الفهرس 
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Abstract
This study aimed to evaluate the anti-diabetic activity of four plants from the Egyptian flora using third-instar larvae of Drosophila melanogaster as an animal model. Type 2 diabetes (T2D) was induced in D. melanogaster by feeding on a high-sugar diet (HSD). The total body weight, hemolymph glucose, and trehalose were measured in the control, HSD-fed, and plant extract-treated larvae. A preliminary phytochemical screening of the four plants: Moringa oleifera, Morus nigra, Tagetes patula, and Atriplex halimus was investigated. Furthermore, the most active plant extract was fractionated with different solvents to determine which fraction has the best activity on the HSD-fed larvae. The biochemical reserves of control, HSD-fed, and fraction-treated larvae were estimated. Additionally, the relative expressions of three genes relevant to T2D were determined. The chemical composition of the active fraction (ethyl acetate) was determined using liquid chromatography coupled with electrospray ionization tandem mass spectrometry (LC-ESIMS/ MS) analysis. 6.1. Effect of different plant extracts on total body glucose of Drosophila melanogaster third-instar larvae The total body glucose of HSD-fed larvae was significantly higher than that in the control. However, when larvae fed on a diet treated with the plant extract or Amaryl drug, the total body glucose significantly decreased. All plant extracts used were able to recover the total body glucose near the control content. 6.2. Effect of different plant extracts on the total body trehalose of Drosophila melanogaster third-instar larvae HSD induced a significant increase in the total body trehalose of D. melanogaster larvae compared with the control. Morenga oleifera, Atriplex halimus and Tagetes patula extracts and Amaryl drug were able to significantly decrease the body trehalose compared with HSD-fed larvae. The contents of body trehalose following the treatment with A. halimus and T. patula extracts reached the control content. 6.3. Effect of different plant extracts on the total body weight of Drosophila melanogaster third-instar larvae HSD significantly reduced the larval weight compared with the control. Upon treatment, the larval weight significantly increased compared with the HSD-fed larvae. All plant extracts and Amaryl drug significantly enhanced the weight compared with the control larvae. 6.4. Effect of Atriplex halimus on the hemolymph glucose and trehalose of Drosophila melanogaster third-instar larvae HSD induced higher levels of hemolymph glucose and trehalose in Drosophila larvae compared with the controls. Tukey test showed that the crude extract of A. halimus was able to significantly decrease the titers of hemolymph glucose and trehalose compared with those in HSD. These levels reached the control level. 6.5. Preliminary phytochemical screening of the plants under investigation Phytochemical analysis showed that all investigated plants contained carbohydrates and/or glycosides, sterols and/or triterpenes, catechol tannins and flavonoids. M. oleifera, T. patula leaves and A. halimus aerial parts contain alkaloids. Saponins are present in both M. oleifera Leaves and A. halimus aerial parts. 6.6. Effect of different fractions of Atriplex halimus extract on the diabetic Drosophila melanogaster third-instar larvae The extract of A. halimus was fractionated using different solvents (petroleum ether 60/80, methylene chloride, ethyl acetate, and n-butanol) 6.6.1. Effect of Atriplex halimus fractions on the total body glucose of Drosophila melanogaster third-instar larvae HSD induced a significant increase in the total body glucose of D. melanogaster larvae compared with the control. Petroleum ether, ethyl acetate and n-butanol fractions at a concentration of 0.05% were able to significantly decrease the body glucose compared with HSD. The contents of body glucose following treatment with petroleum ether, ethyl acetate and n-butanol fractions reached the control content. 6.6.2. Effect of Atriplex halimus fractions on the total body trehalose of Drosophila melanogaster third-instar larvae Results showed that the total body trehalose of HSD-fed larvae was significantly higher than those in controls. However, when larvae fed on a treated diet with the fractions of petroleum ether, ethyl acetate, and n-butanol at a concentration of 0.05%, the total body trehalose significantly decreased again compared with those in HSD-fed larvae. These contents observed were near the control contents. 6.6.3. Effect of Atriplex halimus fractions on the total body weight of Drosophila melanogaster third-instar larvae HSD significantly reduced the larval weight compared with the control. Upon treatment with petroleum ether, methylene chloride, ethyl acetate, and n-butanol fractions at a concentration (0.05%), the larval weight significantly increased compared with the HSD-fed larvae. 6.7. Effect of the ethyl acetate fraction on the hemolymph glucose and trehalose of Drosophila melanogaster third-instar larvae HSD induced higher levels of hemolymph glucose and trehalose in Drosophila larvae compared with the controls. Tukey multiple comparisons demonstrated that the ethyl acetate fraction (0.05%) was able to significantly decrease the titers of hemolymph glucose and trehalose compared with those in HSD. 6.8. Effect of A. halimus ethyl acetate fraction on glycogen, lipid and protein contents in diabetic Drosophila larvae Results demonstrated that HSD induced a significant decrease in the glycogen and lipid contents compared with the control, while it did not cause any significant difference in protein content. Upon treatment with the ethyl acetate fraction, Tukey test did not show any significant differences in glycogen, lipid and protein contents between HSD-fed larvae and treated larvae. 6.9. Effect of A. halimus ethyl acetate fraction on the insulin signaling expressions in Drosophila melanogaster larvae Tukey test demonstrated significant increases in DILP2, DILP3, and AKH expressions in HSD-fed larvae compared with those in the control groups. However, when the larvae fed on ethyl acetate fraction in the diet, the expression of three genes DILP2, DILP3, and AKH significantly decreased compared with those levels in HSD-fed larvae. 6.10. LC-ESI-MS/MS analysis of ethyl acetate fraction of A. halimus L. herb In negative mode, The LC-ESI-MS/MS analysis of ethyl acetate fraction of A. halimus L. herb resulted in a tentative identification of 32 bioactive metabolites. 6.10.1. characterization of flavonoids and flavonoid glycosides: Ten flavonoids and fifteen flavonoid glycosides were identified as follows: Flavonoids: Two Flavonols (quercetin, myricetin), two flavones (luteolin, apigenin), two flavan (hesperetin and (+)-3,3’,4 ,5,7- pentahydroxyflavan), flavanolol (+)taxifolin and three methoxylated flavonoids (3,5,7-trihydroxy-4’-methoxyflavone, 3’-methoxy-4’,5,7- trihydroxyflavonol, and acacetin). Flavonoid Glycosides: Fifteen flavonoid glycosides were identified as: okanin-4’-Oglucoside, isorhamnetin-3-O-glucoside, isorhamnetin-3-O-rutinoside, kaempferol-3-O-α-L-rhamnoside, kaempferol-7-neohesperidoside, kaempferol-3-O-α-L-arabinoside, baicalein-7-O-glucuronide, luteolin-3’,7-di-O-glucoside, luteolin-7-O-glucoside, apigenin-7-Oglucoside, maritimetin-6-O-glucoside, quercetin-3-D-xyloside, rhoifolin, and eriodictyol-7-O-neohesperidoside, and daidzein-8-Cglucoside. 6.10.2. characterization of miscellaneous compounds: D (-) Quinic acid, esculin (coumarin glycosides), E-4,5’- dihydroxy-3-methoxy-3’-glucopyranosylstilbene, E-3,4,5’-trihydroxy- 3’-glucopyranosylstilbene, zearalenone, rosmarinic acid, and gammalinolenic acid.