studied for their effect on the immune system's role in eliminating cancer cells. However, some of these therapies have the unique ability to directly induce cytotoxicity in cancer cells by inducing immunogenic cell death (ICD). Unlike general immune stimulation, ICD triggers specific therapy-induced cell death pathways, based on the release of damage-associated molecular patterns (DAMPs) from dying tumour cells. These activate innate pattern recognition receptors (PRRs) and subsequent adaptive immune responses, offering the promise of sustained anticancer drug efficacy and durable antitumour immune memory. Exploring how onco-immunotherapies can trigger ICD, enhances our understanding of their mechanisms and potential for combination strategies. This review explores the complexities of these immunotherapeutic approaches that induce ICD, highlighting their implications for the innate immune system, addressing challenges in cancer treatment, and emphasising the pivotal role of ICD in contemporary cancer research.

Plants and Plant-Derived Molecules as Natural Immunomodulators

Background. Nowadays, the immunomodulatory properties of plants have been studied extensively with greater interest due to increasing awareness and combating the severity of immunomodulatory diseases. Scope and Approach. This paper highlights the efficacy of the available literature evidence on natural immunomodulators of plant origin and synthetic ones. In addition, several aspects of plants and their phytoconstituents responsible for immunomodulation have been discussed. Moreover, this review also discusses the mechanism involved in immunomodulation. Key Findings. One hundred fifty medicinal immunomodulatory plants are currently identified to find novel immunomodulatory drugs. Of these plants, the plant family Asteraceae also takes the first rank by offering 18 plant species (12%). Similarly of the plants studied so far, 40% belong to the Asteraceae family. Echinacea purpurea of this family is most known for its immunostimulating activity. The most prominent immune-active bioactive molecules are polyphenols, terpenoids, and alkaloids. Also, eight plant bioactive immunomodulators were checked for clinical trials and found in the market. These are six immunosuppressants, resveratrol, epigallocatechin-3-gallate, quercetin, colchicine, capsaicin, and andrographolide, and two immunostimulants, curcumin and genistein. Nowadays, there are a lot of polyherbal traditional medicinal products sold in the market and claimed to their immunomodulators. However, much work is still needed to find more active immunomodulatory agents. The mechanism by which immunomodulatory medicinal plant exert their effect is through the induction of cytokines and phagocyte cells and the inhibition of iNOS, PGE, and COX-2 synthesis.

Ginger Is a Potential Therapeutic for Chronic Toxoplasmosis

Background:Toxoplasma gondii (T. gondii) is an opportunistic parasite that causes serious diseases in humans, particularly immunocompromised individuals and pregnant women. To date, there are limited numbers of therapeutics for chronic toxoplasmosis which necessitate the discovery of effective and safe therapeutics. In the present study, we aimed to evaluate the antitoxoplasmosis potential of ginger extract in mice with experimentally induced chronic toxoplasmosis. Results: Treatment with ginger extract significantly reduced cysts count in the brains of T. gondii-infected mice with a marked alleviation of edema and inflammation, and a reversal of neuronal injury. Moreover, ginger extract treatment reduced inflammation in liver and lungs and protected hepatocytes from infection-induced degeneration. Consistently, apoptosis was significantly mitigated in the brains of ginger extract-treated mice compared to infected untreated animals or spiramycin-treated animals. Methods: Four groups of Swiss albino mice (10 mice each) were used. The first group was not infected, whereas 3 groups were infected with Me49 T. gondii strains. One infected group remained untreated (infected untreated), whereas the other two infected groups were treated with either ginger extract (250 mg/kg) or spiramycin (positive control; 100 mg/kg), respectively. The therapeutic potential of ginger extract was evaluated by calculation of the parasite burden in infected animals, and examination of the infected tissues for reduced pathologic changes. Conclusions: Our results showed for the first time that ginger extract exhibited marked therapeutic effects in mice with chronic T. gondii infection which indicates that it can be used as a safe and effective treatment for chronic toxoplasmosis.

