Alpha-momorcharin regulates cytokine expression and induces apoptosis in monocytes.

Background and aim: Alpha-momorcharin (α-MMC) is a type I ribosome-inactivating protein (RIP) that is purified from Momordica charantia. Despite its strong antitumor activities, α-MMC exerts the undesirable immunotoxicity effects of hypersensitivity or immunosuppression. Since α-MMC is a plant protein, its application in vivo can easily induce hypersensitivity, but its immunosuppressive mechanism is still unclear. Materials and methods: The toxicity of α-MMC to peripheral blood cells and the cytokine expression in peripheral blood mononuclear cells (PBMCs) and spleen immune cells were measured in rats. For further confirmation, experiments were performed in vitro with the mononuclear cell line THP-1, B lymphocyte cell line WIL2-S and T lymphocyte cell line Jurkat. Results: High doses of α-MMC (3.0 mg/kg) resulted in weight loss in rats, a decreased percentage of monocytes, and increased percentages of eosinophils and basophils. Both high-dose and low-dose (1.0 mg/kg) α-MMC inhibited cytokine expression in PBMCs and increased cytokine expression in spleen T cells. In in vitro, α-MMC mainly acted on THP-1 cells, with effects including high dose-induced apoptosis and low dose-induced regulation of inhibitory cytokine expression. Conclusions: The action of α-MMC on immune cells mainly affects monocytes, thereby eliciting its immunosuppressive effect. Its mode of action is to guide functional immunosuppressive regulation at low doses and induce apoptosis at high doses. As the monocytes would be recruited into tumor tissues and are polarized into tumor-associated macrophages, the selective cytotoxicity and cytokine release regulation of α-MMC in monocytes may be an important mechanism of its antitumor effects.

[Alpha-momordicin Regulates Hepatocyte Cytokine Expression].

OBJECTIVE: To investigate the regulation effect of α-momordicin (α-MMC) on the synthesis and secretion of cytokines in hepatocytes cells. METHODS: Hepatocytes L02 were treated with 189 µg/mL α-MMC with culture supernatant and lysate samples were harvested in different timepoint. Expressions of T-helper 17 (TH17) cytokine profile in samples were detected by the Bio-Plex 200 suspension chip assay system. RESULTS: Compared with 0 h, after the α-MMC treatment of L02 hepatocytes for 2 h, 4 h and 8 h, the intracellular synthesis of cytokines interleukin (IL)-1b, IL-6, IL-17A, IL-31, IL-33, soluble CD40 ligand (sCD40L), tumor necrosis factor-α (TNF-α) were all significantly decreased (P<0.05), and IL-6, IL-4, IL-17A, and sCD40L secreted into the extracellular fluid also decreased significantly (P<0.05). CONCLUSION: α-MMC can significantly inhibit the synthesis and secretion of cytokines such as IL-6, IL-17A and TNF-α in hepatocytes, which may become a side effect of its anti-tumor application.

[Research on Molecular Biological Characteristics of Proto-oncogene pim-2].

The purpose of this paper is to present the research on the molecular biological characteristics of proto-oncogene pim-2 and to analyze the related mechanism. Proto-oncogene pim-2 was studied and analyzed by the bioinformatics method and technology. With an online server, the chromosomal localization of pim-2 gene was analyzed, and the exon, open reading frame, CpG island and miRNAs complementary fragments and the like were predicted. With bioinformatics software, the physicochemical property of transcription protein of proto-oncogene pim-2 and various modification sites of protein sequence, such as ubiquitination and glycosylation, were predicted, the antigenic index was calculated, and the spatial structural was modeled. The research findings showed that the proto-oncogene pim-2 comprised six exons, the CDS (coding sequence) transcribed a section of peptide chain including 311 amino acids, a gene promoter has a CpG island, and the 3'UTR region contains an miRNA gene. The molecular weight of the Pim-2 protein was 34,188. 47, the isoelectric point was 5.78, the instability index was 45.87, and the extinction coefficient was 279nm. A plurality of covalent modification sites, two ubiquitination sites, four glycosylation sites, an SUMO sumoylation site, a nitrosation site, two palmitoylation sites and sixteen regions with higher antigenic index were distributed in the protein sequence. This research showed that the related regions and modification sites distributed on the sequence of proto-oncogene pim-2 were closely related to the carcinogenic effect thereof.

