Amelioration of acute myocardial infarction by saponins from flower buds of Panax notoginseng via pro-angiogenesis and anti-apoptosis.

ETHNOPHARMACOLOGICAL RELEVANCE: The root of Panax notoginseng is traditionally used as an anti-hemorrhagic agent to promote blood circulation without causing "congealed" blood. Furthermore, the flower of P. notoginseng is a popular, traditional medicine taken daily for the preventing of hypertension and for reducing blood cholesterol profiles. Besides, the flower of P. notoginseng contains a higher level of saponins, particularly protopanaxadiol-type ginsenosides, as compared to the root. However, detailed pharmacological studies on this flower have rarely been conducted. MATERIAL AND METHODS: In this study, the saponins extracted from the flower of P. notoginseng (FS) were examined on the endothelial cell migration assay, chemically induced vascular insufficiency model in zebrafish larvae and myocardial infraction (MI) model in rats, for determination of their pro-angiogenic and therapeutic effects on MI treatment. RESULTS: Our results demonstrate that FS significantly promoted VEGF-induced migration of human umbilical vein endothelial cells (HUVECs) and partially restored defective intersegmental vessels (ISV) in a chemically induced vascular insufficiency model of zebrafish larvae. When compared to MI group, two weeks post-treatment of FS (25-50mg/kg/day) induced approximately 3-fold upregulation of VEGF mRNA expression and a concomitant increase in blood vessel density in the peri-infarct area of the heart. Moreover, TUNEL analysis indicates a reduction in the mean apoptotic nuclei per field in peri-infarct myocardium upon FS treatment. CONCLUSIONS: The pro-angiogenic effects of FS demonstrated in in vitro and in vivo experimental models suggest that the purified saponin preparation from flowers of P. notoginseng may potentially provide preventive and therapeutic agent for cardiovascular diseases.

Optimizing Electrical Stimulation for Promoting Satellite Cell Proliferation in Muscle Disuse Atrophy.

OBJECTIVE: The aim of this study was to investigate the optimal electrical stimulation (ES) protocol in attenuating disuse muscle atrophy by influencing satellite cell activity. DESIGN: This study used a pretest-posttest design. Six ES protocols of different duration (3 hrs day or 2 × 3 hrs day) and frequencies (2, 10, or 20 Hz) were applied on the soleus muscle in mice (n = 8 in each group) that were hindlimb-suspended for 14 days. Muscle mass, cross-sectional area and fiber-type composition, and peak tetanic force of the muscles were measured. Immunohistochemical staining was used to evaluate satellite cell content, activation, proliferation, and differentiation. Cell apoptosis was detected by TdT-mediated dUTP nick end labeling (TUNEL) assay. RESULTS: ES at 2 Hz for 2 × 3 hrs day achieved the best effect in attenuating the loss of muscle fiber cross-sectional area and force. This stimulation parameter led to a 1.2-fold increase in satellite cell proliferation and was effective in rescuing cells from apoptosis. Besides, satellite cells in the atrophic muscles required different stimulation protocols for different cellular activities such as activation, proliferation, and myogenic differentiation. CONCLUSIONS: This study showed that ES at 2 Hz for 2 × 3 hrs day is the optimal protocol for counteracting muscle disuse atrophy.

Pulsed electromagnetic fields (PEMF) promote early wound healing and myofibroblast proliferation in diabetic rats.

Reduced collagen deposition possibly leads to slow recovery of tensile strength in the healing process of diabetic cutaneous wounds. Myofibroblasts are transiently present during wound healing and play a key role in wound closure and collagen synthesis. Pulsed electromagnetic fields (PEMF) have been shown to enhance the tensile strength of diabetic wounds. In this study, we examined the effect of PEMF on wound closure and the presence of myofibroblasts in Sprague-Dawley rats after diabetic induction using streptozotocin. A full-thickness square-shaped dermal wound (2 cm × 2 cm) was excised aseptically on the shaved dorsum. The rats were randomly divided into PEMF-treated (5 mT, 25 Hz, 1 h daily) and control groups. The results indicated that there were no significant differences between the groups in blood glucose level and body weight. However, PEMF treatment significantly enhanced wound closure (days 10 and 14 post-wounding) and re-epithelialization (day 10 post-wounding), although these improvements were no longer observed at later stages of the wound healing process. Using immunohistochemistry against α-smooth muscle actin (α-SMA), we demonstrated that significantly more myofibroblasts were detected on days 7 and 10 post-wounding in the PEMF group when compared to the control group. We hypothesized that PEMF would increase the myofibroblast population, contributing to wound closure during diabetic wound healing.