Leishmanicidal potentials of Gossypium hirsutum extract and its fractions on Leishmania major in a murine model: parasite burden, gene expression, and histopathological profile

Introduction. Leishmaniasis is a neglected tropical and subtropical disease caused by over 20 protozoan species.Hypothesis. Treatment of this complex disease with traditional synthetic drugs is a major challenge worldwide. Natural constituents are unique candidates for future therapeutic development.Aim. This study aimed to assess the in vivo anti-leishmanial effect of the Gossypium hirsutum extract, and its fractions compared to the standard drug (Glucantime, MA) in a murine model and explore the mechanism of action.Methodology. Footpads of BALB/c mice were infected with stationary phase promastigotes and treated topically and intraperitoneally with G. hirsutum extract, its fractions, or Glucantime, 4 weeks post-infection. The extract and fractions were prepared using the Soxhlet apparatus with chloroform followed by the column procedure.Results. The crude extract significantly decreased the footpad parasite load and lesion size compared to the untreated control group (P<0.05), as revealed by dilution assay, quantitative real-time PCR, and histopathological analyses. The primary mode of action involved an immunomodulatory role towards the Th1 response in the up-regulation of IFN-γ and IL-12 and the suppression of IL-10 gene expression profiling against cutaneous leishmaniasis caused by Leishmania major.Conclusion. This finding suggests that the extract possesses multiple combinatory effects of diverse bioactive phytochemical compositions that exert its mechanisms of action through agonistic-synergistic interactions. The topical extract formulation could be a suitable and unique candidate for future investigation and pharmacological development. Further studies are crucial to evaluate the therapeutic potentials of the extract alone and in combination with conventional drugs using clinical settings.

Spice-infused palmyra palm syrup improved cell-mediated immunity in Wistar Albino rats

Spices attract tremendous attention in the management of viral infections. However, scientific validation is vital to recommend spices as nutraceuticals or functional foods. In the present work, we have selected three spices based on Ayurvedic knowledge and developed a nutraceutical for immunomodulation. Trikatu, a blend of ginger, black pepper, and long pepper, is used in the Indian Ayurvedic system, along with many herbs, for various ailments. We formulated a "Trikatu syrup" (TS) using these three spices and palmyra palm neera. Carbon clearance assay, neutrophil adhesion test, and sheep red blood cell (SRBC)-induced delayed-type hypersensitivity (DTH) reaction was performed to investigate the immunomodulatory potential of TS in Wistar Albino rats. The rats fed with TS showed a dose-dependent increase in footpad thickness compared to control rats, suggesting cell-mediated immunity. The major bioactive piperine in TS was isolated and quantified. PRACTICAL APPLICATIONS: Spices are consumed worldwide as a flavor enhancer in food. Besides, spices have an array of bioactive molecules with a multitude of health benefits. In the backdrop of COVID-19, immunomodulation and antiviral properties of spices are discussed widely. The present study is intended to explore the potential of three selected spices (ginger, black pepper, and long pepper) beyond its application in typical food preparations. The syrup formulated in this study by using these three spices improved cell-mediated immunity in Wistar Albino rats. The study warrants further validation studies of the formulated product for providing indisputable claims for the immunomodulation properties.

Recent researches in effective antileishmanial herbal compounds: narrative review

Leishmaniasis are neglected diseases and a public health problem; they are caused by protozoan species belonging to the genus Leishmania and mostly influences the poor populations in many developing countries. The lack of effective medications, and an approved vaccine, high toxicity and life-threatening side effects and many cases of drug resistance reported in different countries have resulted in the necessity to discover new, efficient, inexpensive, and safe antileishmanial compounds with less or no toxicity. This increase in consumer demand of natural herbal-derived plant extracts as alternative medicines continues despite the low scientific information to establish their efficacy and safety profiles. Various studies have been conducted so far concerning the application of herbal medicines for the treatment of leishmaniasis, but research on relatively effective and low toxic substances is still needed. In this review, we have summarized recent developments and reported studies concerning about herbal and naturally derived therapeutics in the treatment of leishmaniasis, conducted by several researchers worldwide. Some of these medical herbs with promising results have undergone prospective clinical researches, but many others have either not yet been explored. Recent articles described these medical herbs and their active and important molecules, including quinones, phenolic derivatives, lignans, tannins, terpenes, and oxylipins. We searched ISI Web of Science, PubMed, SID, Scholar, Scopus, and Science Direct, and articles published up to 2019 were included. The keywords of leishmaniasis and some words associated with herbal medicines and natural products were used in our search. This review can serve as a quick reference database for researchers.

Anti-Toxoplasma Activities of Zea Mays and Eryngium Caucasicum Extracts, In Vitro and In Vivo

OBJECTIVES

Toxoplasmosis is a worldwide health problem that caused by intracellular apicomplexan parasite, Toxoplasma gondii (T. gondii). Considering that the available drugs for toxoplasmosis have serious host toxicity, the aim of the current study was to survey the in vitro and in vivo anti-Toxoplasma activity of Zea mays (Z. mays) and Eryngium caucasicum (E. caucasicum) extracts.

