Laticifer Identification, Rubber Characterization, Phenolic Content, and Antioxidant Activity of Pergularia tomentosa Latex Extract

Pergularia tomentosa is a perennial twining herb widely spread out arid and semiarid Tunisian regions. It is searched for its richness in enzymes, secondary metabolites, antifungal activity, and milk-clotting activity. Traditional use implies the fresh latex in wounding heals. The present study was aimed at identifying laticifer distribution in Pergularia tomentosa stems, leaves, and petioles. In the present study, the identification of latex extract's components and its valorisation by estimation of phenolic content, flavonoids, and antioxidant activity are conducted. Anatomical structures proved the presence of laticifers in the aerial parts of Pergularia tomentosa. They are particularly observed along the pith and cortical parenchyma in stem, in leaf mesophyll, and in petiole phloem. Identified laticifers were characterized as nonarticulated. FTIR spectroscopy proves the presence of several functional groups in the latex and mainly the cis-1-4-isoprene monomer. Results suggested that Pergularia tomentosa latex contributes significantly as a source of phenol content (62.3 mg Eq GAE/g) and flavonoids (24.8 mg Eq QE/g). Scavenging free radicals of DPPH exhibited IC(50) value of 12 μg/ml. In conclusion, latex extracted from Pergularia tomentosa can be implied in industry as a natural rubber. It can be used, also, in medicine as a therapeutic agent.