[Quality evaluation of Salvianolate for Injection by quantitative analysis of multi-components with single-marker].

Developing high-quality standard is useful for promoting the quality of traditional Chinese medicine injections, which could be evaluated by establishing the comprehensive quality control method. A method for simultaneous determination of salvianolic acid B, rosmarinic acid and lithospermic acid in Salvianolate for Injection was developed for quantitative analysis of multi-components with single-marker(QAMS). ZORBAX Eclipse Plus C_(18) chromatographic column was adopted, with 0.1% phosphoric acid and acetonitrile as mobile phase. The flow rate was set at 1 mL·min~(-1). The column temperature was set at 20 ℃, and the detection wavelength was 286 nm. Salvianolic acid B was used as internal reference. The relative correction factors of rosmarinic acid and lithospermic acid(f_(s/i)) were 0.58 and 0.94, respectively. About 85% of substances in Salvianolate for Injection were quantified by the established QAMS method. The analysis of different batches of intermediates and preparations during four years showed that the contents of salvianolic acid B were 77.1%-81.5% in intermediates and 70.5%-80.1% in preparations; The total content of rosmarinic acid and lithospermic acid was about 6%. The ratio of rosmarinic acid to lithospermic acid was(3.4∶1-10∶1) and(2.5∶1-5∶1), respectively, which showed that the ratio was more stable in preparation. The QAMS method established is feasible for comprehensive quality control of multiple components of in Salvianolate for Injection.

Docosahexaenoic acid inhibits mechanical allodynia and thermal hyperalgesia in diabetic rats by decreasing the excitability of DRG neurons.

Diabetes mellitus is a common metabolic disease in human beings with characteristic symptoms of hyperglycemia, chronic inflammation and insulin resistance. One of the most common complications of early-onset diabetes mellitus is peripheral diabetic neuropathy, which is manifested either by loss of nociception or by allodynia and hyperalgesia. Dietary fatty acids, especially polyunsaturated fatty acids, have been shown the potential of anti-inflammation and modulating neuron excitability. The present study investigated the effects of docosahexaenoic acid (DHA) on the excitability of dorsal root ganglion (DRG) neurons in streptozotocin (STZ)-induced diabetes rats. The effects of DHA on the allodynia and hyperalgesia of diabetic rats were also evaluated. Dietary DHA supplementation effectively attenuated both allodynia and hyperalgesia induced by STZ injection. DHA supplementation decreased the excitability of DRG neurons by decreasing the sodium currents and increasing potassium currents, which may contribute to the effect of alleviating allodynia and hyperalgesia in diabetic rats. The results suggested that DHA might be useful as an adjuvant therapy for the prevention and treatment of painful diabetic neuropathy.

Dietary fish oil inhibits mechanical allodynia and thermal hyperalgesia in diabetic rats by blocking nuclear factor-κB-mediated inflammatory pathways.

One of the most common complications of early-onset diabetes mellitus is peripheral diabetic neuropathy, which is manifested either by loss of nociception or by allodynia and hyperalgesia. Diabetes mellitus is a common metabolic disease in human beings with characteristic symptoms of hyperglycemia, chronic inflammation and insulin resistance. Dietary fatty acids, especially polyunsaturated fatty acids, have been shown anti-inflammatory role in various experimental conditions. The present study investigated the effects of fish oil supplementation on the inflammation in the dorsal root ganglion (DRG) of streptozotocin (STZ)-induced diabetes rats. The effects of diabetes and fish oil treatment on the allodynia and hyperalgesia were also evaluated. Dietary fish oil effectively attenuated both allodynia and hyperalgesia induce by STZ injection. Along with the behavioral findings, DRG from fish oil-treated diabetic rats displayed a decrease in inflammatory cytokines and the expression of nuclear factor-κB (NF-κB) compared with untreated diabetic rats. Fish oil supplementation also increased the phosphorylation of AKT in DRG of diabetic rats. These results suggested that dietary fish oil-inhibited allodynia and hyperalgesia in diabetic rats may stem from its anti-inflammatory potential by regulating NF-κB and AKT. Fish oil might be useful as an adjuvant therapy for the prevention and treatment of diabetic complications.

Fish oil modulates glycogen synthase kinase-3 signaling pathway in diabetes-induced hippocampal neurons apoptosis.