METHODS

Four concentrations (5, 10, 25, and 50 mg mL-1) of Z. mays and E. caucasicum methanolic extracts for 30, 60, 120, and 180 min were incubated with infected macrophages and then the viability of RH strain of T. gondii tachyzoites was evaluated by trypan blue staining method. Also, we evaluated the survival rate of acutely infected mice with the extracts (100 and 200 mg kg-1 day-1) intraperitoneally for 5 days after infection with 2× 104 tachyzoites of T. gondii.

RESULTS

The anti-Toxoplasma effect of the methanolic extracts were extremely significant compared to the negative control group in all exposure times (P < 0.05). The Z. mays (10, 25 and 50 mg mL-1) killed 100% of the parasites after 180 and 120 min exposure, respectively. Also, high toxoplasmacidal activity was observed with E. caucasicum extract. Furthermore, treatment of experimentally infected mice with the Z. mays (100, 200 mg kg-1 day-1) and E. caucasicum (100 mg kg-1 day-1) significantly increased their survival rate compared to untreated infected control (P < 0.05).

CONCLUSION

These extracts are promising candidates for further medicine development on toxoplasmosis. However, further investigations are necessary to clarify effective fractions of the Z. mays and E. caucasicum extracts and the mechanisms of action.

Targeting ubiquitin-proteasome pathway by natural, in particular polyphenols, anticancer agents: Lessons learned from clinical trials

The ubiquitin-proteasome pathway (UPP) is the main non-lysosomal proteolytic system responsible for degradation of most intracellular proteins, specifically damaged and regulatory proteins. The UPP is implicated in all aspects of the cellular metabolic networks including physiological or pathological conditions. Alterations in the components of the UPP can lead to stabilization of oncoproteins or augmented degradation of tumour suppressor favouring cancer appearance and progression. Polyphenols are natural compounds that can modulate proteasome activity or the expression of proteasome subunits. All together and due to the pleiotropic functions of UPP, there is a great interest in this proteasome system as a promising therapeutic target for the development of novel anti-cancer drugs. In the present review, the main features of the UPP and its implication in cancer development and progression are described, highlighting the importance of bioactive polyphenols that target the UPP as potential anti-cancer agents.

Immunomodulatory activity of non starch polysaccharides isolated from green gram (Vigna radiata)

Green gram, rich in dietary fiber is known to enhance the function of immune system. However information pertaining to the immunomodulatory potential of its non starch polysaccharides (NSPs) is scanty. Hence, five different NSPs were extracted successively using water (WSP), hot water (55 ^o C, HWSP), EDTA (0.5%, Pectins) and alkali (10%, Hemicellulose A and B) which varied in their arabinose to galactose ratio, sugar, protein, uronic acid contents, molecular weight distribution and immunomodulatory activity. Hemicellulose B was relatively rich in carbohydrate content (~95%) and also possessed potent immunomodulatory activity among the various NSPs. Hemicellulose B was further fractionated on DEAE-cellulose column into six different fractions by eluting step-wise with water, ammonium carbonate (0.1, 0.2, 0.3 M AC) and sodium hydroxide (0.1 and 0.2 M NaOH). 0.1 M AC eluted fraction was found to be the major one amounting to ~ 50% yield and showed relatively significant (p < 0.001) activity towards splenocyte proliferation and macrophage activation as compared with rest of the DEAE eluted fractions.

Development of botanicals to combat antibiotic resistance

The discovery of antibiotics in the previous century lead to reduction in mortality and morbidity due to infectious diseases but their inappropriate and irrational use has resulted in emergence of resistant microbial populations. Alteration of target sites, active efflux of drugs and enzymatic degradations are the strategies employed by the pathogenic bacteria to develop intrinsic resistance to antibiotics. This has led to an increased interest in medicinal plants since 25-50% of current pharmaceuticals are plant derived. Crude extracts of medicinal plants could serve as an alternate source of resistance modifying agents owing to the wide variety of secondary metabolites. These metabolites (alkaloids, tannins, polyphenols etc.) could act as potentials for antimicrobials and resistance modifiers. Plant extracts have the ability to bind to protein domains leading to modification or inhibition protein-protein interactions. This enables the herbals to also present themselves as effective modulators of host related cellular processes viz immune response, mitosis, apoptosis and signal transduction. Thus they may exert their activity not only by killing the microorganism but by affecting key events in the pathogenic process, thereby, the bacteria, fungi and viruses may have a reduced ability to develop resistance to botanicals. The article is meant to stimulate research wherein the cidal activity of the extract is not the only parameter considered but other mechanism of action by which plants can combat drug resistant microbes are investigated. The present article emphasizes on mechanisms involved in countering multi drug resistance.

