Kaurenoic acid from pulp of Annona cherimolia in regard to Annonaceae-induced Parkinsonism

Bio-Guided Isolation of Acetogenins from Annona cherimola Deciduous Leaves: Production of Nanocarriers to Boost the Bioavailability Properties

Annonaceous acetogenins (ACGs) are lipophilic polyketides isolated exclusively from Annonaceae. They are considered to be amongst the most potent antitumor compounds. Nevertheless, their applications are limited by their poor solubility. The isolation of ACGs from Annona cherimola leaves, an agricultural waste, has not been reported to date. Molvizarin (1) cherimolin-1 (2), motrilin (3), annonacin (4) and annonisin (5) are isolated for the first time from A. cherimola deciduous leaves. Annonacin was found to be four- and two-times more potent in tumoral cells (HeLa, 23.6% live cells; IGROV-1, 40.8% live cells for 24 h) than in HEK-293 at 50 µM (24 h, 87.2% live cells). Supramolecular polymer micelles (SMPMs) were synthesized to encapsulate the major ACG isolated, annonacin, in order to improve its solubility in aqueous media. The bioavailability of this compound was increased by a factor of 13 in a simulated human digestive system when compared with free annonacin and an encapsulation efficiency of 35% was achieved. In addition, the cytotoxic activity of SMPMs that hosted annonacin (100 µM, 24 h, 5.8% live cells) was increased compared with free annonacin in water (100 µM, 24 h, 92% live cells). These results highlight the use of by-products of A. cherimola, and their pure compounds, as a promising source of anticancer agents. The use of SMPMs as nanocarriers of ACGs could be an alternative for their application in food field as nutraceutical to enhance the administration and efficacy.

Pharmacokinetic Profile of Kaurenoic Acid after Oral Administration of Araliae Continentalis Radix Extract Powder to Humans

The objective of this study was to characterize pharmacokinetics (PKs) of kaurenoic acid (KAU) after administration of the clinical usual dose of Araliae Continentalis Radix extract powder to Korean subjects for the first time and evaluate the mechanism of its absorption in vitro. A simple, sensitive, and selective analytical method was developed for the detection of KAU in human plasma. Concentrations of KAU were quantified by ultra-performance liquid chromatography tandem mass spectrometry after simple liquid–liquid extraction. This pharmacokinetic model of KAU was best described by a two-compartment model with first-order absorption. To identify efflux transporters involved in the absorption of KAU, a Caco-2 monolayer model was used. Estimated PK parameters were: systemic clearance, 23.89 L/h; inter-compartmental clearance, 15.55 L/h; rate constant for absorption, 1.72 h⁻¹; volume of distribution of the central compartment, 24.44 L; and volume of distribution of the peripheral compartment, 64.05 L. Results from Caco-2 bidirectional transport study suggested that KAU was a potential substrate of efflux transporters. In summary, PKs of KAU were successfully characterized after administration of a usual dose of Araliae continentalis Radix extract powder in human with the newly developed bioanalytical method and the mechanism of absorption of KAU was identified clearly.

Medicinal Plants from North and Central America and the Caribbean Considered Toxic for Humans: The Other Side of the Coin

The consumption of medicinal plants has notably increased over the past two decades. People consider herbal products as safe because of their natural origin, without taking into consideration whether these plants contain a toxic principle. This represents a serious health problem. A bibliographic search was carried out using published scientific material on native plants from Mexico, Central America, and the Caribbean, which describe the ethnobotanical and toxicological information of medicinal plants empirically considered to be toxic. A total of 216 medicinal plants belonging to 77 families have been reported as toxic. Of these plants, 76 had been studied, and 140 plants lacked studies regarding their toxicological effects. The toxicity of 16 plants species has been reported in clinical cases, particularly in children. From these plants, deaths have been reported with the consumption of Chenopodium ambrosioides, Argemone mexicana, and Thevetia peruviana. In most of the cases, the principle of the plant responsible for the toxicity is unknown. There is limited information about the toxicity of medicinal plants used in Mexico, Central America, and the Caribbean. More toxicological studies are necessary to contribute information about the safe use of the medicinal plants cited in this review.

Antihyperglycemic Activity of the Leaves from Annona cherimola Miller and Rutin on Alloxan-induced Diabetic Rats

Background:

Annona cherimola, known as “chirimoya” has been reported in Mexican traditional medicine for the treatment of diabetes.

Objective:

The aims of the present study were to validate and assess the traditional use of A. cherimola as an antidiabetic agent.

Materials and Methods:

The ethanol extract from A. cherimola (300 mg/kg, EEAc), subsequent fractions (100 mg/kg), and rutin (30 mg/kg) were studied on alloxan-induced type 2 diabetic (AITD) and normoglycemic rats. In addition, oral glucose tolerance test (OGTT) and oral sucrose tolerance test (OSTT) were performed in normoglycemic rats. Molecular docking technique was used to conduct the computational study.

