Pongamia pinnata (Linn.), popularly known as Karanja or Indian Beech, is a medicinal plant known for its multitude of benefits. Its seeds contain about 28-34% oil with a high percentage of polyunsaturated fatty acids. Pongamia is rich in phenylated flavonoids. Pongamia seed oil contains a bioactive molecule known as karanjin. Six compounds (two sterols, three sterol derivatives and one disaccharide) and eight fatty acids (three saturated and five unsaturated) have also been isolated from the seeds of Pongamia pinnata.1

Pongamia is used for the treatment of various inflammatory and infectious diseases.2 The antifungal and antibacterial activity of Karanja is attributed to Pongarotene, a rotenoid, and karanjin, a flavonol.3 Karanja has traditionally been prescribed for cutaneous affections and vaginal discharge.4

Wagh et al assessed the antifungal and antibacterial activity of Pongamia oil against Aspergillus niger, A. fumigatus, Staphylococcus aureus and Pseudomonas aeruginosa. The oil exhibited high degree of antimycotic and antibacterial activity.5

A study investigated the antibacterial activity of Karanj (Pongamia pinnata) and Neem (Azadirachta indica) seed oil in vitro against 14 strains of pathogenic bacteria. About 57.14% and 21.42% of the pathogens were inhibited at 500 microl/ml; 14.28% and 71.42% at 125 microl/ml; and 28.57% and 7.14% at 250 microl/ml of Karanj and Neem oils, respectively. Pongamia oil was found to have potential bactericidal activity. This could be attributed to the inhibition of cell-membrane synthesis in the bacteria.6 Ujwal and colleagues7 evaluated the antimicrobial activity of Pongamia against Bacillus subtilis, Escherichia coli, P. aeruginosa, S. aureus and Candida albicans. Extracts of petroleum ether and ethyl acetate from seeds exhibited maximum inhibition zone on Bacillus subtilis while leaf extract of petroleum ether and ethyl acetate had comparable activity against S. aureus. The bark extract of petroleum ether exhibited a zone of inhibition on Escherichia coli.

Bajpai et al2 noted in their study that P. pinnata extracts exhibited potential antibacterial effect against B. Subtilis ATCC6633, S. aureus ATCC6538, Listeria monocytogenes ATCC19118, L. monocytogenes ATCC19166, Pseudomonas aeruginosa ATCC6432 and Salmonella typhimurium ATCC2512. The chloroform, ethyl acetate and methanol extracts exhibited significantly higher antibacterial activity as compared to streptomycin.

Methanol extract of Pongamia has been found to cause moderate inhibition of C. albicans and significant inhibition of C. tropicalis fungal isolates.3 In an evaluation of antifungal activity of Pongamia pinnata extracts on C. albicans strains, the extracts were found to have significant anticandidal activity.8

Pongamia extracts thus show potential antibacterial and antifungal effects and be used to manage infections caused by a range of bacteria and fungi.

References

1. Arote SR, Yeole PG. Pongamia pinnata L: A Comprehensive Review. Int J PharmTech Res. 2010;2(4):2283-90.
2. Bajpai VK, Rahman A, Shukla S, et al. Antibacterial activity of leaf extracts of Pongamia pinnata from India. Pharmaceutical Biology 2009;47(12):1162-7.
3. Patil U. Antifungal activity of karanja (Pongamia glabra) on medically important clinical isolates of Candida fungi. IJAAR 2017;III(1):43-47.
4. Khare CP. Indian Herbal Remedies: Rational Western Therapy, Ayurvedic and Other Traditional Usage, Botany. Springer; 2004.
5. Wagh P, Rai M, Deshmukh SK, Durate MCT. Bio-activity of oils of Trigonella foenum-graecum and Pongamia pinnata. African J Biotech 2007;6(13):1592-6.
6. Baswa M, Rath CC, Dash SK, Mishra RK. Antibacterial activity of Karanj (Pongamia pinnata) and Neem (Azadirachta indica) seed oil: a preliminary report. Microbios. 2001;105(412):183-9.
7. Ujwal P, Kumar MPMP, Naika HR, Hosetti BB. Antimicrobial activity of different extracts of Pongamia pinnata. Medicinal and Aromatic Plant Science and Biotechnology 2007;1(2):285-7.
8. Buvanaratchagan A, Jayakumar P, Jaikumar S. Pongamia pinnata: a potential topical herbal antifungal agent against Candida albicans. International Journal of Biological and Pharmaceutical Research. 2016;7(2):102-105.