Lethal dose and reproductive parameters of p-nonylphenol in rats

Leaves, seeds and exocarp of Ginkgo biloba L. (Ginkgoaceae): A Comprehensive Review of Traditional Uses, phytochemistry, pharmacology, resource utilization and toxicity

ETHNOPHARMACOLOGICAL RELEVANCE

Ginkgo biloba L. (Ginkgoaceae) is a treasure species with high medicinal value. The Ming Dynasty "Compendium of Materia Medica" and Qing Dynasty "Bencao Fengyuan" in China recorded this herbal medicine can reduce phlegm, clear poison, treat diarrhea and frequent urination, etc. AIM OF THE STUDY: Until now, there is no painstakingly summarized review on leaves, seeds and exocarp of G. biloba simultaneously. This review will systematically summarize and compare current knowledge of G. biloba.

MATERIALS AND METHODS

Ample original publications related to traditional uses, phytochemistry, pharmacology, resource utilization and toxicity of G. biloba leaves, seeds and exocarp till the end of 2021 were searched and collected by using various literature databases, including China National Knowledge Infrastructure, PubMed, Elsevier, Springer, Google Scholar and Web of Science database.

RESULTS

According to classical Chinese herbal books and Chinese Pharmacopoeia, relieving cough, reducing phlegm, clearing poison and relieving diarrhea are the main pharmacological effects of G. biloba. The common chemical ingredients in different parts of G. biloba are flavonoids, terpenoids, phenolic acids, polysaccharides and endotoxin, etc. Among them, flavonoids and terpenoids are the main bioactive compounds in G. biloba leaves. Phenolic acids are the main bioactive compounds in G. biloba exocarp. G. biloba seeds are rich in nutritional ingredients, such as starch, adipose, protein, etc. Modern pharmacological studies showed that the crude extracts or compounds of G. biloba leaves, seeds and exocarp can be used for treating cardiovascular and cerebrovascular diseases, Alzheimer's disease, atherosclerosis, cancer, asthma, non-alcoholic fatty liver, diabetic complications and other diseases. In daily life, G. biloba seeds were usually used as raw material or additives for commodities, healthy food, drinks, even insecticides and antibacterial agents, etc. G. biloba leaves and seeds have been mainly applied for treating cardiovascular and cerebrovascular diseases, cough and asthma in clinical. However, endotoxins and ginkgolic acids have been identified as the dominating toxic ingredients in different parts of G. biloba. Besides, flavonoids and ginkgolides also have been proved to have toxicity recently.

CONCLUSIONS

This review systematically sums up and compares the traditional uses, phytochemistry, pharmacology, resource utilization and toxicity research progress of G. biloba leaves, seeds and exocarp for the first time. It will provide some comprehensive reference data and suggestions for future research on this herbal medicine.

Dose- and time-effects responses of Nonylphenol on oxidative stress in rat through the Keap1-Nrf2 signaling pathway

Nonylphenol (NP) is a representative environmental endocrine-disrupting compound that can induce oxidative stress in organisms. The Kelch-like ECH-associated protein 1 (Keap1)-nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway acts an important role in preventing oxidative stress. The aim of this study was to investigate the influence of oxidative stress caused by NP on Keap1-Nrf2 pathway in rats. Rats were treated with NP (30, 90, 270 mg/kg) for different exposure time (7, 14 and 28 days). The levels of reactive oxygen species (ROS) in serum and glutathione S-transferase (GST), UDP-Glucuronosyl Transferase (UGT) in liver were detected by ELISA kits. Western blot was used to detect Keap1, Nrf2 protein expression in liver and cerebral cortex. The results showed that 28 days of NP exposure significantly increased ROS levels in NPH group. And 14 days exposure to NP significantly enhanced the levels of GST and UGT, while 28 days of exposure showed a suppressive effect. In liver, Keap1 levels was upregulated at 7, 14 and 28 days of NP exposure, while nuclear Nrf2 levels decreased at 7 and 28 days but increased at 14 days. In cerebral cortex, Keap1 and Nrf2 expression increased at 14 days but decreased at 28 days. Besides, with the prolongation of NP exposure time, the GST and UGT levels in NPM and NPH groups were increased firstly and then decreased, while Keap1 and Nrf2 protein levels were constantly decreased in liver and cerebral cortex. In conclusion, the lower dose and shorter exposure time of NP activated the Keap1-Nrf2 pathway that may reduce the damage of oxidative stress, but when further exposed to NP at higher dose and time, the pathway could be inhibited.

Effect of nonylphenol on spermatogenesis: A systematic review

Nonylphenol (NP) is known as an environmental pollutant that has adverse effects on the spermatogenesis process. In this review, we focus on (1999-2020) studies on the effect of this pollutant on the sperm parameters and the male reproductive system. Spermatogenesis is a process in which male spermatogonia (primary germ cells) is divided into meiosis and produce spermatozoa. NP and its isomers can cause oxidative stress and alter the production of sex hormones, and thereby disrupting this vital process. By searching in the scientific databases of PubMed, Google Scholar, Science Direct, Springer and Web of Science related articles were extracted. As a result, all observations have confirmed that NP can cause multiple damages to the spermatogenesis and male reproductive system.

