Determination of Antioxidant, Antidiabetic and Toxicity Capabilities of Christia vespertilionis (Pokok Rerama) Leaves

Diabetes mellitus has been one of public health concern since years ago. The prevention and treatment of the metabolic disorder using medicinal plant has been done broadly in previous studies. Christia vespertillionis is known to have medicinal properties to treat various health problems because of its phytochemicals. This study characterizes total phenolic content, antioxidant and antidiabetic activities, and also toxicity evaluation in the leaves of Christia vespertillionis. Total phenolic content of Christia vespertillionis leaves was determined by improved Folin-Ciocalteu method. The antioxidant activity of the leaves sample was determined by DPPH assay with butylated hydroxytoluene (BHT) used as reference compound. Antidiabetic activity of Christia vespertillionis leaves was determined using α-amylase inhibition assay, and metformin
was used as standard. Besides, the cytotoxicity of compounds in Christia vespertillionis leaves extract was investigated using brine shrimp lethality bioassay. The total phenolic
content in the leaves extract was found to be 128.852 ± 3.90 mg gallic acid equivalent per g of dried sample. The percentage of free radical scavenging activity of Christia
vespertillionis leaves varied from 34.72% to 2.01% from the highest (200 mg/ml) to the lowest (6.25 mg/ml) concentrations. The IC50 value calculated for its antioxidant activity was found to be 39.987 mg/ml. The percentage of α-amylase inhibition in concentration
250 mg/ml of Christia vespertilionis leaves extract was 23.33%, while 20.14% in concentration 500 mg/ml and followed by 15.34% in concentration 125 mg/ml. The IC50 value for α-amylase inhibitory activity in the extract was found to be 35.2 mg/ml. For toxicity evaluation of Christia vespertilionis crude extract, the percentage of mortality of brine shrimp varied from 21.59% to 10.87% from the highest (200 mg/ml) to the lowest (12.5 mg/ml) concentration. The level of toxicity of the extract was low, thus increase in
potential therapeutic property. The study revealed that the extract of Christia vespertilionis has potential biological efficiencies.