Evaluation of the endocrine-disrupting effects of homosalate (HMS) and 2-ethylhexyl 4-dimethylaminobenzoate (OD-PABA) in rat pups during the prenatal, lactation, and early postnatal periods

Abstract

Homosalate (HMS) and 2-ethylhexyl 4-dimethylaminobenzoate (OD-PABA) are ultraviolet filters. We aimed to investigate the effects of dermal exposure to HMS and OD-PABA during the prenatal, lactation, and early infancy periods on pubertal development and thyroid function in male and female rats. The thyroid glands, uteri, testes, prostate glands, and seminal vesicles were excised and weighed, the reproductive organs were analyzed histologically, and the serum hormone levels were measured. In the prenatal period, the thyroxine (T4) levels increased in the female rats in the exposed groups ( p < 0.05); the thyroid weights, reproductive organ weights, and gonadal hormone levels were not altered. In males, the testosterone levels decreased ( p < 0.05), but the thyroid weights, T4 levels, prostate, and testis weights were not changed. In the lactation period, the weights of the thyroid glands increased in the exposed female groups ( p < 0.05), but the T4, gonadal hormone levels, and reproductive organ weights were not changed. In the males, the thyroid gland weights, T4 levels, reproductive organ weights, and gonadal hormone levels were not changed. During infancy, the thyroid gland weights increased in the female rats in the exposed groups ( p < 0.05), but the T4 levels, gonadal hormone levels, and reproductive organ weights were not affected. In the male rats in the exposed groups, the T4 levels were increased ( p < 0.05), but the thyroid and reproductive organ weights, gonadal hormone levels were not affected. Organ histopathology was not affected in all groups. HMS and OD-PABA do not have endocrine disruptor effects on thyroid function and the pubertal development of female and male rats.

Risk Assessment of Ethylhexyl Dimethyl PABA in Cosmetics

“…According to a report by Erol et al . (6), dermal exposure to OD-PABA did not affect pubertal development or thyroid function in female or male rats. As such, OD-PABA was not classified as an endocrine disrupting chemical.…”

Sunscreen and Suntan Preparations

“…Both octisalate and homosalate are water insoluble that leads to their high substantivity, which is the ability to retain its effectiveness after exposure to water and perspiration [72]. HMS does not have endocrine disruptor effects on thyroid function and the pubertal development of female and male rats [73]. Another study says HMS is a potential endocrine disruptor and studies in cells suggest it may impact hormones.…”

A Pharmacological Review of Sunscreen and Suntan Preparations

“…Both octisalate and homosalate are water insoluble that leads to their high substantivity, which is the ability to retain its effectiveness after exposure to water and perspiration [110]. HMS does not have endocrine disruptor effects on thyroid function and the pubertal development of female and male rats [111]. Another study says HMS is a potential endocrine disruptor and studies in cells suggest it may impact hormones.…”

“…In 2018, the EWG reported that a large increase in these inorganic ilters with ~41% of sunscreens in the United States designated as mineral only. This igure has more than doubled (from 17%) since 2007 [111] [63]. Only two sunscreen active ingredients approved in the US, avobenzone (butylmethoxydibenzoylmethane) and zinc When corals absorb these chemicals, they have a similar reaction as they would if surrounding water temperatures were to get too warm.…”