The chemical characterisation and bioactive potential of secondary metabolites in curry leaf (Murraya koenigii L. Spreng)

• Main Author: Nagappan, Thilahgavani
• Format: Thesis
• Language: English; English
• Published: 2014
• Subjects: QK710-899 Plant physiology
• Online Access: https://eprints.ums.edu.my/id/eprint/38503/1/24%20PAGES.pdf; https://eprints.ums.edu.my/id/eprint/38503/2/FULLTEXT.pdf; https://eprints.ums.edu.my/id/eprint/38503/
• Institution: Universiti Malaysia Sabah

Murraya koenigii L. Spreng (curry leaf) is a small perennial shrub in the family Rutaceae. Widely distributed throughout tropical Asia, its aromatic leaves are used in culinary and folk medicine. Extraction efficiency using three different solvent systems was investigated using soxhlet system where ethanol produced the best quality and quantity. Hence, specimens from seven locations in Malaysia were investigated for their chemical fingerprint and bioactive potentials. Essential oil was extracted using hydro-distillation technique and Gas Chromatography Mass Spectroscopy (GCMS) analysis revealed the presence of 61 types of volatile metabolites. Major chemotaxonomical markers were β-caryophyllene and ahumulene and the minor chemotaxonomical markers were β-elemene, aromadendrene, β-selinene, spathulenol, caryophyllene oxide, viridiflorol, 2- naphthalenemethanol, trivertal and juniper camphor. High Performance Liquid Chromatography (HPLC) technique yielded three major metabolites and their structures elucidated as mahanine (I), mahanimbicine (II) and mahanimbine (III). Preparative Thick Layer Chromatography (PTLC) technique isolation gave koenimbine (IV), koenidine (V) and neo-mahanine (VI) were isolated and elucidated. Antibacterial activity of extract revealed potent inhibition against four environmental strains and pathogenic strains with the MIC between 0.25 to 0.063 mg/ml while mahanine (I), mahanimbicine (II), mahanimbine (III) and essential oil activity against antibiotic resistant strains showed promising MIC and MBC values. Essential oil exhibits bacteriostatic potential against Escherchia coli and Salmonella thypimurium by suppressing the growth to 105 and 104 CFU/ml respectively within 12 hours at 25 °c and to 104 CFU/ml ranged from Day 1 to Day 3 at 4 °c in food model. Cytotoxicity against mahanine (I), mahanimbicine (II), mahanimbine (III) and essential oil were evaluated against MCF-7, HeLa and P388. The IC50 values of mahanimbine (III) against MCF-7 cell line, P388 cell line and Hela cell line were 2.12 μg/ml, 5.0 μg/ml and 1.98 μg/ml respectively while the IC50 values of essential oil against MCF-7 cell line, P388 cell line and HeLa were 6.00 μg/ml, 7.01 μg/ml and 2.83 μg/ml. Mahanimbine (III) was found to cause cell arrest in sub Gl phase of MCF-7 cells and induce apoptosis via up-regulation of pro-apoptotic proteins, down-regulation of anti-apoptotic protein, activation caspase-7 and cleavage of PARP. Wound treated with mahanimbicine (II) and extract showed the highest rate of collagen deposition with well-organized collagen bands, formation of fibroblasts, hair follicle buds and reduced number of inflammatory cells as extract promotes significant wounds contraction by Day 4. This plant is an ideal candidate for further pharmacological investigation.