Selective inhibition of T-cell-dependent immune responses by bisbenzylisoquinoline alkaloids in vivo

pH-sensitive HPMCP-chitosan nanoparticles containing 5-aminosalicylic acid and berberine for oral colon delivery in a rat model of ulcerative colitis

Ulcerative colitis (UC) with continuous and extensive inflammation is limited to the colon mucosa and can lead to abdominal pain, diarrhea, and rectal bleeding. Conventional therapies are associated with several limitations, such as systemic side effects, drug degradation, inactivation, and limited drug uptake, leading to poor bioavailability. These restrictions necessitate drug delivery to the colon so that the drug passes through the stomach unchanged and has selective access to the colon. The present study aimed to formulate 5-aminosalicylic acid (5-ASA) and berberine (BBR) in chitosan nanoparticles cross-linked by HPMCP (hydroxypropyl methylcellulose phthalate) as a colon drug delivery system for UC. Spherical nanoparticles were prepared. They showed appropriate drug release in the simulated intestinal fluid (SIF), while the release did not occur in the simulated gastric fluid (SGF). They improved disease activity parameters (DAI) and ulcer index, increased the length of the colon, and decreased the wet weight of the colon. Furthermore, histopathological colon studies showed an improved therapeutic effect of 5-ASA/HPMCP/CSNPs and BBR/HPMCP/CSNPs. In conclusion, although 5-ASA/HPMCP/CSNPs showed the best effect in the treatment of UC, BBR/HPMCP/CSNPs, and 5-ASA/BBR/HPMCP/CSNPs were also effective in vivo study, and this study anticipated they could be helpful in future clinical applications for the management of UC.

Absolute configuration of tetrandrine and isotetrandrine influences their anti-proliferation effects in human T cells via different regulation of NF-κB

Natural compound tetrandrine was reported to inhibit the proliferation of T cells by inhibiting activation of NF-κB. Chemically, isotetrandrine differs from tetrandrine only in the stereochemistry at the chiral centers. The present study aimed to compare their anti-proliferation effects on human T cells with a focus on NF-κB. The IC₅₀ values of tetrandrine against MOLT-4 cells, MOLT-4/DNR cells, and concanavalin A-activated peripheral blood mononuclear cells of healthy subjects and dialysis patients were 4.43 ± 0.22, 3.62 ± 0.22, 1.91 ± 0.22 and 3.03 ± 0.28 μM, respectively. Whereas, the IC₅₀ values of isotetrandrine against the above immune cells were 2.19 ± 0.27, 2.28 ± 0.33, 1.29 ± 0.14 and 1.55 ± 0.26 μM, respectively. The inhibitory effect of isotetrandrine against the proliferation of T cells was stronger than that of tetrandrine significantly (p < 0.05). Molecular mechanism investigation showed that 10 μM of isotetrandrine largely decreased the expression of p-NF-κB and NF-κB in both MOLT-4 and MOLT-4/DNR T cells (p < 0.05), whereas 10 μM of tetrandrine slightly inhibited the phosphorylation of p-NF-κB with little influence on the expression of NF-κB. Taken together, absolute configurations of tetrandrine and isotetrandrine are suggested to influence on their anti-proliferation effects in human T cells via different regulation of NF-κB.

Molecular mechanisms and therapeutic implications of tetrandrine and cepharanthine in T cell acute lymphoblastic leukemia and autoimmune diseases

Inappropriately activated T cells mediate autoimmune diseases and T cell acute lymphoblastic leukemia (T-ALL). Glucocorticoid and chemotherapeutic agents have largely extended lives of these patients. However, serious side effects and drug resistance often limit the prognosis of considerable number of the patients. The efficient treatment of autoimmune diseases or T-ALL with drug resistance remains an important unmet demand clinically. Bisbenzylisoquinoline alkaloids tetrandrine and cepharanthine have been applied for the treatment of certain types of autoimmune diseases and cancers, while studies on their action mechanisms and their further applications combined with glucocorticoids or chemotherapeutic agents remains to be expanded. This review introduced molecular mechanisms of tetrandrine and cepharanthine in T cells, including their therapeutic implications. Both tetrandrine and cepharnthine influence the growth of activated T cells via several kinds of signaling pathways, such as NF-κB, caspase cascades, cell cycle, MAPK, and PI3K/Akt/mTOR. According to recent preclinical and clinical studies, P-glycoprotein inhibitory effect of tetrandrine and cepharnthine could play a significant role on T cell-involved refractory diseases. Therefore, tetrandrine or cepharanthine combined with glucocorticoid or other anti-leukemia drugs would bring a new hope for patients with glucocorticoid-resistant autoimmune disease or refractory T-ALL accompanied with functional P-glycoprotein. In conclusion, bisbenzylisoquinoline alkaloids tetrandrine and cepharanthine can regulate several signaling pathways in abnormally activated T cells with low toxicity. Bisbenzylisoquinoline alkaloids deserve to be paid more attention as a lead compound to develop new drugs for the treatment of T cell-involved diseases in the future.

