Inhibitory effects of astragaloside IV on diabetic peripheral neuropathy in rats

Abstract

Astragaloside IV (AGS-IV), a new glycoside of cycloartane-type triterpene isolated from the root of Astragalus membranaceus (Fisch.) Bunge, has been used experimentally for its potent immune-stimulating, anti-inflammatory, and antioxidative actions. A recent study has shown AGS-IV to be an aldose-reductase inhibitor and a free-radical scavenger. This study examined the effects of AGS-IV on motor nerve conduction velocity (MNCV), tailflick threshold temperature, biochemical indexes, and the histology of the sural nerve after diabetes was induced in rats with 75 mg/kg streptozotocin (STZ). AGS-IV (3, 6, 12 mg/kg, twice a day) was administered by oral gavage for 12 weeks after diabetes was induced. Compared with control (nondiabetic) rats, obvious changes in physiological behaviors and a significant reduction in sciatic MNCV in diabetic rats were observed after 12 weeks of STZ administration. Morphological analysis showed that AGS-IV suppressed a decrease in myelinated fiber area, an increase in myelinated fiber density, and an increase in segmental demyelination in diabetic rats. The protective mechanism of AGS-IV involved a decrease in declining blood glucose concentration and HbA1C levels, and an increase in plasma insulin levels. AGS-IV increased the activity of glutathione peroxidase in nerves, depressed the activation of aldose reductase in erythrocytes, and decreased the accumulation of advanced glycation end products in both nerves and erythrocytes. Moreover, AGS-IV elevated Na+,K+-ATPase activity in both the nerves and erythrocytes of diabetic rats. These results indicate that AGS-IV exerts protective effects against the progression of peripheral neuropathy in STZ-induced diabetes in rats through several interrelated mechanisms.

Astragali Radix elicits anti-inflammation via activation of MKP-1, concomitant with attenuation of p38 and Erk

“…Traditionally, AR was used to treat weakness, wounds, anemia, fever, multiple allergies, chronic fatigue, loss of appetite, uterine bleeding, and uterine prolapse . Medicinally, AR is used as a diuretic and tonic herb in many Asian countries, to enhance physical strength and endurance, strengthen the immune system, lower blood pressure, and promote excretion and circulation (Zhao et al, 1990;Sheng et al, 2001;Yu et al, 2006). Clinically, AR is used to treat chronic phlegmatic disorders and general gastrointestinal disturbances including stomach ulcers and diarrhea (Yang, 1993;Hei et al, 2005).…”

Cigarette smoke enhances -defensin 2 expression in rat airways via nuclear factor- B activation

“…AS-IV, an active monomer of Astragalus membranaceus, has been suggested to have a potentially protective role in various disorders [13][14][15][16][17], with immunoregulatory and anti-inflammatory functions [36,37]. Noticeablely, DU et al [17] have reported that AS-IV suppressed the progression of airway inflammation, airway hyperresponsiveness and airway remodelling (goblet cell hyperplasiain and subepithelial fibrosis) in a ovalbumin-induced murine model of chronic asthma, indicating the protective effects of AS-IV on airway inflammatory injury.…”

“…In addition, astragaloside IV (AS-IV) is a new glycoside of cycloartane-type triterpene isolated from the root of Astragalus membranaceus Bunge, a Chinese medicinal herb, which has been reported to have protective effects on various animal and in vitro disease models [13][14][15][16][17]. As the effect of AS-IV on CS-induced airway inflammation is not clear, the investigation of the effect of AS-IV on this process was also performed in this study.…”

Astragaloside IV facilitates glucose transport in C2C12 myotubes through the IRS1/AKT pathway and suppresses the palmitate-induced activation of the IKK/IκBα pathway

“…Bunge, is one of the most widely used plant-derived drugs in traditional Chinese medicine for diabetes therapy (10). The saponin astragaloside IV has been reported to exert various pharmacological effects; astragaloside IV inhibited hepatic glycogen phosphorylase (GP) and glucose-6-phosphatase (G6P) activities thereby decreasing serum glucose levels in diabetic mice (12), attenuated lipolysis and reduced insulin resistance induced by tumor necrosis factor α (TNFα) in 3T3-L1 adipocytes (13), improved the symptoms of metabolic syndrome in fructose-fed rats (14), prevented human cardio vascular pathological changes and protected against cardiovascular injury in rats (15)(16)(17)(18) improved renal function (19)(20)(21)(22), reduced the progression of peripheral neuropathy (23), and attenuated inflammatory responses by suppressing the nuclear factor-κB (NF-κB) pathway (24)(25)(26). Xu et al (27) reported that other astragalosides, astragaloside II and isoastragaloside I, elevated serum levels of adiponectin and alleviated insulin resistance and glucose intolerance in obese mice.…”