Abstract

• This research focuses on the chemical and pharmacological studies of bioactive secondary metabolites from Pseudomonas aeruginosa isolated by serial dilution plate method from the clinical soil sample collected in the Insein General Hospital, Yangon Region. The isolated bacteria P.aeruginosa identified by biochemical tests was cultured on nutrient agar medium in the large scale subsequently, the culture was centrifuged (20 min, 4 ºC, 3500 rpm). The cell-free supernatant was extracted with chloroform for 10 times to get the chloroform soluble compounds by liquid-liquid partition between chloroform and the culture solution 1:1 (v:v).This process was done according to the ultrasound-assisted extraction to give 0.03 % (w/v) of chloroform extract which was applied to investigate the chemical constituents and some biological activities. The preliminary screening of chemical constituents indicated the presence of alkaloids, -amino acids, carbohydrates, flavonoids, phenolic compounds, polyphenols, steroids, tannins and terpenoids in the chloroform extract of P.aeruginosa. The total carbohydrates content (TCC), total tannins content (TTC), total phenols content (TPC), total steroids content (TSC), total flavonoids content (TFC) and total protein content of the chloroform extract determined according to the appropriate reported methods were found to be 283±2.15 mg GE/g ,177.58±5.8 mg GAE/g, 50.64±1.5 mg GAE/g, 50.43±4.01 mg CE/g , 24.70 ± 2.2mg QE/g and 4.43±0.8 mg BSAE/g respectively. The chloroform extract was found to exhibit the high antimicrobial activity against all seven tested microorganisms such as Bacillus subtilis (N.C.T.C-8236), Staphylococcus auerus (N.C.P.C-6371), Pseudomonas aeruginosa (6749), Bacillus pumilus (N.C.I.B-8982), Candida albicans (-), Agrobacterium tumefacines(N.I.T.E-09678 ) and Escherichia coli (N.C.I.B-8134) (20 mm ~40 mm) determined by agar well diffusion method. The antioxidant activity of chloroform extract was determined by DPPH radical scavenging activity assay (IC50 = 128.6 mg/mL).The chloroform extract was also subjected to investigate the antidiabetic activity via -amylae and -glucosidase inhibition activities assays. The extract was observed to possess the -amylase inhibitory effect (IC50= 3.16 g/mL) and -glucosidase inhibitory effect (IC50 = 19.5 g/mL), however, those were weaker than the standard drug acarbose (IC50 = 0.02 g/mL) and (IC50 = 0.04 g/mL). The chloroform extract of P. aeruginosa showed significant toxicity against brine shrimp with an LD50 value of 1.90 mg/mL after 24 h. In antitumor activity analysis, Agrobacterium tumerfaceins (N.I.T.E -09678) cell was used as the tumor cell. In this study, the chloroform extract of P. aeruginosa was found to exhibit low value (IC50 =147.54 µg/mL) against A. tumefacines cell. In vitro antiproliferative activity of the chloroform extract was evaluated against A 549 (lung), Hela (cervical) and MCF-7 (breast) human cancer cell lines by using CCK-8 Assay (Cell Counting Kit8). It was found that, the chloroform extract has the antiproliferative activity against A 549 lung cancer cell lines (IC50 = 12.18 µg/mL), Hela cervical cancer cell line (IC50 = 49.93 µg/mL) and MCF-7 breast cancer cell line (IC50 = 16.59 µg/mL). Furthermore, in vitro antiproliferative activity of the chloroform extract was also evaluated against six microorganisms such as P.aeruginosa (IC50=98.38µg/mL), S.auerus(IC50=155.76µg/mL),B. pumilus (IC50 = 360.23µg/ mL ), B. subtilis (IC50 = 411.03 µg/mL ) , C. albicans (IC50 = 422.16 µg/mL), A. tumefacines (IC50 = 147.54 µg/mL ) and E. col (IC50=440.58 µg/mL).