ABSTRACT
Objective:
To investigate the pharmacodynamics of
volatile oil in couplet medicines of Moslae Herba and Pogostemonis Herba, to establish a
method for simultaneous
determination of three essential ingredients (
thymol, carvacrol and
patchouli alcohol) in
volatile oil of the couplet medicines by
gas chromatography (GC), to optimize the preparation process of β-
cyclodextrin (β-CD) inclusion complex of
volatile oil in the couplet medicines and to confirm the formation of the inclusion complex.
Method:
An
in vitro inflammatory response model was established by
hyaluronidase activity inhibition test in order to detect the anti-inflammatory activity of the
volatile oil. Also, the
antioxidant activity of the
volatile oil was assessed by 1, 1-diphenyl-2-trinitrophenylhydrazine (DPPH)
free radical scavenging
method. The inclusion of
volatile oil in couplet medicines of Moslae Herba and Pogostemonis Herba was prepared by scaturated aqueous
solution method,
colloid milling
method and grinding
method, respectively. GC was used to determine the contents of
thymol, carvacrol and
patchouli alcohol in
volatile oil for optimizing extraction and inclusion processes of
volatile oil. Scanning
electron microscope, infrared
spectroscopy, thermal differential
analysis, and
X-ray diffraction (XRD) were used to verify the formation of the inclusion complex.
Result:
The
volatile oil not only inhibited
hyaluronidase activity to a certain extent, but also eliminated DPPH and increased with the increase of concentration. There was a good linear relationship between the peak area and concentration of
thymol, carvacrol and
patchouli alcohol at 0.021 3-0.426, 0.020 04-0.400 8, 0.022 6-0.452 g·L-1 (R2>0.999), respectively. Their recoveries were 99.59%(RSD 1.6%), 100.15%(RSD 1.5%), 100.70%(RSD 1.4%), respectively. The
colloid milling
method was optimized, and the formation of the inclusion complex was verified by the aforementioned
methods.
Conclusion:
The
volatile oil in couplet medicines of Moslae Herba and Pogostemonis Herba has certain anti-inflammatory activity and anti-
oxidation ability. The
colloid milling
method was the best inclusion process for the
volatile oil. The established GC has the advantages of simple, sensitive, accurate, reliable and reproducible, which can meet the requirements of simultaneous
determination of
thymol, carvacrol and
patchouli alcohol in the inclusion complex.