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

Histological study of the femur and the lumbar vertebrae in ovariectomized adult albino rats following administration of collagen hydrosylate

Introduction: Osteoporosis is the most common skeletal disorder that has become a leading cause of morbidity and mortality worldwide. Its prophylaxis and therapy are still unresolved challenges

Aim of the study: The aim of the study was to investigate the possibility that collagen hydrosylate [CH] can ameliorate osteoporotic bone loss in ovariectomized rats with special reference to bone mineral content [BMC], some biochemical parameters of bone turnover, and histology

Materials and methods: Forty adult female albino rats [180-200 g] were categorized into four equal groups: a sham-operated control group [group I], a sham-operated CH-treated group [group II], an ovariectomized group [group III], and a CH-treated ovariectomized group [group IV]. The experiment continued for 12 weeks. At its end, the animals were sacrificed under anesthesia. Blood samples were collected for estimation of serum calcium, osteocalcin, bone-specific alkaline phosphatase, and C-terminal telopeptide of type I collagen [CTX]. The left femora and lumbar vertebrae were excised for histological examination by H and E and Gomori's trichrome stains. The area percentage of collagen was further assessed using an image analyzer. The right femur of each rat was used for BMC measurement by energy-dispersive X-ray analysis

Results: In sham-operated CH-treated rats [group II] there was no significant variation in bone turnover markers and BMC as compared with their respective controls. Normal bone microstructure was depicted as well. In group III rats, ovariectomy [OVX] was associated with enhanced bone turnover as depicted by significant decrease in the mean value of serum calcium, whereas osteocalcin, bone-specific alkaline phosphatase, and CTX revealed significant increase compared with controls. Moreover, an evident reduction in bone calcium content was depicted in the femora of this group. Histologically, evidence of bone resorption was manifested in the femoral diaphysis and lumbar vertebrae with multiple resorption cavities, irregularly eroded endosteal surface containing osteoclasts, and thinned out bone trabeculae along with wide bone marrow cavities. A significant decrease in bone collagen content of both cortical and trabecular bones was evidenced in trichrome-stained sections. In contrast, CH administration after OVX [in group IV] reduced bone turnover markers and improved BMC as well as histological characteristics of examined bones as compared with the OVX group

Conclusion: The study suggested that CH may be a potentially useful agent in preventing bone loss due to ovarian hormone deficiency

Effect of toluene exposure on pulmonary alveolar structure of adult male albino rats. toxicological and histological study

Toluene is an aromatic volatile solvent included in widely distributed commercial products like j gasoline, paints, glues and thinners. It is largely abused as a neurostimulant agent in adolescents and young adults in low socioeconomic classes. The present work aimed at investigating the effect of long-term toluene administration on the histological structure of pulmonary alveoli of adult male albino rats. It was further extended to evaluate the possibility of recovery after toluene withdrawal. Thirty adult male albino rats [100-120 g] were randomly categorized among 3 equal groups; group I [control group]. Group II: rats were orally intubated with 10 mI/kg body weight of toluene in corn oil at a dose of 650 mg/kg/day, five days per week for 8 successive weeks. Group III [withdrawal group]: rats were subjected to oral ivluene administration in a similar way to group II and for the same period. Then, they were kept free from toluene exposure for the next 4 weeks to test for spontaneous recovery. By the end of the experimental periods, blood samples were collected from all animals for estimation of blood toluene levels by gas chromatography. Then, the rats were sacrificed by decapitation after anaesthesia. Lung specimens were taken from all animals and processed for light microscopic examination using H and E stain, as well as transmission electron microscopic examination. Toluene administration in group II rats resulted in an evident increased in blood toluene levels as compared to the control group. Histologically, toluene exposure resulted in evident alteration of the pulmonary alveolar architecture with focal areas of collapsed alveoli, marked thickening of the inter-alveolar septa along with peribronchiolar and perivascitlar cellular infiltration as well as vascular congestion. Ultrastructurally, type II pneumocytes formed the predominant lining cells of many alveoli and revealed small dense nuclei, and numerous wicuoles, while others exhibited rarfied cytoplasm and empty lame lIar bodies. Increased deposition of collagen and elastic fibers in the inter-alveolar septa was depicted as well. After 4 weeks of toluene withdrawal [group III], an evident decrease in blood toluene levels was enco4nte red. Nevertheless, it was still high in relation to the control levels. Histologically, only mild amelioration of the alveolar lesions was revealed. Some alveoli were still collapsed. The inter-alveolar septa were moderately thickened with increased collagen deposition. Some morphological changes of type Ilpneumocytes were still depicted. Long-term exposure to toluene has the potential to endanger the pulinonaty alveolar structure. Therefore, laws and penalties should be legislated to prohibit the abuse of such substance. Public health efforts are recommended to raise the awareness about its hazards particularly among high risk population

Effect of tinuvin 770 [a light stabilizer] on ventricular cardiomyocytes of albino rats and possible protective role of lycopene. toxicological and histological study