Structure-Activity-Relationship and Mechanistic Insights for Anti-HIV Natural Products

Acquired Immunodeficiency Syndrome (AIDS), which chiefly originatesfroma retrovirus named Human Immunodeficiency Virus (HIV), has impacted about 70 million people worldwide. Even though several advances have been made in the field of antiretroviral combination therapy, HIV is still responsible for a considerable number of deaths in Africa. The current antiretroviral therapies have achieved success in providing instant HIV suppression but with countless undesirable adverse effects. Presently, the biodiversity of the plant kingdom is being explored by several researchers for the discovery of potent anti-HIV drugs with different mechanisms of action. The primary challenge is to afford a treatment that is free from any sort of risk of drug resistance and serious side effects. Hence, there is a strong demand to evaluate drugs derived from plants as well as their derivatives. Several plants, such as Andrographis paniculata, Dioscorea bulbifera, Aegle marmelos, Wistaria floribunda, Lindera chunii, Xanthoceras sorbifolia and others have displayed significant anti-HIV activity. Here, weattempt to summarize the main results, which focus on the structures of most potent plant-based natural products having anti-HIV activity along with their mechanisms of action and IC50 values, structure-activity-relationships and important key findings.

Cepharanthine Hydrochloride Improves Cisplatin Chemotherapy and Enhances Immunity by Regulating Intestinal Microbes in Mice

Chemotherapy is one of the major treatment strategies for esophageal squamous cell carcinoma (ESCC). Unfortunately, most chemotherapeutic drugs have significant impacts on the intestinal microbes, resulting in side effects and reduced efficiency. Therefore, new strategies capable of overcoming these disadvantages of current chemotherapies are in urgent need. The natural product, Cepharanthine hydrochloride (CEH), is known for its anticancer and immunoregulatory properties. By sequencing the V4 region of 16S rDNA, we characterized the microbes of tumor-bearing mice treated with different chemotherapy strategies, including with CEH. We found that CEH improved the therapeutic effect of CDDP by manipulating the gut microbiota. Through metagenomic analyses of the microbes community, we identified a severe compositional and functional imbalance in the gut microbes community after CDDP treatment. However, CEH improved the effect of chemotherapy and ameliorated CDDP treatment-induced imbalance in the intestinal microbes. Mechanically, CEH activated TLR4 and MYD88 innate immune signaling, which is advantageous for the activation of the host's innate immunity to exert a balanced intestinal environment as well as to trigger a better chemotherapeutic response to esophageal cancer. In addition, TNFR death receptors were activated to induce apoptosis. In summary, our findings suggest that chemotherapy of CDDP combined with CEH increased the effect of chemotherapy and reduced the side effects on the microbes and intestinal mucosal immunity. We believe that these findings provide a theoretical basis for new clinical treatment strategies.

Cepharanthine mitigates pro-inflammatory cytokine response in lung injury induced by hemorrhagic shock/resuscitation in rats

BACKGROUND

Cepharanthine possesses strong anti-inflammation capacity. We sought to clarify whether cepharanthine could mitigate pro-inflammatory cytokine production in acute lung injury induced by hemorrhagic shock/resuscitation (HS/RES). The involvement of heme oxygenase-1 (HO-1) was also investigated.

METHODS

Male Sprague Dawley rats were allocated to receive HS/RES, HS/RES plus iv cepharanthine or HS/RES plus cepharanthine plus the HO-1 activity inhibitor tin protoporphyrin (SnPP) and denoted as the HS/RES, HS/RES+CEP, and HS/RES+CEP+SnPP group, respectively. HS/RES was achieved by blood drawing to lower mean arterial pressure (40-45 mmHg for 60 min) followed by shed blood/saline mixtures re-infusion. The rats were monitored for another 5h before sacrifice.

RESULTS

Arterial blood gas, lung permeability and histologic assays (including histopathology, neutrophil infiltration, and lung water content) confirmed that HS/RES induced significant lung injury. Significant increases in pulmonary levels of tumor necrosis factor-α, interleukin-1β, interleukin-6, prostaglandin E2 and cyclooxygenase-2 confirmed that HS/RES induced a significant inflammatory response in the lungs. Cepharanthine significantly attenuated the pulmonary pro-inflammatory cytokine production and lung injury induced by HS/RES. However, the protective effects of cepharanthine were blocked by SnPP, the potent HO-1 activity inhibitor.

CONCLUSION

Cepharanthine significantly mitigates pro-inflammatory cytokine response in acute lung injury induced by HS/RES in rats. The mechanism may involve the HO-1 pathway.