[Effect of PEGylation of alpha-Momorcharin against its hepatotoxicity in rats].

OBJECTIVE: To explore the effect of PEGylation of alpha-Momorcharin (alpha-MMC), one of ribosome-inactivating proteins from bitter melon seed, against its hepatotoxicity in rats. METHODS: SD rats were randomized into NS group, alpha-MMC treated groups, and alpha-MMC-PEG treated groups. The doses of alpha-MMC and alpha-MMC-PEG were high, middle, and low dose (6.25, 2.08, 0.70 mg/kg). The rats were given different dose of alpha-MMC, or alpha-MMC-PEG via caudal vein every other day for consecutive 28 days and then left for 14 days recovery. The general condition of animals was observed, blood and liver samples were collected for liver function study and pathological examination on day 28 after initiation of administration and on day 14 after withdrawal. RESULTS: On day 28 after initiation of administration, the liver function damages were found in high-dose and middle-dose of alpha-MMC treated groups, such as the decreasing of ALB, increasing of GLB, A/G ratio decreasing and the dose-dependant increasing of AST, BIL and CHO. The pathological changes of hepatotoxicity were also observed in these two groups, including the massive hepatocyte, swelling degeneration, inflammatory cell infiltration, congestion and diffusive necrosis. However, the liver function and pathological changes in alpha-MMC-PEG treated groups were better than those in alpha-MMC treated groups. CONCLUSION: PEGylation could reduce the hepatotoxicity of alpha-MMC to rats.

PEGylation is effective in reducing immunogenicity, immunotoxicity, and hepatotoxicity of α-momorcharin in vivo.

BACKGROUND AND AIM: α-momorcharin (α-MMC), a type I ribosome-inactivating protein (RIP) from Momordica charantia, is well known for its antitumor and antivirus activities. However, the immunotoxicity and hepatotoxicity hampers its potential therapeutic usage. In order to reduce its toxicity, we had modified the α-MMC with polyethylene glycol (PEG), and detected the toxicity of the PEGylated α-MMC conjugates (α-MMC-PEG) in vivo. MATERIALS AND METHODS: After α-MMC purified from bitter melon seeds, α-MMC-PEG was constructed with a branched 20 kDa (mPEG) 2-Lys-NHS, the tests of immunogenicity, immunotoxicity, and general toxicity of α-MMC-PEG were conducted in guinea pig and rat. RESULTS: The titer of specific IgG in rats, immunized by α-MMC-PEG, were approximately one-third of those that by α-MMC, all the guinea pigs treated with α-MMC died of anaphylaxis shock within 5 min, while no animals treated with α-MMC-PEG died in the active systemic anaphylaxis (ASA) test. The passive cutaneous anaphylaxis (PCA) reaction of α-MMC-PEG challenge in rats was significantly smaller than that of the α-MMC. The liver damage was greatly released, such as the change of globulin (GLB), aspartate aminotransferase (AST), total bilirubin (TBIL) cholesterol (CHOL), albumin (ALB), and the degree of hepatocyte necrosis in repeated toxicity study. CONCLUSIONS: PEGylation is effective in reducing the immunogenicity, immunotoxicity, and hepatotoxicity of α-MMC in vivo.

Alpha-Momorcharin Inhibits Proinflammatory Cytokine Expression by M1 Macrophages but Not Anti-Inflammatory Cytokine Expression by M2 Macrophages.

