ANTIBACTERIAL ACTIVITIES OF CRUDE Curcuma longa EXTRACT MEDIATED SILVER NANO PARTICLES AGAINST ISOLATES FROM DIABETIC PATIENTS WITH FOOT INFECTIONS

Abstract

ABSTRACT

Curcuma longa are traditionally used for the treatment of ulcers, hepatic disorder, wound healing and boost glucose control. This study assessed the phytochemical compositions (quantitative and qualitative), antibacterial activities of C. longa crude extracts, synthesis and characterisation of silver nanoparticles, antibacterial activity of extract-mediated silver nanoparticles and wound activity of EeaAgNPs. The antibacterial activity of crude extracts and extract mediated silver nanoparticles (AgNPs) of C. longa rhizomes were evaluated against isolates from patients with diabetic foot infection using agar well diffusion method. Quantitative determination of phytoconstituents revealed a significant amount of phytates (6577.9 mg/100 g), cyanides (2741.8 mg/100 g) and saponins (618.0 mg/100 g). Cold maceration of rhizome with 70% ethanol yielded a crude extract (E). Successive partitioning of extract E with chloroform and ethyl acetate yielded chloroform (Ec), ethyl acetate (Eea) soluble fractions, as well as aqueous residual fraction (Eaq). Qualitative screening of the extract and fractions revealed the presence of flavonoids, reducing sugars, anthraquinones, tannins and saponins. The extract and its fractions at 100 mg/ml were inactive on Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae, Streptococcus pyogenes and Staphylococcus aureus while, fraction Eea at 200mg/ml was active on P. aeruginosa, E. coli and S. pyogenes. The wavelength of E-AgNPs, Ec-AgNPs, Eea-AgNPs, and Eaq-AgNPs were 405 nm, 406 nm, 409 nm and 410 nm respectively. The FTIR indicated the presence of aromatic, alkanes, alkynes, alkenes and carboxylic functional groups while the SEM micrograph of Eea-AgNPs revealed clustered rod-like morphology. The highest XRD peak was at 2ϴ (340). The Eea-AgNPs at 200 mg/ml was active on S. pyogenes, P. aeruginosa, E. coli and K. pneumoniae with zones of inhibition of 7 ± 1.7 mm, 10 ± 0.7 mm, 11 ± 1.1 mm and 14 ± 0.5 mm respectively. The MIC of Eea-AgNPs against test isolates was at 12.5 mg/ml. The extract was bacteriostatic on the test isolates. There was significant (P<0.05) wound closure observed in rats (groups 1 to 6) topically treated with Eea-AgNPs ointment from Day 0 (1.24 ± 0.00 mm to 1.29 ± 0.19 mm) to Day 14 (0.4 ± 0.1 mm to 0.73 ± 0.00 mm) compared to group 7 (Diabetes + Wound only) with (1.23 ± 0.00 to 1.1 ± 0.3 mm). Histology of the treated rats indicated wound healing characterized with collagens, fibroblasts, inflammatory cells, new blood vessels, granulation tissues and complete epithelialization. The application of ointment on rats produced no allergic reactions, rashes and other forms of skin irritation. These findings showed the potentials of C. longa as a safe therapeutic agent to treat and heal infected ulcer.