Antiproliferative Effect and the Isolated Compounds of Pouzolzia indica

Friedelane, isolated from Pouzolzia indica Gaud. exhibits toxic effect against melanoma

Melanoma is a predominant cause of skin cancer-related deaths. It was reported that, the methanolic extract of Pouzolzia Indica (P. indica) on chromatography gave five compounds (1-hentriacontanyl palmitate, myricyl alcohol, 6,7-dimethoxycoumarin, trichadonic acid and friedelane), which inhibited the acute promyelocytic leukemia cell lines, NB4, and HT93A. Friedelane was extracted as active compound from methanolic extract of P. indica. In this study, friedelane was tested on murine metastatic B16F10 and B16BL6 melanoma cell lines. To achieve the target, the cell viability using trypan blue exclusion, acridine orange/EtBr staining and cell cytotoxicity were tested using MTT assay. Caspase-3, caspase-9, Cyt-c, BAD and Bax protein were assayed to evidence the apoptosis induction. The compound friedelane shows potent cytotoxic effect against metastatic melanoma mouse cell lines in 10 µg/ml concentration.

Friedelin Synthase from Maytenus ilicifolia: Leucine 482 Plays an Essential Role in the Production of the Most Rearranged Pentacyclic Triterpene

Among the biologically active triterpenes, friedelin has the most-rearranged structure produced by the oxidosqualene cyclases and is the only one containing a cetonic group. In this study, we cloned and functionally characterized friedelin synthase and one cycloartenol synthase from Maytenus ilicifolia (Celastraceae). The complete coding sequences of these 2 genes were cloned from leaf mRNA, and their functions were characterized by heterologous expression in yeast. The cycloartenol synthase sequence is very similar to other known OSCs of this type (approximately 80% identity), although the M. ilicifolia friedelin synthase amino acid sequence is more related to β-amyrin synthases (65-74% identity), which is similar to the friedelin synthase cloned from Kalanchoe daigremontiana. Multiple sequence alignments demonstrated the presence of a leucine residue two positions upstream of the friedelin synthase Asp-Cys-Thr-Ala-Glu (DCTAE) active site motif, while the vast majority of OSCs identified so far have a valine or isoleucine residue at the same position. The substitution of the leucine residue with valine, threonine or isoleucine in M. ilicifolia friedelin synthase interfered with substrate recognition and lead to the production of different pentacyclic triterpenes. Hence, our data indicate a key role for the leucine residue in the structure and function of this oxidosqualene cyclase.