Protective effect of rutin on humoral and cell mediated immunity in rat model

Diet and dietary intake can persuade the development, safeguard and proper functioning of immune system. Ruin, an important bioflavonoid, is abundantly found in various foodstuffs. Rutin has been acknowledged for its protective and beneficial effects on various aspects of the biological system. The present study was aimed to examine the effect of rutin on the regulation of the immune response in experimental animal models. Effect of rutin of cellular immunity was determined by delayed-type hypersensitivity (DTH) response, carbon clearance assay, leucocyte mobilization test, and cyclophosphamide-induced myelosuppression, whereas humoral immunity was analyzed by the haemagglutinating antibody (HA) titre assay. Rutin (25, 50 and 100 mg/kg, p.o.) evoked a significant increase in antibody titre in the haemagglutination test, increased immunoglobulin levels, and enhanced the delayed type hypersensitivity reaction induced by sheep red blood cells. It also significantly restored the functioning of leucocytes in cyclophosphamide treated rats and augmented phagocytic index in the carbon clearance assay. The outcomes from the present study indicate that rutin possesses sufficient potential for increasing immune activity by cellular and humoral mediated mechanisms.

The efficacy of sulfated polysaccharides from Padina tetrastromatica in modulating the immune functions of RAW 264.7 cells

Immunomodulation is a collective term of immunostimulation and immunosuppression. Immunotherapy by means of immunomodulation is gaining additional significance as the frequency of mutant microbes as well as cancer cases are increasing in the present time. A wide population of marine vegetation has contributed to the traditional and modern therapeutic regimens owing to the abundance of bioactive molecules. Among the seaweed born macromolecules, the sulfated polysaccharides (SPS) from marine macro algae were reported to exhibit excellent biological activities in addition to their structural and nutritional roles. Interestingly, SPS from the marine brown algae Padina tetrastromatica is not yet explored for their immunomodulatory potential. In the present study, SPS were extracted by ethanol precipitation, purified using DEAE cellulose column chromatography, and named as Ethanolic Sulfated Polysaccharide-Column Purified (ESPs-CP). The study includes, evaluation of macrophage proliferation, prostaglandin and nitric oxide production, COX-2, 5-LOX, and iNOS estimation and gene expression studies in RAW 264.7 cells. ESPs-CP strongly stimulated macrophage proliferation and production of prostaglandin and nitric oxide. They also increased COX-2, 5-LOX, and iNOS concentration in macrophages, which was comparable to that of LPS stimulated macrophages. Increase of prostaglandin and NO production may be due to increased expression of COX-2 and iNOS as observed in gene expression studies. The mRNA expression of pro- inflammatory cytokines such as IL-6, IL-1β, TNF-α and anti-inflammatory cytokines IL-10 and TGF-β were also enhanced by ESPs-CP. The evaluations signify the possibilities of SPS as potent immunostimulators during immune deficiencies.

HPTLC Analysis of Bioactivity Guided Anticancer Enriched Fraction of Hydroalcoholic Extract of Picrorhiza kurroa

Objective. Hydroalcoholic extract of Picrorhiza kurroa and its fractions were subjected to in vitro screening for cytotoxicity; further best active fraction (BAF) obtained was tested against Ehrlich ascites carcinoma (EAC) model in Balb/c mice after its quality control analysis. Methods. Cytotoxicities of all the fractions and mother extract of P. kurroa were determined, using MTT assay on breast cancer (MCF-7, MDA-MB 231) and cervical cancer (HeLa, SiHa) cell lines. Metabolic fingerprinting was developed using HPTLC with quantification of biomarkers (cucurbitacins B and E; betulinic acid; picrosides 1 and 2; and apocynin) in BAF. The EAC tumor-bearing mice were used for in vivo anticancer activity after oral administration (50 mg Kg⁻¹) for 10 days. Results. Cytotoxicity assay of mother extract and its fractions over breast cancer and cervix cancer cell lines showed that dichloromethane (DCM) fraction was most cytotoxic (IC₅₀ 36.0–51.0 µg mL⁻¹ at 72 h). Oral administration of DCM fraction showed significant reduction in tumor regression parameters, viable tumor cell count and restoration of hematological parameters may be due to presence of cucurbitacins B and E; betulinic acid; picrosides 1 and 2; and apocynin, as compared to the untreated mice of the control group. Conclusion. The DCM fraction of P. kurroa displayed potent anticancer activity and can be further explored for the development of a potential candidate for cancer therapy.