Results:

Bioassay-guided fractionation of EEAc afforded as major antihyperglycemic compound, rutin. EEAc attenuated postprandial hyperglycemia in acute test using AITD rats (331.5 mg/dL) carrying the glycemic levels to 149.2 mg/dL. Rutin after 2 h, attenuated postprandial hyperglycemia in an acute assay using AITD rats such as EEAc, with maximum effect (150.0 mg/dL) being seen at 4 h. The antihyperglycemic activities of EEAc and rutin were comparable with acarbose (151.3 mg/dL). In the subchronic assay on AITD rats, the EEAc and rutin showed a reduction of the blood glucose levels since the 1^st week of treatment, reaching levels similar to normoglycemic state (116.9 mg/kg) that stayed constant for the rest of the assay. OGTT and OSTT showed that EEAc and rutin significantly lowered blood glucose levels in normoglycemic rats at 2 h after a glucose or sucrose load such as acarbose. Computational molecular docking showed that rutin interacted with four amino acids residues in the enzyme α-glucosidase.

Conclusion:

The results suggest that rutin an α-glucosidase inhibitor was responsible in part of the antihyperglycemic activity of A. cherimola. Its in vivo antihyperglycemic activity is in good agreement with the traditional use of A. cherimola for the treatment of diabetes.

SUMMARY

The ethanol extract from Annona cherimola (300 mg/kg, EEAc), subsequent fractions (100 mg/kg) and rutin (30 mg/kg) were studied on alloxan-induced type 2 diabetic (AITD) and normoglycemic rats. The results suggest that rutin; an α-glucosidase inhibitor was responsible in part of the antihyperglycemic activity of A. cherimola. Its in vivo antihyperglycemic activity is in good agreement with the traditional use of A. cherimola for the treatment of diabetes.

Abbreviations Used: EEAc: The ethanol extract from Annona cherimola, AITD: Alloxan-induced type 2 diabetic rats, OGTT: Oral glucose tolerance test, OSTT: Oral sucrose tolerance test, DM: Diabetes mellitus

Identification of the environmental neurotoxins annonaceous acetogenins in an Annona cherimolia Mill. Alcoholic Beverage Using HPLC-ESI-LTQ-Orbitrap

Epidemiological and toxicological studies have suggested Annonaceaeous acetogenins to be environmental neurotoxins responsible for sporadic atypical parkinsonism/dementia in tropical areas. These compounds are present in the tropical genus Annona (Annonaceae), known for its fruit-yielding cultivated species such as Annona cherimolia. This species is widely cultivated in South America, Spain, and Portugal and yields acetogenins in its seeds, stems, and roots. The presence of these compounds in the pulp of its fruit and in derived food products is unclear. An innovative and sensitive methodology by HPLC-ESI-LTQ-Orbitrap with postcolumn infusion of lithium iodide was used to identify the presence of low levels of acetogenins in an A. cherimolia Mill. fruit-based commercial alcoholic beverage. More than 80 representatives were detected, and the 31 most intense acetogenins were identified. All together these findings indicate that this species should be considered as a risk factor within the framework of a worldwide problem of food toxicity.

The remarkable structural diversity achieved in ent-Kaurane Diterpenes by fungal biotransformations

The use of biotransformations in organic chemistry is widespread, with highlights of interesting applications in the functionalization of natural products containing unactivated carbons, like the kaurane diterpenes. A number of compounds with kaurane skeletons can be isolated in large amounts from several plant species and a myriad of biological activities has been related to these compounds. Studies on structure versus activity have showed that, in most cases, in kaurane diterpenes, activity increases with the increase of functionalization. Since naturally occurring kaurane diterpenes usually have limited functional groups to be used as targets for semi-synthetic modifications, production of more polar derivatives from kaurane diterpenes have been achieved mostly through the use of fungal biotransformations. In this review, selected examples the wonderful chemical diversity produced by fungi in kaurane diterpenes is presented. This diversity includes mainly hydroxylation of nearly all carbon atoms of the kaurane molecule, many of them carried out stereoselectively, as well as ring rearrangements, among other chemical modifications. Sources of starting materials, general biotransformation protocols employed, fungi with most consistent regioselectivity towards kaurane skeleton, as well as biological activities associated with starting materials and products are also described.

Chemical constituents from the leaves of Annona reticulata and their inhibitory effects on NO production

In the present study, the chemical investigation of the leaves of Annona reticulata has resulted in the identification of nine compounds, including annonaretin A, (1), a new triterpenoid. The purified compounds were subjected to the examination of their effects on NO inhibition in LPS-activated mouse peritoneal macrophages and most of them exhibited significant NO inhibition, with IC₅₀ values in the range of 48.6 ± 1.2 and 99.8 ± 0.4 μM.