Antagonistic effects of a mixture of low-dose nonylphenol and di-n-butyl phthalate (monobutyl phthalate) on the Sertoli cells and serum reproductive hormones in prepubertal male rats in vitro and in vivo

The estrogenic chemical nonylphenol (NP) and the antiandrogenic agent di-n-butyl phthalate (DBP) are regarded as widespread environmental endocrine disruptors (EDCs) which at high doses in some species of laboratory animals, such as mice and rats, have adverse effects on male reproduction and development. Given the ubiquitous coexistence of various classes of EDCs in the environment, their combined effects warrant clarification. In this study, we attempted to determine the mixture effects of NP and DBP on the testicular Sertoli cells and reproductive endocrine hormones in serum in male rats based on quantitative data analysis by a mathematical model. In the in vitro experiment, monobutyl phthalate (MBP), the active metabolite of DBP, was used instead of DBP. Sertoli cells were isolated from 9-day-old Sprague-Dawley rats followed by treatment with NP and MBP, singly or combined. Cell viability, apoptosis, necrosis, membrane integrity and inhibin-B concentration were tested. In the in vivo experiment, rats were gavaged on postnatal days 23-35 with a single or combined NP and DBP treatment. Serum reproductive hormone levels were recorded. Next, Bliss Independence model was employed to analyze the quantitative data obtained from the in vitro and in vivo investigation. Antagonism was identified as the mixture effects of NP and DBP (MBP). In this study, we demonstrate the potential of Bliss Independence model for the prediction of interactions between estrogenic and antiandrogenic agents.

Evaluation of genotoxicity and effects on reproduction of nonylphenol in Oreochromis niloticus (Pisces: Cichlidae)

Nonylphenol ethoxylate (NPE) is widely used as a component of detergents, paints, pesticides, and many other products. In the aquatic environment NPE breakdown to 4-nonylphenol (NP), which is more stable and persistent. NP is estrogenic in fish, avian, and mammals and is described as an environmental pollutant with endocrine disruptor characteristics. The genotoxicity of NP was evaluated through micronuclei assay and single cell gel electrophoresis (Comet assay) in peripheral erythrocytes of Oreochromis niloticus exposed in vivo. The study on reproductive development was also carried out in male and female gonads of O. niloticus. Lethal concentration (LC 50%) of 0.032 ml l(-1) was previously determined. We ran assays with O. niloticus exposed to concentrations of 1.0, 10.0, and 16.0 microl l(-1) of NP diluted in water. Our results showed that NP was not genotoxic. However, 3-day exposure to NP in concentrations of 1.0, 10.0, and 16.0 microl l(-1) of water increased the frequency of reproductive stages in males and females. The histology of the reproductive tract of the treated fish was significantly altered in females treated with 16.0 microl l(-1) of water when compared to controls. Analogous estrogenic effects were observed, such as accelerated maturation of oocytes and spermatogenesis. These results showed that the O. niloticus reproductive system is sensitive to NP estrogenicity.

Effect of gestational exposure to nonylphenol on the development and fertility of mouse offspring

Nonylphenol (NP), a kind of environmental chemical, is thought to imitate endogenous hormones, inhibit the actions of hormones, and induce reproductive abnormalities. A number of experimental animals, usually rats, have been used to evaluate the potential reproductive toxicity of NP. However, the findings of previous studies were contradictory in some cases. Therefore, we used ICR mice as a biomodel for in utero study of NP. After mating, 8- to 12-week-old females were assigned to four groups (n=8) for subcutaneous injections from day 5 to 20 of gestation. Group I animals received corn oil alone as a control, while the mice of groups II, III and IV received NP at concentrations of 1/1000, 1/100 and 1/10 of the LD(50), respectively. A dose-dependent decrease was observed in terminal body weights of males of the F1 generation; however, a very small negative effect was only found in the females of the NP1/10 group. No significant effect was found on the liver weights of both sexes. The weights of the testis and epididymis were slightly decreased in the NP1/10 group. The NP1/100 treatment increased ovary weight considerably. The uterus weight tended to be increased in the NP treatment groups; however, there were large variations. The gestational exposure of the groups had no significant effect on the rate of pregnancy (94.4-100%) and the number of fetuses per litter (13.6-14.3 males, 12.3-13.7 females) compared with the control group. However, the overall mortality of fetuses/embryos was increased considerably in the NP1/100 (male: 13.9%) and NP1/10 (female: 9.8%) groups. These results suggest that exposure to NP in utero possibly affects the body weight and some reproductive organ weights, but does not influence the potential fertility of the F1 generation.

