Involvement of kisspeptin in androgen-induced hypothalamic endoplasmic reticulum stress and its rescuing effect in PCOS rats.

Endoplasmic reticulum (ER) stress, with adaptive unfolded protein response (UPR), is a key link between obesity, insulin resistance and type 2 diabetes, all of which are often present in the most common endocrine-metabolic disorder in women of reproductive age, polycystic ovary syndrome (PCOS), which is characterized with hyperandrogenism. However, the link between excess androgen and endoplasmic reticulum (ER) stress/insulin resistance in patients with polycystic ovary syndrome (PCOS) is unknown. An unexpected role of kisspeptin was reported in the regulation of UPR pathways and its involvement in the androgen-induced ER stress in hypothalamic neuronal cells. To evaluate the relationship of kisspeptin and ER stress, we detected kisspeptin and other factors in blood plasm of PCOS patients, rat models and hypothalamic neuronal cells. We detected higher testosterone and lower kisspeptin levels in the plasma of PCOS than that in non-PCOS women. We established a PCOS rat model by dihydrotestosterone (DHT) chronic exposure, and observed significantly downregulated kisspeptin expression and activated UPR pathways in PCOS rat hypothalamus compared to that in controls. Inhibition or knockdown of kisspeptin completely mimicked the enhancing effect of DHT on UPR pathways in a hypothalamic neuronal cell line, GT1-7. Kp10, the most potent peptide of kisspeptin, effectively reversed or suppressed the activated UPR pathways induced by DHT or thapsigargin, an ER stress activator, in GT1-7 cells, as well as in the hypothalamus in PCOS rats. Similarly, kisspeptin attenuated thapsigargin-induced Ca2+ response and the DHT- induced insulin resistance in GT1-7 cells. Collectively, the present study has revealed an unexpected protective role of kisspeptin against ER stress and insulin resistance in the hypothalamus and has provided a new treatment strategy targeting hypothalamic ER stress and insulin resistance with kisspeptin as a potential therapeutic agent.

Identification of active compound combination contributing to anti-inflammatory activity of Xiao-Cheng-Qi Decoction via human intestinal bacterial metabolism.

Human intestinal bacteria play an important role in the metabolism of herbal medicines, leading to the variations in their pharmacological profile. The present study aimed to investigate the metabolism of Xiao-Cheng-Qi decoction (XCQD) by human intestinal bacteria and to discover active component combination (ACC) contributing to the anti-inflammatory activity of XCQD. The water extract of XCQD was anaerobically incubated with human intestinal bacteria suspensions for 48 h at 37 °C. A liquid chromatography-hybrid quadrupole time-of-flight mass spectrometry (LC-Q-TOF/MS) method was performed for identification of the metabolites. In addition, the anti-inflammatory effects of XCQD and biotransformed XCQD (XCQD-BT) were evaluated in vitro with cytokines in RAW264.7 cells induced by lipopolysaccharide (LPS). A total of 51 compounds were identified in XCQD and XCQD-BT. Among them, 20 metabolites were proven to be transformed by human intestinal bacteria. Significantly, a combination of 14 compounds was identified as ACC from XCQD-BT, which was as effective as XCQD in cell models of inflammation. In conclusion, this study provided an applicable method, based on intestinal bacterial metabolism, for identifying combinatory compounds responsible for a certain pharmacological activity of herbal medicines.

The activity of Hou-Po-Da-Huang-Tang is improved through intestinal bacterial metabolism and Hou-Po-Da-Huang-Tang selectively stimulate the growth of intestinal bacteria associated with health.

