Acupuncture attenuates hyperglycaemia and improves ovarian function in female rats subjected to continuous light exposure

Effects of melatonin and metformin on the ovaries of rats with polycystic ovary syndrome

OBJECTIVE

To study the combined and isolated effects of melatonin and metformin in the ovarian tissue of rats with PCOS.

DESIGN

Experimental study using a rat model of PCOS induced by continuous light exposure.

INTERVENTION(S)

Forty adult female rats were divided into 5 groups: physiological estrus phase (Sham); permanente estrus with PCOS induced by continuous lighting exposure for 60 consecutive days (control); with PCOS treated with melatonin; with PCOS treated with metformin; with PCOS treated with melatonin + metformin. After 60 days of treatments, all rats were killed, and ovaries were collected and processed for paraffin-embedding. Formalin-fixed paraffin-embedded sections were stained with hematoxylin and eosin or subjected to immunohistochemistry for proliferation (Ki-67) and apoptosis (cleaved caspase 3) detection markers.

SETTING

Federal University of São Paulo, Brazil.

ANIMALS

Forty adult female Wistar rats (Rattus norvegicus albinus).

MAIN OUTCOME MEASURE(S)

Number of corpus luteum and ovarian cysts, number of ovarian follicles (primary and antral follicles), number of interstitial cells, percentage of ovarian follicles (primary and antral follicles), and of interstitial cells immunostained to cleaved caspase-3 and Ki-67.

RESULTS

Absence of corpus luteum, a higher number of cysts, and increased nuclear volume and area of interstitial cells, along with a decrease in primary and antral follicle numbers, were noticed in the control group compared with the Sham group. Melatonin and metformin treatments attenuated these effects, although the combined treatment did not mitigate the increased number of cysts and ovaries induced by PCOS. An increase in theca interna cell apoptosis was observed in the control group, whereas melatonina and metformin treatments reduced it significantly. A higher percentage of caspase-3-immunostained granulosa cells was noted in the Sham and all treated groups compared with the control group; no aditive effects on ovarian cell apoptosis were observed in the combined treatment. The percentage of Ki-67- immunostained granulosa cells was significantly higher in the control group compared with the Sham group. However, the combined treatment, not melatonin and metformin alone, mitigated this effect. A higher percentage of Ki-67-immunostained interstitial cells was observed in all treated groups compared with the Sham and control groups, whereas no additive effects in that immunoreactivity were observed in the combined treatment.

CONCLUSIONS

Melatonin and metformin may improve ovarian function in rats with PCOS. The combined melatonin and metformin treatment is more effective in attenuating excessive granulosa cell proliferation, but it is not more effective in improving ovarian function than these drugs applied alone in rats with PCOS.

The role of light pollution in mammalian metabolic homeostasis and its potential interventions: A critical review

Irregular or unnatural artificial light causes severe environmental stress on the survival and health of organisms, which is rapidly becoming a widespread new type of environmental pollution. A series of disruptive behaviors to body homeostasis brought about by light pollution, including metabolic abnormalities, are likely to be the result of circadian rhythm disturbances. Recently, the proposed role of light pollution in metabolic dysregulation has accelerated it into an emerging field. Hence, the regulatory role of light pollution in mammalian metabolic homeostasis is reviewed in this contribution. Light at night is the most widely affected type of light pollution, which disrupts metabolic homeostasis largely due to its disruption of daily food intake patterns, alterations of hormone levels such as melatonin and glucocorticoids, and changes in the rhythm of inflammatory factor production. Besides, light pollution impairs mammalian metabolic processes in an intensity-, photoperiod-, and wavelength-dependent manner, and is also affected by species, gender, and diets. Nevertheless, metabolic disorders triggered by light pollution are not irreversible to some extent. Potential interventions such as melatonin supplementation, recovery to the LD cycle, time-restricted feeding, voluntary exercise, wearing blue light-shied goggles, and bright morning light therapy open a bright avenue to prevent light pollution. This work will help strengthen the relationship between light information and metabolic homeostasis and provide new insights for the better prevention of metabolic disorders and light pollution.

The Effect of Acupuncture on Glucose Metabolism and Lipid Profiles in Patients with PCOS: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Objective

To evaluate the effectiveness of acupuncture on glucose metabolism and lipid profiles in patients with polycystic ovary syndrome (PCOS).

Methods

Databases, including the China National Knowledge Infrastructure (CNKI), the China Science and Technology Journal Database (VIP), Wanfang, PubMed, and the Cochrane Library were searched for the relevant literature, with the retrieval deadline being February 2020. Two reviewers independently screened, selected, and extracted the data and validated the results. The methodological quality of the included studies was evaluated with the risk of bias tool, and the meta-analysis was performed using the RevMan 5.3.5 software.

