الفهرس 
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Abstract
Lambda-cyhalothrin (LCT) is a well-known type II pyrethroid pesticides with multiple applications in agriculture, public and animal health. Despite claims to be with low mammalian toxicity, many investigations reported its mammalian toxicity by mediating oxidative stress causing severe hepatic, pulmonary and testicular damage.
The current study aims to investigate the ameliorative effect of two tested doses (100 and 200 mg /kg b. wt. /day) of panax ginseng, a medicinal plant with well-documented antioxidant properties, against LCT (60 mg /kg b. wt. /day) induced toxicity in liver, lung and testis of adult male albino rats for 60 days.
To achieve the aim, 36 male adult laboratory rats (Rattus norvegicus domestica), which weighed around 120-150 g were separated randomly to 6 groups (as 6 rats per group) group 1 (control): rats received normal saline through intraperitoneal (i.p.) injection daily. group 2 (Ginseng 100): rats received ginseng at a daily dose of 100 mg/kg b. wt. dissolved in normal saline by i.p. injection. group 3 (Ginseng 200): rats received ginseng at a daily dose of 200 mg/kg b. wt. by i.p. injection. group 4 (LCT): rats received LCT at a daily dose of 61.2 mg/kg b. wt. (1/10 of LD50) by oral gavage. group 5 (LCT +100): rats received the same dose of LCT, as in group 4, followed immediately by ginseng, as in group 2, daily. group 6 (LCT +200): rats received the same dose of LCT, as in group 4, followed immediately by ginseng, as in group 3, daily. The doses were adjusted weekly regarding to body weight changes to sustain comparable dose per kg rat’s body weight till the end of experiment period.
At the end of experimental period, after 60 daays, Final body weights were recorded, Body weight gain (% BWG) was calculated. All groups of rats are sacrificed under anesthesia of diethyl ether. Blood samples were collected and allowed to coagulate at room temperature then centrifuged at 4000 r.p.m. for 10 minutes. The clear non-haemolyzed supernatant sera was quickly removed and kept at -20ºC for subsequent biochemical analysis (ALT, AST and ALP activities).
Liver, lung and testis were rapidly taken out, washed with ice-cold saline and weighted to calculate relative organ weights then, splitted into 3 parts. 1st part (10% w/v) was homogenized using Teflon tissue homogenizer in phosphate-buffered saline, then centrifuged for 10 min at 3000 rpm, the clear homogenates were obtained and frozen at -80° C for subsequent analysis of oxidative stress parameters. The 2nd part was kept frozen at -80° C for gene and protein expression analysis. The 3rd part was used for electron and light microscopic examination.
LCT- intoxication caused reduction of terminal body weight, relative weight of liver, lung and testis. Also caused extensive damage in the liver of rats that was confirmed by marked elevations of AST, ALT and ALP activities, which are the circulating markers of hepatocytes injury. Oxidative stress markers revealed that LCT produced a significant increase in level MDA level and the activities of antioxidant enzymes (SOD and CAT) and T. thiol content were decreased significantly in the liver, lung and testis tissues. In addition to, a significant upregulation in mRNA and protein expression levels of the pro-apoptotic P53 and a significant down- regulation in the expression of the anti- apoptotic Bcl2 in liver, lung and testis of LCT intoxicated rats.
The present histopathological observations of liver sections of LCTintoxicated rats showed mononuclear inflammatory cell infiltration, congested portal vein with thickened wall and proliferated bile duct was also detected. Moreover, hyperemic sinusoids, fatty changes and oedema. Degenerative changes were seen in the hepatocytes in the form of vacuolar degeneration, hypereosinophilic cytoplasm, pyknosis and karyolysis
Also, the histopathological study of lung of LCT-intoxicated rats demonstrated that the administration of the LCT induced variable degenerative changes in the pulmonary tissue compared with the control group. These histopathological observations represented by severe alveolar damage in the form of collapsed alveoli separated with markedly thickened inter-alveolar septa with compensatory dilatation of neighboring ones. Bronchiolitis manifested by marked hyperplasia of dilated and bronchioles wall extravasation of red blood cells in the bronchiole lumen. Blood vessels showed congestion and thickening in wall with cellular infiltration in the surrounding tissue beside to numerous hyperemia in some tissues.
In addition to, histopathological examination of testes of LCT intoxicated rats demonstrated that the administration induced variable degenerative changes in the testicular tissue. These changes include pathological alterations in the structure of the seminiferous tubules and interstitial tissue. Some of the affected tubules appeared devoid of sperm (maturation arrest) due to inhibition of the process of spermatogenesis as a result of drug administration. On the other tubules, the germinal epithelium showed hypoplasia, vacuolation, exfoliation, in addition to disorganization of germ cells of the affected tubules.
Matching with histopathological findings our ultrastructural study showed that LCT-intoxicated rats exhibited damaged bile canaliculi with destructed microvilli, Kupffer cell showed shrinked nucleus, Hepatocytes with vacuolated mitochondria, cytoplasmic vacuolations, fat droplets and collagen fibers
Also, the present ultrastructural study showed that the alveolar tissue of LCTtreated group revealed ultrastructural alterations including, cytoplasmic vacuolation, pyknotic nuclei, empty lamellar bodies and absence of microvilli of type 2 pneumocytes. Type 1 pneumocytes revealed shrinkage in nucleus and vacuolated cytoplasm. Inter-alveolar septum appeared thickened.
In addition to, electron microscopic examination of testis of LCT intoxicated rats revealed ultrastructural alterations including, thickening of the basement membrane. Sertoli cells showed marked degenerative changes. Its cytoplasm contains degenerated mitochondria, lysosomes, large vacuoles. The spermatogonia revealed large cytoplasmic vacuoles and lysosomes. The cytoplasm of the primary spermatocytes showed many vacuoles and lysosomes. Spermatids appeared with shrinked nucleus, cytoplasmic vacuoles and lysosomes. Marked decrease in number of sperms in lumen of seminiferous tubule were seen. Moreover, the cytoplasm of Leydig cells exhibited an obvious decrease in the amount of lipid droplets, numerous vacuoles and irregular nuclear envelope were observed.
In our study treatment of rats with LCT in concomitant with ginseng 100 or 200 mg /kg b. wt. /day increased terminal body weight, relative weight of liver, lung and testis as compared to LCT-intoxicated ones. Also, produced a profound improvement of the altered ALT, AST and ALP activities in serum. In addition to, a significant decrease in the mean value of MDA, a significant increase in the mean values of antioxidant enzymes (SOD and CAT) activities and T. thiol content, significantly down-regulates P53 and up-regulates Bcl-2 genes and protein expression in liver, lung and testis as compared with LCT-intoxicated group. Moreover, maintaining approximately the normal histological and ultrastructural tissue configuration of liver, lung and testis but ginseng 200 mg /kg b. wt. /day seems to be more potent.
The current study reported that ginseng has an ameliorative efficacy against LCT-induced histopathological and ultrastructural hepatic, pulmonary and testicular damage in rats. Moreover, the mechanisms sharing in its therapeutic efficacy involved free radicals scavenging, enhancing the antioxidants status and antiapoptotic properties.