Table 2. Effect of OB/T2D and treatment with Ziziphus fruits at different maturation stages (ZFU, ZFHR, ZFR) and leaves (ZL) on key metabolic enzyme activities. The activities of glucose anabolic enzymes (G6PDH, G6P, FBP, PEPCK), glucose catabolic enzymes (HK, PFK, LDH), and Krebs cycle enzymes (IDH, SDH, MDH) were evaluated. Oral administration of Ziziphus fruit and leaf extracts suppressed glucose anabolism and promoted glucose catabolism both in the plasma and through Krebs cycle activity, thereby contributing to improved glucose regulation, with the most pronounced protective effects against metabolic dysregulation observed in rats treated with semi-ripe fruits. Statistical significance was determined as follows: *p ≤ 0.05 vs. Con; @p ≤ 0.05 vs. OB/T2D; αp ≤ 0.05 vs. ZFU; βp ≤ 0.05 vs. ZFHR; Ωp ≤ 0.05 vs. ZFR; ¥p ≤ 0.05 vs. ZLa.
| Con | OB/T2D | OB/T2D-ZFU | OB/T2D-ZFHR | OB/T2D-ZFR | OB/T2D-ZL | OB/T2D-ORL | |
|---|---|---|---|---|---|---|---|
| Liver glucose anabolic enzymes activities (U per mg protein) | |||||||
| G6PDH | 218 ± 7 | 489 ± 13* | 369 ± 11*@ | 286 ± 9*@α | 342 ± 12*@α | 409 ± 15*@αβΩ | 249 ± 9*@αβΩ¥ |
| G6P | 987 ± 37 | 1897 ± 68* | 1254 ± 43*@ | 1098 ± 38*@α | 1487 ± 54*@αβ | 1589 ± 67*@αβΩ | 1603 ± 75*@αβΩ |
| FBP | 412 ± 11 | 789 ± 23* | 564 ± 19*@ | 498 ± 22*@α | 619 ± 27*@αβ | 668 ± 31*@αβ | 681 ± 26*@αβΩ |
| PEPCK | 87 ± 4 | 256 ± 11* | 187 ± 7*@ | 113 ± 5*@α | 155 ± 6*@αβ | 203 ± 8*@αβΩ | 98 ± 4*@αβΩ¥ |
| Liver glucose catabolic enzymes activities (U per mg protein) | |||||||
| HK | 187 ± 6 | 87.9 ± 7* | 134 ± 6*@ | 163 ± 4*@α | 123 ± 7*@β | 103 ± 3*@αβΩ | 96.4 ± 4*αβΩ¥ |
| PK | 197 ± 7 | 91.2 ± 3* | 142 ± 6*@ | 172 ± 7*@α | 112 ± 5*@αβ | 119 ± 5*@αβ | 110 ± 6*@αβ |
| LDH | 785 ± 23 | 478 ± 26* | 598 ± 24*@ | 709 ± 27*@α | 642 ± 27*@β | 637 ± 29*@αβ | 643 ± 26*@αβ |
| PFK | 378 ± 22 | 107 ± 5* | 323 ± 11*@ | 364 ± 9@α | 262 ± 8*@αβ | 207 ± 6*@αβΩ | 189 ± 7*@αβΩ¥ |
| Liver Krebs cycle enzymes activities (U per mg protein) | |||||||
| IDH | 3.78 ± 0.1 | 1.7 ± 0.08* | 2.98 ± 0.1*@ | 3.18 ± 0.1*@α | 2.7 ± 0.1*@αβ | 2.89 ± 0.17*@αβ | 2.3 ± 0.09*@αβ¥ |
| SDH | 2.87 ± 0.2 | 1.43 ± 0.1* | 2 ± 0.23@ | 2.4 ± 0.17*@α | 2.1 ± 0.15*@β | 1.94 ± 0.16*@β | 1.7 ± 0.13*@αβΩ |
| MDH | 1.89 ± 0.2 | 0.4 ± 0.08* | 1.3 ± 0.2*@ | 1.6 ± 0.02*@ | 1.2 ± 0.14*@β | 0.74 ± 0.1*@αβΩ | 0.6 ± 0.05*@αβΩ |
a
Abbreviations: glucose-6-phosphate dehydrogenase (G6PDH), hexokinase (HK), phosphofructokinase (PFK), pyruvate kinase (PK), glucose-6-phosphatase (G6P), fructose-1,6-bisphosphatase (FBP), lactate dehydrogenase (LDH), phosphoenolpyruvate carboxykinase (PEPCK), isocitrate dehydrogenase (IDH), succinate dehydrogenase (SDH), and malate dehydrogenase (MDH).