Background: Alpha-momorcharin (α-MMC) is a natural medicine derived from bitter melon and has been found to exert immunomodulatory effects. Our previous study indicated that α-MMC can regulate cytokine release from monocytes, but it remains unknown about its regulatory effect on different types of cytokines, such as inflammatory cytokines or anti-inflammatory cytokines. Methods: LPS-induced M1-type macrophages model and IL-4-induced M2-type macrophages model were established, and the expression of proinflammatory cytokines and anti-inflammatory cytokines were assessed by ELISA after α-MMC was administered. Then, a LPS-induced acute pneumonia mouse model was established, the proinflammatory cytokines levels and inflammatory lesions in lung tissues were examined by ELISA or H&E staining. Furthermore, omics screening analysis and Western blotting verification were performed on TLR4 and JAK1-STAT6 signalling pathway-related proteins to elucidate the regulatory mechanism of α-MMC in those M1 macrophages and M2 macrophages. Results: At a noncytotoxic dose of 0.3 µg/mL, α-MMC significantly inhibited the LPS-induced expression of inflammatory cytokines, such as TNF-α, IL-1ß, IL-6, IL-8, MIP-1α and MCP-1, by M1 macrophages in a time-dependent manner, but α-MMC did not inhibit the IL-4-induced synthesis of anti-inflammatory cytokines, such as IL-10, IL-1RA, EGF, VEGF, TGF-ß and CCL22, by M2 macrophages. Moreover, α-MMC also inhibited inflammatory cytokine expression in an LPS-induced acute pneumonia mouse model and alleviated inflammation in lung tissues. Furthermore, omics screening and Western blotting analysis confirmed that α-MMC inhibited TAK1/p-TAK1 and subsequently blocked the downstream MAPK and NF-κB pathways, thus inhibiting the LPS-induced inflammatory cytokine expression. Conclusion: Our results reveal that α-MMC inhibits proinflammatory cytokine expression by M1 macrophages but not anti-inflammatory cytokine expression by M2 macrophages. The efficacy of α-MMC in selectively inhibiting proinflammatory cytokine expression renders it particularly suitable for the treatment of severe inflammation and autoimmune diseases characterized by cytokine storms.

Immunoaffinity purification of α-momorcharin from bitter melon seeds (Momordica charantia).

α-Momorcharin (α-MMC), a type I ribosome-inactivating protein (RIP), has shown therapeutic potential such as anti-tumor and anti-viral agent. Traditional process of α-MMC purification from bitter melon seeds was time consuming and low efficient. To take this challenge, we made an affinity matrix by coupling the monoclonal antibody (McAb) with Sepharose 4B. Using this attractive strategy, 196 mg of α-MMC was obtained from 100 g of bitter melon seeds as the starting material. The yield of the protein was 2.7%. The homogeneity and properties of the protein were assessed by SDS-PAGE, acidic PAGE, RP-HPLC and N-terminal sequence as well as Western blot. Purified α-MMC showed remarkable inhibition to the melanoma cell line JAR and EMT-62058. In addition, it also displayed obvious inhibition on hepatitis B virus (HBV). This work provided a simple, rapid and efficient approach for α-MMC purification from Momordica charantia.

PEGylation of alpha-momorcharin: synthesis and characterization of novel anti-tumor conjugates with therapeutic potential.

Alpha-momorcharin (alpha-MMC) is a ribosome-inactivating protein (RIP) with excellent cytotoxicity to tumor cells. However, its strong immunogenicity and short plasma half-life limit its clinical applications. To overcome this, we have to PEGylated alpha-MMC using a branched 20 kDa (mPEG) (2)-Lys-NHS. Homogeneous mono-, di- and tri-PEGylated alpha-MMCs were synthesized, purified and characterized. In vitro and in vivo analysis indicated that the serial PEG-conjugates preserved moderate anti-tumor activity with 36% acute toxicity and at most 66% immunogenicity decrease. These results suggested the potential application of alpha-MMC-PEG conjugates as an anti-tumor agent.

In-silico analysis of ligand-receptor binding patterns of α-MMC, TCS and MAP30 protein to LRP1 receptor.

Alpha-momorcharin (α-MMC), trichosanthin (TCS), and momordica anti-HIV protein of 30 kD (MAP30) are potential anti-tumor drug candidates but have cytotoxicity to normal cells. The binding of these proteins to LRP1 receptor and the subsequent endocytosis are essential to their cytotoxicity, but this binding process remains largely unknown. This study, in-silico analysis of the binding patterns, was conducted via the protein-protein docking software, ZDOCK 3.0.2 package, to better understand the binding process. Specifically, α-MMC, TCS and MAP30 were selected and bound to binding subunits CR56 and CR17 of LRP1. After docking, the 10 best docking solutions are retained based on the default ZDOCK scores and used for structural assessment. Our results showed that, α-MMC bound to LRP1 stably at the amino acid residues 1-20, at which 8 residues formed 21 hydrogen bonds with 15 residues of CR56 and 10 residues formed 15 hydrogen bonds with 12 residues of CR17. In contrast, TCS and MAP30 bound mainly to LRP1 at the residues 1-57/79-150 and residues 58-102, respectively, which were functional domains of TCS and MAP30. Since residues 1-20 are outside the functional domain of α-MMC, α-MMC is considered more suitable to attenuate by mutating the receptor binding site. Thus, our analysis lays the foundation for future genetic engineering work on α-MMC, and makes important contributions to its potential clinical use in cancer treatment.

