Potential role of Indian long pepper (Piper longum L.) volatiles against free radicals and multidrug resistant isolates

In the present study, the extracted volatiles from dried leaf and fruit of Piper longum were analysed by gas chromatography-mass spectrometry (GC-MS) and each detected 53 constituents having 92.41% and 96.31% of the total volatiles respectively. E-nerolidol (19.56%), beta-pinene (17.07%) and alpha-pinene (6.8%) were main constituents in leaf volatiles whereas the fruit volatiles dominated by germacrene-D (23.38%), 8-heptadecene (8.95%) and beta-caryophyllene (8.20%). Antioxidant potential of the volatiles were assessed by DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS (2,2 '-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid) assays. The fruit volatiles revealed higher radical scavenging activities as compared to leaf. The samples were also evaluated against multidrug resistant (MDR) isolates including one non MDR fungal strain. The fruit volatiles showed a very strong activity against Acinetobacter baumannii than others whereas leaf volatiles possessed strong activity against Klebsiella pneumoniae as compared to other strains. Thus, the dried fruits can be exploited for drug development towards therapeutic purpose.

Automated summary

The study analyzed the volatile components in Piper longum leaf and fruit, showing that the fruit volatiles had higher antioxidant and free radical scavenging activities, exhibiting strong activity against multidrug resistant bacteria, particularly Acinetobacter baumannii. Therefore, dried fruits may be used for drug development.