ABSTRACT
Objective::To investigate the effects of Ginseng Radix et Rhizoma, Notoginseng Radix et Rhizoma and Chuanxiong Rhizoma extracts (GNC) on the protein expression of α-smooth muscle actin (α-SMA) and runt-related transcription factor2(Runx2) after high glucose-induced vascular aging in mice, and elucidate the protective mechanism of GNC in delaying vascular aging. Method::Totally 130 male C57BL/6 mice were randomly divided into normal control group and high glucose group. The mice in high glucose group were intraperitoneally injected with streptozotocin (STZ). After successful modeling, the mice received high-fat diet for 7 months, and then they were randomly divided into model group, GNC low-dose and high-dose groups (0.819, 1.638 g·kg-1), and metformin group (150 mg·kg-1). The drug was given by intragastric administration once a day for 9 weeks. Seven days before tissues collection, a new batch of 4-week-old male C57BL/6 mice were purchased and fed normally for 1 week as a youth group. The general condition of the mice was observed. Morphological changes of the common carotid artery in mice were determined by hematoxylin-eosin (HE) staining and transmission electron microscopy (TEM). Masson trichromatic staining was used to observe the fibrosis of common carotid artery in mice. The expression levels of matrix metalloproteinases-2 (MMP-2), cyclin-dependent kinase inhibitor 2A (p16), cyclic-dependent kinase inhibitor 1A (p21), α-SMA and Runx2 in the common carotid arteries of mice were detected by immunohistochemistry. Result::The results of HE, TEM and Masson showed that there was almost no change in the inimal and adventitial thickness, ultrastructure and relative contents of collagen and elastic fibers in the common carotid arteries of mice between the youth group and normal control group. As compared with the normal control group, the intima of the common carotid artery in the model group was not smooth, the endothelial cells were almost completely detached, the cytoplasm was lysed, the inner elastic membrane became thinner, fractured, or even detached, and the proliferating collagen fibers sneaked into the tunica media. The hyperplasia of tunica media and tunica adventitia was obvious and disordered (P<0.01). The vascular smooth muscle cells showed deformations, protuberances, bifurcations, and even fragmentation, and focal necrosis was observed. There were significantly more vacuoles, lysosomes, and obvious autophagy vesicles. The relative content of collagen and elastic fibers in vascular walls increased significantly (P<0.01). Compared with the model group, the above situation was relieved in each administration group (P<0.01). The results of immunohistochemistry showed that high glucose induced high expression of MMP-2, p16, p21 and Runx2 in the common carotid arteries(P<0.01), low expression of α-SMA(P<0.01), and the protein expression tended to be normal after drug intervention(P<0.05, P<0.01). Conclusion::High glucose can induce the aging of common carotid artery in mice and change the expression of α-SMA and Runx2 proteins. The Ginseng Radix et Rhizoma, Notoginseng Radix et Rhizoma and Chuanxiong Rhizoma extracts can delay vascular aging by regulating the protein expression of α-SMA and Runx2.
ABSTRACT
Objective::To investigate the protective effect of Ginseng Radix et Rhizoma, Notoginseng Radix et Rhizoma and Chuanxiong Rhizoma extracts on vascular calcification induced by high glucose in mice by observing the expression of osteopontin (OPN) and smooth muscle 22α (SM22α) as well as vascular calcium deposition in the common carotid artery and thoracic aorta of mice. Method::Totally 130 male C57BL/6 mice were randomly divided into normal control group and high glucose group. The mice in high glucose group were intraperitoneally injected with streptozotocin(STZ), and fed on a high-fat diet for 7 months. Then, the mice were randomly divided into model group, low-dose and high-dose Ginseng Radix et Rhizoma, Notoginseng Radix et Rhizoma and Chuanxiong Rhizoma extracts groups (0.819, 1.638 g·kg-1), and metformin group (150 mg·kg-1). Each group was intragastrically administered once a day for 9 weeks. The changes in blood glucose were measured. Seven days before the end of the administration, a group of 4-week old male C57BL/6 mice were purchased and fed normally for one week as a youth group. At the end of the administration, the common carotid artery and thoracic aorta tissues of the mice were collected. Von Kossa staining was used to determine the degree of calcium deposition in the common carotid artery and thoracic aorta. The expression levels of OPN and SM22α protein in the common carotid artery and thoracic aorta were detected by immunohistochemistry. The expression of OPN and SM22α protein in the common carotid artery of mice was determined by Western blot. Result::As compared with the young group, the blood glucose of the normal control group was slightly increased without statistical difference, the common carotid artery and thoracic aorta were uniformly stained, and no black granular precipitate was observed. As compared with the normal control group, the blood glucose of the model group was increased (P<0.01), with a large amount of brown-black particles deposited in the intimal elastic fibers, showing obvious calcium salt deposition. As compared with the model group, blood glucose was significantly decreased in each administration group (P<0.05, P<0.01), and the degree of vascular calcium salt deposition was significantly reduced. There were no significant changes in expression levels of OPN protein and SM22α protein in the common carotid artery and thoracic aorta between the youth group and normal control group. As compared with the normal control group, the expression of intimal OPN protein in the common carotid artery and thoracic aorta of the model group was positive, SM22α protein expression was weakly positive, and the gray value of OPN protein expression in the common carotid artery was significantly increased (P<0.01), while the gray value of SM22α protein was decreased significantly (P<0.01). As compared with the model group, the expression levels of intimal OPN protein and SM22α protein in the common carotid artery and thoracic aorta of each administration group were significantly improved, and the gray value of OPN protein expression in the common carotid artery was reduced (P<0.05, P<0.01), while SM22α protein expression was significantly increased (P<0.01). Conclusion::High glucose can induce calcification of common carotid artery and thoracic aorta in mice and accelerate vascular aging. This formation process may be related to the expression of OPN and SM22α. Ginseng Radix et Rhizoma, Notoginseng Radix et Rhizoma and Chuanxiong Rhizoma extracts can reduce vascular calcification and delay vascular aging by regulating the expression of OPN and SM22α.