Anti-tumor activity and immunological modification of ribosome-inactivating protein (RIP) from Momordica charantia by covalent attachment of polyethylene glycol.

Ribosome-inactivating proteins (RIPs) are a family of enzymes that depurinate rRNA and inhibit protein biosynthesis. Here we report the purification, apoptosis-inducing activity, and polyethylene glycol (PEG) modification of RIP from the bitter melon seeds. The protein has a homogenous N-terminal sequence of NAsp- Val-Ser-Phe-Arg. Moreover, the RIP displayed strong apoptosis-inducing activity and suppressed cancer cell growth. This might be attributed to the activation of caspases-3. To make it available for in vivo application, the immunogenicity of RIP was reduced by chemical modification with 20 kDa (mPEG)(2)-Lys-NHS. The inhibition activity of both PEGylated and non-PEGylated RIP against cancer cells was much stronger than against normal cells, and the antigenicity of PEGylated RIP was reduced significantly. Our results suggested that the PEGylated RIP might be potentially developed as anti-cancer drug.

[Study on the immunotoxicity of ribosome inhibiting protein of Momordica charantia].

OBJECTIVE: To separate and purify ribosome inhibiting protein (RIP) from Momordica charantia (bitter melon) seeds and to evaluate its acute toxicity and immunotoxicity in animal. METHODS: Ion exchange chromatography and gel filtration chromatography were applied in the separating and purifying of RIP from Momordica charantia seeds. Then the acute toxicity testing of RIP in mice was conducted to obtain its half lethal dose (LD50). Active systemic anaphylaxis(ASA)test in guinea pig and passive cutaneous anaphylaxis test (PCA) in rat were performed to evaluate its immunotoxicity. RESULTS: The LD50 (iv) in mice of RIP was 25.2 mg/kg in ASA, guinea pigs of the higher and lower RIP group all appeared stong allergic responses and most of them died quickly. In PCA, obvious blue dye in skin were observed in SD rats of the RIP group. CONCLUSION: RIP getting from Momordica charantia seeds had a relatively strong immunotoxicity in animals.

LRP1 receptor-mediated immunosuppression of α-MMC on monocytes.

Alpha-MMC is a type I ribosome-inactivating protein purified from bitter gourd that has strong anti-tumour and antiviral activity. Alpha-MMC also has immunosuppressive effects, but the mechanism of these immunosuppressive effects remains unclear. It is reported that the binding of α-MMC to its specific cell membrane LRP1 receptor is key to its biological effects. In this study, we investigated the effect of α-MMC on cytotoxicity and cytokine release regulation in three immune cells, human monocyte THP-1 cells, B-lymphocyte WIL2 cells and T-lymphocyte H9 cells, and explored the correlation between this effect and LRP1 receptor distribution on these three cell types. We demonstrate that α-MMC has a significant effect of apoptosis induction and cytokine release in THP-1 cells but has no effect on WIL2-S and H9 cells. Specifically, at a non-cytotoxic dose (80 µg/ml), α-MMC regulates THP-1 cells by inhibiting IL-1ß, IL-2, IL-8, IL-9, IL-12, MIP-1α/ß, MCP-1 and TNF-α expression and enhancing IL-1ra and RANTES expression, resulting in the inhibition of cellular immune function. Subsequent experiments showed that the cytokine expression regulated by α-MMC can be blocked by silencing the LRP1 receptor of α-MMC. Further research indicated that phosphorylation of 9 signalling proteins of the MAPK pathway was significantly regulated by α-MMC and was blocked by LRP1 silencing. We conclude that the regulation of cytokine expression induced by α-MMC in monocyte THP-1 cells is mediated by the LRP1 receptor, likely via the MAPK signalling pathway. Our results suggest that the inhibition effect on monocytes/macrophages mediates the immunosuppressive function of α-MMC. Due to the selective cytotoxicity and cytokine release regulation of α-MMC in monocytes/macrophages, α-MMC may be used for killing Tumour-Associated Macrophages (M2 subtypes) or inhibiting their cytokine release in the tumour microenvironment.

[Effects of KH901, a tumor-specific oncolytic recombinant adenovirus, on antitumor and expressing GM-CSF in xenograft tumor models].

