Abstract:
Bioactive potentials of selected Malvaceous plants were studiesin vitro. The purposes of this present study were to investigate the bioactive properties of selected Malvaceae plant materials. The crude drugs from stems, roots, and leaves of SidaacutaBurm. f., Abutilon indicum(Linn.) Sweet and Malvastrumcoromandelianum (Linn.) Garcke were sequentially extracted by soxhlet apparatus with dichloromethane and methanol respectively. The study found that S. acuta exhibited antimicrobial potential against all tested microorganisms. However, the antimicrobial effect was selective depended on the microorganism species as well as parts of the plants and types of extractives solvents. The methanolic extract of leaves of S. acuta showed promising antimalarial activity against both K1 chloroquine resistant and 3D7 chloroquine sensitiveP. falciparum with the IC50 of 4.60 and 4.00μg/ml respectively. Crude alkaloid was isolated from S. acuta whole plants and demonstrated antimalarial activity with IC50 of 6.26 and 9.36 μg/ml respectively. The yeast alpha-glucosidase, rat alpha-glucosidase and pancreatic alpha-amylase inhibition testings among S. acuta, A. indicum and M. coromandelianum extracts were determinedin vitro. The results showed that the dichloromethane extracts of roots from A. indicum had strong effect on yeast alpha-glucosidase inhibition compared to 1-deoxynojirimycin with the IC50 of 0.36 and 0.58 mg/ml respectively. The methanolic extract of roots from A. indicum has a highest effect on rat alpha-glucisidase inhibition compared to 1-deoxynojirimycin with the IC50 of 0.08 and 0.11 mg/ml respectively. Moreover, the results showed that the dichloromethane extracts of roots and methanolic extracts of stems from M. coromandelianum had a strongest effect on alpha-amylase inhibition compared to acarbose with the IC50 of 0.07 and 2.7 mg/ml respectively. The greatest scavenger of DPPH radical was dichloromethane extracts of S. acuta roots (IC50=0.20 mg/ml). The highest NO scavenging activity was shown from the dichloromethane extract of S. acuta leaves (IC50=0.11 mg/ml). The dichloromethane extract of leaves and methanolic extract of roots from S. acuta showed great potential on metal chelation with IC50 of 1.6 mg/ml. However, the highest reducing capacity was exhibited by the extracts of leaves from dichloromethane fraction of S. acuta (IC50=2.45 mg/ml). Furthermore, Brine shrimp lethality assay demonstrated that all tested concentrations of S. acuta caused no lethality to brine shrimp (LC50 value 9000 μg/ml). Selected Malvaceous plants including S. acuta, M. coromandelianum and A. indicum demonstrated potent inhibitory activities against key carbohydrate digestive enzymes which control postprandial blood glucose level. S. acuta was revealed for its potency on antimicrobial, antimalarial and antioxidant activities.