Therapeutic potential of the biscoclaurine alkaloid, cepharanthine, for a range of clinical conditions

Cepharanthine (CEP) is a naturally occurring alkaloid extracted from the plant Stephania cepharantha Hayata. It has been widely used in Japan for more than 40 years to treat a wide variety of acute and chronic diseases. CEP inhibits tumor necrosis factor (TNF)-α-mediated NFκB stimulation, plasma membrane lipid peroxidation and platelet aggregation and suppresses cytokine production. It has also been shown to scavenge free radicals and to have a protective effect against some of the responses mediated by pro-inflammatory cytokines such as TNF-α, interleukin (IL)-1β and IL6. CEP has successfully been used to treat a diverse range of medical conditions, including radiation-induced leukopenia, idiopathic thrombocytopenic purpura, alopecia areata, alopecia pityrodes, venomous snakebites, xerostomia, sarcoidosis, refractory anemia and various cancer-related conditions. No safety issues have been observed with CEP, and side effects are very rarely reported.

The effects of berberine on the magnitude of the acute inflammatory response induced by Escherichia coli lipopolysaccharide in broiler chickens

One hundred twenty-six 19-d-old male broiler chickens were used to determine the effects of berberine on the magnitude of the acute inflammatory response induced by Escherichia coli lipopolysaccharide (LPS). The birds were weighed and randomly allotted to 1 of 3 treatments at d 19 (3 treatments x 7 replicates x 6 birds). The treatments comprised a control group in which saline was injected at d 21, an LPS-treated group in which LPS (3 mg/kg of BW) was injected at d 21, and finally a berberine and LPS-treated group in which berberine (15 mg/kg of BW) was orally administered from d 19 to d 24 with LPS injection (3 mg/kg of BW) at d 21. Injection of LPS alone decreased (P < 0.01) weight gain, feed intake, and feed conversion compared with the control and the berberine-administered group. Relative liver weight was increased (P < 0.05) in the LPS-treated group 72 h postinjection compared with the control and the berberine-treated group. Total counts of white blood cells and lymphocytes were also increased (P < 0.05) in the LPS-treated group 72 h postinjection. The heterophil concentration of the LPS-treated group was greater (P < 0.05) than that of both the control and the berberine-administered group 24 h postinjection. Broilers in the LPS-treated group had greater (P < 0.05) total serum protein compared with birds in the control and the berberine-administered group both 24 and 72 h postinjection. In addition, the plasma interleukin-6 level of the LPS-treated group was significantly elevated (P < 0.01) at 24 h compared with that of the control and the berberine-administered group. Our results indicate that LPS injection initiated a series of physiological changes typical of an acute phase response in broiler chickens. These effects were largely mitigated by oral administration of berberine.

Biscoclaurine alkaloid cepharanthine inhibits the growth of primary effusion lymphoma in vitro and in vivo and induces apoptosis via suppression of the NF-kappaB pathway

Primary effusion lymphoma (PEL) is a unique and recently identified non-Hodgkin's lymphoma that was originally identified in patients with AIDS. PEL is caused by the Kaposi sarcoma-associated herpes virus (KSHV/HHV-8) and shows a peculiar presentation involving liquid growth in the serous body cavity and a poor prognosis. As the nuclear factor (NF)-kappaB pathway is activated in PEL and plays a central role in oncogenesis, we examined the effect of a biscoclaurine alkaloid, cepharanthine (CEP) on PEL derived cell lines (BCBL-1, TY-1 and RM-P1), in vitro and in vivo. An methylthiotetrazole assay revealed that the cell proliferation of PEL cell lines was significantly suppressed by the addition of CEP (1-10 microg/ml). CEP also inhibited NF-kappaB activation and induced apoptotic cell death in PEL cell lines. We established a PEL animal model by intraperitoneal injection of BCBL-1, which led to the development of ascites and diffuse infiltration of organs, without obvious solid lymphoma formation, which resembles the diffuse nature of human PEL. Intraperitoneal administration of CEP inhibited ascites formation and diffuse infiltration of BCBL-1 without significant systemic toxicity in this model. These results indicate that NF-kappaB could be an ideal molecular target for treating PEL and that CEP is quite useful as a unique therapeutic agent for PEL.

Activity of Berberis aetnensis root extracts on Candida strains

The antifungal activity of methanolic extract and alkaloidal fraction of Berberis aetnensis against Candida species was investigated. The crude extract was active against Candida species, this activity being higher than that of the alkaloidal fraction and berberine.