Results

A total of 737 patients with PCOS from 10 randomized controlled trials were included in the meta-analysis. A pooled analysis showed significant decreases in body mass index (mean difference (MD) = –1.47, 95% CI –2.35 to –0.58, P < 0.001) and waist-to-hip ratio (MD = –0.04, 95% CI [–0.06, –0.02], P < 0.001) in the acupuncture group along with significant improvements in fasting plasma glucose (MD = –0.38, 95% CI [–0.70, –0.07], P = 0.02), homeostasis model assessment of insulin resistance (MD = –0.22, 95% CI [–0.41, –0.02], P = 0.03), and triglycerides (MD = –0.26, 95% CI [–0.48, –0.04], P = 0.02). No significant differences were observed in the Ferriman–Gallwey score, 2 h fasting plasma glucose, fasting insulin, 2 h fasting insulin, serum total cholesterol, low-density lipoprotein cholesterol, or high-density lipoprotein cholesterol.

Conclusion

Acupuncture is relatively effective and safe in improving glucose metabolism and insulin sensitivity in patients with PCOS. The included studies were generally of not bad methodological quality, but further large-scale, long-term randomized controlled trials with rigorous methodological standards are still warranted.

Continuous Light-Induced PCOS-Like Changes in Reproduction, Metabolism, and Gut Microbiota in Sprague-Dawley Rats

The interplay between genetic and environmental risk factors contributes to the pathogenesis of metabolic disease. Polycystic ovary syndrome (PCOS) is the most common endocrine and metabolic disorder in women of reproductive age. Circadian rhythm disruption is an important risk factor for PCOS. In this study, we evaluated the effect of circadian disorder on reproduction as well as metabolism, and determined its influence on gut microbiota in a rat model. Female Sprague Dawley (SD) rats were kept under continuous light exposure (12-h:12-h light/light cycle, L/L group) or a control cycle (12-h:12-h light/dark cycle, L/D group) for four consecutive weeks. Manifestations in endocrine hormones and metabolism were detected and gut microbiota were analyzed with the 16s rRNA gene sequencing technique. To our knowledge, this is the first study to report PCOS-like reproductive manifestation, such as anti-Müllerian hormone (AMH) elevation induced by continuous light exposure. Moreover, continuous light resulted in abnormal glucose metabolism and gut microbial community variations, including enrichment of the microbial genus of Parasutterella and reduced abundance of genus Corynebacterium, genus Odoribacter, and genus Acinetobacter. Increased Parasutterella abundance was positively correlated with serum testosterone level. A PICRUSt analysis revealed that reproductive and metabolic-related genes were enriched in rats of L/D group. In conclusion, the present study demonstrates that continuous light exposure, an important environmental factor, contributes to the occurrence and developmental progress of PCOS and changes in microbial component and structure. Continuous light exposure is one of vital causes of PCOS, which is closely related to microbial structure and functions.

Effect of transcutaneous electrical acupoint stimulation on protecting against radiotherapy- induced ovarian damage in mice

Background

Premature ovarian insufficiency (POI) is characterized by early loss of ovarian function that affects women before the age of 40. We aim to explore the protective effects of transcutaneous electrical acupoint stimulation (TEAS) against irradiation-induced ovarian damage in mice.

Methods

C57BL6 mice were randomly divided into control and irradiation (IR) groups. Then, control group was divided into two treatment subgroups: mock TEAS treatment (control-) and TEAS treatment (control+). IR group was divided into four subgroups according to the time of treatment started: mock TEAS treatment initiated at 2 days after irradiation (IR 2D-), TEAS treatment initiated at 2 days after irradiation (IR 2D+), mock TEAS treatment initiated at 1 week after irradiation (IR 1 W-), and TEAS treatment initiated at 1 week after irradiation (IR 1 W+). The radiation model mice were exposed to single whole body X-ray irradiation (4 Gy), and the control mice received 0 Gy. TEAS stimulation (2 Hz, 1 mA, 30 min/day) was given once a day for six consecutive days per week for 2 weeks. Estrous cycle, ovarian weight, serum AMH level and follicle counts were evaluated. Then, proliferation markers, apoptotic markers and oxidative stress markers were examined.

Results

Compared with the control group, the estrous cycle was disordered, and the ovarian weight, serum AMH, and primordial, primary and secondary follicles counts decreased (all P < 0.01) in the IR 2D- and IR 1 W- groups. In the irradiation with early TEAS treatment group (IR 2D+), the estrous cycle improved, the AMH level and primordial follicular significantly increased compared to the irradiation with mock group (IR 2D-). However, there were no significant differences in the estrous cycle, AMH level and follicle counts between IR 1 W- and IR 1 W+ groups. Moreover, IR 2D+ mice reduced the expression of Bax protein and increased the levels of Bcl-2 and PCNA compared to the IR 2D- group. Furthermore, the early TEAS treated mice showed significantly lower levels of oxidative stress and number of TUNEL (+) granulosa cells than that in the IR 2D- group.

Conclusion

This study is first to evaluate TEAS as a potential therapy to attenuate irradiation-induced ovarian failure through inhibiting primordial follicles loss, increasing serum AMH secretion, inducing antioxidant, and anti-apoptotic systems.