[Observations on organic components of thermal mud: morphohistochemical and biochemical studies on lipid components of mud of the Terme dei Papi (Laghetto del Bagnaccio, Viterbo). Chemical bases of the interpretation of biological and therapeutic actions of thermal mud]. / Osservazioni sulla componente organica dei fanghi termali: indagini morfoistochimiche e biochimiche sui componenti lipidici dei fanghi delle Terme dei Papi (Laghetto del Bagnaccio, Viterbo). Basi chimiche per l'interpretazione di azioni biologiche e terapeutiche dei fanghi termali.

In previous findings the lipidic fractions extracted acc. to Folch from the mature muds of the majority of the Italian thermal springs hot baths was studied, with the aim to identify the organic substrates of their therapeutical activity. The organic components of the "mature" peloids are produced by the metabolism of the microphytozooplankton growing spontaneously in the clay-substrate, in contact with the hot water. The Popes thermal springs (Bagnaccio's Lake) are characterised by an unique environmental situation, because the muds are naturally matured in the hot thermal water, but not in artificial baths. The morphohistochemical aspects of thermal algae growing in the Bagnaccio's lake have been studied by means of Computerised Optic Probe Video-Microscopy, using a not contact zoom objective 70-400x. Peloid types, both the "white" and the "black" contains yellow pigments, fragments of hyphae, monocellular algae, Diatomeae, Cyanophyceae and few other species. The biochemical aspects of the muds extracts are characterised by the presence of Phospholipids (PC, PE, PS, SP), a series of Hydrocarbons ranging from C30 to C38, Phytosterols (beta-sitosterol, Campesterol, Stigmasterol and traces of Cholesterol), Free Fatty Acids (Palmitic, Palmitoleic, Myristic, Stearic, Oleic and Linoleic, heptadecenoic and heptadecanoic) and Terpenes (beta-amirrhyne, 24-methylene-cyclo-arthanole). In our opinion, the therapeutic effects of the mature muds are related to its organic components, with special regards to Phospholipids, Phytosterols and Terpenes. The richness of these components in the Popes Thermal springs seems to be great interest in the dermatological and cosmetic applications, other then the traditional use.