The effects of biscoclaurine alkaloid cepharanthine on mammalian cells: implications for cancer, shock, and inflammatory diseases

The extract of Stephania cepharantha Hayata contains biscoclaurine alkaloids such as cepharanthine, which have been used widely in Japan for the treatment of patients with radiation-induced leukopenia, alopecia areata, exudative otitis media, and venomous snakebites. Many investigations have proven that the alkaloid cepharanthine exerts diverse pharmacological effects that include membrane-stabilizing, multidrug resistance-reversing, antitumor, apoptosis-inducing, anti-inflammatory, free radical scavenging, anti-HIV-1, antiallergic and immunomodulatory effects. The purpose of our review is to describe various therapeutic approaches using cepharanthine and their potential efficacy.

Suppressive effects of Stephania tetrandra on the neutrophil function in patients with rheumatoid arthritis

Crude preparations of Stephania tetrandra (ST), a traditional herbal medicine, have been used safely for arthritis and silicosis in China. The concentration of granulocyte elastase - alpha 1 protease inhibitor complex in plasma is enhanced in inflammatory processes, e.g. in septicaemia and rheumatoid arthritis (RA), being an expression of granulocyte activation during inflammatory response. It has previously been reported that ST showed beneficial and immunomodulatory effects in the treatment of relatively mild RA. After the administration of ST for 12 weeks, the proportion of granulocytes and the granulocyte count in peripheral blood decreased significantly. The lipid peroxide and human granulocyte elastase levels of stored plasma declined significantly. Furthermore, both the leukocyte/elastase ratio and granulocyte/elastase ratio increased significantly. The findings of this study suggest that the suppressive effect of ST administration on excessive granulocyte activation resulted in the improvement of inflammation with rheumatoid arthritis.

Induction of apoptosis in human hepatoblastoma cells by tetrandrine via caspase-dependent Bid cleavage and cytochrome c release

Tetrandrine, a bis-benzylisoquinoline alkaloid from the root of Stephania tetrandra, induces apoptosis in human T-cell lines, lung carcinoma and hepatoblastoma cells. However, the mechanisms by which tetrandrine inhibits tumor cell growth are poorly understood. The purpose of the present study was to investigate the intracellular signaling mechanism of tetrandrine-induced apoptosis in HepG2 cells. The induction of apoptosis was determined by morphological analysis and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay. Treatment of cells with tetrandrine caused the upregulation of p53, downregulation of Bcl-X(L), cleavage of Bid and Bax, and release of cytochrome c, which were accompanied by activation of caspases 9, 3 and 8. The activation of caspases 9 and 3 preceded that of caspase 8. A broad-spectrum caspase inhibitor and a caspase 8-specific inhibitor completely blocked tetrandrine-induced Bid processing, cytochrome c release, activation of caspase 3, and cell death. These findings and data showing the early release of cytochrome c, cleavage of Bid and downregulation of Bcl-X(L) suggest that the mitochondrial pathway is primarily involved in tetrandrine-induced apoptosis. The activation of caspase 8 after early caspases 9 and 3 activation might act as an amplification loop for activation of upstream signals such as Bid cleavage or cytochrome c release. These data suggest that tetrandrine may constitute a plausible therapeutic for hepatocellular carcinoma.

A comparative study on the anti-inflammatory, antinociceptive and antipyretic effects of isoquinoline alkaloids from the roots of Turkish Berberis species

Roots and barks of various Berberis species are used as folk remedy for the treatment of various inflammatory diseases such as lumbago, rheumatism and to reduce fever. Six isoquinoline alkaloids namely berberine, berbamine, palmatine, oxyacanthine, magnoflorine, and columbamine were isolated as the main components of alkaloidal fraction from the roots of Turkish Berberis species and effects were studied using various in vivo models in mice. All alkaloids inhibited inflammations in varying degrees, among them berberine, berbamine and palmatine were shown to possess significant and dose-dependent inhibitory activity against serotonin-induced hind paw oedema both on oral and topical applications and acetic acid-induced increase in vascular permeability on oral administration. Moreover, these three alkaloids were also shown to possess dose-dependent antinociceptive activity, which assessed by using the model based on the inhibition of p-benzoquinone-induced writhing movements as well as antipyretic activity on FCA-induced increased rectal temperature on subacute administration. However, all alkaloids induced gastric lesions in varying degrees.

Separation of bisbenzylisoquinoline alkaloids by micellar electrokinetic chromatography

The micellar electrokinetic chromatographic (MEKC) separation of seven bisbenzylisoquinoline alkaloids has been developed. The effects of various separating factors were studied. Optimum separation was achieved using a buffer (pH 9.2) of 20 mM sodium borate and 20 mM sodium dihydrogen phosphate buffer containing 55 mM sodium cholate; the optimum voltage and injection time were 21 kV and 0.05 min, respectively. Highest peak efficiency was obtained when the analytes were dissolved in 10 mM sodium dodecyl sulphate as sample matrix for injection. The elution order of the bisbenzylisoquinoline alkaloids was related to their lipophilicity. The resolution, run time and detection limits of the MEKC method were compared with those of an HPLC method developed previously.

