THE OCCURRENCE OF IRIDOID GLYCOSIDES IN THE VERBENACEAE*

Lamiide and Ipolamiide: A Comprehensive Review of Their Bioactive Properties and Therapeutic Potential

There is an increasing interest in using iridoids and secoiridoids as major targets for chemical synthesis and biosynthesis. Iridoids can be found in numerous species of Lamiaceae, Verbenaceae, Scrophulariaceae, and other families. Iridoids possess a chemical structure characterized by a cyclopentane ring with oxidative substituents, forming a six-membered ring. Various research groups have used these structures as valuable starting materials for regioselective and stereoselective synthesis. This approach has enormous potential for the production of bioactive alkaloids, prostaglandin analogues, and other bioactive natural compounds. Because there is currently no review on lamiide and ipolamiide, this review intends to pique researchers' interest in this vital topic of natural science for drug discovery from naturally occurring iridoids. Lamiide and ipolamiide have the potential to be useful tools in the pharmaceutical sector, enabling the use of these plant metabolites in a variety of medicinal compositions. Given that these molecules appear to be potential natural substances for treating human ailments, we get light on them as alternative therapeutic approaches using these compounds alone or in combination with other substances which will potentially lead to future (pre)-clinical investigations.

Quality, Safety and Biological Studies on Campylanthus glaber Aerial Parts

In Cabo Verde, several endemic species are used in traditional medicine. However, no scientific studies have been conducted on the quality, efficacy, and safety of most of these plants. This study focused on establishing the botanical and chemical identification parameters required for a quality monograph of Campylanthus glaber Benth. aerial parts, a medicinal plant of Cabo Verde traditionally used to treat fever and muscular pain. In addition, in vitro antioxidant and antihyperglycemic activity, cytotoxicity, and genotoxicity were assessed for this medicinal plant. Optical microscopy, LC/UV-DAD-ESI/MS, and colorimetric assays were used for botanical, chemical, and biological studies, respectively. Cytotoxicity was assessed by the MTT assay with HepG2 cells, and genotoxicity by the Ames test. Microscopically, the xeromorphic leaf of C. glaber presents a thick cuticle (13.6-25.5 µm), thick-walled epidermal cells, anomocytic-type stomata, glandular trichomes (stalk length = 49.4-120.8 µm), and idioblasts containing calcium oxalate microcrystals. The chemical screening of aqueous and hydroethanolic extracts of this medicinal plant revealed the presence of organic acids, iridoids, phenylethanoids, and flavonoids as the main classes of marker compounds, with malic acid, citric acid, and verbascoside being the main marker compounds identified. Both extracts showed similar LC/UV-DAD/ESI-MS qualitative profiles and DPPH radical scavenger activity (IC50 = 130.9 ± 1.4; 134.3 ± 3.1 µg/mL). The hydroethanolic extract inhibited both α-amylase and α-glucosidase enzymes in a dose-dependent manner. Both extracts showed no cytotoxicity (up to 1000 µg/mL) by the MTT assay and no genotoxic potential with or without metabolic activation up to 5 mg /plate. The results obtained are an important contribution to the monographic quality assessment of C. glaber aerial parts and suggest that this medicinal plant may be safe and potentially used as an herbal drug raw material for pharmaceutical purposes.

Two new iridoid glycosides from Hedyotis diffusa

Two new iridoid glycosides, named productasperulosidic acid butyl ester (1) and E-6-O-3-hydroxy-p-methoxycinnamoyl scandoside methyl ester (2), along with nine known ones (3-11), were isolated from Hedyotis diffusa Willd. The structures of them were elucidated by extensive 1D, 2D NMR and HR-ESI-MS spectral data. Compounds 1-11 showed no significant cytotoxic activity against HeLa cells.

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.

Harpagide: Occurrence in plants and biological activities - A review

In this review article, the occurrence of harpagide in the plant kingdom and its associated biological activities are presented and detailed for the first time. The presence of harpagide has been reported in several botanical families within Asteridae, and harpagide has been observed to exert a wide number of biological activities such as cytotoxic, anti-inflammatory, and neuroprotective. These results show how harpagide can be recovered from several natural sources for several pharmacological purposes even if there is a lot to still be studied. Nowadays, the interest is related to its presence in phytomedicines. Threfore, these studies are useful to support and validate the large use of several plants in the folklore medicine.

Incorporation of an introduced weed into the diet of a native butterfly: consequences for preference, performance and chemical defense

The introduction of exotic plants, animals, and pathogens into non-native ecosystems can have profound effects on native organisms. Plantago lanceolata, narrow-leaf or ribwort plantain (Plantaginaceae), is a weed that was introduced to North America from Eurasia approximately 200 years ago and that has been incorporated into the diet of a variety of native North American herbivores. Plantain contains two iridoid glycosides, aucubin and catalpol, that can be toxic or deterrent to non-specialized herbivores or herbivores that have recently incorporated this species into their diet. Anartia jatrophae (Nymphalidae), the white peacock, feeds on plants in five families including the Plantaginaceae, and was recently observed feeding on plantain; however, the effects of feeding on this novel host plant are unknown. In this study, we performed a series of experiments to assess larval preference and performance on the introduced P. lanceolata and on a native host plant that does not contain iridoid glycosides, water hyssop, Bacopa monnieri (Plantaginaceae). We also tested whether or not white peacocks were able to sequester iridoid glycosides and compared this ability with an iridoid specialist, the buckeye, Junonia coenia (Nymphalidae). White peacocks successfully developed to the adult stage on plantain; larvae grew more slowly but pupae were heavier when compared with larvae and pupae reared on the native host plant. Larvae showed induced feeding preferences for the host plant on which they were reared. Furthermore, larvae sequestered small amounts of iridoids that were also retained in pupae and adults. These results suggest that incorporation of the introduced weed, plantain, into the diet of the white peacock may have important consequences for larval performance and preference, as well as for interactions with natural enemies.

Gynecological efficacy and chemical investigation of Vitex agnus-castus L. fruits growing in Egypt

Flavonoid glycosides, orientin and apigenin 3, 8-di-C-glycosides in addition to, iridoid compound, aucubin were isolated from the ethanolic extract of Vitex agnus-castus fruits. Their structures were identified on the basis of the spectroscopic data. The estrogenic activity of the ethanolic extract in two dose levels 0.6 and 1.2 g kg(-1) per body weight (b.w.) was studied by the vaginal smear, and uterine weight methods for normal and ovariectomized female rats. The extract induced significant increase in the uterine weight of ovariectomized rats at two dose levels comparable to that of control group. The percentages of the total average number of scores were increased significantly too. Significant increases in plasma progesterone and total estrogens levels were shown at the two dose levels when compared to that of control group. On the other side, the extract induced significant reduction in luteinizing and plasma prolactin hormones.