Predictive value of trypan blue exclusion viability measurements for colony formation in a human tumor cloning assay

Isolation and chatacterization of homoisoflavonoids from Dracaena cochinchinensis and their osteogenic activities in mouse mesenchymal stem cells

Two new homoisoflavonoids, dracaeconolide A (1) and dracaeconolide B (2), together with ten known compounds, namely (3R)-7,4'-dihydroxy-8-methoxyhomoisoflavane (3), (3R)-7-hydroxy-3-(4-hydroxybenzyl)chromane (4), (3R)-7,4'-dihydroxy-5-methoxy-homoisoflavane (5), (3R)-6,4'-dihydroxy-8-methoxyhomoisoflavan (6), 7,4'-dihydroxy-8-methylflavan (7), (2R)-7,4'-dihydroxy-5-methoxy-8-methylflavan (8), 5,4'-dihydroxy-7-methoxy-6-methylflavane (9), 7,4'-dihydroxy-3'-methoxyflavan (10), 7,4'-dihydroxyflavan (11), 4,4'-dihydroxy-2,6-dimethoxydihydrochlcone (12), were isolated from the red resin of Dracaena cochinchinensis (dragon's blood, DB). All the compounds were then evaluated for their effects on mouse bone marrow-derived mesenchymal stem cells (MSCs) proliferation using CCK8 assay and their abilities in promoting MSCs differentiating into osteoblast through the assay of alkaline phosphatase (ALP) activity in vitro. Compounds 2, 3, 4, 7, 9, and 11, at a concentration of 10μM with no cytotoxicity, significantly promoted MSC osteogenic differentiation by increasing the levels of ALP activity to percents of 159.6±5.9, 167.6±10.9, 162.0±1.4, 151.3±4.0, 171.0±8.2, and 169.9±7.3 in relative to the control, respectively. The results of ALP staining were in accordance to that of ALP activity.

Isolation of antiosteoporotic compounds from seeds of Sophora japonica

Chemical investigation of Sophora japonica seeds resulted in the isolation of seven metabolites identified as: genistin (1), sophoricoside (2), sophorabioside (3), sophoraflavonoloside (4), genistein 7,4'-di-O-β-D-glucopyransoide (5), kaempferol 3-O-α-L-rhamnopyranosyl(1 → 6)β-D-glucopyranosyl(1 → 2)β-D-glucopyranoside (6) and rutin (7). Compounds 1, 2 and 5 showed significant estrogenic proliferative effect in MCF-7 cell in sub-cytotoxic concentration range. Compounds 1 and 2 showed minimal cell membrane damaging effect using LDH leakage assay. Accordingly, compound 2 (sophoricoside, (SPH)) was selected for further in-vivo studies as a potential anti-osteoporosis agent. The anti-osteoporotic effect of SPH was assessed in ovarectomized (OVX) rats after oral administration (15 mg/kg and 30 mg/kg) for 45 days compared to estradiol (10 µg/kg) as a positive control. Only in a dose of 30 mg/kg, SPH regained the original mechanical bone hardness compared to normal non-osteoporotic group. However, SPH (15 mg/kg) significantly increased the level of alkaline phosphatase (ALP) to normal level. Treatment with SPH (30 mg/kg) increased the level of ALP to be higher than normal group. SPH (15 mg/kg) did not significantly increase the serum level of osteocalcin (OC) compared to OVX group. On the other hand, treatment with SPH (30 mg/kg) significantly increased the level of OC to 78% higher than normal non-ovarectomized animals group. In addition, SPH (15 mg/kg) decreased the bone resorption marker, acid phosphatase (ACP) to normal level and SPH (30 mg/kg) further diminished the level of serum ACP. Histopathologically, sophoricoside ameliorated the ovarectomy induced osteoporosis in a dose dependent manner. The drug showed thicker bony trabeculae, more osteoid, and more osteoblastic rimming compared to OVX group.

Effect of hyperthermia and X-irradiation on survival and occurrence of metastases in mice bearing P388 tumor

Survival of P388 lymphoid tumor-bearing mice and the occurrence of metastasis was studied after combined modality treatment with hyperthermia and X-irradiation. P388 ascites tumor cells were treated at 42 degrees C or 43.5 degrees C for 1 hr in vitro and transplanted on B6D2F1 mice intraperitoneally (i.p.) or intramuscularly (i.m.). Hyperthermic treatment at 43.5 degrees C increased the median survival time (MST). Increased life-span (ILS) was found after i.p. transplantation (54%) and after i.m. transplantation (30%). During the life-span of tumor-bearing animals, significantly fewer metastases were observed in liver and spleen after hyperthermia and 5-10% metastasis occurred after transplantation of ascites tumor cells treated at 43.5 degrees C in vitro compared with 90% in the untreated control animals. The lower occurrence of metastasis could not be ascribed to the higher cell-killing effect of hyperthermia. When both modalities were combined the best tumor growth retardation effect was obtained when ascites tumor cells were treated at 43.5 degrees C for 1 hr before being transplanted i.m. and 1 day later locally X-irradiated with 6 Gy. In this case, 77% ILS was found demonstrating a synergistic effect of the two modalities. While X-irradiation alone did not change the occurrence of metastasis, after combined modality treatment it was as low as with hyperthermia alone (5-10%). In connection with the significantly lower occurrence of metastasis, the possible alterations of P388 tumor cell membrane and surface proteins induced by in vitro hyperthermic treatment are discussed.

Differential response of normal and tumour oesophageal explant cultures to radiation

An in vitro method is described which allows radiation dose response data to be obtained for samples of oesophageal mucosa obtained from patients undergoing resection for adeno or squamous cell carcinoma. Data are obtained using a growth endpoint from explant cultures and may be expressed in terms of absolute growth inhibition or reduced rate of growth. Radiation dose response curves suggest that cell survival is in the range expected for mammalian cells but that, as is found clinically, tumour cells are far more resistant to radiation than normal cells. The technique provides a means of assessing differential radiation response in normal and tumour tissues from the same patient, as it is unusual for both to be amenable to clonogenic assay.