Immunomodulatory activity of purified arabinoxylans from finger millet (Eleusine coracana, v. Indaf 15) bran

Biological activities of alkali extracted (Barium hydroxide: BE-480 kDa, Potassium hydroxide: KE1-1080 and KE2-40 kDa), purified arabinoxylans (AX) from the finger millet bran varying in their molecular weight, phenolic acid content, arabinose to xylose ratios were evaluated for their immune-stimulatory activities using murine lymphocytes and peritoneal exudate macrophages. All three purified AX displayed significant (p < 0.001) mitogenic activity and activation of macrophages including phagocytosis. Among these BE has shown higher enhancing lymphocyte proliferation (>2 fold) and macrophage phagocytosis than KE1 and KE2. The above results clearly documented that the immunostimulatory activity of arabinoxylans is directly proportional to the amount of ferulic acid content (0.11 mg/100 g), whereas molecular weight as well as arabinose/xylose ratio, did not have any bearing. Purified AX from the finger millet bran can be explored as a potent natural immunomodulator.

Immunomodulatory effects of Potentilla indica and Dendrophthoe pentandra on mice splenocytes and thymocytes

Immunomodulators are agents that are able to stimulate or inhibit the immune response. The leaf extracts from Potentilla indica and Dendrophthoe pentandra were analyzed in vitro for immunomodulatory activity and an MTT colorimetric assay was conducted to determine the proliferation of mice splenocytes and thymocytes. A bromodeoxyuridine assay was performed to analyze DNA synthesis and the Trypan blue exclusion method was conducted to evaluate the changes in total cell population. The results indicated that treatment with P. indica and D. pentandra produced a time- and dose-dependent increase in cell viability and proliferation. Following 72 h of treatment with P. indica and D. pentandra, thymocyte proliferation was augmented by 18 and 41%, respectively and splenocyte proliferation increased by 35 and 42%, respectively, when compared with untreated cells. The present study demonstrated that these extracts may act as potential immunostimulants and, thus, represent an alternative source of immunomodulatory compounds for the treatment of human immune-mediated diseases.

Traditional medicines in Africa: an appraisal of ten potent african medicinal plants

The use of medicinal plants as a fundamental component of the African traditional healthcare system is perhaps the oldest and the most assorted of all therapeutic systems. In many parts of rural Africa, traditional healers prescribing medicinal plants are the most easily accessible and affordable health resource available to the local community and at times the only therapy that subsists. Nonetheless, there is still a paucity of updated comprehensive compilation of promising medicinal plants from the African continent. The major focus of the present review is to provide an updated overview of 10 promising medicinal plants from the African biodiversity which have short- as well as long-term potential to be developed as future phytopharmaceuticals to treat and/or manage panoply of infectious and chronic conditions. In this endeavour, key scientific databases have been probed to investigate trends in the rapidly increasing number of scientific publications on African traditional medicinal plants. Within the framework of enhancing the significance of traditional African medicinal plants, aspects such as traditional use, phytochemical profile, in vitro, in vivo, and clinical studies and also future challenges pertaining to the use of these plants have been explored.

Protective effects of Zhuyeqing liquor on the immune function of normal and immunosuppressed mice in vivo

Background

Zhuyeqing Liquor (ZYQL), a well-known Chinese traditional health liquor, has various biological properties, including anti-oxidant, anti-inflammatory, immunoenhancement and cardiovascular protective effects.

Methods

The protective effects of Zhuyeqing Liquor (ZYQL) on the immune function was investigated in vivo in normal healthy mice and immunosuppressed mice treated with Cyclophosphamide (Cy, 100 mg/kg) by intraperitoneal injection on days 4, 8 and 12. ZYQL (100, 200 and 400 mg/kg) was administered via gavage daily for 14 days. The phagocytotic function of mononuclear phagocytic system was detected with carbon clearance methods, the levels of interleukin-6 (IL-6) and interferon-gamma (IFN-γ) in serum were detected with Enzyme linked immunosorbent assay (ELISA). Immune organs were weighed and organ indexes (organ weight/body weight) of thymus and spleen were calculated. Meanwhile, the activity of lysozyme (LSZ) in serum and the activity of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT) in spleen tissue were measured.