Berberis crataegina DC. root exhibits potent anti-inflammatory, analgesic and febrifuge effects in mice and rats

Extracts obtained from the roots and barks of various Berberis species are used as folk remedy worldwide for the treatment of various inflammatory ailments including lumbago, rheumatism and to reduce fever. Effects of the extracts and fractions from the roots of Berberis crataegina DC. (Berberidaceae) were studied using various in vivo models of inflammation in mice and rats and observed potent inhibitory activity against carrageenan- and serotonin-induced hind paw oedema, acetic acid-induced increased vascular permeability, castor oil-induced diarrhoea, and Freund's complete adjuvant-induced (FCA) arthritis models. Through bioassay-guided fractionation berberine was isolated as the main active ingredient. Moreover, a dose-dependent analgesic activity was determined, which assessed by using the model based on the inhibition of acetic acid-induced writhing reflexes, as well as antipyretic activity on FCA-induced increased body temperature. Acute and subchronic toxicity studies were also performed.

Effect of Mahonia aquifolium stem bark crude extract and one of its polysaccharide components on production of IL-8

The crude hydroalcoholic extract of Mahonia aquifolium stem bark and a polysaccharide isolated from the extract were tested for their activity on interleukin-8 (IL-8) production by human monocytic cell line THP-1. The crude extract partly inhibited the IL-8 spontaneous production after 48-h treatment of the cells, while the polysaccharide was found to be a potent inducer of IL-8 production.

Suppression of cytokine production and neural cell death by the anti-inflammatory alkaloid cepharanthine: a potential agent against HIV-1 encephalopathy

Inflammatory cytokines and human immunodeficiency virus type 1 (HIV-1) gp120 are considered to play an important role in the pathogenesis of HIV-1-associated CNS disorders. These substances are produced predominantly by HIV-1-infected or activated macrophages and microglia in the brain and induce neural cell death. Cepharanthine is a biscoclaurine alkaloid isolated from Stephania cepharantha Hayata and has been shown to have anti-inflammatory, anti-allergic, and immunomodulatory activities in vivo. We previously reported that this compound could inhibit tumor necrosis factor (TNF)-alpha- or phorbol 12-myristate 13-acetate-induced HIV-1 replication in latently infected U1 cells through the inhibition of nuclear factor-kappaB, a potent inducer of HIV-1 gene expression. In the present study, we demonstrated that cepharanthine suppresses the production of inflammatory cytokines and a chemokine, i.e. TNF-alpha, interleukin (IL)-1beta, IL-6, and IL-8, in human monocytic cell cultures, including primary monocyte/macrophage cultures. This effect of cepharanthine was concentration-dependent, and significant suppression was observed at 0.1 microg/mL. Furthermore, the compound also inhibited TNF-alpha- and gp120-induced death of differentiated human neuroblastoma cells at a concentration of 0.04 to 0.2 microg/mL. It penetrates the blood-brain barrier, and a medicine containing cepharanthine as a major component has been used in Japan for the treatment of patients with chronic inflammatory diseases. Thus, cepharanthine should be investigated further for its therapeutic and prophylactic potential in HIV-1-associated CNS disorders.

Anti-HIV-1 activity and structure-activity relationship of cepharanoline derivatives in chronically infected cells

Cepharanthine (12-O-methyl cepharanoline) is a plant alkaloid and has been shown to inhibit tumour necrosis factor-alpha- or phorbol 12-myristate 13-acetate-induced HIV-1 replication in the chronically infected promonocytic cell line, U1. Its mechanism of action is considered to be the inhibition of nuclear factor kappaB, a potent inducer of HIV-1 gene expression. In this study, we have synthesized 96 derivatives of cepharanoline, including cepharanthine, and examined their inhibitory effects on HIV-1 replication in U1 cells. Among the 12-O-alkyl derivatives, cepharanthine proved to be the most active, and the activity decreased as the length of the alkyl chain increased. All of the 12-O-acyl derivatives were totally inactive, while a few 12-O-carbamoyl derivatives displayed modest activity. Since 12-O-ethyl derivatives were found to be as active as cepharanthine against HIV-1 replication, we further synthesized various 12-O-ethyl derivatives of cepharanoline. Among the derivatives, five proved to be more active inhibitors than cepharanthine, and the most active compound was 12-O-ethylpiperazinyl cepharanoline. The 50% effective concentrations of this compound and cepharanthine were 0.0041 and 0.028 microg/ml (0.0060 and 0.046 microM), respectively.