OBJECTIVE: Conditionally replicating oncolytic adenovirus KH901 was engineered with a genetically modified telomerase reverse transcriptase promoter and a cDNA of human granulocyte macrophage colony stimulating factor (GM-CSF). The objective of this study was to evaluate the anti-tumor efficacy and the selective GM-CSF expression of KH901 in xenograft tumor models. METHODS: After intratumoral administration of KH901, the rates of Relative Tumor Growth (T/C%) and inhibition in Hep3B and LNcap xenograft models were measured for observing the KH901 antitumor efficacy. At various time points, the GM-CSF expression levels in tumor tissues and the blood of A549 xenograft model were determined by ELISA method. RESULTS: In both Hep3B and LNcap xenograft models, KH901 showed the significantly higher restraint tumor rates at high dose (3 X 10(10) VP, P<0. 05) compared to 5-FU or Cisplatin. Even at the low dose (3 X 10(8) VP), the KH901 antitumor effect was similar to 5-FU (P>0. 05). In A549 xenograft model, the level of GM-CSF was continuously elevated and the peak values were found on day 7 in the blood and on day 11 in the tumor tissues. Then GM-CSF expression gradually reduced in both blood and tumor tissues. CONCLUSION: KH901 can significantly inhibit the tumor growth in xenograft tumor model, and also express a high level of human GM-CSF in tumor tissue and release to circulating system to form a CM-CSF peak value in the blood.

[Tumor-selective replication, cytotoxicity and GM-CSF production of oncolytic recombinant adenovirus in KH901 injection].

OBJECTIVE: To study the tumor-selective replication, cytotoxicity and GM-CSF production of the recombinant virus in KH901 injection used to infect the cells cultured in vitro. METHODS: A panel of tumor and normal cells was infected with recombinant adenovirus in KH901 and wild-type adenovirus type 5 at a MOI of 2 PPC, the cells were harvested at 72 hours after infection and made a titer after three cycles of freeze/thaw; A panel of tumor and normal cells was infected with recombinant adenovirus KH901 at MOI of 1 or 10 PPC. For 24 hours after infection the medium was harvested to determine the biological activity of GM-CSF; A panel of tumor and normal cells was infected with KH901 of recombinant adenovirus and wild-type adenovirus type 5 at MOIs of 0, 0.1, 1, 10, 100, and 1000 PPC. At 7 days after infection, cell viability was determined by the MTT assay, and ECso was determined too. RESULTS: The data showed that wild-type adenovirus type 5 replicated efficiently in and killed both the tumor and normal cells, however, the recombinant adenovirus in KH901 replicated hugely in tumor cells [(2526.4+/-136.8)-(2796.6+/-104.6) TCID50/cell), and produced significant amount of GM-CSF [(1177. 793 +/-6.62)-(3924.497+/-17.79) IU/(10(6) cell x 24h)] and killed the tumor cells [EC50: (0.31+/-0.06)-(0.19+/- 0.01) pfu/cell] while was replicating poorly in non-permissive human normal cells [(56.8+/-9.2)-(90.1+/-14.4) TCID50/ cell], and producing very small amount of GM-CSF [(13.397+/-0.82) IU/(10(6)cell x 24 h)] and attenuating human primary cells killed [EC50: (92.33 +/- 9.12)-(121.20 +/- 19.94) pfu/cell], with which there was statistically a significant difference between wild-type adenovirus type 5 and recombinant adenovirus in KH901 (P<0.05). CONCLUSION: In vitro studies show that the tumor-selective replication, cytotoxicity, GM-CSF production of recombinant adenovirus lead the injection KH901 containing the recombinant adenovirus, as oncolytic agent, to have a potential utility for the treatment of solid tumors.

Cytotoxicity mechanism of α-MMC in normal liver cells through LRP1 mediated endocytosis and JNK activation.

