Bactericidal Effect and Anti-Inflammatory Activity of Cassia garettiana Heartwood Extract

Abstract

Natural products are used as alternative drugs in traditional medicine to treat infection and inflammation and relieve pain. Heartwood of Cassia garettiana Craib has been investigated as an ingredient in Thai traditional medicine for anti-HIV protease, but there is no report on its antibacterial and anti-inflammatory activities. The objectives of this study were to investigate the anti-inflammatory and antibacterial activities, time-kill profile, and main active constituents of an ethanolic extract of C. garettiana heartwood. The study followed the generally accepted experimental design. All tests were investigated in triplicate. The heartwood of C. garettiana was extracted by maceration with 95% EtOH. The antibacterial activity of the extract and its chemical constituents were determined by their MIC values using resazurin as an indicator. Time-kill profile was determined at 0, 2, 4, 6, 8, 10, 12, and 24 hrs and expressed as log CFU/mL. The anti-inflammatory activity of the extract and its chemical components was investigated by their inhibiting effect on IL-6 and TNF-α production by ELISA. The ethanolic extract was analyzed for its chemical constituents by HPLC technique. The ethanolic extract showed both dose- and time-dependent bactericidal effects against Staphylococcus aureus, methicillin-resistance Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa, Salmonella Typhi, Salmonella Typhimurium, Klebsiella pneumoniae, and Shigella dysenteriae with MIC values of 312.5, 312.5, 312.5, 1,250, 2,500, 625, 625, 2,500, and 625 μg/mL, respectively. It showed an inhibiting effect on IL-6 production at concentrations of 12.5 to 100 μg/mL. The main active chemical constituent of C. garettiana was piceatannol that showed antibacterial activity against all test bacteria except P. aeruginosa. C. garettiana showed a broad spectrum of antibacterial activity against both Gram-negative and Gram-positive bacteria. Piceatannol and resveratrol from the plant strongly inhibited IL-6 production. Based on these results, we concluded that the ethanolic extract of C. garettiana showed both an antibacterial activity and inhibition of IL-6. Piceatannol is the active constituent of the extract and showed anti-inflammatory and antibacterial activities against Gram-negative and Gram-positive bacteria.

Antibacterial, Antioxidant Activities, GC-MS Analysis and Docking Studies of Guiera senigalensis (L.) Ethanol Leaves Extract

“…Subsequently, all concentrations that showed no change in color were transferred onto nutrient agar and incubated at 37°C overnight, also the concentration exposed a turbidity was subculture in the agar plate as a confirmatory test, the lowest concentration with no growth of bacteria was considered as MBC. 27 The MBC was determined as the lowest concentration that eliminate 99.9% of the initial bacterial population. 3 Evaluation of antioxidant characteristics DPPH assay DPPH radical scavenging activity of G. senigalensis leaves extract was measured following previously reported methods with some modification.…”

Antibacterial, Antioxidant Activities and GC-MS Analysis of <i>Dichrostachys cinera</i> (L.) Ethanolic Leaves Extract

“…Serial dilution of (50 mg/ml, 25 mg/ml, 12.5 mg/ml and 6.25 mg/ml) was made in the tubes containing the broth media except for the last one which inoculated with 100 μl of the solvent to be considered as the negative control and the all different tubes were inoculated with 100 μl of the bacterial suspension. Subsequently, all concentrations that showed no change in color were transferred onto nutrient agar and incubated at 37˚C for overnight, the lowest concentration with no growth of bacteria was considered as MBC [30], which is known as the lowest concentration that eliminate 99.9% of the initial bacterial population [2].…”