Results

ZYQL significantly upgrades the K value for clearance of carbon particles in normal mice treated with ZYQL (400 mg/kg) and immunosuppressed mice treated with ZYQL (100, 200 and 400 mg/kg) together with Cy (100 mg/kg) in vivo. The treatment of ZYQL (100, 200 and 400 mg/kg) effectively increased the activity of serum lysozyme as well as promoted the serum levels of IL-6 and IFN-γ in normal mice and immunosuppressed mice. Furthermore, ZYQL (100, 200 and 400 mg/kg) had an antioxidant effects in immune system by enhancing the antioxidant enzyme activity of SOD, CAT and GSH-Px in vivo. In addition, ZYQL (100, 200 and 400 mg/kg) effectively elevated the Cy-induced decreased organ index (thymus and spleen).

Conclusions

The present work shows that the dose-dependent administration of ZYQL is capable of influencing immune responses, which implying that its valuable functional health may be attributed partly to its protective effects for the immune function.

Overview of biologic response modifiers in infectious disease

The conventional treatment of infectious agents is increasingly encountering antimicrobial resistance. This resistance has led to an intense search for novel treatment modalities for infectious diseases. Elucidation of the mechanisms underlying the inhibitory activity of chemokines has been instrumental in the rational design of anti-human immunodeficiency virus chemokine drugs. The immune-based therapies, in combination with antimicrobial drugs, for viral hepatitis have attracted much attention. Recognition of toll-like receptors by synthetic immunomodulators is used for certain viral infections. New methodologies have the potential to identify novel targets and foster the development of individually tailored immunomodulatory drug treatments.

Natural products and Chagas' disease: a review of plant compounds studied for activity against Trypanosoma cruzi

Here, we review studies that have investigated the activity of plant-derived compounds against Trypanosoma cruzi, the etiologic agent of Chagas’ disease. In the last decade, more than 300 species belonging to almost 100 families have been evaluated for activity, and here we describe the compounds isolated; 85 references are cited.

C7 Anti-infective activity of immunomodulators

Infectious diseases continue to impact human morbidity and mortality. Every individual is vulnerable to microbial infections regardless of socioeconomic status, gender, age group or ethnic background. There has been an explosion of international air travel with an estimated 2 billion passengers travelling on commercial airlines every year. The rapid expansion of globalization and mass tourism has facilitated the spread of disease-causing pathogens from one continent to another at unprecedented rates.

Possible role of macrophages induced by an irridoid glycoside (RLJ-NE-299A) in host defense mechanism

In order to explore the possible role of macrophages and other necessary immune competent (T and B) cells in the modulation of immune responses, an attempt was made to study the immunomodulatory effect of an irridoid glycoside (RLJ-NE-299A) isolated from the roots of Picrorhiza kurroa. Both in vitro and in vivo studies were used to evaluate the effect of RLJ-NE-299A on humoral, cellular, and phagocytic activity of macrophages. The data obtained in the present study showed that RLJ-NE-299A significantly increased sheep red blood cell (SRBC) and induced antibody (IgM and IgG) titer and delayed type hypersensitivity (DTH) reaction in mice. Besides augmenting the humoral and cell-mediated immune response, it induced macrophage phagocytosis and stimulated cytokine-induced macrophage activation and nitric oxide (NO) production, which resulted in a high degree of protection against Candida albicans and Salmonella typhimurium infections. Flow cytometric analysis indicated the enhanced expression of co-stimulatory surface molecules CD80 and CD86. The ability of RLJ-NE-299A to upregulate these cell surface antigens involved in antigen presentation may provide an explanation for the increased T-cell mediated immunity involving macrophages. Taken together this in vitro and in vivo preclinical data suggests that RLJ-NE-299A acts as an effective immunomodulator specifically to improve macrophage function during infections. The effects of this agent on these cells at concentrations relevant to in vivo therapy support its immunopharmacologic application to modify cellular immunity.