Alpha-momorcharin (α-MMC), a type I ribosome-inactivating protein isolated from Momordica charantia, is a potential drug candidate with strong anti-tumor activity. However, α-MMC has a severe hepatotoxicity when applied in vivo, which may greatly hinders its use in clinic in the future. The biological mechanism of hepatotoxicity induced by α-MMC is largely unknown, especially the mechanism by which α-MMC enters the hepatocytes. In this study, we investigated α-MMC-induced cytotoxicity in normal liver L02 cell line as well as the mechanism underlying it. As expected, α-MMC is more toxic in L02 cells than in various normal cells from other organs. The cytotoxic effect of α-MMC on L02 cells is found to be mediated through cell apoptosis as detected by flow cytometry and fluorescence microscopy. Importantly, α-MMC was shown to bind to a specific receptor on cell membrane, as the density of the cell membrane receptor is closely related to both the amount of α-MMC endocytosed and the cytotoxicity in different cell lines. By using LRP1 competitive inhibitor α2-M or siRNA targeting LRP1, we further identified that LRP1 protein served as the membrane receptor for α-MMC. Both α2-M and siRNA targeting LRP1 can significantly inhibit α-MMC's endocytosis as well as its cytotoxicity in L02 cells. In addition, it was found that α-MMC can activate the JNK signalling pathways via LRP1 in L02 cells. As JNK activation often leads to cell apoptosis, the activation of JNK may play an important role in α-MMC-induced cytotoxicity. To our knowledge, this is the first report showing that LRP1 mediates the cytotoxicity of α-MMC through (1) endocytosis and induced apoptosis and (2) the activation of the JNK pathway. Our findings shed light on the fundamental mechanism of hepatotoxicity of α-MMC and offer reference to understand its mechanism of lymphocytotoxicity and neurotoxicity.

PEGylation alleviates the non-specific toxicities of Alpha-Momorcharin and preserves its antitumor efficacy in vivo.

Alpha-Momorcharin (α-MMC) is a ribosome inactivating protein from Momordica charantia with anti-tumor activity. Previously, we had observed that modification of α-MMC with polyethylene glycol (PEG) could reduce toxicity, but it also reduces its anti-tumor activity in vitro. This study aims to investigate whether the metabolism-extended properties of α-MMC resulting from PEGylation could preserve its anti-tumor efficacy in vivo through pharmacokinetics and antitumor experiments. The pharmacokinetics experiments were conducted in rats using the TCA (Trichloroacetic Acid) method. Antitumor activity in vivo was investigated in murine mammary carcinoma (EMT-6) and human mammary carcinoma (MDA-MB-231) transplanted tumor mouse models. The results showed that PEGylation increased the plasma half-life of α-MMC in rats from 6.2-7.5 h to 52-87 h. When administered at 1 mg/kg, α-MMC-PEG and α-MMC showed similar anti-tumor activities in vivo, with a T/C% of 38.56% for α-MMC versus 35.43% for α-MMC-PEG in the EMT-6 tumor model and 36.30% for α-MMC versus 39.88% for α-MMC-PEG in the MDA-MB-231 tumor model (p > 0.05). Importantly, at the dose of 3 mg/kg, all the animals treated with α-MMC died while the animals treated with α-MMC-PEG exhibited only moderate toxic reactions, and α-MMC-PEG exhibited improved anti-tumor efficacy with a T/C% (relative tumor growth rate) of 25.18% and 21.07% in the EMT-6 and MDA-MB-231 tumor models, respectively. The present study demonstrates that PEGylation extends the half-life of α-MMC and alleviates non-specific toxicity, thereby preserving its antitumor efficacy in vivo, and a higher lever of dosage can be used to achieve better therapeutic efficacy.

TOA02, a recombinant adenovirus with tumor-specific granulocyte macrophage colony-stimulating factor expression, has limited biodistribution and low toxicity in rhesus monkeys.

TOA02 is a genetically modified oncolytic adenovirus that contains human granulocyte macrophage colony-stimulating factor (hGM-CSF). It has been verified in vitro that TOA02 can specifically replicate in tumor cells that possess high telomerase reverse transcriptase activity and Rb pathway deficiency. However, the replication specificity, hGM-CSF expression, and toxicity of TOA02 in vivo are still unknown. Therefore, the biosafety of TOA02 remains a critical issue before its potential clinical use. In this study, viral replication and hGM-CSF expression levels were investigated in both xenograft nude mouse models and rhesus monkeys, and chronic toxicity was evaluated in rhesus monkeys. Our results show that (1) the replication and hGM-CSF expression of TOA02 are high in tumor model, (2) there are no hGM-CSF expression and continuous viral replication in rhesus monkeys except in pancreas and epididymis, and (3) the antiadenovirus antibody was positive in the chronic toxicity experiment, but pathological change of blood cytology and blood biochemistry were not found. There were no other histopathology lesions apart from skin inflammation of the administration region, lymphadenitis of draining lymph nodes. Our findings suggest that TOA02 is relatively safe for in vivo application, thus laying the foundation for future clinical trials with TOA02.

