Anticancer properties of phospholipase A2 fromDaboia siamensis venom on human skin melanoma cells

Background Phospholipase A2 (PLA2) is a major component of theDaboia siamensis venom, which is able to hydrolyse the membrane of various cells. For this reason, the activity of PLA2was investigated regarding its pharmaceutical properties. This study was conducted to explore the pharmacological properties of a PLA2from Daboia siamensis (dssPLA2) venom on human skin melanoma cell line (SK-MEL-28). Methods dssPLA2 was isolated by ion exchange and gel filtration columns. Various concentrations of dssPLA2were investigated for cytotoxic activity and inhibition of migration on SK-MEL-28 cells. Cell death analysis, mRNA expression levels of Notch I-III and BRAF V600E genes were also determined. Results dssPLA2 exhibited cytotoxicity on SK-MEL-28 for 24 and 72 h as compared with untreated cells. However, it had no toxic effects on CCD-1064sk cells under the same conditions. dssPLA2 (0.25 and 0.5 μg/mL) induced 17.16 and 30.60 % of apoptosis, while activated 6.53 and 7.05 % of necrotic cells. dssPLA2 at 0.25, 0.5, 1 and 2 μg/mL could inhibit migration on SK-MEL-28 cells for 24 h by 31.06, 41.66, 50 and 68.75 %, respectively. The action of dssPLA2 significantly reduced the levels of Notch I and BRAF V600E genes expression on SK-MEL-28 cells compared with untreated cells at 72 h. Conclusions This study indicates that dssPLA2 had potential effects of apoptosis, necrosis, cytotoxicity and inhibition of migration on SK-MEL-28 cells. dssPLA2 could possibly be a selective agent that targets cancer cells without affecting normal cells.(AU)

Anticancer properties of phospholipase A2 fromDaboia siamensis venom on human skin melanoma cells

Phospholipase A2 (PLA2) is a major component of theDaboia siamensis venom, which is able to hydrolyse the membrane of various cells. For this reason, the activity of PLA2was investigated regarding its pharmaceutical properties. This study was conducted to explore the pharmacological properties of a PLA2from Daboia siamensis (dssPLA2) venom on human skin melanoma cell line (SK-MEL-28). Methods dssPLA2 was isolated by ion exchange and gel filtration columns. Various concentrations of dssPLA2were investigated for cytotoxic activity and inhibition of migration on SK-MEL-28 cells. Cell death analysis, mRNA expression levels of Notch I-III and BRAF V600E genes were also determined. Results dssPLA2 exhibited cytotoxicity on SK-MEL-28 for 24 and 72 h as compared with untreated cells. However, it had no toxic effects on CCD-1064sk cells under the same conditions. dssPLA2 (0.25 and 0.5 g/mL) induced 17.16 and 30.60 % of apoptosis, while activated 6.53 and 7.05 % of necrotic cells. dssPLA2 at 0.25, 0.5, 1 and 2 g/mL could inhibit migration on SK-MEL-28 cells for 24 h by 31.06, 41.66, 50 and 68.75 %, respectively. The action of dssPLA2 significantly reduced the levels of Notch I and BRAF V600E genes expression on SK-MEL-28 cells compared with untreated cells at 72 h. Conclusions This study indicates that dssPLA2 had potential effects of apoptosis, necrosis, cytotoxicity and inhibition of migration on SK-MEL-28 cells. dssPLA2 could possibly be a selective agent that targets cancer cells without affecting normal cells.

A lyophilized formulation to extend the shelf-life of tuberculin PPD.

This study was aimed to develop a dry purified protein devirative (PPD) preparation to extend the shelf-life of tuberculin PPD. Five percent sucrose (S), 6.5% mannitol (M), 2.5% trehalose (T) or 0.3% Hemaccel (H) was added to each formulation. In vivo and in vitro analyses were carried out to determine the efficacy of the lyophilized products. In the in vivo test, the delayed type hypersensitivity (DTH) responses of the lyophilized preparations were compared to the liquid preparation (CL) after injection into BCG vaccinated guinea pigs. The preparations of H, M, T, and S generated DTH responses of 100, 90, 89, and 60%, as compared to the response of CL, respectively. There was no loss of tuberculin activity in the H formula. A statistically significant difference in activity was found between S and CL (p < 0.05). The cellular test for IFN-gamma secretions was performed using the whole blood of human subjects screened for DTH response to tuberculin PPD Mantoux tests. The detection of IFN-gamma secretions was done using ELISA and the efficacy was expressed in terms of percentage of IFN-gamma responses to the tuberculin antigens. The results of CL, H, M, T and S were 3.28, 10.40, 0.84, 1.52 and 1.29%, compared to mitogen stimulation, respectively. The lyophilized H, M and T formulations and the liquid CL were studied for their shelf-life stabiliy. Accelerated degradation was done by storing the samples at higher temperatures of 37 degrees C and 56 degrees C for 3, 6, 9 and 12 months. All the tuberculin PPD solutions were injected into BCG vaccinated guinea pigs at the end of each storage period and the activity of each solution was evaluated. The formulation with the Hemaccel as excipient gave a superior response than the others at the normal storage temperature of 40 micro C for 12 months. Therefore, Hemaccel provides protection for PPD activity. This supports the potential for the development of lyophilized tuberculin PPD with the addition of 0.3% Hemaccel to extend shelf life.

Leptospirosis in northeastern Thailand: hypotension and complications.

During an outbreak of leptospirosis in northeastern Thailand, 148 patients with serologically diagnosed leptospirosis were seen in Loei Hospital. The clinical features were consistent with those described for the classic manifestation of the disease. However, hypotension was a common finding: noted in 94 patients (64%) upon admission or early in the course of the disease. Of these hypotensive patients, 64 (68%) had impaired renal function: 30 patients (32%) had prerenal azotemia and 34 (36%) were in renal failure. Pulmonary complications, including pulmonary edema, hemorrhage, ARDS, and interstitial pneumonitis, occurred in 22% of patients and were often associated with renal failure. A clear association existed between hypotension and renal failure and pulmonary complications. The overall mortality rate was 3.4%. The causes of death were pulmonary complications, renal failure, and sepsis. The death rate among patients with complications was 11.6%. Blood exchange, in addition to conventional treatment, was beneficial in severe leptospirosis with complications and hyperbilirubinemia.