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Plant Species from the Atlantic Forest Biome and Their Bioactive Constituents
Published in Luzia Valentina Modolo, Mary Ann Foglio, Brazilian Medicinal Plants, 2019
Rebeca Previate Medina, Carolina Rabal Biasetto, Lidiane Gaspareto Felippe, Lilian Cherubin Correia, Marília Valli, Afif Felix Monteiro, Alberto José Cavalheiro, Ângela Regina Araújo, Ian Castro-Gamboa, Maysa Furlan, Vanderlan da Silva Bolzani, Dulce Helena Siqueira Silva
Further investigation on the mutagenic properties of C. sylvestris was carried out using Tradescantia micronucleus assay, the MN test in mouse bone marrow cells, and the comet assay. The same extract (ELCS) and casearin X (44) (Figure 9.8), another clerodane diterpene isolated from this extract, were evaluated as protective agents against the harmful effects of airborne pollutants from sugarcane burning. The mutagenic agent in this case was total suspended particulate (TSP) from air, collected near Araraquara (São Paulo, Brazil) during the sugarcane-burning season. ELCS exhibited antimutagenic activity in the Tradescantia micronucleus assay and was able to reduce DNA damage caused by TSP in the MN test and in the comet assay, while compound 44 reduced only DNA damage assessed by the comet assay. Such data suggested that C. sylvestris extract and the isolated diterpenes might act by different mechanisms to protect DNA against damage, including repairable and non-repairable damages (Prieto et al., 2012).
Antimicrobial Properties of Traditional Medicinal Plants: Status and Potential
Published in Megh R. Goyal, Durgesh Nandini Chauhan, Plant- and Marine-Based Phytochemicals for Human Health, 2018
V. Duraipandiyan, T. William Raja, Naif Abdullah Al-Dhabi, Ignacimuthu Savarimuthu
Clerodane diterpene [(5R, 10R)-4R, 8 dihydrox-2S, 3R: 15, 16-diepoxycleroda-13 (16), 17, 12S, 18, 1S-dilactone] is isolated from an ethanolic extract of Tinospora cordifolia.10 This compound, depicted in Figure 2.1a, has antimicrobial activity against bacteria and fungi. Friedelin (Fig. 2.1b) is fractionated from hexane, ethyl acetate, and methanoicl extracts of Azima tetracantha leaves.
Protecting Pancreatic β-cells from Metabolic Insults
Published in Christophe Wiart, Medicinal Plants in Asia for Metabolic Syndrome, 2017
Ethanol extract of aerial part of Croton klozchianus (Wight) Twaites given orally to streptozotocin-induced diabetic Sprague–Dawley rats at a dose of 300 mg/kg/day for 3 weeks lowered glycemia by 44.3% and normalized plasma triglycerides and cholesterol.123In vitro, this extract at 2 mg/mL boosted insulin secretion from MIN6 cells challenged with glucose.123 The active constituent(s) involved here are to date unknown. Members of the genus Croton L. are known to elaborate diterpenes such as trans-dehydrocrotonin, which given orally at a single dose of 50 mg/kg to Wistar rats 1 hour before streptozotocin administration reduced glycemia by 61% after 72 hours.124 Likewise, a single oral administration of trans-dehydrocrotonin 48 hours after streptozotocin administration evoked a transient fall of glycemia from about 450 to 250 mg/dL.124 Trans-dehydrocrotonin from Croton cajucara Benth., evoked gastroprotective activity of on account of histamine H2 and muscarinic receptors antagonism.125 In rodents, muscarinic M3 and M1 activation induces the release of insulin whereas in human isolates, M3 muscarinic receptors are the most abundant.126–128 Gautam et al. (2006) made the interesting demonstration that mutant mice lacking the muscarinic receptor M3 in pancreatic β-cells had impaired glucose tolerance and reduced insulin release. In contrast, mutant mice overexpressing M3 receptors in pancreatic β-cells had increased glucose tolerance and insulinotropic potencies conferring resistance to diet-induced glucose intolerance and hyperglycemia.129 In a subsequent study, Kong et al. (2010), provided additional evidence that M3 muscarinic receptor stimulation not only enhances insulin release via protein kinase C activation and increase in intracellular calcium but induces 3-Phosphoinositide-dependent protein kinase 1 activation which augments insulin release by promoting trafficking of secretory vesicles to the plasma membrane.130 Thus, natural products with the ability to stimulate M3 muscarinic receptors in β-cells stimulate insulin secretion and the hypothesis of a cholinergic insulinotropic effect by a trans-dehydrocrotonin-like diterpene from Croton klotzschianus (Wight) Twaites need to be explored. Human islets are known to express histamine receptors (Amisten et al., 2013) and the parenteral administration of histamine H1 and H2 antagonists in healthy volunteers result in a decrease of insulin secretion compared with placebo.126,131 Therefore it would be of interest to explore further the insulinotropic mechanisms of Croton klotzschianus (Wight) Twaites and clerodane diterpene constituents with special emphasis on the type of receptors involved.