Mechanism of Trypanosoma cruzi death induced by Cratylia mollis seed lectin

Incubation of T. cruzi epimastigotes with the lectin Cramoll 1,4 in Ca(2+) containing medium led to agglutination and inhibition of cell proliferation. The lectin (50 microg/ml) induced plasma membrane permeabilization followed by Ca(2+) influx and mitochondrial Ca(2+) accumulation, a result that resembles the classical effect of digitonin. Cramoll 1,4 stimulated (five-fold) mitochondrial reactive oxygen species (ROS) production, significantly decreased the electrical mitochondrial membrane potential (Delta Psi(m)) and impaired ADP phosphorylation. The rate of uncoupled respiration in epimastigotes was not affected by Cramoll 1,4 plus Ca(2+) treatment, but oligomycin-induced resting respiration was 65% higher in treated cells than in controls. Experiments using T. cruzi mitochondrial fractions showed that, in contrast to digitonin, the lectin significantly decreased Delta Psi(m) by a mechanism sensitive to EGTA. In agreement with the results showing plasma membrane permeabilization and impairment of oxidative phosphorylation by the lectin, fluorescence microscopy experiments using propidium iodide revealed that Cramoll 1,4 induced epimastigotes death by necrosis.

Immunomodulatory activity of oenothein B isolated from Epilobium angustifolium

Epilobium angustifolium has been traditionally used to treat of a number of diseases; however, not much is known regarding its effect on innate immune cells. In this study, we report that extracts of E. angustifolium activated functional responses in neutrophils and monocyte/macrophages. Activity-guided fractionation, followed by mass spectroscopy and NMR analysis, resulted in the identification of oenothein B as the primary component responsible for phagocyte activation. Oenothein B, a dimeric hydrolysable tannin, dose-dependently induced a number of phagocyte functions in vitro, including intracellular Ca(2+) flux, production of reactive oxygen species, chemotaxis, NF-kappaB activation, and proinflammatory cytokine production. Furthermore, oenothein B was active in vivo, inducing keratinocyte chemoattractant production and neutrophil recruitment to the peritoneum after intraperitoneal administration. Biological activity required the full oenothein B structure, as substructures of oenothein B (pyrocatechol, gallic acid, pyrogallol, 3,4-dihydroxybenzoic acid) were all inactive. The ability of oenothein B to modulate phagocyte functions in vitro and in vivo suggests that this compound is responsible for at least part of the therapeutic properties of E. angustifolium extracts.

A historical, scientific and commercial perspective on the medicinal use of Pelargonium sidoides (Geraniaceae)

ETHNOPHARMACOLOGICAL CONTEXT: A detailed review of the ethnobotany and commercial history of Pelargonium sidoides is presented, together with a brief summary of pre-clinical and clinical scientific results that support the use of the plant in modern, evidence-based phytomedicines. The aim is to identify the main factors responsible for the success in product development.

MATERIALS AND METHODS

The literature studied includes all modern scientific papers and also old documents and books that are no longer readily accessible.

RESULTS

Available ethnobotanical information shows that several tuberous Pelargonium species (including Pelargonium sidoides) are important traditional medicines with a rich ethnobotanical history. A summary of the interesting history of the commercial development of Stevens' Cure or Umckaloabo in Europe is presented. Scientific evidence for the efficacy of the product, mainly as a treatment for acute bronchitis, is reviewed. These include numerous in vitro studies as well as 18 clinical studies. The botanical identity of the plant and its complex mixture of coumarins and other chemical constituents are summarised.

CONCLUSIONS

The use of Pelargonium stems or tubers for a variety of ailments (including the complications of dysentery) is an important but hitherto under-estimated part of traditional medicine in southern Africa. Key elements in the successful development of Pelargonium sidoides from a profound traditional remedy to a highly successful phytomedicine include the choice of species, a favourable cost-benefit ratio, innovative marketing over many years, good scientific evidence of the botanical and chemical identity of the product and convincing proof of concept.

