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ABSTRACT Medicinal plants play an important role in human health care. It is estimated that about 25–30% of all drugs are evaluated as therapeutic agents derived from natural products. Research in the pharmaceutical industry has demonstrated that for complex diseases, natural products still represent a valuable source for the production of new chemical compounds, since they possess privileged structures. Among Brazilian biodiversity, "catuaba" is popularly used as a tonic to treat fatigue, stress, impotence, memory deficits, and digestive disorders. Studies show antibacterial, trypanocidal, antioxidant, antiarrhythmic, antidepressant, improvement of memory, anti-inflammatory and antinociceptive activities, as well as phytocosmetic activity in cellulite treatment and in anti-ageing. The Brazilian plants known and used as catuaba are represented by more than twenty different species; however, the plant most commonly found in Brazil as "catuaba" is the species Trichilia catigua A. Juss., Meliaceae. Thus, the aim of this paper is to present a review of T. catigua, with emphasis on biological activities, chemical and analytical development and formulations in order to provide a broader and deeper insight, seeking a herbal medicine and/or phytocosmetic as well as future prospects for commercial exploitation and directions for future studies.
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The flowers of Tagetes patula L., Asteraceae, commonly known as French marigold, are used in folk medicine as an antiseptic, diuretic, blood purifier and insect repellent. This study was conducted to optimize the extraction process through the biomonitoring of flavonoids, using a statistical mixture simplex-centroid design, to evaluate the effect of the solvents water, ethanol and acetone, as well as mixtures of these solvents, assessed by the total flavonoid content. The extracts were tested for dry residue, radical scavenging activity, chromatographic profile, and larvicidal activity. The acetone extract had the highest total flavonoid content, 25.13 ± 1.02% (4.07%); and the best radical scavenging activity, with IC50 of 15.74 μg/ml ± 1.09 (6.92%), but with lower dry residue, 6.62 ± 1.33% (20.10%). The water extracts showed higher levels of dry residue, but lower total flavonoid content and radical scavenging activity than the acetone extract. The positive correlation between the total flavonoid content and radical scavenging activity of the extracts showed that flavonoids contribute significantly to the antioxidant capacity. The statistical mixture design allowed us to optimize the extraction of flavonoids from flowers of T. patula, with acetone as the best extraction solvent. Preliminary studies on the biological activity of the optimized extracts demonstrated a larvicidal effect of the acetone extract on Aedes aegypti mosquitoes.
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The use of thin-layer chromatography (TLC) is a commonplace practice and can be of significant help to different laboratories with quality control, especially those that work with plant extracts and phytotherapeutics. This study evaluated ten species of plants (Schinus terebinthifolius; Arctium lappa; Trichilia catigua; Camellia sinensis; Mikania glomerata; Croton echioides; Achyrocline satureioides; Heteropterys aphrodisiaca; Plantago major; Arctostaphylos uva-ursi) that are commonly sold by compounding pharmacies, using TLC with reference substances and pharmacopoeic physical and chemical tests (loss on drying, level of extractives, and total ash content). The results showed that the ten species showed losses on drying consonant with the literature. The level of extractives for two species and total ash for five species were also consonant with the literature, and those of the other species were established in this study. The semipurified extracts of the ten species were assayed by TLC, and the analysis with the use of reference substances proved to be effective, in addition to being practical, simple, versatile, and economically viable.
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We report the results of a preliminary estimation of the stability of the dried extract from bark of Guazuma ulmifolia Lam. ("Mutamba"), with and without added colloidal silicon dioxide (CSD). The physical and chemical properties and the compatibility of CSD in the extract were evaluated for 21 days of storage under stress conditions of temperature (45 ± 2°C) and humidity (75 ± 5%). Thermogravimetry (TG) was supplemented using selective high-performance liquid chromatography (HPLC) for determination of stability of the characteristic constituents (chemical markers), namely, procyanidin B2 (PB2) and epicatechin (EP). The results showed that PB2 is an appropriate compound to be used as a chemical marker in the quality control of dried extracts of G. ulmifolia. The stress study showed that there was no significant difference between the two formulations. However, considering the TG data and the high temperatures involved, the results suggest that CSD increases the stability of the dried extract of G. ulmifolia.
RESUMO
Stem bark of the two species Stryphnodendron polyphyllum Mart. and Stryphnodendron obovatum Benth., Leguminosae, was investigated for wound healing, antibacterial and antioxidant activity. These plants contain 12 and 19% tannins in their stem bark, respectively, and are widely used in traditional medicine in Brazil. The total content of phenolics of the crude extract (CE) of Stryphnodendron obovatum was 76.95 +/- 2.98% (CV = 3.87%) and of the ethyl-acetate fraction (EAF) was 89.13 +/- 0.34% (CV = 0.38%); whereas in Stryphnodendron polyphyllum the CE phenolics content was 51.62+/-1.53% (CV = 2.96%) and the EAF phenolics content was 59.00 +/- 1.91% (CV = 3.24%). The tannin content of CE from Stryphnodendron obovatum [36.58 +/- 0.35% (CV = 0.98%)] was about 11% higher than in CE from Stryphnodendron polyphyllum [25.43 +/- 0.96% (CV = 3.77%)]. The difference between the species was even greater in the EAF: in Stryphnodendron obovatum the EAF phenolics content was 55.01 +/- 0.36% (CV = 0.65%), whereas in Stryphnodendron polyphyllum the content was 36.16 +/- 0.42% (CV = 1.16%). The healing effect of ointments containing 2.5% crude lyophilised extract (PCE) and 2.5% ethyl-acetate lyophilised fraction (PEA) of the stem bark of Stryphnodendron polyphyllum and Stryphnodendron obovatum was studied in cutaneous wounds of Wistar rats after 4, 7 and 10 days of treatment. Epithelial cell proliferation in the area of re-epithelialisation of the wounds was evaluated by counting the metaphases blocked by vincristine sulfate. With PCE an increase in epidermal growth was observed after 4 and 7 days of treatment with Stryphnodendron polyphyllum, and after 7 and 10 days of treatment with Stryphnodendron obovatum. Wounds treated with PEA of Stryphnodendron obovatum showed increased epidermal growth only 4 days after the treatment; for Stryphnodendron polyphyllum, epidermal growth was observed after 4 and 7 days of treatment. Both the CE and the EAF fractions of Stryphnodendron polyphyllum and Stryphnodendron obovatum showed antibacterial activity against Staphylococcus aureus with MIC values of 125 and 250 microg/ml, respectively. Gram-negative bacteria tested were not inhibited by extracts and fractions at concentrations > 1000 microg/ml. The antioxidant activity through reduction of the DPPH radical in TLC, confirmed the anti-radical properties of these extracts in both species. CE and EAF of both species showed a radical scavenging activity (RSA) and protected DPPH from discolouration, already at 0.032 microg/ml. The extract from Stryphnodendron polyphyllum were more effective than those Stryphnodendron obovatum, although the former had a lower tannin content.
