Can gold nanoparticles affect the histological structure of the pulmonary alveoli in adult albino rats?

Gold nanoparticles [GNPs] are currently used in several consumer products as well as in laboratory-based research either as a diagnostic imaging agent or as a therapeutic agent in gene delivery and photothermal cancer therapy. They are synthesized by chemical methods in which toxic reducing agents are involved. There is a growing need to develop environmentally benign NP synthesis processes that are free from toxic chemicals. The study aimed to ascertain the possible histological alterations that might occur in the pulmonary alveoli of adult albino rats after intraperitoneal administration of 10 nm GNPs prepared by two different methods [chemically prepared and green synthesized]. Fifty adult male albino rats [140-160 g] were assigned to three groups. Group I was the control group. The rats in this group were further divided into three equal subgroups Ia, Ib, and Ic that received daily intraperitoneal injection of PBS, trisodium citrate, and cumin-gum Arabic solutions, respectively. Rats in group II received a daily intraperitoneal injection of 100 micro l of chemically prepared GNPs using trisodium citrate. Rats in group III received a daily intraperitoneal injection of 100 micro l of green-synthesized GNPs using cumin and gum Arabic. After 7 days, the animals were euthanized and specimens from the lungs were taken and processed for histological and immunohistochemical studies. H and E-stained sections of group II rats depicted multifocal thickening of the interalveolar septa and collapsed alveoli. Immunohistochemical analysis revealed high vimentin expression. Ultrastructurally, type II pneumocytes showed degenerative changes. Relatively thick interalveolar septa with many active interstitial cells were also seen. GNPs were detected in pneumocytes and alveolar macrophages. In contrast, the lung sections of group III rats showed considerable preservation of normal alveolar architecture with nearly normal vimentin immunoreactivity. GNPs were detected in the pneumocytes and interalveolar septa as well. Green-synthesized GNPs using cumin-gum Arabic are safer for the pulmonary alveoli compared with chemically prepared GNPs using trisodium citrate. Long-term studies are required to verify the toxicity of GNPs on various cell types

Histological study of adult male rat seminiferous tubules following triclosan administation and the possible protective role of pomegranate juice

Triclosan [TCS] is an antimicrobial agent, widely incorporated in a variety of personal care products, household items, medical devices, and clinical settings. Recently, concern has been raised over TCS's potential for endocrine and reproductive disruption. The study aimed to elucidate the impact of TCS on the histological structure of the seminiferous tubules [STs] in adult male albino rats, as well as the possible protective role of pomegranate juice [PJ] coadministration. A total of 32 adult male albino rats [140-160 g] were randomly categorized into four equal groups. Group I [the control group]: rats in this group received PBS [1 ml/kg/day] orally. Group II: rats in this group received PJ orally at a dose of 10 ml/kg/day. Group III: rats in this group received TCS orally at a dose of 20 mg/kg/day. Group IV: rats in this group received TCS at the same dose as group III in conjunction with PJ daily. The experiment continued for 60 days. At the end of the experiment, blood samples were collected from the retro-orbital venous plexus of all rats for estimation of serum testosterone level. The animals were then euthanized. The testes of all rats were harvested for both light and transmission electron microscopic examination of the STs. The germinal epithelial height and the number of germ cells/high-power field [HPF] were estimated morphometrically in H and E-stained sections and statistically analyzed. The study revealed that PJ administration was safe as it did not alter serum testosterone levels as compared with the control group. Histologically, the STs of these animals exhibited normal appearance similar to that of the control group. TCS administration was associated with significantly lowered serum testosterone levels as compared with the control group. Histologically, the STs were lined with relatively few spermatogenic cells with deeply stained nuclei. Cytoplasmic vacuolation of the lining cells and exfoliation of germ cells in the tubular lumina were seen as well. Ultrastructurally, vacuolar degenerative changes involving all types of spermatogenic cells as well as Sertoli cells were revealed. Moreover, the germinal epithelial height and the number of germ cells/HPF were significantly reduced compared with the control group. Coadministration of PJ with TCS resulted in a significant increase in serum testosterone level as compared with the TCS group. Histologically, most of the STs retained normal appearance and epithelial stratification. Only some tubules revealed vacuolation of germ cells in the basal compartment with deeply stained nuclei. Mild ultrastructural alterations of germ cells were evidenced as well. These results were confirmed histomorphometrically by the significant increase in the germinal epithelial height and number of germ cells/HPF as compared with the TCS group. The study clearly indicates that TCS has the potential to adversely impact the testicular structure and function, and that PJ is able to ameliorate such adverse effects

Light and electron microscopic study of thyroid follicular cells in adult albino rats following green tea administration

Green tea [GT] is one of the most popular beverages with high daily consumption worldwide. It has a rich content of polyphenols, among which catechins predominate. Its extracts are widely used as ingredients in dietary supplements, beverages, and functional foods, which may lead to a higher consumption of GT polyphenols by the general population. Recently, a relationship between GT administration and disruption of thyroid homeostasis was suggested. The goal of the study was to clarify the impact of GT administration on the histological structure of thyroid follicular cells of adult albino rats. Thirty adult male albino rats [140-160 g] were categorized into three equal groups: group I served as the control group; groups II and III received 1.25 and 5.0 g% GT extract orally at a dose of 10 ml/kg body weight, respectively, every day for 30 days. At the end of the experiment, blood samples were collected from all animals for estimation of serum triiodothyronine [T[3]], thyroxine [T[4]], and thyroid stimulating hormone. Rats were then euthanized and the thyroid glands were harvested for histological examination of thyroid follicular cells by light and transmission electron microscopy. The follicular epithelial height and colloid area of thyroid follicles were morphometrically evaluated and statistically analyzed. GT in small concentrations [in group II] did not induce any significant change in hormonal, histological, and histomorphometric assessments as compared with the control group. However, some follicular cells exhibited mildly dilated rough endoplasmic reticulum and multiple lysosomes. In contrast, GT administration in group III induced hypothyroidism as evidenced by significant reduction in serum T[3] and T[4] levels along with substantial increase in thyroid stimulating hormone level compared with controls. Histologically, many follicles displayed signs of hyperactivity as evidenced by focal hypertrophy and hyperplasia of the follicular cells along with colloid depletion. Ultrastructurally, dilated rough endoplasmic reticulum and disrupted mitochondria were encountered. Some severely degenerated follicular cells were revealed as well. Histomorphometrically, there was a significant increase in the mean follicular epithelial height, whereas the colloid area was significantly lowered as compared with the respective controls. The study clearly indicates that GT in large concentrations has the potential to disrupt thyroid follicular cell structure and function