Microbiological and Pharmacological Evaluation of the Micropropagated Rubus liebmannii Medicinal Plant

Antigiardial Activity of Podophyllotoxin-Type Lignans from Bursera fagaroides var. fagaroides

Giardiasis, a diarrheal disease, is highly prevalent in developing countries. Several drugs are available for the treatment of this parasitosis; unfortunately, all of them have variable efficacies and adverse effects. Bursera fagaroides has been known for its anti-inflammatory and antidiarrheal properties in Mexican traditional medicine. We investigated the in vitro anti-giardial activities of four podophyllotoxin-type lignans from Bursera fagaroides var. fagaroides, namely, 5'-desmethoxy-β-peltatin-A-methylether (5-DES), acetylpodophyllotoxin (APOD), burseranin (BUR), and podophyllotoxin (POD). All lignans affected the Giardia adhesion and electron microscopy images revealed morphological alterations in the caudal region, ventral disk, membrane, and flagella, to different extents. Only 5-DES, APOD, and POD caused growth inhibition. Using the Caco-2 human cell line as a model of the intestinal epithelium, we demonstrated that APOD displayed direct antigiardial killing activity and low toxicity on Caco-2 cells. This finding makes it an attractive potential starting point for new antigiardial drugs.

Natural Compounds from Mexican Medicinal Plants as Potential Drug Leads for Anti-Tuberculosis Drugs

In Mexican Traditional Medicine 187 plant species are used in the treatment of respiratory conditions that may be associated with tuberculosis. In this contribution, we review the ethnobotany, chemistry and pharmacology of 63 species whose extracts have been assayed for antimycobacterial activity in vitro. Among these, the most potent is Aristolochia brevipes (MIC= 12.5 µg/mL), followed by Aristolochia taliscana, Citrus sinensis, Chrysactinia mexicana, Persea americana, and Olea europaea (MIC<64 µg/mL). Other potent extracts (inhibition > 95%, 50 µg/mL) include: Amphipterygium adstringens, Larrea divaricata, and Phoradendron robinsoni. Several active compounds have been identified, the most potent are: Licarin A (isolated from A. taliscana), and 9-amino-9-methoxy-3,4-dihydro-2H-benzo[h]-chromen-2-one (transformation product of 9-methoxytariacuripyrone isolated from Aristolochia brevipes), both with MIC= 3.125 µg/mL, that is 8-fold less potent than the reference drug Rifampicin (MIC= 0.5 µg/mL). Any of the compounds or extracts here reviewed has been studied in clinical trials or with animal models; however, these should be accomplished since several are active against strains resistant to common drugs.

Phytochemical Composition and Biological Activities of Selected Wild Berries (Rubus moluccanus L., R. fraxinifolius Poir., and R. alpestris Blume)

Berries, from the genus Rubus, are among the vital components in a healthy diet. In this study, 80% methanol extracts from the three wild Rubus species (Rubus moluccanus L., Rubus fraxinifolius Poir., and Rubus alpestris Blume) were evaluated for their phytochemical contents (total phenolics, flavonoid, anthocyanin, and carotenoid content), antioxidant (DPPH, FRAP, and ABTS assays), antiacetylcholinesterase, and antibacterial activities. GC-MS was used for quantification of naturally occurring phytochemicals. The results showed that R. alpestris contained the highest total phenolic [24.25 ± 0.1 mg gallic acid equivalent (GAE)/g] and carotenoid content [21.86 ± 0.63 mg β-carotene equivalents (BC)/g], as well as the highest DPPH scavenging and FRAP activities. The highest total flavonoid [18.17 ± 0.20 mg catechin equivalents (CE)/g] and anthocyanin content [36.96 ± 0.39 mg cyanidin-3-glucoside equivalents (c-3-gE)/g] have been shown by R. moluccanus. For antibacterial assays, R. moluccanus and R. alpestris extracts showed mild inhibition towards Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Salmonella enteritidis. Anticholinesterase activity for all extracts was in the range of 23-26%. The GC-MS analysis revealed the presence of at least 12, 21, and 7 different organic compounds in 80% methanol extracts of R. alpestris, R. moluccanus, and R. fraxinifolius, respectively, which might contribute to the bioactivity.