Hou-Po-Da-Huang Tang (HPDHT) was used for the treatment of intestinal tract diseases in China. However, the underlying mechanisms via the intestinal bacteria remain largely unclear. Therefore, the aim of this study was to evaluate the metabolism of HPDHT by the human intestinal bacteria and its modulating effect on the intestinal bacteria. As a result, a total of 34 compounds were identified in HPDHT and transformed HPDHT (T-HPDHT). Among them, 12 metabolites were proved to be transformed by human intestinal bacteria. In vitro assays showed that T-HPDHT exhibited more significant elevation of free radical scavenging activity and suppression on the production of nitric oxide (NO) and TNF-α when comparing to HPDHT. Additionally, in vivo experiment confirmed that HPDHT significantly increased activity of superoxide dismutase (SOD), attenuated the malondialdehyde (MDA) and TNF-α levels in the conventional rats compared with that of pseudo germ-free (PGF) rats. In addition, HPDHT could significantly enhance the mean counts of Bifidobacterium and Lactobacillus and inhibit the growth of Clostridium, and Enterobacteriaceae, relative to controls. Due to the transformation of HPDHT being dependent on the bacterial strain, the effect of HPDHT on the selective growth of Bifidobacterium bifidum 29521 and Lactobacillus plantarum 8014 was evaluated. The kinetic parameters of microbial growth and prebiotic activity scores indicated that HPDHT could selectively stimulate the growth of the strains Bifidobacterium bifidum 29521 and Lactobacillus plantarum 8014. Taken together, metabolism of HPDHT by intestinal bacteria is a critical step towards the emergence of their anti-oxidation, anti-inflammation and prebiotic activities. This study provided valuable information for further pharmacological research on HPDHT.

Metabolic profile and underlying improved bio-activity of Fructus aurantii immaturus by human intestinal bacteria.

Fructus aurantii immaturus (FAI) is the dried young fruit of Citrus aurantium L. or Citrus sinensis L. Osbeck. The purpose of this paper was to investigate the metabolic fate of FAI upon incubation with human intestinal bacteria, meanwhile to evaluate the antioxidant and anti-inflammatory activities of FAI and the transformed Fructus aurantii immaturus (TFAI). The water extract of FAI was anaerobically incubated with human intestinal bacterial suspensions for 48 h at 37 °C. Liquid chromatography-hybridised with quadrupole-time-of-flight mass spectrometry (LC-Q-TOF/MS) was applied to identify FAI metabolites. A total of 45 compounds were identified in FAI, eleven of which were metabolized by human intestinal bacteria. Nine major metabolites were identified as eriodictyol, naringenin, hesperetin, luteolin, apigenin, chryseriol, isosakuranetin, phloretin and diosmetin. The metabolic profile of FAI was elucidated on the basis of metabolite information. We found that the concentrations of acetic, propionic and butyric acids in FAI culture were all increased during fermentation relative to those of the control. Further bioactive evaluations showed that TFAI exhibited more potent antioxidant and anti-inflammatory abilities than FAI in vitro. Additionally, in vivo experiment confirmed that FAI significantly attenuated the blood endotoxin and TNF-α levels in the conventional rats compared to those of pseudo-germ-free (PGF) rats. This study revealed that metabolites may play a key role in the antioxidant and anti-inflammatory capacities of FAI.

In vitro biotransformation of red ginseng extract by human intestinal microflora: metabolites identification and metabolic profile elucidation using LC-Q-TOF/MS.

Ginseng is an important and widely used herbal medicine in Asia and has gained popularity in the western countries. Ginseng products are usually administered orally, after which their complicated components are brought into contact with intestinal microflora in the alimentary tract and metabolized. The metabolic investigation of ginseng in intestinal tract is necessary for elucidating its pharmacological activities. However, most of the reports about the metabolism of ginseng with intestinal microflora are focused on single ginseng saponin with the whole action of ginseng extract ignored. In the present paper, in vitro biotransformation of red ginseng extract by human intestinal microflora was conducted, and a rapid liquid chromatography with time-of-flight mass spectrometry (LC-Q-TOF/MS) method was used for rapid identification of the metabolites and metabolic profile of ginseng saponins. A total of 37 ginseng saponins in red ginseng extract were characterized, 17 of which were assessed to be metabolized by human intestinal microflora. Also, 30 metabolites, mostly deglycosylated, were detected and identified in the biotransformed red ginseng extract, including 4 original ingredients of red ginseng, 6 ginsenoside lactate esters, and 2 glycosylated metabolites. The metabolic profile of ginseng saponins biotransformed by human intestinal microflora was elucidated based on the metabolite information. The results indicated that deglycosylation was the major metabolic pathway of saponins in red ginseng. The esterification and glycosylation reaction also occurred during the biotransformation. Our study indicated that there was some differences in the biotransformation of single ginseng saponin and red ginseng extract. It must be noted that the ginsenoside lactate esters were firstly found in the metabolites of ginsenosides.