Phenylpropanoid conjugated iridoids with anti-malarial activity from the leaves of Morinda morindoides

Two phenylpropanoid conjugated iridoids, deglucosyl gaertneroside (1) and morindoidin (2), were isolated from the leaves of Morinda morindoides (Rubiaceae) by activity-guided fractionation using an anti-malarial activity assay. The known related iridoids molucidin (3) and prismatomerin (4), two lignans, abscisic acid, two megastigmanes, and two flavonol glycosides were also identified. The structures of isolated compounds were elucidated using spectroscopic analysis. The isolated compounds were evaluated for anti-malarial activity against the chloroquine/mefloquine-sensitive strains of Plasmodium falciparum together with cytotoxicity against adult mouse brain cells. Potent anti-malarial activity of 3 and 4 (IC50 of 0.96 and 0.80 μM, CC50 of 1.02 and 0.88 μM, and SI of 1.06 and 1.10 μM, respectively) was shown, while new iridoids 1 and 2 and pinoresinol (5) displayed moderate activity (IC50 of 40.9, 20.6, and 24.2 μM) without cytotoxicity (CC50 > 50 μM). These results indicate that 1–5 may be promising lead compounds for anti-malarial drugs. In addition, our results imply the necessity of the quality control of the extract of M. morindoides leaves based on the contents of 1–5 in terms of the safety and efficacy.

Phenylpropanoid conjugated iridoids with anti-malarial activity from the leaves of Morinda morindoides

Two phenylpropanoid conjugated iridoids, deglucosyl gaertneroside (1) and morindoidin (2), were isolated from the leaves of Morinda morindoides (Rubiaceae) by activity-guided fractionation using an anti-malarial activity assay. The known related iridoids molucidin (3) and prismatomerin (4), two lignans, abscisic acid, two megastigmanes, and two flavonol glycosides were also identified. The structures of isolated compounds were elucidated using spectroscopic analysis. The isolated compounds were evaluated for anti-malarial activity against the chloroquine/mefloquine-sensitive strains of Plasmodium falciparum together with cytotoxicity against adult mouse brain cells. Potent anti-malarial activity of 3 and 4 (IC50 of 0.96 and 0.80 µM, respectively) was shown, while new iridoids 1 and 2 and pinoresinol (5) displayed moderate activity (IC50 of 40.9, 20.6, and 24.2 µM, respectively). These results indicate that 1–5 may be promising lead compounds for anti-malarial drugs and that extracts of M. morindoides leaves could be effective remedies for malaria infection.

Evaluation of the toxic effect of aqueous extract of the bark of Morinda morindoides root in male Wistar rats

The toxic effect of the aqueous extract of the bark of the root of Morinda morindoides was studied in 24 sexually matured, male Wistar rats weighing between 150-200g. The rats were randomly divided into four groups (I-IV). Rats in groups I, II and III received 400 mg/kg, 800 mg/kg and I,600 mg/kg of 50mg/ml of the aqueous extract respectively once daily for 28 days while the control group (Group IV) was given distilled water (5ml/kg) once daily for 28 days after which the rats were euthanized. Following euthanasia, about 3 ml of blood was collected and was divided into 1.5ml each for haematology and serum chemistry. In addition, samples of the kidney, liver, heart, lungs and spleen were also harvested for histopathology. Haematological and serum biochemical values were expressed as mean ± standard error of mean and were analyzed using One-way Analysis of Variance (ANOVA) followed by Duncan’s multiple range test. Lesions observed in histopathology were scored as mild, moderate or severe. Results were considered statistically significant at 95% confidence interval (P<0.05). In this study, there was no significant difference in the haematological parameters, alanine aminotransferase and aspartate aminotransferase between the treated groups and the control. Histopathologically, the extract caused mild, diffuse degeneration of the liver, mild tubular nephrosis; mononuclear cellular infiltration in the heart and mild hypoplasia of the lymphoid nodules in the spleen of rats to which 1,600 mg/kg of the extract was administered. It was therefore concluded that aqueous extract of the root of Morinda morindoides may produce subchronic toxicity at the dosage of 1600mg/kg.

Chemo-Diversity of Antibacterial Anthraquinones from the Roots of Morinda morindoides

Background: Morinda morindoides (Baker) (Rubiaceae) is a medicinal plant with antimicrobial properties currently used in Côte d'Ivoire and other countries. These properties have been described but most of the studies are dealing with crude extracts. Objective: The chemical structures of the bioactive compounds extracted from Morinda morindoides roots have been characterized. Methods: The root extracts were analyzed by using HPLC. Fourteen fractions were detected among which 11 compounds have been structurally identified by using a combination of 1H-NMR and 13CNMR and LC-HRMS methodologies. Results: All these compounds belong to anthraquinone family. The antibacterial activity of the eleven compounds was tested against six strains of microorganisms with ofloxacin as standard (two Gram-negative bacteria, two Gram-positive bacteria and two yeasts). The Minimal Inhibitory Concentrations recorded, varies from 8 to 128 μg / ml. Staphylococcus aureus was the most susceptible organism. Conclusion: We highlight the chemo-diversity of the antibacterial anthraquinones in the roots of Morinda morindoides.