β3-Adrenoceptor agonist AJ-9677 reduces body fat in obese beagles

Research progress of indole compounds with potential antidiabetic activity

New types of antidiabetic agents are continually needed with diabetes becoming the epidemic in the world. Indole alkaloids play an important role in natural products owing to their variable structures and versatile biological activities like anticonvulsant, anti-inflammatory, antidiabetic, antimicrobial, and anticancer activities, which are a promising source of novel antidiabetic drugs discovery. The synthesized indole derivatives possess similar properties to natural indole alkaloids. In the last two decades, more and more indole derivatives have been designed and synthesized for searching their bioactivities. This present review describes comprehensive structures of indole compounds with the potential antidiabetic activity including natural indole alkaloids and the synthetic indole derivatives based on the structure classification, summarizes their approaches isolated from natural sources or by synthetic methods, and discusses the antidiabetic effects and the mechanisms of action. Furthermore, this review also provides briefly synthetic procedures of some important indole derivatives.

A Systematic Review and Meta-Analysis of Serum Adiponectin Measurements in the Framework of Dog Obesity

Adiponectin is an abundant plasma protein that is closely related to obesity and obesity-related pathologies. The molecule can be found in three different isoforms, each with different biological activities. Studies on canine obesity have suggested that adiponectin concentrations are decreased in obesity; however, no canine meta-analyses have been performed that feature all the required data. The aim of this study is to perform a systematic review and meta-analysis of studies that pertain to total and high molecular weight (HMW) adiponectin in relation to canine obesity. From 20 different studies, a total of 366 dogs with obesity and 349 normal weight dogs are included in the meta-analysis. Client-owned dogs were most represented, accounting for 54.3% of the dogs used, while experimental dogs enrolled in the studies made up the remaining 45.7%. The concentrations of total adiponectin in dogs with obesity were significantly lower compared with normal weight dogs. Additionally, adiponectin concentrations were significantly higher in dogs after a successful weight loss protocol compared to the start of the protocol and were significantly lower in dogs after gaining weight. In conclusion, although caution should be taken due to the relatively low number of studies that exist and the high heterogeneity between them, this meta-analysis indicates that adiponectin is decreased in obese dogs.

Leptin as a potential therapeutic target for breast cancer prevention and treatment

IMPORTANCE OF THE FIELD

Obesity is considered to be an important risk factor for postmenopausal breast cancer. Elevated estrogen levels are thought to be a growth factor associated with this relationship. However, there is increasing evidence that factors produced directly in adipose tissue, adipokines, can also affect breast cancer development. Leptin is one of the adipokines that is measured in serum/plasma in increasing amounts as body weight/body fat increases.

AREAS COVERED IN THIS REVIEW

We highlight important aspects of leptin in relationship to mammary/breast tumor development. This includes findings from human, in vitro and animal studies. Information on leptin-related compounds which may have therapeutic use is presented. Additionally strategies to alter serum leptin levels by dietary and pharmacological interventions are discussed.

WHAT THE READER WILL GAIN

The reader will gain insights into the relationship of an adipose tissue protein and its potential role in breast cancer development as well as ways to intervene in leptin's actions.

TAKE HOME MESSAGE

Continued research will determine if interfering with the action of leptin has preventive or therapeutic applications in breast cancer.

Various emetogens increase the secretion of salivary amylase in rats: a potential model in emesis research

We investigated the effects of various emetic agents: cisplatin, apomorphine, lithium chloride (LiCl), rolipram, sibutramine, and the beta(3)-adrenoceptor (AR) agonist CL316243 on salivary amylase secretion in rats. We also determined the inhibitory effect of granisetron, a 5-HT(3)-receptor antagonist, on cisplatin-induced increased salivary amylase activity and the inhibitory effect of bilateral abdominal vagotomy on increases in salivary amylase activity induced by cisplatin and LiCl. Granisetron was administered 15 min before and 1 h after cisplatin administration. Cisplatin (10 - 15 mg/kg, i.v.) increased salivary amylase activity dose-dependently and induced an acute increase from 1.5 h post-treatment with 15 mg/kg. Apomorphine (1 - 3 mg/kg, s.c.), LiCl (120 mg/kg, i.p.), rolipram (3 - 10 mg/kg, p.o.), and sibutramine (10 mg/kg, p.o.) induced significant increases in salivary amylase secretion. On the other hand, CL316243 did not stimulate salivary amylase secretion. The increased amylase activity induced by cisplatin (15 mg/kg, i.v.) was inhibited significantly by granisetron (1 or 3 mg/kg x 2, i.v.) or tended to be inhibited by bilateral abdominal vagotomy, whereas an increase in amylase activity produced by LiCl was not inhibited by abdominal visceral nerve section. These results suggest that salivary amylase activity is useful as a marker for emesis in rats, a species that does not exhibit vomiting.

Role of uncoupling protein 1 in the anti-obesity effect of beta3-adrenergic agonist in the dog

We have reported that chronic treatment with beta3-adrenoceptor agonists reduces body fat content and induces the expression of mitochondrial thermogenic uncoupling protein 1 (UCP1) in adipose tissue in the dog. To evaluate the role of UCP1 in the anti-obesity effect of the agonists, we isolated adipocytes from subcutaneous fat pad of beagles before and after a 2-week treatment with AJ-9677, a specific beta3-adrenoceptor agonist, and examined their thermogenic activity in vitro. Histological and protein analysis revealed that adipose tissues before the treatment were composed of unilocular cells filled with a single large droplet, while the tissues after the treatment contained many smaller and some multilocular adipocytes expressing UCP1 and abundant mitochondrial proteins. Before the treatment, oxygen consumption rate was very low and did not change even when the cells were stimulated by AJ-9677. Two-week AJ-9677 treatment increased basal oxygen consumption rate by 7-fold, and produced a clear responsiveness to AJ-9677 stimulation. Thus, chronic treatment with AJ-9677 induced UCP1 in adipocytes, where oxygen consumption increased in response to AJ-9677 stimulation. It was suggested that UCP1-dependent energy expenditure in adipose tissue contributes to the anti-obesity effect of beta3-adrenoceptor agonist in dogs.