Complement modulatory activity of bisbenzylisoquinoline alkaloids isolated from Isopyrum thalictroides--I. Influence on classical pathway in human serum

Eleven bisbenzylisoquinoline alkaloids (BBI) were isolated from the plant Isopyrum thalictroides (L.). Treatment of normal human serum (NHS) with BBI resulted in a diminution of the haemolytic activity of the classical pathway (CP). The mode of action of the main alkaloids isopyruthaline (It1), fangchinoline (It2) and isotalictrine (It3) on CP activation was investigated in vitro. The inhibition was time- and temperature-related and for Itl and It3 depended on the concentration of Ca2+ and Mg2+ ions. It was established that the substances reduced C1 haemolytic activity. It2 and It3 enhanced the complement consumption caused by heat aggregated human IgG (HAGG). The BBI prevented the formation of C3 convertase of the classical pathway. The loss of haemolytic activity was partially restored by the addition of C142 reagent (zymosan-treated guinea pig serum) to alkaloids-treated NHS. The addition of the late components C3-9 (EDTA-treated rat sera) recovered to some extent the haemolytic activity of It1-treated NHS, but not of It2- and It3-treated NHS.

Inhibition of human immunodeficiency virus type 1 replication by combination of transcription inhibitor K-12 and other antiretroviral agents in acutely and chronically infected cells

8-Difluoromethoxy-1-ethyl-6-fluoro-1,4-dihydro-7-[4-(2-methoxyp hen yl)-1- piperazinyl]-4-oxoquinoline-3-carboxylic acid (K-12) has recently been identified as a potent and selective inhibitor of human immunodeficiency virus type 1 (HIV-1) transcription. In this study, we examined several combinations of K-12 and other antiretroviral agents for their inhibitory effects on HIV-1 replication in acutely and chronically infected cell cultures. Combinations of K-12 and a reverse transcriptase (RT) inhibitor, either zidovudine, lamivudine, or nevirapine, synergistically inhibited HIV-1 replication in acutely infected MT-4 cells. The combination of K-12 and the protease inhibitor nelfinavir (NFV) also synergistically inhibited HIV-1, whereas the synergism of this combination was weaker than that of the combinations with the RT inhibitors. K-12 did not enhance the cytotoxicities of RT and protease inhibitors. Synergism of the combinations was also observed in acutely infected peripheral blood mononuclear cells. The combination of K-12 and cepharanthine, a nuclear factor kappa B inhibitor, synergistically inhibited HIV-1 production in tumor necrosis factor alpha-stimulated U1 cells, a promonocytic cell line chronically infected with the virus. In contrast, additive inhibition was observed for the combination of K-12 and NFV. These results indicate that the combinations of K-12 and clinically available antiretroviral agents may have potential as chemotherapeutic modalities for the treatment of HIV-1 infection.

Potent inhibition of HIV type 1 replication by an antiinflammatory alkaloid, cepharanthine, in chronically infected monocytic cells

Cepharanthine is a biscoclaurine alkaloid isolated from Stephania cepharantha Hayata and has been shown to have antiinflammatory, antiallergic, and immunomodulatory activities in vivo. As several inflammatory cytokines and oxidative stresses are involved in the pathogenesis of HIV-1 infection, we investigated the inhibitory effects of cepharanthine on tumor necrosis factor alpha (TNF-alpha)- and phorbol 12-myristate 13-acetate (PMA)-induced HIV-1 replication in chronically infected cell lines. Two chronically HIV-1-infected cell lines, U1 (monocytic) and ACH-2 (T lymphocytic), were stimulated with TNF-alpha or PMA and cultured in the presence of various concentrations of the compound. HIV-1 replication was determined by p24 antigen level. The inhibitory effects of cepharanthine on HIV-1 long terminal repeat (LTR)-driven gene expression and nuclear factor kappaB (NF-kappaB) activation were also examined. Cepharanthine dose dependently inhibited HIV-1 replication in TNF-alpha- and PMA-stimulated U1 cells but not in ACH-2 cells. Its 50% effective and cytotoxic concentrations were 0.016 and 2.2 microg/ml in PMA-stimulated U1 cells, respectively. Cepharanthine was found to suppress HIV-1 LTR-driven gene expression through the inhibition of NF-kappaB activation. These results indicate that cepharanthine is a highly potent inhibitor of HIV-1 replication in a chronically infected monocytic cell line. Since biscoclaurine alkaloids, containing cepharanthine as a major component, are widely used for the treatment of patients with various inflammatory diseases in Japan, cepharanthine should be further pursued for its chemotherapeutic potential in HIV-1-infected patients.

