Thesis (Ph.D.) - Cairo University - Faculty of Pharmacy - Department of Pharmacognosy

Asclepiadaceae species have been reported to include several biologically active compounds such as steroid C21, which comprise the largest class of secondary plant substances. Therefore, this family is a productive source of pregnane glycosides, which they can be exploited for the treatment of many diseases such as anti-cancer, anti-obesity and antidiabetic. This study provided a detailed report on the characterization of Caralluma hexagona Lavranos, Caralluma eremastrum O. Schwartz or Huernia macrocarpa (A. Richard) Sprenger as well as the isolation and characterization of isolated compounds from the CH₂Cl₂ fraction of C. hexagona. On other hand, the crude aqueous and methanolic extracts and methanolic fractions of all species and isolated compounds were evaluated for their possible anti-metabolic syndrome in in vitro by measuring their antioxidant capacity and inhibitory activities against Ü-glucosidase and pancreatic lipase enzymes, and inhibition of AGEs generation through BSA{u2010}fructose (bovine serum albumin), BSA-methylglyoxal, and arginine methylglyoxal models and in vivo using high fat diet/streptozotocin-induced metabolic syndrome (MetS) rats. In vitro antiausterity activity also studied. Phytochemical characterization results showed that the greatest steroidal content was observed for the CH₂Cl₂ fractions. The investigation of the CH₂Cl₂ fraction of C. hexgaona led to the isolation and identification of seven new pregnane glycosides were termed Hexagonaside I - VII, along with four known compounds luteolin 4`-O-neohesperidoside, apigenin-8-C-neohesperoside, Ý-sitosterol and Ý-sitosterol glucoside. Regarding the enzyme assays, CH₂Cl₂ fractions showed the most potent Ü-glucosidase and lipase inhibitory effects

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