Trichosanthin inhibits breast cancer cell proliferation in both cell lines and nude mice by promotion of apoptosis

A lower pH value benefits regeneration of Trichosanthes kirilowii by somatic embryogenesis, involving rhizoid tubers (RTBs), a novel structure

A new approach was established for the regeneration of Trichosanthes kirilowii from root, stem, and leaf explants by somatic embryogenesis (SE), involving a previously unreported SE structure, rhizoid tubers (RTBs). During SE, special rhizoids were first induced from root, stem, and leaf explants with average rhizoid numbers of 62.33, 40.17, and 11.53 per explant, respectively, on Murashige and Skoog (MS) medium (pH 4.0) supplemented with 1.0 mg/L 1-naphthaleneacetic acid (NAA) under dark conditions. Further, one RTB was formed from each of the rhizoids on MS medium (pH 4.0) supplemented with 20 mg/L thidiazuron (TDZ) under light conditions. In the suitable range (pH 4.0-9.0), a lower pH value increased the induction of rhizoids and RTBs. Approximately 37.77, 33.47, and 31.07% of in vivo RTBs from root, stem, and leaf explants, respectively, spontaneously developed into multiple plantlets on the same MS medium (supplemented with 20 mg/L TDZ) for induction of RTBs, whereas >95.00% of in vitro RTBs from each kind of explant developed into multiple plantlets on MS medium supplemented with 5.0 mg/L 6-benzylaminopurine (BAP). Morphological and histological analyses revealed that RTB is a novel type of SE structure that develops from the cortex cells of rhizoids.

Cytotoxic genes from traditional Chinese medicine inhibit tumor growth both in vitro and in vivo

OBJECTIVE

Little effort has been made to study the protein-encoding genes isolated from traditional Chinese medicine (TCM) drugs, and the delivery of these genes into malignant cells through recombinant adeno-associated virus (rAAV) vectors has not been attempted.

METHODS

We synthesized the cDNAs of five known cytotoxic proteins isolated from TCM drugs and the FLAG epitope-tagged cDNAs were subcloned into a rAAV plasmid vector. The protein expression was confirmed by Western blot assay. Various cancer cell lines were transfected with the above plasmids and cell growth was monitored both in vitro and in vivo. The best cytotoxic gene was further packaged into rAAV vectors, under the control of a liver cancer-specific promoter. The liver tumor growth was then monitored following intratumor administration of the rAAV vectors.

RESULTS

The expression plasmids, encoding individual potential cytotoxic genes tagged with FLAG epitope, were successfully generated and sequenced. Among these genes, trichosanthin (TCS) gene yielded the most promising results for the inhibition of cancer cell growth in vitro. The over-expressed TCS functioned as a type I ribosome-inactivating protein, followed by inducing apoptosis that is associated with the Bcl-PARP signaling pathway. Furthermore, intratumor injection of rAAV vectors containing the TCS gene significantly inhibited the growth of human hepatocellular carcinoma tumors in a murine xenograft model.

CONCLUSION

Our studies suggest that the use of TCM cytotoxic genes is a useful therapeutic strategy for treating human cancers in general, and liver tumors in particular.

Hedyotis diffusa Willd extract inhibits the growth of human glioblastoma cells by inducing mitochondrial apoptosis via AKT/ERK pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Hedyotis diffusa Willd (Rubiaceae) (HDW) has been widely applied for the treatment of tumors, inflammation and toxication in traditional Chinese medicine. The antitumor effect of HDW on glioblastoma has been rarely reported. We aim to evaluate the activity of this extract and explore the underlying mechanism in U87 human glioblastoma cell line.

MATERIALS AND METHODS

Cytotoxicity of HDW extract on U87 cells was measured by MTT assay. Apoptosis, cell cycle arrest and mitochondrial membrane potential (MMP) collapse induced by HDW extract were determined by flow cytometry. Caspase activity was analyzed based on colorimetric assay with a microplate spectrophotometer. Protein expression was examined by Western blot.

RESULTS

HDW extract suppressed U87 cells growth in a dose- and time-dependent manner. Flow cytometry showed that HDW extract induced significant apoptosis, S/G2-M phase arrest and MMP collapse in U87 cells. Furthermore, dose-dependent activation of caspase-3, Bcl-2, Bax and ERK was observed with HDW extract treatment. Decreased Bcl-2/Bax ratio and Akt suppression were readily found as well.

