# State-of-the-Art and Opportunities for Bioactive Pentacyclic Triterpenes from Native Mexican Plants
## 2 Pentacyclic Triterpenes from Mexican Plants
### Biological Activity Survey of PCTs Found in Mexican Plants
reported the presence of three hopane-type triterpenes in _Cridoscolus spinosus_ with anti-inflammatory activity on mouse edema, and with antiparasitic and yeast \(\alpha\)-glucosidase influence inhibitory activities [37]. For the anti-inflammatory profiling, the edema was induced in mice by administrating a solution of 1.25 \(\mu\)g/ear of TPA (12-O-tetradecanoylphorol acetate) after the administration of the tested compounds. Indomethacin was used as the positive control at the same dose, and CHCl\({}_{3}\) was the negative control. After this first step, the compounds that showed an inhibition percentage greater than 50% were evaluated at a dose range from 0.18 to 1 \(\mu\)mol in 20 \(\mu\)L of chloroform. At a dose of 0.31 \(\mu\)mol/ear, 3\(\beta\)-acetoxy-hop-22(29)-ene **(22)** had the highest inhibitory activity among the three PCTs (57.27 \(\pm\) 16.99%), followed by 3\(\beta\)-hydroxy-hop-22(29)-ene **(23)** (27.05 \(\pm\) 7.38%) and 3-oxo-hop-22(29)-ene **(24)** (17.5 \(\pm\) 4.11%). The authors identified that the most effective PCT **(22)** had a dose-dependent activity, with an ID\({}_{50}\) of 0.36 \(\mu\)mol/ear, in comparison with indomethacin, the ID\({}_{50^{\prime}}\) of which was 0.24 \(\mu\)mol/ear. Regarding the inhibitory activity of \(\alpha\)-glucosidase, the authors used a mammalian (rat) (type 2 \(\alpha\)-glucosidaseases) and yeast (type 1 \(\alpha\)-glucosidaseases) model, testing PCTs at 1, 10, and 100 \(\mu\)M. The activity was concentration dependent. The highest inhibition was shown by compound **(22)**, which had an activity of 11.49, 83.5, and 98.79% for doses of 1, 10, and 100 \(\mu\)mol/ear, respectively. In second place, compound **(23)** showed an inhibition of 3.75, 4.41, and 23.47%; and lastly, the PCT **(24)** showed no inhibition at 1 \(\mu\)mol/ear but inhibited the enzyme by 1.51 and 7.39% at the remaining concentrations [37]. In this study, the authors found that the \(\alpha\)-glucosidase inhibitory activity was lower in the mammalian test. In addition, the antiparasitic activity against epimastigotes of _Trypanosoma cruzi_ Silvio, Cl Brener, and Queretaro strains and _T. rangeli_ and _Leishman mexicana_ was measured at a concentration of 50 \(\mu\)M. Compounds **(23)** and **(24)** reduced the viability of the Queretaro strain by more than 20% without affecting the viability of the host (Vero cells). Compound **(24)** was subsequentially tested at 50, 100, 200, and 400 \(\mu\)M, and **(22)** at 50 \(\mu\)M after 24 and 48 h. It is important to note that at 24 h, **(24)**reduced the viability of the Queretaro strain by more than 20% at all tested concentrations in a dose-dependent manner. It also had moderate effects on _T. rangeli_ and _L. Mexicana_, but it did not affect the viability of the Vero cells at any of the studied doses. On the other hand, the same PCT **(24)** lost its antiparasitic activity against the _T. cruzi_ strain after 48 h, but it started to affect the viability of the Vero cells. However, it showed inhibition on the Cl Brener and Silvio strains and _L. mexicana_. Finally, after 48 h, compound **(23)** did not affect the Vero cells nor the viability of _T. cruzi_[37]. In another study, [PERSON] and [PERSON] identified the presence of 12-ursene **(25)** in _Agarista mexicana_[38]. They analyzed the effects of the PCT on blood glucose levels in normal and alloxan-diabetic mice. Diabetes was induced by applying 70 mg/kg of alloxan 3 times every third day. Then, the triterpenes were administered intraperitoneally at a concentration of 50 mg/kg. In the normoglycemic mice, the animals were fasted 12 h prior to the experiment, and the blood glucose levels were measured after triterpene administration at 1.5, 2, 4.5, and 24 h [38]. Tolbutamide at 50 mg/kg was applied as a control, since this drug is responsible for stimulating pancreas \(\beta\)-cells, leading to an increase in insulin secretion [46]. In normal mice, the greatest glucose reduction was achieved 4.5 h after the administration of PCT.