RESUMO
This study investigated the effect of boiling on the inhibitory action of spices on digestive enzymes. Unboiled extracts of Trigonella foenum-graecum (seed) (25.42%), Myristica fragrans (seed) (22.70%), and Cuminum cyminum (seed) (19.17%) showed significantly (p < 0.05) a higher lipase inhibitory activity than their respective boiled extracts (20.23%, 15.74%, and 12.57%). Unboiled extracts of Cinnamomum zeylanicum (stem bark) (-16.98%) and Foeniculum officinale (seed) (-16.05%) showed an activation of lipase enzyme, and boiling significantly (p < 0.05) changed the activity into lipase inhibition as 8.47% and 9.54%, respectively. Unboiled extracts of Coriandrm sativum (seed), C. cyminum, and Elettaria cardamomum (seed) showed an activation of amylase enzyme, and boiling these extracts significantly reduced the enzyme activation. The other unboiled extracts showed a higher amylase inhibition than the boiled extracts, whereas the boiled extracts of C.longa (rhizome) and Syzygium aromaticum (flower) exhibited significantly (p < 0.05) lower values. Unboiled extracts of C. zeylanicum, M. fragrans, and S. aromaticum showed an insignificantly higher glucosidase inhibitory activity than the boiled extracts. Inhibition of digestive enzymes by nutritional intervention is one avenue to be considered in treating diet-induced obesity and in the management of postprandial hyperglycemia. Spices, used as food additives, could be a potential source of digestive enzyme inhibitors. The current study revealed that unboiled extracts of T. foenum-graecum (seed), C. cyminum (seed), and M. fragrans (seed) are more effective than the boiled extracts as an antiobesity therapy. Moreover, it endorses the use of infusion of T. foenum-graecum seeds as an antiobesity therapy.
RESUMO
BACKGROUND: Identification of novel sources for developing new antibiotics is imperative with the emergence of antibiotic resistant bacteria. The fruits of Terminalia bellirica (Gaertn) Roxb., widely used in traditional medicine, were evaluated for antibacterial activity against multidrug-resistant (MDR) bacteria, antioxidant activity and cytotoxicity. METHODS: Twelve solvent extracts of T. bellirica fruits were prepared by direct aqueous extraction and sequential extraction with dichloromethane, methanol and water using Soxhlet, bottle-shaker and ultrasound sonicator methods. Antibacterial activity of the extracts was tested against 16 strains MDR bacteria-methicillin-resistant Staphylococcus aureus (MRSA), extended spectrum ß-lactamase (ESBL) producing Escherichia coli and MDR Acinetobacter spp., Klebsiella pneumoniae and Pseudomonas aeruginosa-and 4 control organisms, using the cut-well diffusion method. The minimum inhibitory concentration (MIC) was determined using an agar dilution method. The radical scavenging activity of six antibacterial extracts was screened against 2,2'-diphenyl-2-picrylhydrazyl (DPPH) and correlation was established between EC50 (50% effective concentration) values and the total phenolic content (TPC). Cytotoxicity was determined for the most potent antibacterial extract on baby hamster kidney (BHK-21) cells by Tryphan Blue exclusion method. Statistical analysis was carried out by one-way analysis of variance at significant level p < 0.05 using "SigmaPlot 10" and "R 3.2.0" software. RESULTS: All aqueous and methanol extracts displayed antibacterial activity (MIC 0.25-4 mg/mL) against all strains of MRSA, MDR Acinetobacter spp. and MDR P. aeruginosa. The sequential aqueous extracts (MIC, 4 mg/mL) inhibited ESBL producing-E. coli. None of the extracts exhibited activity against MDR K. pneumoniae (MIC > 5 mg/mL). The sequential methanol extract (Soxhlet) recorded high antibacterial activity and the highest DPPH radical scavenging activity (EC50, 6.99 ± 0.15 ppm) and TPC content (188.71 ± 2.12 GAE mg/g). The IC50 (50% inhibition concentration) values of the most potent antibacterial extract-the direct aqueous extract from reflux method-on BHK-21 cells were 2.62 ± 0.06 and 1.45 ± 0.08 mg/ml with 24 and 48 h exposure, respectively. CONCLUSIONS: Results indicate that T. bellirica fruit is a potential source for developing broad-spectrum antibacterial drugs against MDR bacteria, which are non-toxic to mammalian cells and impart health benefits by high antioxidant activity.