Tinuvin 770 is a substance used as an ultraviolet light and radiation stabilizer employed universally in the manufacture of plastic materials. It has recently been suggested to possibly cause cardiovascular manifestations. Lycopene is a potent antioxidant carotenoid without provitamin A activity. It is present in many fruits and vegetables; however, tomatoes and processed tomato products constitute its major sources. Lycopene has recently gained great attention for its protective effect against several pathological disorders, particularly coronary heart diseases [CHDs]. This work aimed at evaluating the potential toxic effects of tinuvin 770 on rat myocardium, as well as the possible cardioprotective role of pre-and concomitant lycopene administration, both histologically and biochemically. 50 adult male rats were divided among 5 equal groups. Group I served as a control group. Group II received lycopene orally [4.6 mg/ kg b.w/ day] for 9 weeks. Group III received tinuvin 770 [lmg/ kg b.w] intraperitoneally 3 times a week for 5 weeks. Group IV received lycopene simultaneously with tinuvin for 5 weeks. Group V received lycopene 4 weeks prior to and concurrent with tinuvin 770 for another 5 weeks. The last urine samples and myocardial specimens were collected at the end of the experiment for estimation of norepinephrine levels and histological examination of the ventricular cardiomyocytes respectively. Tinuvin 770 evoked marked increase in norepinephrine urine levels and evident myocardial lesions in group III rats included waviness, myocytolysis and focal hypereosinophilia of the muscle fibers. Ultrastructurally, evident alterations of the myofibrils, mitochondria, sarcoplasmic reticulum and intercalated discs were revealed. On simultaneous lycopene and tinuvin administration [group IV], mild amelioration of the myocardial lesions was depicted, whereas prior treatment with lycopene [group V] resulted in considerable myocardial protection. Tinuvin 770 might be considered as a cardiotoxic agent, and lycopene is especially beneficial in ameliorating its effects

Histological study on the toxic effect of 2-bromopropane on the seminiferous tubules of adult male albino rats

2-Bromopropane [2-BP] is a haloalkane used in industry as an alternative to ozone layer depleting solvents. It has recently been suspected to be a causative agent for some reproductive dysfunctions in both male and female workers exposed to it in electronic factories. The study was carried out to evaluate the possible toxic effects of 2-BP administration on the seminiferous tubules [S. Ts] of rat testis, and its potential reversibility after 2-BP withdrawal. The study was conducted on 30 adult male albino rats weighing from 100-150g each. They were categorized into 3 equal groups. Group I: served as a control group. Group II: rats received daily subcutaneous injection of 2-BP [400 mg/kg b.w.] for 28 days. Group III: rats received 2-BP in the same dose and for the same duration as group II followed by a further 28-day recovery period. At the end of experiment, blood samples were collected to detect testosterone levels, and the rat testes were weighed and examined for the daily sperm production. Specimens were taken from the testes of all animals and subjected to both light and electron microscopic examinations. 2-BP administration [in group II] significantly decreased absolute testicular weight and daily sperm production as well as serum testosterone levels. Histologically, atrophy of the S.Ts accompanied by interstitial oedema was evident. Moderate to severe degenerative changes involving all types of spermatogenic cells, including spermatogonia, were also demonstrated. Furthermore, Leydig cells depicted ultrastructural evidence of decreased activity. After a 4-week recovery period [group III], mild increase in serum testosterone levels as well as other laboratory parameters were noticed. However, they were still much less as compared to the control. Histologically, only limited amelioration of the testicular lesions in the germinal epithelium as well as Leydig cells was revealed. Such persistent lesions were attributed to the damaging effect of 2-BP on testicular stem cells; spermatogonia. The study demonstrates vulnerability of the testicular tissue to 2-BP intoxication. Therefore, careful consumption of 2-BP containing solvents and pharmaceuticals is necessary

Effects of neuropeptide derivative FPF 1070 [cerebrolysin] administration on experimental acute spinal cord injury: a histological study

Cerebrolysin is a neuropeptide-derived synthetic preparation produced by enzymatic breakdown of lipid-free animal neuroproteins. It regulates the neuronal energy metabolism and is supposed to afford brain protection by its neurotrophic stimulation. The present study aimed at assessing the possible neuroprotective effects of Cerebrolysin on an experimentally induced spinal cord injury in dogs depending on clinical and histological bases. The experiment was conducted on 20 adult male dogs, which were divided among five groups: A sham operated control group [subjected only to laminectomy of the midthoracic vertebrae], a positive control group [subjected to laminectomy with subsequent daily Cerebrolysin administration for 15 days], an acute spinal cord injury group [injury was induced by compression using an inflated balloon of the Folleyis catheter over the mid-thoracic spinal cord segments] and the animals were killed 24 hours after the surgery, a spinal cord injury group with subsequent daily administration of isotonic saline for 15 days and a spinal cord injury group with subsequent daily Cerebrolysin administration for 15 days. Clinical follow up of the experimental animals was daily recorded for 30 days, after which serial sections were prepared from the injured spinal cord segments of the different sacrificed groups. They were examined histologically by routine haematoxylin and eosin and by toluidine blue stains. The end results proved that Cerebrolysin achieved satisfactory protection to the nervous tissue. It prevented the setting in of degenerative changes in the majority of the anterior horn neurons of the injured spinal cord segments and subsequently its propagation in the axonal nerve fibers in the white matter. Therefore, Cerebrolysin administration was recommended as a successful treatment during the management of acute spinal cord injuries. It was also suggested that studies should be extended to investigate a possible similar effect in the case of human spinal cord injury as well as in chronic lesions