Evaluation of interconversion pharmacokinetics of 16α-hydroxycleroda-3,13(14)Z-dien-15,16-olide – a novel HMG-CoA reductase inhibitor and its acid metabolite using multi-compartmental pharmacokinetic model in mice
Published in Xenobiotica, 2019
Tulsankar Sachin Laxman, Santosh Kumar Puttervu, Anjali Mishra, Sarvesh Verma, S. P. Singh, K. V. Sashidhara, C. M. Marandi, Shivani Saxena, Manoj K. Yadav, Rabi S. Bhatta
4655K-09, clerodane diterpene reported for its anti-hyperlipidemic potential. The present IV pharmacokinetic investigations of 4655K-09 (lactone form) and its acid metabolite K-9T revealed the partial conversion of parent to metabolite and vice versa (Table 1). These results suggested that compounds underwent reversible metabolism along with irreversible elimination. However, the primary pharmacokinetic parameters of compounds undergoing reversible metabolism are often contaminated by the disposition characteristics of its metabolite (DiStefano, 1976; Oppenheimer & Gurpide, 1979). Therefore, to delineate reversible and irreversible disposition of parent and metabolite we utilized multi-compartmental interconversion model based data analysis (Gabrielsson & Weiner, 2015). In the present model, the linear reversible metabolism of parent and metabolite was assumed because the AUC of K-9T upon parent administration (Table 1 and Supplementary Figure 1). Also, the AUC versus dose plots for both parent and metabolite upon their administration exhibited linearity (r2) > 0.99 (Supplementary Figure 1). The organs involved in reversible and irreversible elimination of parent and metabolite constitute the rapidly perfused organs like liver, kidney, etc., which were lumped into central compartment. Therefore, in the present model it was also assumed that both reversible and irreversible elimination of parent and metabolite occurs primarily through central compartment.
Antinociceptive and anxiolytic-like effects of a neo-clerodane diterpene from Salvia semiatrata aerial parts
Published in Pharmaceutical Biology, 2020
Nancy Ortiz-Mendoza, Lizeth M. Zavala-Ocampo, Martha J. Martínez-Gordillo, María Eva González-Trujano, Francisco A. Basurto Peña, Iván J. Bazany-Rodríguez, José Alberto Rivera Chávez, Alejandro Dorazco-González, Eva Aguirre-Hernández
From the pharmacological evaluation of the extracts, it was obtained that the medium polar extract showed the highest yield, being 5- and 2-fold more abundant than the hexane and methanol, respectively (Figure 1). The chromatographic separation of the ethyl acetate extract lead to the isolation of the of the most abundant metabolite, identified as 7-keto-neo-clerodan-3,13-dien-18,19: 15,16-diolide (1), a neo-clerodane diterpene. This compound was purified for the first time from S. semiatrata as a crystalline form (Figure 2).