Abstract:
Pogostemon heyneanus Benth.(Lamiaceae) is an industrially important, medicinal plant
cultivated for essential oils used in modern perfumery and cosmetic industries. Therefore,
the present study was undertaken to determine the distribution of constituents of essential
oils, total antioxidant capacity (TAC), total phenol content (TPC) and total flavonoid content
(TFC) in different parts (leaf, stem and root) of Pogostemon heyneanus. Powdered
materials of leaf, stem and root were distilled in a Clevenger-type apparatus for 5 hrs. Gas
chromatography-mass spectrometric (GC-MS) analysis was carried out to identify the
components of essential oils. TPC, TFC and TAC of leaf, stem and root were determined
by colorimetric Folin-Ciocalteu method, aluminium nitrate method and Ferric Reducing
Antioxidant Power (FRAP) assay respectively. More than 90% of the total oil profile was
identified and it was found that the essential oil composition was quite different in all three
parts of the plant. Patchouli alcohol was presented in all the plant components leaf, stem
and root in higher percentages as 44.56 ± 1.2, 20.72 ± 1.23 and 5.76 ± 1.00 respectively.
Caempferol was found as the main component in roots (80.49%). Significantly higher TPC,
TFC and TAC were observed in leaf extracts. The order in increase of TPC, TFC and TAC
in P. heyneanus was leaf > root > stem. Presence of higher constituents of essential oil,
TPC, TFC and TAC in P. heyneanus leaves, scientifically validate the traditional claim of
harvesting of P. heyneanus leaves for better therapeutic value. The higher TPC and TFC
in leaf demonstrated the value of leaf for the development of effective drugs instead of root
and stem.
Keywords: Pogostemon heyneanus Benth, Lamiaceae, antioxidant capacity, essential oil
