الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 268 |  |  |
| | | from | 268 | | |
Abstract
Plant growth regulators (PGRs), both naturally occurring and synthetic, are used extensively to help growers solve production problems and to improve grower returns. Gibberellic acid (GA3) is a naturally occurring PGR that is widely used to promote the growth of a variety of fruits and vegetables. Ethephon is an ethylene-based PGR used in agriculture as an artificial ripening agent, but excessive use of these chemicals would almost certainly result in numerous health risks. Some food dyes, including Tartrazine (E102) and Allura red (E129) are added to main food stuffs with an aim to give color to food, or to restore its natural color. These coloring agents can impart color to food, drugs or cosmetics, but, these agents have been linked to breathing problems, hyperactivity and skin rash, as a result, there are many different viewpoints on the safety of these chemicals.
Vitamin C (ascorbic acid), which is a major water-soluble vitamin, is believed to be among the most important antioxidants. It is an essential co-factor involved in many biochemical functions and acts as an electron donor or reducing agent. Reports have linked vitamin C with prevention of hepatotoxicity induced by drugs, heavy metals, organophosphate insecticides and some chemical agents. Vitamin C is an important free radical scavenger, trapping radicals and protecting bio-membranes from peroxide damage.
The present study aimed to investigate the role of vitamin C as antioxidant agent in improving the adverse effects of Gibberellic acid, Ethephon, Tartrazine and Allura red on liver, kidney and testis functions, lipid and protein profiles, oxidative stress, in addition to some hematological and immunological aspects in male albino rats. Also, to investigate the ameliorative effect of vitamin C on histopathological changes induced by these agents.
Sixty adult male albino rats were divided into (10) groups, each with six rats and group (1) was administered saline orally (1ml/rat); group (2) was administered 200 mg/kg of vitamin C; group (3) was orally administered with gibberellic acid (75 mg/kg); group (4) was orally administered with Ethephon (150 mg/kg); group (5) was co-administered with vitamin C and Gibberellic acid orally; group (6) was co-administered with vitamin C and Ethephon orally; group (7) was administered 75 mg/kg of tartrazine; group (8) was administered 70 mg/kg of Allura red; group (9) was administered both tartrazine and vitamin C; group (10) was administered Allura red and vitamin C for 6 consecutive weeks, with the same doses.
At the end of the experiment after 6 weeks, the rats from all groups were sacrificed under anesthesia and blood, liver, kidney and testis samples were collected for detecting hematological, biochemical and immunological analysis and histological study.
The results showed significant increase in total WBCs and lymphocytes and significant decrease in neutrophils in Gibberellic acid (GA3) and Ethephon groups, in addition to, significant decrease in RBCs count and hemoglobin content compared with control group. Significant decrease in levels of total immunoglobulins (Igs), IgG, IgA and IgM and increase in serum pro-inflammatory cytokines INF-γ, TNF-α, IL-1β and IL-6 compared with control group. The anti-inflammatory cytokine IL-10 was increased insignificantly. Moreover, significant elevated levels of ALT, AST, ALP, GGT, bilirubin and alpha-fetoprotein and decreased levels of total proteins and albumins were indicated in GA3 and Ethephon groups. Liver and testis lipid peroxidation (MDA) and nitric oxide (NO) levels were significantly elevated and antioxidant enzymes SOD and CAT and GSH content were significantly decreased in both liver and testis homogenates in GA3 and Ethephon groups. Serum urea, creatinine, total lipids, triglycerides and total cholesterol were significantly elevated in these groups. It was observed also that serum testosterone hormone concentrations were decreased significantly in rats administered with those plant growth regulators. Administration of vitamin C with GA3 and Ethephon ameliorated most of the previous changes caused by GA3 or Ethephon.
Also, the present results revealed changes in the Tartrazine and Allura red groups compared to control group represented in significant decline in (RBCs) count and (Hb) concentrations accompanied with significant elevations in (WBCs) count and percentage of lymphocytes, significant decrease in neutrophils percentage, significant increased levels in lipid peroxidation (MDA) and nitric oxide (NO) activities and significant decrease in levels of (GSH), (SOD) and catalase in both liver and testis homogenates Significant decrease in levels of total immunoglobulins (Igs), IgG, IgA and IgM and significant increase in the serum inflammatory cytokines INF-γ, TNF-α, IL-1β, and IL-6. IL-10 was increased insignificantly. Serum liver enzymes as (ALT, AST, ALP, GGT), alpha-fetoprotein, total bilirubin, urea, creatinine, total lipids, triglycerides and total cholesterol were significantly elevated in the food dyes groups. Serum testosterone hormone concentrations were decreased significantly in rats intoxicated with Tartrazine and Allura red. Combining vitamin C with Tartrazine or Allura red significantly improved most of the changes induced by Tartrazine or Allura red.
The present study demonstrated the potential histopathological changes induced by the plant growth regulators and food dyes on the liver, testis and kidneys of male albino rats represented mainly in dilated and congested central vein, disturbance in typical hepatic cords organization and highly vacuolated hepatocytes. The testis sections showed disorganized spermatogenic cells, large intracellular spaces between spermatocytes and decreased number of sperms and interstitial Leydig cells.
In addition, histopathological changes and degenerations in renal tubules and corpuscles were noticed. Signs of histopathological improvement on the liver, testis and kidney could be observed in rat groups treated with GA3, Ethephon, Tartrazine, Allura red and vitamin C.
In conclusion, this study demonstrated the potential toxicity of plant growth regulators (GA3 and Ethephon) and food azo dyes (Tartrazine and Allura red) on the liver, kidneys and testis functions in male albino rats that was indicated by histopathological changes, in addition to, hematological, immunological and biochemical alterations and administration of vitamin C ameliorated most of the previous changes that was because of the anti-oxidant and anti-inflammatory properties of this vitamin.
Upon the findings of this study, in order to preserve public health, it is recommended to limit the use of food products containing synthetic food dyes as Tartrazine and Allura red and growers should avoid excessive use of plant growth regulators, especially GA3 and Ethephon, in solving production problems and improving returns as overuse of these chemicals would almost certainly result in numerous health risks.