Alpha-momorcharin (α-MMC) exerts effective anti-human breast tumor activities but has a narrow therapeutic window in vivo.

Alpha-momorcharin (α-MMC), a ribosome inactivating protein (RIP) extracted from the seeds of Momordica charantia, exerts anti-tumor, antiviral, and anti-fungal activities. However, α-MMC has an obvious toxicity that limits its clinical application. We examined the effect of α-MMC on the inhibition of human breast cancer and assessed its general toxicity to find the therapeutic window in vivo for its potential clinical use. It was purified using column chromatography, and then injected into the xenograft nude mouse model induced by MDA-MB-231 and MCF-7. The anti-tumor efficacy was evaluated with T/C%. Next, the α-MMC was injected at a series of doses to Balb/C mice to assess its general toxicity. The MTT assay, the apoptosis test, and the cell cycle inhibition of α-MMC in human breast cancer cells were performed. In the xenografted tumors induced by MDA-MB-231 and MCF-7, α-MMC exerted an obvious inhibition effects on tumor growth at the dosage of 1.2mg/kg and 0.8 mg/kg. For in vivo toxicity experiments of α-MMC in Balb/C mice, the minimal toxic dose of α-MMC was 1.2mg/kg. Alpha-MMC induced apoptosis by increasing caspase3 activities, and the cell cycle was arrested at the G0/G1 or G2/M phases. The measurements of IC50 were 15.07 µg/mL, 33.66 µg/mL, 42.94 µg/mL for MDA-MB-231, MCF-7 and MDA-MB-453 respectively. Alpha-MMC exhibits anti-tumor effects in human breast cancer in vivo and in vitro. It inhibits breast cancer cells through the inhibition of tumor growth and induction of cell apoptosis. However, due to its obvious toxicity, α-MMC has a relatively narrow therapeutic window in vivo.

Alpha-momorcharin possessing high immunogenicity, immunotoxicity and hepatotoxicity in SD rats.

UNLABELLED: Momordica charantia L., a genus of Momordica Linn. of the family Cucurbitaceae, commonly known as bitter melon, has been widely planted in China, Southeast Asia, Turkey and other areas, and has been used as a medicine for a long time. Alpha-momorcharin (α-MMC) extracted and purified from bitter melon seeds has significant anti-tumor and anti-virus effects, and has potential toxicity as well, especially when taken overdose. However, up to date studies on its safety evaluation are still insufficient. AIMS OF THE STUDY: The immunogenicity, immunotoxicity and general toxicity of α-MMC were investigated in rats and guinea-pigs, and the potential toxic effects of the agent on the body were also examined. MATERIALS AND METHODS: The major ribosome-inactivating protein was isolated by column chromatographies from the protein extracted from bitter melon seeds, and was verified as α-MMC. After rats were immunized by α-MMC, titers of specific antibody to α-MMC in immunized rats serum were detected by indirect ELISA. Guinea-pigs and rats immunized with α-MMC were used to evaluate the active systemic anaphylaxis and passive cutaneous anaphylaxis induced by α-MMC relatively. α-MMC of 6.25 mg/kg, 2.08 mg/kg and 0.70 mg/kg was administered to rats every 2 days. Five weeks later, animals were sacrificed, and then, biochemical examination, analysis of bone marrow and peripheral blood cells, and histopathologic examination were performed. RESULTS: The ribosome-inactivating protein isolated and purified from bitter melon seeds was identified as α-MMC. It induced high titer (1:46.4) of specific IgG and high positive results of the active systemic anaphylaxis and passive cutaneous anaphylaxis tests in animals. With the time of the α-MMC administration increasing, the body weights of the animals administered with α-MMC of 6.25 mg/kg decreased significantly, and point necrosis was also observed in liver cells, along with abnormal findings in serum chemistry, hematology and bone marrow histopathology test. The toxic effect lessened with the decrease of the dose of α-MMC and further reduced after the convalescence stage. CONCLUSIONS: The results of the study show that α-MMC has high immunogenicity and immunotoxicity, and can cause obvious organic liver lesion.