Comparative effectiveness and molecular pharmacological mechanisms of antiallergic agents on experimental conjunctivitis in mice

The purpose of this study was to determine the effectiveness of antiallergic agents in the treatment of experimental murine ragweed conjunctivitis. SWR/J mice were divided into eight groups: 1; normal controls (unmanipulated); 2, untreated; 3, lodoxamide; 4, cromolyn; 5, livocarbastine; 6, nedocromil; 7, buffer solution (BS); and 8, tetrandine (TDR). Groups 2-8 were exposed to ragweed pollen through topical application to conjunctival and nasal mucosa, followed by conjunctival challenge with the allergen. Allergic conjunctivitis was evaluated by scoring of the clinical signs and histopathology. mRNA gene expression of interleukin 1beta (IL-1beta), IL-6 and tumor necrosis factor alpha (TNF-alpha) in conjunctiva was analyzed by reverse transcription polymerase chain reaction techniques. Exposed mice developed allergic conjunctivitis clinically and histologically that was modulated by topical lodoxamide, cromolyn, livocarbastine, or nedocromil eye drops or TDR intraperitoneally injected. Histopathologic analysis demonstrated that the drugs and TDR significantly reduced conjunctival eosinophil infiltration and the number of intact and degranulating mast cells. IL-1beta and TNF-alpha mRNA gene expression in conjunctiva of treated mice was inhibited compared with untreated and BS-treated controls. No IL-6 mRNA expression was observed even on the conjunctiva of the untreated mice. The antiallergic drugs and TDR exerted a similar action on the murine model of allergic conjunctivitis and demonstrated pharmacologic effectiveness on the conjunctival mRNA expression of cytokines IL-1beta and TNF-alpha.

Potent inhibitory effect of tetrandrine on experimental allergic conjunctivitis in mice

This study investigated the effectiveness of tetrandrine (TDR) on experimental allergic conjunctivitis secondary to ragweed pollen. SWR/J mice were divided as follows: group 1, normal controls; group 2, sensitized but untreated; group 3, sensitized, buffered saline (BS)-treated; and group 4, sensitized, TDR-treated. The last three groups were exposed to ragweed through topical contact on the nasal and conjunctival mucosae followed by challenge with the allergen on the conjunctiva. Groups 3 and 4 received doses of BS and TDR, respectively. The allergic conjunctivitis was evaluated by scoring of the clinical signs and histopathology. mRNA gene expression of interleukin 1 beta (IL-1 beta) and IL-5 in the conjunctiva was analyzed by polymerase chain reaction techniques. All mice exposed to ragweed developed allergic conjunctivitis clinically and histologically. The conjunctivitis was significantly modulated by intraperitoneal injection of a new anti-inflammatory agent, TDR. Histopathologic analysis demonstrated that TDR strikingly reduced the conjunctival eosinophil infiltration and the number of intact and degranulating mast cells. IL-1 beta and Il-5 mRNA gene expression in the conjunctiva of TDR-treated mice was dramatically down-regulated compared with untreated and BS-treated controls. The results indicate that TDR may have potential clinical use in the treatment of conjunctivitis.

Tetrandrine potently inhibits herpes simplex virus type-1-induced keratitis in BALB/c mice

This study investigated the effect of tetrandrine (TDR) on experimental herpes simplex keratitis (HSK) in mice. BALB/c mice were divided as follows: Group 1, untreated; Group 2, acyclovir (ACV)-treated from day 0 postinfection; Group 3, ACV-treated from day 7; Group 4, TDR-treated from day 0; and Group 5, TDR-treated from day 7. All mice were infected in the right cornea with herpes simplex virus (HSV) type I. TDR 30 mg/kg and ACV 120 mg/kg were administered intraperitoneally daily. The mice were observed for 14 days postinfection. Clinical inflammatory reactions and ocular histopathology were analyzed. The herpes specific antibody response and the delayed type hypersensitivity (DTH) response were studied. Of the 22 untreated mice, 16 developed HSK (incidence, 72.7%). TDR given from day 7 reduced the HSK incidence to 8.5% (p < 0.01); the incidence of HSK was 45.4% in mice treated with TDR from day 0 (p > 0.05). Systemic ACV given from day 0 inhibited HSK development (p < 0.01); ACV given from day 7 resulted in an HSK incidence of 50% (p > 0.05). The specific anti-HSV antibody response in the serum of mice treated with TDR or ACV either from day 0 or day 7 was significantly less than that of untreated mice (p < 0.01 and p < 0.05, respectively), and TDR treatment suppressed DTH responses to HSV (p < 0.05). Systemic TDR administered after HSV inoculation of the cornea significantly modulates murine HSK development at least partly by modifying the host immune/inflammatory response to the virus.

