Consumption of the nonnutritive sweetener acesulfame potassium increases central precocious puberty risk

The prevalence of precocious puberty and the consumption of nonnutritive sweeteners (NNS) is rapidly growing worldwide. However, the effects of NNSs on precocious puberty remain unclear. We examined the impact of acesulfame potassium (AceK), one of the most widely used NNS, on central precocious puberty (CPP) development using ex vivo and in vitro studies. 884 girls aged 6-12 were enrolled with complete AceK consumption data and CPP outcome assessment in the Taiwan Pubertal Longitudinal Study from 2018 to 2022. After adjustment for confounders, compared with no AceK consumption, AceK consumption at more than the median dose was associated with higher CPP risk in girls (odds ratio = 1.88, 95% confidence interval = 1.16-3.06; p for trend = 0.003). In rats, AceK consumption from in-utero to post-weaning stages accelerated puberty onset, accompanied by increased brain gonadotropin-releasing hormone (GnRH) expression. Intracerebroventricular AceK injection also induced early puberty onset in rats. In N44 hypothalamic neuron cells, AceK treatment increased reactive oxygen species production, which led to protein kinase A (PKA) activation and increased GnRH expression. These findings suggest that prepubertal girls should consume soft drinks or food products containing AceK more cautiously.

Tiao Geng decoction for treating menopausal syndrome exhibits anti-aging effects likely via suppressing ASK1/MKK7/JNK mediated apoptosis in ovariectomized rats

ETHNOPHARMACOLOGICAL RELEVANCE

TG-decoction (Tiao Geng decoction) is the extract of a Chinese herb mixture that has been used for treating menopausal symptoms for over 30 years. We have previously reported anti-aging and anti-oxidative effects of the TG-decoction on hypothalamic neurons in ovariectomized (OVX) rats.

AIM OF THE STUDY

The present study further investigates the effects of TG-decoction on the prevention of aging-related ultrastructural changes in menopausal hypothalamic neurons and the likely molecular mechanism.

MATERIALS AND METHODS

A total of 120 four-month-old female SPF Sprague Dawley rats were divided into six groups. Five groups were ovariectomized (OVX) and one group served as a sham control. Three OVX groups received TG-decoction at three different doses. The remaining two OVX groups served as positive and negative controls by receiving estradiol valerate and saline solution. The sham group received saline. After one month, aging-related ultrastructural alterations in hypothalamic neurons were evaluated using transmission electron microscopy. Nissl staining was used to assess the pathomorphological changes of the hypothalamic neurons. Cell apoptosis was evaluated by TUNEL. Expression of Bcl-2 family genes was studied using qRT-PCR. Expression of the apoptosis-related proteins ASK1, MKK7, JNK, c-Jun, Bax, Casp3 and Bcl-2 was studied using western blotting.

RESULTS

Ovariectomy of female rats led to visible damage and aging-like alterations in the mitochondria and endoplasmic reticulum as well as large deposits of lipofuscin in hypothalamic tissue. TG-decoction treatment prevented this visible damage and lipofuscin deposition, increased the number of nerve cells and normally-shaped Nissl bodies, and reduced the number of TUNEL-positive cells. Expression of Bcl-2 gene was increased, while Bax gene reduced. Expression of the proteins ASK1, MKK7, JNK, c-Jun, Bax and Casp3 was reduced, while that of Bcl-2 was increased.

CONCLUSION

TG-decoction reduces aging-related ultrastructural changes in hypothalamic neurons, likely by suppressing ASK1/MKK7/JNK-mediated apoptosis in neuronal mitochondria or nuclei.