RESUMEN
Objective: To evaluate antifungal and cytotoxic activities of four underutilised fruit species, i.e. Artocarpus altilis (breadfruit), Cynometra cauliflora (nam-nam), Mangifera pajang (M. pajang) (Bambangan) and Physalis minima (wild gooseberry). Methods: Extracts from the fresh flesh of Artocarpus altilis and Cynometra cauliflora, the flesh and kernel of M. pajang, and the whole fruit of Physalis minima were obtained by sequential extraction using hexane, chloroform, ethyl acetate, ethanol, methanol and distilled water. Each extract was assessed against six species of human fungal pathogens using a colourimetric broth microdilution method. The cytotoxicity was evaluated using African monkey kidney epithelial (Vero) cells. Results: All 30 extracts showed inhibitory activity against Cryptococcus neoformans. However, none of the extracts were active against Aspergillus fumigatus. The ethanol, methanol and water extracts from the kernel of M. pajang fruit showed the strongest activity against three species of Candida and Trichophyton interdigitale, with a minimum inhibitory concentration range of 0.001 - 0.630 mg/mL. The corresponding mean 50% cytotoxic concentrations for these three extracts were 358.7, 158.4 and 261.3 μg/mL, respectively against Vero cells. In contrast, the flesh of M. pajang fruit (hexane, chloroform and ethyl acetate extracts) showed statistically significant (P<0.001; ANOVA) strong toxicity against the cells, with 30.6, 13.5 and 22.2 μg/mL of mean values of 50% cytotoxic concentrations, respectively. Conclusions: The results suggest that the bioactivity of the kernel of M. pajang fruit is more selective towards fungi and thus is a potential source of new antifungal agents.
RESUMEN
The purpose of this investigation was to determine the antioxidant potentials and anti-glucosidase activities of six tropical medicinal plants. The levels of phenolic constituents in these medicinal plants were also quantified and compared. Antioxidation potentials were determined colorimetrically for scavenging activities against DPPH and NO radicals. Metal chelating assay was based on the measurement of iron-ferrozine absorbance at 562 nm. Anti-diabetic potentials were measured by using alpha-glucosidase as target enzyme. Medicinal plants' total phenolic, total flavonoid and hydroxycinnamic acid contents were determined using spectrophotometric methods, by comparison to standard plots prepared using gallic acid, quercetin and caffeic acid standards, respectively. Radical scavenging and metal chelating activities were detected in all medicinal plants, in concentration-dependent manners. Among the six plants tested, C. nutans, C. formosana and H. diffusa were found to possess alpha-glucosidase inhibitory activities. Spectrophotometric analysis indicated that the total phenolic, total flavonoid and hydroxycinnamic acid contents ranged from 12.13-21.39 mg GAE per g of dry sample, 1.83-9.86 mg QE per g of dry sample, and 0.91-2.74 mg CAE per g of dry sample, respectively. Our results suggested that C. nutans and C. formosana could potentially be used for the isolation of potent antioxidants and anti-diabetic compounds. To the best of our knowledge, this study represents the first time that C. nutans [Acanthaceae family] was reported in literature with glucosidase inhibition activity