CONCLUSIONS

Induction of mitochondria-mediated apoptosis played an essential role in antitumor activity of HDW extract in U87 cells, in which ERKs and Akt signaling proteins were also involved. These findings contributed to the feasibility of using HDW extract in glioblastoma treatment and the understanding of the molecular mechanism.

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.

In vivo and in vitro antitumor effects of platycodin d, a saponin purified from platycodi radix on the h520 lung cancer cell

Platycodin D is a major pharmacological constituent of Platycodi radix and has showed various pharmacological activities through oxidative stress defense mechanisms. Here, possible antitumor, anticachexia, and immunomodulatory activities of platycodin D were observed on the H520 tumor cell-bearing athymic nude mice after confirming the in vitro cytotoxicity. Platycodin D was orally administered at dose levels of 200, 100, and 50 mg/kg, once a day for 35 days from 15 days after implantation. The results were compared with gemcitabine 160 mg/kg intraperitoneally treated mice (7-day intervals). Platycodin D showed favorable cytotoxic effects on the H520 cells, and also dose-dependently decreased the tumor volumes and weights with increases of apoptotic cells (caspase-3 and PARP immunopositive cells), iNOS and TNF-α immunoreactivities, decreases of COX-2 immunoreactivities in tumor masses. Platycodin D also showed dose-dependent immunostimulatory and anticachexia effects. Gemcitabine showed favorable cytotoxity against H520 tumor cell and related in vivo antitumor effects but aggravated the cancer related cachexia and immunosuppress in H520 tumor cell-bearing athymic nude mice. Taken together, it is considered that oral treatment of platycodin D has potent antitumor activities on H520 cells through direct cytotoxic effects, increases of apoptosis in tumor cells, and immunostimulatory effects and can be control cancer related cachexia.

Bioactive proteins and peptides isolated from Chinese medicines with pharmaceutical potential

Some protein pharmaceuticals from Chinese medicine have been developed to treat cardiovascular diseases, genetic diseases, and cancer. Bioactive proteins with various pharmacological properties have been successfully isolated from animals such as Hirudo medicinalis (medicinal leech), Eisenia fetida (earthworm), and Mesobuthus martensii (Chinese scorpion), and from herbal medicines derived from species such as Cordyceps militaris, Ganoderma, Momordica cochinchinensis, Viscum album, Poria cocos, Senna obtusifolia, Panax notoginseng, Smilax glabra, Ginkgo biloba, Dioscorea batatas, and Trichosanthes kirilowii. This article reviews the isolation methods, molecular characteristics, bioactivities, pharmacological properties, and potential uses of bioactive proteins originating from these Chinese medicines.

A novel method for simultaneous production of two ribosome-inactivating proteins, α-MMC and MAP30, from Momordica charantia L

Alpha-momorcharin (α-MMC) and momordica anti-HIV protein (MAP30) from Momordica charantia L. have been confirmed to possess anti-tumor and anti-virus activities. Traditional purification methods of these two ribosome-inactivating proteins (RIPs) were separate which was time consuming and cost effective as well as low efficient. In order to obtain sufficient samples for researches, a strategy combining ion-exchange and gel filtration chromatography was developed and optimized in this study. Using this novel purification method, averagely 1162 mg of α-MMC and 535 mg of MAP30 were obtained from 400 g of Momordica charantia L seeds. The homogeneities of them were assessed by electrophoresis analysis. Determination of molecular weights of α-MMC and MAP30 were 28.585 kDa and 29.094 kDa by MALDI-TOF/TOF and pI were 9.02 and 9.12, respectively. The single glycoproteins were identified by Periodate-Schiff's base (PAS) and the saccharide content was tested to be 1.25% and 1.1% by anthrone-sulfuric acid method. Biological activities were evidenced by their ability to inhibit proliferation of lung adenocarcinoma A549 cell and to convert supercoiled plasmid pUC18 into relaxed forms. Finally, we also found that both two RIPs exhibited no superoxide dismutase (SOD) activity.