Exudate and Propolis from Escallonia pulverulenta: Phytochemical Characterization and Antibacterial Activity.

Propolis is a complex mixture formed from exudates that bees collect from plants and then mix with beeswax and their own salivary enzymes. Chilean propolis is characterized by the presence of phenolic compounds, which are considered responsible for the biological activities. The endemic species Escallonia pulverulenta (Ruiz and Pav.) Pers. [Escalloniaceae] is a recognized source of exudate to produce propolis. This study reports for the first time the chemical profile and antibacterial activity of E. pulverulenta exudate and leaves, as well as two samples of Chilean propolis. Palynological and morphological analysis showed the presence of E. pulverulenta as one of the main species in the propolis samples. UPLC-MS/MS analyses enabled the identification of phenolic acids in the leaves and in the propolis. Conversely, flavonoids are mainly present in exudates and propolis. Quercetin is the most abundant flavonol in the exudate, with similar concentrations in the propolis samples. Nevertheless, the main compound present in both samples of propolis was the flavanone pinocembrin. The antibacterial results obtained for exudate and propolis have shown a similar behavior, especially in the inhibition of Streptococcus pyogenes. These results show the importance of the exudates collected by the bees in the chemical composition and antibacterial capacity of propolis.

Subtribe Hyptidinae (Lamiaceae): A promising source of bioactive metabolites.

ETHNOPHARMACOLOGICAL RELEVANCE: The subtribe Hyptidinae contains approximately 400 accepted species distributed in 19 genera (Hyptis, Eriope, Condea, Cantinoa, Mesosphaerum, Cyanocephalus, Hypenia, Hyptidendron, Oocephalus, Medusantha, Gymneia, Marsypianthes, Leptohyptis, Martianthus, Asterohyptis, Eplingiella, Physominthe, Eriopidion and Rhaphiodon). This is the Lamiaceae clade with the largest number of species in Brazil and high rates of endemism. Some species have been used in different parts of the world mainly as insecticides/pest repellents, wound healing and pain-relief agents, as well as for the treatment of respiratory and gastrointestinal disorders. AIM OF THE REVIEW: This review aims to discuss the current status concerning the taxonomy, ethnobotanical uses, phytochemistry and biological properties of species which compose the subtribe Hyptidinae. MATERIALS AND METHODS: The available information was collected from scientific databases (ScienceDirect, Pubmed, Web of Science, Scopus, Google Scholar, ChemSpider, SciFinder ACS Publications, Wiley Online Library), as well as other literature sources (e.g. books, theses). RESULTS: The phytochemical investigations of plants of this subtribe have led to the identification of almost 300 chemical constituents of different classes such as diterpenes, triterpenes, lignans, α-pyrones, flavonoids, phenolic acids and monoterpenes and sesquiterpenes, as components of essential oils. Extracts, essential oils and isolated compounds showed a series of biological activities such as insecticide/repellent, antimicrobial and antinociceptive, justifying some of the popular uses of the plants. In addition, a very relevant fact is that several species produce podophyllotoxin and related lignans. CONCLUSION: Several species of Hyptidinae are used in folk medicine for treating many diseases but only a small fraction of the species has been explored and most of the traditional uses have not been validated by current investigations. In addition, the species of the subtribe appear to be very promising as alternative sources of podophyllotoxin-like lignans which are the lead compounds for the semi-synthesis of teniposide and etoposide, important antineoplastic agents. Thus, there is a wide-open door for future studies, both to support the popular uses of the plants and to find new biologically active compounds in this large number of species not yet explored.

Hepatoprotective species from the Chilean medicinal flora: Junellia spathulata (Verbenaceae).

ETHNOPHARMACOLOGICAL RELEVANCE: Chilean population relies on medicinal plants for treating a wide range of illnesses, especially those of the gastrointestinal system. Junellia spathulata (Gillies & Hook.) Moldenke var. spathulata (Verbenaceae), called as "verbena-azul-de-cordilleira", is a medicinal plant native to Argentina and Chile traditionally used for treating digestive disorders. Although the species of the genus are important as therapeutic resources for the Andean population, the plants are very scarcely studied. AIMS OF THE STUDY: The purpose of the present study was to find out the main constituents and investigate the protective effect of J. spathulata against oxidative stress induced by the potent oxidant 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH) in human hepatoblastoma cells. MATERIALS AND METHODS: The crude methanol extract of J. spathulata and an iridoid obtained by chromatographic processes were tested to access the hepatoprotective effect and cytotoxicity in HepG2 cell. In addition, the reducing power of the samples and their ability to scavenge free radicals were evaluated using FRAP and ORAC assay systems. RESULTS: The iridoid asperuloside, the main compound of the crude methanol extract of J. spathulata, was isolated and identified by means of NMR analysis. The crude methanol extract of J. spathulata and asperuloside protected HepG2 cells against oxidative damage triggered by AAPH-derived free radicals. This effect can be credited to the ability of the extract and asperuloside to protect the liver cells from chemical-induced injury, which might be correlated to their free radical scavenging potential. CONCLUSIONS: This study experimentally evidenced the ethnopharmacological usefulness of J. spathulata as a treatment of digestive disorders. Our result could stimulate further investigations of hepatoprotective agents in other Chilean Junellia species.

Antinociceptive Activity of Phloroglucinol Derivatives Isolated from Southern Brazilian Hypericum Species.

The south Brazilian Hypericum species have revealed the presence of a series of biologically active phloroglucinol derivatives. In this study, a mixture of japonicine A and an isomer with an unreported structure, named japonicine E, was isolated from the roots of H. polyanthemum. Additionally, uliginosin A from H. myrianthum, isouliginosin B from H. polyanthemum, hyperbrasilol B and isohyperbrasilol B from H. caprifoliatum and cariphenone A from H. carinatum were also isolated. The structures were elucidated using 1D- and 2D-NMR experiments and by comparison with previously reported data. The compounds japonicines A/E, uliginosin A, isouliginosin B, hyperbrasilol B and cariphenone A exhibited antinociceptive activity in the mice hot-plate test and did not induce motor impairment in the rotarod apparatus.