Protective effect of L-carnitine on platelet apoptosis during storage of platelet concentrate.

BACKGROUND: Platelet apoptosis is considered as one of the important factors involved in platelet storage lesion (PSL) and affect the quality of platelets during storage. The beneficial effect of L-carnitine (LC) on platelet apoptosis during platelet concentrates (PCs) storage has not been fully investigated. The aim of this study was to evaluate the effects of LC on platelets of PC regarding their apoptosis markers during storage. METHODS: Ten PCs from healthy donors were investigated in this study. PCs were prepared by platelet rich plasma (PRP) method and stored at 22±2°C with gentle agitation during storage. The effects of LC (15mM) on the platelet apoptosis were assessed by analyzing different indicative presence or absence of LC. Sampling was performed to evaluate apoptosis markers during platelet storage. RESULTS: The results indicated significantly higher mitochondrial membrane potential for LC-treated platelets than the untreated on the days 2 and 5 of storage (Pday2=0.001, Pday5=0.001). Phosphatidylserine (PS) exposure significantly increased on the untreated compared with LC-treated platelets on the second and third days of storage (Pday2=0.014, Pday3=0.012). Also, active caspase 3 was lower in the LC- treated platelets than the control group on the day 5 of storage (Pday5=0.004). Cytosolic cytochrome C was so significantly lower in LC-treated compared to the untreated platelets during storage time (Pday2=0.002, Pday3=0.001, Pday5=0.001). CONCLUSION: The results of this study indicate that the use of LC as an additive solution in platelets may be useful to reduce PSL by decreasing platelet apoptosis via mitochondrial pathway and increase platelet quality during storage.

Effect of beta-carotene supplementation and lactation on carotenoid metabolism and mitogenic T lymphocyte proliferation.

BACKGROUND: Information is lacking regarding the effects of beta-carotene supplementation, early lactation, or both on circulating carotenoid concentrations and T lymphocyte proliferation. OBJECTIVES: This study investigated the effects of short-term beta-carotene supplementation (30 mg/d for 28 d) during early lactation (days 4-32 postpartum) on circulating carotenoid concentrations and on the T lymphocyte proliferative response to phytohemagglutinin. DESIGN: Subjects aged 19-39 y were paired [lactating (4 d postpartum) and nonlactating (never pregnant, healthy women)] and randomly assigned to receive either beta-carotene or a placebo. During the study, subjects provided eight 24-h food records for analysis with the NUTRITIONIST IV and US Department of Agriculture carotenoid databases. Nonfasting blood samples were collected at baseline and at 28 d. Plasma analysis included quantification of alpha-carotene, beta-carotene, lutein, lycopene, retinol, and alpha-tocopherol, complete differential blood cell counts, and lymphocyte proliferative activity. RESULTS: beta-Carotene supplementation increased beta-carotene (P < 0.001) and alpha-carotene (P < 0.05) concentrations but did not affect lycopene concentrations significantly. Supplemented women showed significant decreases in plasma lutein (P < 0.03), as did lactating subjects (P < 0.02). Neither lactation nor beta-carotene supplementation affected the T lymphocyte proliferative response to phytohemagglutinin. CONCLUSIONS: Our results suggest that beta-carotene supplementation as well as some events related to parturition, initiation of lactation, or both alter circulating concentrations of lutein. beta-Carotene supplementation does not enhance T lymphocyte immune competence in healthy women.