Immunopharmacological activity of aporphinoid alkaloid oxoglaucine

The ability of aporphinoid alkaloid oxoglaucine to influence T- and B-cell immune response was studied in mice models. The substance inhibited in vitro mitogen-induced lymphocyte proliferation and suppressed antibody response to sheep red blood cells (SRBC) and lipopolysaccharide (LPS) in vivo effectively. The action depended on the relative timing of antigen and oxoglaucine administration. The substance manifested stimulatory effect in popliteal lymph node (PLN) reaction and LPS-induced B-cell activation. In the chronic inflammatory model of adjuvant arthritis oxoglaucine exhibited stimulatory or suppressive action related to the kinetics of the process. At low doses (1 or 2 mg kg-1) oxoglaucine improved the outcome of Klebsiella pneumoniae infection, while at higher doses (10 or 20 mg kg-1) the substance caused an impairment of host resistance to infectious agent. The comparison with cyclophosphamide in some tests showed that oxoglaucine was effective in manifold lower doses. In conclusion, oxoglaucine exerted immunomodulatory effects in vivo in a dose-dependent and protocol-dependent manner. Yet, its overall action might be attributed to the different sensitivity of the cells involved in the developing immune response.

In vitro inhibition of proliferation of HL-60 cells by tetrandrine and coriolus versicolor peptide derived from Chinese medicinal herbs

Coriolus versicolor polysaccharide peptide (CVP) and the bis-benzylisoquinoline alkaloids, tetrandrine (TET) and berbamine (BER), the active ingredients isolated from Chinese medicinal herbs known to possess antitumor activities, concentration-dependently inhibited the proliferation of human leukemic HL-60 cells. CVP did not affect the growth of normal human peripheral blood lymphocytes (PBL), whereas TET elicited concentration-dependent cytotoxic effects. Morphological observation and DNA analysis revealed that CVP elicited no effect on the morphological features of HL-60 cells and did not cause DNA fragmentation, but TET and BER caused cell shrinkage with the formation of apoptotic bodies, and showed clear evidence of DNA fragmentation. These findings indicate that TET and BER, but not CVP, inhibited the proliferation of HL-60 cells via induction of apoptosis.

Antimicrobial and immunological activity of ethanol extracts and fractions from Isopyrum thalictroides

The antimicrobial and immunological properties of ethanol extracts, non-alkaloid, tertiary alkaloid and quaternary alkaloid fractions, obtained from roots and aerial parts of Isopyrum thalictroides were examined. The non-alkaloid fraction from aerial parts inhibited the growth of seven test microorganisms and was the most effective suppressor of classical pathway (CP) complement activity in normal human serum (NHS) and guinea pig serum (GPS). The alkaloid fractions, containing quaternary alkaloids expressed suppressive effect on mitogen-induced splenocyte proliferation. The in vitro antibody response against sheep red blood cells (anti-SRBC) was inhibited by ethanol extracts and quaternary alkaloid fraction. The intraperitoneal (i.p.) application of ethanol extract and tertiary alkaloid fraction from aerial parts showed that they possess in vivo effect on alternative pathway (AP) complement activity, anti-SRBC response and delayed type hypersensitivity (DTH).

Study on the anti-inflammatory action of Berberis vulgaris root extract, alkaloid fractions and pure alkaloids

Extracts obtained from the roots of Berberidaceae species have been used in Eastern and Bulgarian folk medicine in rheumatic and other chronic inflammatory disorders. The investigations of the chemical composition and immunological properties show that their activity is mainly due to the alkaloid constituents. In the present study the anti-inflammatory properties of total ethanol extract (TEE), three alkaloid fractions, a major alkaloid berberine and oxyacanthine isolated from Berberis vulgaris roots were compared. All these were applied in acute inflammation (carrageenan- and zymosan-induced paw oedema), as the TEE showed the highest reducing effect. Their ability to alter in vivo and in vitro complement activity was determined. Also, the TEE was most effective in a chronic inflammatory model of adjuvant arthritis. The protoberberine fractions Bv2, Bv3 and berberine suppressed a delayed type hypersensitivity (DTH) reaction. Fraction Bv1 and berberine diminished antibody response against SRBC in vivo. The in vitro treatment of splenocytes with berberine showed that the anti-SRBC antibody synthesis was influenced in a different manner depending on the time course of its application. Oxyacanthine was less effective than berberine in the tests used.

Inhibitory effect of bisbenzylisoquinoline alkaloids on nitric oxide production in activated macrophages

Bisbenzylisoquinoline (BBI) alkaloids are anti-inflammatory constituents of plants of the families Menispermaceae and Ranunculaceae, which have been used as folk remedies in Japan and China. Five BBI alkaloids (cepharanthine, chondocurine, cycleanine, isotetrandrine and tetrandrine) were tested for suppressive effect on in vitro nitric oxide (NO) production by lipopolysaccharide-stimulated peritoneal macrophages, which were induced with thioglycollate or bacillus Calmette-Guerin in mice. All these BBI alkaloids significantly suppressed NO production at 5 micrograms/mL. Cepharanthine, isotetrandrine and cycleanine were slightly more inhibitory than tetrandrine and chondocurine. The suppression persisted for at least 48 hr. As NO is one of the critical mediators in inflammation, these results may explain some aspects of the anti-inflammatory mechanisms of BBI compounds.