Luis C. Marques

Development and validation of a LC-method for the determination of phenols in a pharmaceutical formulation containing extracts from Stryphnodendron adstringens

A sensitive RP-HPLC method with UV detection successfully measured phenol(s) in an ointment containing 3% Stryphnodendron adstringens extract. Chromatography used acetonitrile (0.05% trifluoroacetic acid):water (0.05% trifluoroacetic acid) (v/v), flow rate 0.8 mL min-1. Quantitation was accomplished by the external-standard method. Linearity for 2.00 to 16.00 μg mL-1 (gallic acid) and 1.14 to 18.24 μg mL-1 (gallocatechin) was established. Intra- and inter-day precision levels were under 5%. LOD and LOQ were 0.231 and 0.770 μg mL-1 (gallic acid) and 0.151 and 0.504 μg mL-1 (gallocatechin), respectively. Determination of phenols was unaffected by product excipients.

Morphoanatomy and pharmacognostic study of the wood of Croton echioides, the Northeastern Marapuama

Croton echioides Baill., Euphorbiaceae, is a small tree found in Bahia, Northeastern Brazil. Its stem bark has been widely sold as an aphrodisiac and tonic, as a substitute for the roots of Ptychopetalum olacoides Benth. Olacaceae, the Amazon Muira Puama or Marapuama, and C. echioides is characterized as the Northeastern Marapuama. This contribution describes a morphoanatomical analysis and pharmacognostic study of stem bark of this species. The stem has a thick cortex with compound starch grains and laticifers; a sclerenchymatic sheath which consists of brachysclereids with large crystals externally to the phloem, and abundant fiber in the secondary xylem, as the main features of the species. The data obtained for water content (9.26±0.07%), water-soluble extractives (3.92±0.19%), total ash (1.24±0.06%) and acid-insoluble ash (0.16±0.01%), together with the chromatographic profile obtained by TLC, contribute to the quality control and standardization for the plant drug. The pharmacological screening indicated LD50 values above 500 mg/kg orally and equal to 500 mg/kg by the i.p. route, as well as some stimulant potential, depending on the dose.

Bioactive Indole Alkaloids from Croton echioides

Bioguided fractionation of a hydroethanolic extract from the stem bark of Croton echioides Baill. led to isolation of the new indole alkaloid N-trans-feruloyl-3,5-dihydroxyindolin-2-one as a stereoisomeric mixture and the known alkaloids N-trans-p-coumaroyl-tryptamine, N-trans-pcoumaroyl-5-hydroxytryptamine, N-trans-4-methoxy-cinnamoyl-5-hydroxytryptamine, N-transferuloyl-5-hydroxytryptamine (moschamine), from the ethyl acetate fraction. The flavonoids 3-o-methyl kaempferol, 3-o-methyl quercetin, 3,7-di-o-methyl quercetin and 3,3’-di-o-methyl quercetin, together with the benzoic acid derivatives 4-hydroxybenzoic acid, 4-hydroxy-3methoxybenzoic acid and 4-hydroxy-3,5-dimethoxybenzoic acid were also isolated. Alkaloids and the flavonoids showed strong antioxidant properties in vitro radical scavenging assay (2,2-diphenyl1-picrylhydrazyl, DPPH), with IC50 values ranging from 9.2 to 17.5 µmol L -1 , lower than those of the positive control Trolox (IC50 = 17.9 µmol L -1 ). Alkaloids showed cytotoxic activity against the HCT-116 human cancer cell line, with IC50 values ranging from 86.8 to 210.7 µmol L -1 . Compound N-trans-4-methoxy-cinnamoyl-5-hydroxytryptamine was the most active, with an IC50 value of 86.8 µmol L -1

Influence of the preparation method on the low efficacy of multi-herb commercial products: the example of João da Costa e Associações

Native medicinal plants have been used for decades by Brazilian pharmaceutical companies to create commercial products. In this study, we have investigated the herb-combined product Joao da Costa e Associacoes® (JCA) commercialized for thirty years to treat dysmenorrhoea. JCA is prepared by decoction of Himatanthus lancifolius (Muell. Arg.) Woodson (Apocynaceae), Chondodendron platyphyllum Miers (Menispermaceae), Gossypium herbaceum L. (Malvaceae), Rosmarinus officinalis L. (Lamiaceae) and Echites peltata (Apocynaceae), followed by addition of sugar. The efficacy of JCA was verified by antinociceptive studies. The chemical composition was determined by fingerprint analysis in HPLC/ DAD. A weak inhibition of the second phase of the nociceptive effect induced by formalin indicated an activity similar to those steroids and not-steroids anti-inflammatories. Despite being prepared by decoction of five plants, the fingerprint analysis showed only two peaks. None of them corresponds to the chemical compounds observed in ethanol extracts prepared with the same plant material. We argue that the methods of preparation of the formulas should be considered in studies of multi-herbs products, since they can be the responsible for inefficacy or low activity of such products.