Previous research has demonstrated that diabetes induces learning and memory deficits. However, the mechanism of memory impairment induced by diabetes is poorly understood. Dietary fatty acids, especially polyunsaturated fatty acids, have been shown to enhance learning and memory and prevent memory deficits in various experimental conditions. The present study investigated the effects of fish oil supplementation on the neuron apoptosis in the hippocampus of streptozotocin (STZ)-induced diabetes rats, further explored the effect of fish oil on the phosphorylation of protein kinase B and glycogen synthase kinase-3 beta. The effects of diabetes and fish oil treatment on the spatial learning and memory were also evaluated using the Morris Water Maze. STZ-induced diabetes impaired spatial learning and memory of rats, which was associated with the apoptosis of hippocampal neurons and oxidative stress. Fish oil administration ameliorated cognitive deficit, reduced oxidative stress, increased AKT phosphorylation, decreased GSK-3ß phosphorylation, and decreased pro-apoptotic molecules expression, which protected the hippocampal neurons from apoptosis in diabetic rats. These results suggested a potential role for fish oil as an adjuvant therapy for the prevention and treatment of diabetic complications.

A high ratio of dietary n-3/n-6 polyunsaturated fatty acids improves obesity-linked inflammation and insulin resistance through suppressing activation of TLR4 in SD rats.

Dietary ratios of n-3/n-6 polyunsaturated fatty acids (PUFAs) have been implicated in controlling markers of metabolic disorders, including obesity, insulin resistance (IR), inflammation, and lipid profiles, which are also presumed to be partly related to type 2 diabetes mellitus (T2DM). However, molecular mechanisms of the different PUFAs related to metabolic disorders have not been systematically addressed. The present study aimed to investigate the impact of dietary n-3/n-6 PUFA ratios on obesity and IR and, further, to determine the underlying mechanisms. For 16 weeks, 32 SD male rats, randomly divided into four groups (n = 8 per group), received one of the following diets: normal chow, high saturated fatty acid (SFA), high n-3/n-6 PUFA ratio (1∶1, PUFA¹:¹), or low n-3/n-6 PUFA ratio (1∶4, PUFA¹:4). Following the experimental diet period, metabolic parameters related to obesity and IR were measured. Compared to SFA diet-fed rats, PUFA¹:¹ diet-fed rats exhibited decreased body and visceral fat weight, lowered blood lipids, and improved glucose tolerance and insulin sensitivity. Interestingly, these changes were accompanied with decreased expression levels of circulating pro-inflammatory cytokines, including tumor necrosis factor α, interleukin-6, and C-reactive protein. Moreover, the TLR4 protein and mRNA levels were markedly down-regulated by PUFA¹:¹ compared with SFA; however, PUFA¹:4 diet-fed rats failed to exhibit these changes. Cumulatively, our data highlight a role for a PUFA¹:¹ diet in the prevention of obesity and related metabolic disorders by suppressing the activation of TLR4, a critical modulator of pro-inflammatory cytokines.

Effects of dietary fish oil on learning function and apoptosis of hippocampal pyramidal neurons in streptozotocin-diabetic rats.

Previous research has demonstrated that diabetes induces learning and memory deficits. However, the mechanism of memory impairment induced by diabetes is poorly understood. Dietary fatty acids, especially polyunsaturated fatty acids, have been shown to enhance learning and memory and prevent memory deficits in various experimental conditions. The present study investigated the effects of fish oil supplementation on the neuron apoptosis in the hippocampus of streptozotocin (STZ)-induced diabetes rats. The effects of diabetes and fish oil treatment on the spatial learning and memory were also evaluated using the Morris Water Maze. Diabetes impaired spatial learning and memory of rats. Diabetes increased the expression of Bax and caspase-3, which led the apoptosis of the CA1 pyramidal neurons, and further contributed to the deficits in learning and memory processing. Fish oil dietary supplementation in diabetic rats conducts neuron-protective function through an anti-apoptotic pathway and significantly improves the ability of learning and memory. These results partially explain the mechanism of the effect of diabetes and fish oil treatment on learning and memory, supporting a potential role for fish oil as an adjuvant therapy for the prevention and treatment of diabetic complications.