Myristoleic acid, a cytotoxic component in the extract from Serenoa repens, induces apoptosis and necrosis in human prostatic LNCaP cells.

BACKGROUND: Prostatic tumors are well known to progress to hormonal therapy-resistant terminal states. At this stage, there are no chemotherapeutic agents to affect clinical outcome. An effective cell death inducer for these prostate cells may be a candidate as an attractive antitumor agent. The extracts from S. repens have been used to improve the state of prostatic diseases and we have attempted to identify the effective component from the extract. METHODS: Cell viability was examined in LNCaP cells, an in vitro model for hormonal therapy-resistant prostatic tumor. RESULTS: We found that exposure of the extract from S. repens resulted in cell death of LNCaP cells. We also identified myristoleic acid as one of the cytotoxic components in the extract. The cell death exhibited both apoptotic and necrotic nuclear morphology as determined by Hoechst 33342 staining. Cell death was also partially associated with caspase activation. CONCLUSIONS: It was demonstrated that the extract from S. repens and myristoleic acid induces mixed cell death of apoptosis and necrosis in LNCaP cells. These results suggest that the extract and myristoleic acid may develop attractive new tools for the treatment of prostate cancer.

Extract from Serenoa repens suppresses the invasion activity of human urological cancer cells by inhibiting urokinase-type plasminogen activator.

We used three human urological cancer cell lines, PC-3, LNCaP and SKRC-1, to investigate the effects of the extract from Serenoa repens (Palmae) on tumor cell invasion. The invasion activity of these cell lines was determined in vitro using a Transwell cell-culture chamber. The invasion activity of PC-3 cells into Matrigel was effectively suppressed by the extract at the concentration range of 1-10 microg/ml, while that of LNCaP and SKRC-1 cells was unaffected by the extract. The extract did not affect the viability, adhesion ability, or motility of the cell lines. uPA is more strongly expressed on the membrane fraction of PC-3 cells than that of LNCaP or SKRC-1 cells. The purified uPA activity is inhibited by the extract from S. repens in a dose-dependent manner, suggesting that the suppression of PC-3 cell invasion by the extract is based on an inhibition of the uPA activity which is necessary for tumor cell invasion. These data suggest that the extract from S. repens specifically inhibits the uPA activity and may therefore be useful for the therapeutic treatment of prostate cancer.

Antidiabetic effect of an acidic polysaccharide (TAP) from Tremella aurantia and its degradation product (TAP-H).

Continuous oral administration of the acidic polysaccharide (TAP) solution (0.5 g/l) and the TAP-H (degradation products of TAP) solution (1.5 g/l) instead of water for 10 weeks were found to depress plasma glucose increases in diabetes using genetically non-insulin-dependent diabetic model (KK-Ay) mice. TAP and TAP-H significantly lowered levels of insulin, total-cholesterol and triglyceride in the blood of the mice. In excretion to feces, TAP and TAP-H significantly increased the total bile acid, while the cholesterol content of both groups was less than that of the control. Furthermore, TAP and TAP-H significantly decreased the plasma lipoperoxide level. The study shows that TAP and TAP-H have an antidiabetic effect on diabetes model mice.

Structural features and hypoglycemic activity of a polysaccharide (CS-F10) from the cultured mycelium of Cordyceps sinensis.

A polysaccharide (CS-F10) purified from a hot water extract of the cultured mycelium of Cordyceps sinensis was composed of galactose, glucose and mannose in a molar ratio of 43:33:24; its molecular weight was estimated to be about 15000. The results of chemical and spectroscopic investigations suggest that CS-F10 has a comb-type structure, and has alpha-D-glucopyranosyl residues on the terminal of the side-chains and characteristic sugar residues of C. sinensis i.e., 1,5-linked beta-D-galactofuranosyl residues. CS-F10 significantly lowered the plasma glucose level in normal, streptozotocin (STZ)-induced diabetic and epinephrine-induced hyperglycemic mice after intraperitoneal administration (50 mg/kg). Administration of CS-F10 to STZ-induced diabetic mice significantly increased the activity of hepatic glucokinase. A significant reduction in the hepatic glucose output was observed following the infusion of CS-F10 using the perfused rat liver. CS-F10 also significantly decreased protein content of facilitative glucose transporter isoform 2 (GLUT2) from rat liver following i.p. administration. These effects presumably contribute to the hypoglycemic activity.

Phloroglucinols from Baeckea frutescens.

Two new phloroglucinols, named BF-1 and BF-2, were isolated from the dried leaves of Baeckea frutescens. Their structures were determined by their 1H and 13C NMR and mass spectral data. BF-2 exhibited strong cytotoxic activity (IC50 = 5.0 micrograms ml-1) against leukaemia cells (L 1210) in tissue culture.

Parabolic flight experiments on physiological data acquisition and processing technologies using small jet aircraft (MU300).

The parabolic aircraft flight provides a short low gravity environment for approximately 20 seconds, which may not be sufficient for a research on the physiological phenomenon induced by actual weightlessness in space. However, the method is still useful to reveal essential and characteristic feature of physiological signs, and is available for testing hardware and also training of crew member during altered gravity. This paper reports the summary of parabolic flight experiments recently conducted as a NASDA program (1990-1992). The program is providing opportunities in low gravity research with small jet aircraft for researchers and agencies. The flight experiments in the life science area have been conducted mostly focused on a physiological changes and basic methodology which may be effective under the altered gravity condition. In this study, the following research team, NASDA, Research Institute of Environmental Medicine, Nagoya University, Toyohashi University of Technology, Tokyo Metropolitan Hospital, Torey Research Center and JSUP were involved and coordinated for the research.