Macrophage immunomodulatory activity of polysaccharides isolated from Opuntia polyacantha

Opuntia polyacantha (prickly pear cactus) has been used extensively for its nutritional properties; however, less is known regarding medicinal properties of Opuntia tissues. In the present study, we extracted polysaccharides from O. polyacantha and used size-exclusion chromatography to fractionate the crude polysaccharides into four polysaccharide fractions (designated as Opuntia polysaccharides C-I to C-IV). The average M(r) of fractions C-I through C-IV was estimated to be 733, 550, 310, and 168 kDa, respectively, and sugar composition analysis revealed that Opuntia polysaccharides consisted primarily of galactose, galacturonic acid, xylose, arabinose, and rhamnose. Analysis of the effects of Opuntia polysaccharides on human and murine macrophages demonstrated that all four fractions had potent immunomodulatory activity, inducing production of reactive oxygen species, nitric oxide, tumor necrosis factor alpha, and interleukin 6. Furthermore, modulation of macrophage function by Opuntia polysaccharides was mediated, at least in part, through activation of nuclear factor kappaB. Together, our results provide a molecular basis to explain a portion of the beneficial therapeutic properties of extracts from O. polyacantha and support the concept of using Opuntia polysaccharides as an immunotherapeutic adjuvant.

Antimicrobial susceptibility ofEnterococcus species isolated from slovak bryndza cheese

Three hundred and ten enterococcal isolates (178 Enterococcus faecium, 68 E. durans, 49 E. faecalis, 8 E. italicus, 3 E. gallinarum, 3 E. casseliflavus, and 1 E. hirae) from Slovak Bryndza cheese were evaluated for susceptibility to nine antimicrobial agents (vancomycin, teicoplanin, ampicillin, streptomycin, gentamicin, erythromycin, rifampicin, nitrofurantoin, and ciprofloxacin). All enterococcal isolates from Bryndza cheese were susceptible to ampicillin, streptomycin, gentamicin, vancomycin, and teicoplanin as determined by the disk diffusion method. Vancomycin resistance genes vanA and vanB were not detected. Resistance rates of enterococcal isolates to rifampicin, erythromycin, ciprofloxacin, and nitrofurantoin were 24, 26, 2, and 1 %, respectively. Thirty-six % of E. faecium isolates and 22 % of the E. faecalis isolates were resistant to erythromycin. Resistance to rifampicin was similar in E. faecium (31 %) and E. faecalis (29 %). Both E. faecium and E. faecalis strains showed the same resistance to ciprofloxacin (2 %). E. durans isolates showed low levels of resistance to rifampicin, erythromycin, ciprofloxacin, and nitrofurantoin (1-4 %). Forty-eight (30 %) of the E. faecium isolates, two (3 %) of the E. durans isolates, and six (12 %) of the E. faecalis isolates exhibited multidrug resistance. The highest frequency of resistant enterococci was observed in Bryndza produced in winter season.

Aromatic diamidines as antiparasitic agents

Parasitic infections are widespread in developing countries and frequently associated with immunocompromised patients in developed countries. Consequently, such infections are responsible for a significant amount of human mortality, morbidity and economic hardship. A growing consensus has identified the urgent need for the development of new antiparasitic compounds, mostly due to the large number of drug-resistant parasites and the fact that currently available drugs are expensive, highly toxic, require long treatment regimens and frequently exhibit significantly reduced activity towards certain parasite strains and evolutive stages. In this context, the activity of aromatic diamidines has been explored against a widespread range of micro-organisms, and the authors' present aim is to review the current status of chemotherapy with these compounds against human parasitic infections.

Macrophage immunomodulatory activity of polysaccharides isolated from Juniperus scopolorum

Extracts of cones and leaves of different species of the genus Juniperus have been used for centuries to treat a variety of medical problems; however, little is known about the active components conferring therapeutic properties to these extracts. To address this issue, we extracted water-soluble polysaccharides from Juniperus scopolorum cones and used ion exchange and size exclusion chromatography to separate them into five fractions, with estimated Mr of 30, 60, 100, 200, and 680 kDa, respectively. All fractions contained type II arabinogalactan in their structure, as determined by reaction with Yariv reagent and structural analysis by proton nuclear magnetic resonance spectroscopy, but lacked complement fixing activity. Analysis of the effects of Juniper polysaccharides on murine peritoneal macrophages, cultured J774.A1 macrophages, and human mononuclear phagocytes demonstrated that the high molecular weight polysaccharide fractions (200 and 680 kDa) had potent immunomodulatory activity. These polysaccharide fractions primed macrophages for an enhanced respiratory burst, directly stimulated NO production via induction of nitric oxide synthase, and induced macrophages to secrete both inflammatory (IL-1, IL-6, TNF-alpha, and IL-12) and anti-inflammatory (IL-10) cytokines. These data suggest that at least part of the beneficial therapeutic effects reported for extracts of juniper cones are due to modulation of monocyte/macrophage immune functions.