Studies on the reproductive, cytological and biochemical toxicity of Ginkgo Biloba in Swiss albino mice

Ginkgo biloba (an herbal product), used as a folkloric medicine in the treatment of dementia, was evaluated for its effects on reproductive, cytological and biochemical toxicity in male Swiss albino mice. The mice were treated with different doses (25, 50 and 100mg/kg/day) of the aqueous suspension of Ginkgo biloba for 90 days by oral gavage. The following parameters were evaluated: (1) reproductive organ weight; (2) motility and content of sperms; (3) spermatozoa morphology; (4) cytology of the testes chromosomes; (5) study on reproduction; (6) biochemical study on proteins, nucleic acids, malondialdehyde (MDA) and nonprotein sulfhydryl (NP-SH). The treatment caused significant changes in the weight of caudae epididymis, prostate, chromosomal aberrations, rate of pregnancy and pre-implantation loss. However, the percent motility, sperm count and morphology of spermatozoa were not affected. Our study on biochemical parameters showed depletion of nucleic acids, NP-SH and increase of MDA, which elucidated the role of free radical species in the induced changes in testis chromosomes and the reproductive function. The exact mechanism is not known, however, the activation of GABA, glycine and glutamate under the influence of Ginkgo biloba and its constituents might have generated free radicals and depleted cellular glutathione by calcium influx and membrane depolarization. The observed toxicity is attributed to the toxic constituents (ginkgolic acids, biflavones, cardanols, cardols, bilobalides and quercetin) of Ginkgo biloba. Our results warrant careful use of Ginkgo biloba as a remedy for impotence and/or erectile dysfunction.

The male reproductive system and its susceptibility to endocrine disrupting chemicals

In the past years, there has been increased interest in assessing the relationship between impaired male fertility and environmental factors. Human male fertility is a complex process and therefore a great variety of sites may be affected by exogenous noxae. Lifestyle factors as well as various environmental and occupational agents may impair male fertility. Many studies have been published reporting on reproductive dysfunctions in male animals and humans. Especially environmental pollutants with endocrine activity are discussed as a possible cause of this detrimental development. Evidence from animal experiments show that substances with oestrogenic and antiandrogenic properties may cause hypospadia, cryptorchidism, reduction of sperm density and an increase of testicular tumours. Many adverse effects on animal male fertility have been documented for phthalates and some chlorinated hydrocarbons such as polychlorinated biphenyls and polychlorinated dibenzo-p-dioxins. For other chemicals such as bisphenol A and nonylphenols animal data are conflicting. Environmental pollutants may mediate their effects by receptor binding, modulation of hormone-regulated mechanisms or direct toxic effects. Data on environmental chemicals and human male fertility are scarce, and risk assessment is mostly based on the results of animal studies. However, there are indications that exposure to endocrine active chemicals during early development may alter hormone responsiveness in adulthood. Furthermore, some of the chemicals are found in fluids that are associated with human reproduction, such as follicular fluid, seminal fluid and cervical mucus. Recent studies suggest a correlation between pesticide exposure and standard semen parameters as well as in vitro fertilization rates.

The toxic effects of nonylphenol on the reproductive system of male rats

Male Sprague-Dawley (SD) rats were exposed to 4-t-nonylphenol (NP) by gavage at dosages of 0, 125 and 250 mg/kg/day for 50 days. Organ weights of liver, kidney, testis and epididymis were measured. Sperm number in the head of epididymis was counted. Several hormones including testosterone, luteinizing hormone and follicle stimulating hormone were measured. Testicular sections were observed by light and electron microscopy. Terminal dideoxynucleotidyl transferase dUTP nick end labeling assay was performed to probe the apoptotic cells in seminiferous tubules. When rats were treated with nonylphenol at 250 mg/kg/day, the absolute and relative weight of epididymis decreased dramatically, while the relative weights of kidney and liver increased by 14 and 22%, respectively. In addition, the sperm density of the head of epididymis and the testosterone level descended at 250 mg/kg/day. The levels of luteinizing hormone and follicle stimulating hormone increased in both nonylphenol treated groups. Pathological changes were detected by microscopy and the transferase dUTP nick end labeling (TUNEL) assay showed that the number of apoptotic cells in testes increased with nonylphenol in a dose-dependent manner.

Effects of p-nonylphenol and resveratrol on body and organ weight and in vivo fertility of outbred CD-1 mice

The aim of this study was to analyse the multigenerational effects of para-nonylphenol (NP) and resveratrol (RES) on the body weight, organ weight and reproductive fitness of outbred CD-1 mice. The data indicate that in male mice, NP had an effect on the weight of selected reproductive organs and the kidneys in the parental (P) generation males. Effects on selected reproductive organs, the liver and kidneys in the F1-generation males were also seen. In females, effects of NP on body weight and kidney weight were seen in the P generation, but no effects on any measured parameter were seen in the F1 generation. RES had no effect on body weight but did have some effect on selected male and female reproductive organs in the P generation. RES altered the spleen and liver weights of P-generation males and the kidney weight of F1-generation males. Acrosomal integrity (using a monoclonal antibody against intra-acrosomal sperm proteins) was assessed for both generations of NP- and RES-treated mice. A significant reduction in acrosomal integrity was seen in both generations of NP-treated, but not in RES-treated, mice. Fewer offspring were observed in the second litter of the F2 generation of mice treated with NP; no similar effect was seen in RES-treated mice. The litter sex ratio was not different from controls. Unlike RES, NP had a negative effect on spermatogenesis and sperm quality with a resultant impact on in vivo fertility.