Quality control of herbal medicines by using spectroscopic techniques and multivariate statistical analysis

Figures & data

Table 1.  Specific peaks (in cm⁻¹) in Fourier transform infrared–fingerprint spectra (FTIR–FPS) of herbal medicines for their characterization.

Herbal plant/medicine	Part used	Peak (cm^−1)
Arjuna Terminalia arjuna L. (Combretaceae)	Bark	Strong 516, 780, 1316 Weak 884, 1445
Tulsi Ocimum sanctum L. (Lamiaceae)	Leaves	Strong 751, 1375, 1759 Weak 1060, 1029
Aawala Emblic myrobalan Burm. (Phyllanthaceae)	Fruits	Strong 876, 1035, 1097, 1371 Weak 472, 1216
Aswagandha Withania somnifera L. (Solanaceae)	Bark	Strong 520, 576, 1077, 1383 Weak 616, 1106
Vaasa Adhatoda vasica Nees. (Acanthaceae)	Leaves	Strong 430, 765, 1401, 1610 Weak 898, 1102, 1550
Bitter Neem Azadirachta indica L. (Meliaceae)	Leaves	Strong 1062, 1317, 1599 Weak 1155, 1255
Meethi Neem Murraya koenigi L. (Rutaceae)	Leaves	Strong 782, 1152, 1729 Weak 667, 959

Figure 1.  Fourier transform infrared (FTIR) spectra of (a) Arjuna (Terminalia arjuna L.), (b) Aswagandha (Withania somnifera L.), (c) Aawala (Emblic myrobalan Burm.), and (d) Tulsi (Ocimum sanctum L.) from different places showing similarity among them. J, Jaipur; M, Mumbai; V, Varanasi; A, Ahmedabad.

Figure 2.  Second derivative Fourier transform infrared (FTIR) spectra of Arjuna (Terminalia arjuna L.) collected from different places.

Table 2.  Ratios of areas of assigned characteristic peaks.

Herbal plant/medicine	Peaks selected	Ratio of areas of peaks
		Varanasi	Jaipur	Ahmedabad	Mumbai
Arjuna Terminalia arjuna L. (Combretaceae)	780/516	1.21	1.19	1.18	1.13
Tulsi Ocimum sanctum L. (Lamiaceae)	1759/1375	27.90	29.15	26.83	29.45
Aawala Emblic myrobalan Burm. (Phyllanthaceae)	1035/876	1.26	1.34	1.28	1.25
Aswagandha Withania somnifera L. (Solanaceae)	520/1077	3.14	3.35	3.26	3.45
Vaasa Adhatoda vasica Nees. (Acanthaceae)	1401/765	1.69	1.62	1.62	1.59
Bitter Neem Azadirachta indica L. (Meliaceae)	1317/1062	3.39	3.61	3.73	3.73
Meethi Neem Murraya koenigi L. (Rutaceae)	1152/782	2.54	2.42	2.68	2.65

Figure 3.  Graph showing consistent nature of ratio of areas of marked characteristic peaks for herbal samples collected from different places.

Table 3.  Eigen values and percentages of total variance from principal component analysis (PCA) of Fourier transform infrared spectral data for each of first seven principal components.

Principal component	Eigen value	% Total variance	Cumulative % total variance
1	346,772	80.36	80.36
2	78,144	18.11	98.47
3	3568.17	0.83	99.30
4	1803.42	0.42	99.72
5	498.65	0.12	99.84
6	409.673	0.095	99.935
7	259.054	0.060	99.995

Figure 4.  Principal component (PC) plots showing clustering of herbal medicines into different groups.

Table 4.  Heavy metal concentration (in ppm) in crude herbal/commercial Ayurvedic medicines.

Herbal medicine	Cd	Pb	Cr	As
Arjuna
V	0.049 ± 0.012	0.425 ± 0.038	0.105 ± 0.012	0.09 ± 0.003
A	0.076 ± 0.117	0.500 ± 0.042	0.070 ± 0.008	0.03 ± 0.002
J	0.046 ± 0.012	<DL	0.072 ± 0.008	0.08 ± 0.015
M	0.012 ± 0.000	0.423 ± 0.048	0.098 ± 0.008	0.12 ± 0.018
Powder*	0.035 ± 0.027	0.496 ± 0.046	0.246 ± 0.021	0.20 ± 0.033
Gritha*	<DL	0.098 ± 0.008	0.195 ± 0.016	0.11 ± 0.008
Aawala
V	0.024 ± 0.003	0.265 ± 0.024	0.056 ± 0.003	0.07 ± 0.010
A	0.030 ± 0.002	0.210 ± 0.0016	0.101 ± 0.014	0.16 ± 0.032
J	0.033 ± 0.006	0.140 ± 0.012	0.095 ± 0.008	0.13 ± 0.021
M	ND	ND	ND	ND
Aswagandha
V	0.027 ± 0.002	0.030 ± 0.005	0.170 ± 0.013	0.15 ± 0.025
A	0.026 ± 0.003	0.110 ± 0.013	0.058 ± 0.006	0.24 ± 0.026
J	0.012 ± 0.002	0.230 ± 0.034	0.071 ± 0.007	0.06 ± 0.008
M	0.019 ± 0.004	0.260 ± 0.021	0.186 ± 0.01	0.27 ± 0.018
Tablet*	0.008 ± 0.001	0.010 ± 0.003	0.241 ± 0.042	0.28 ± 0.031
Powder*	0.032 ± 0.006	0.410 ± 0.033	.164 ± 0.009	0.09 ± 0.016
Capsule*	< DL	0.060 ± 0.013	0.085 ± 0.013	0.12 ± 0.018
Tulsi
V	0.012 ± 0.002	0.286 ± 0.029	0.159 ± 0.009	ND
A	0.017 ± 0.003	0.330 ± 0.019	0.120 ± 0.011	0.03 ± 0.000
J	0.016 ± 0.002	0.396 ± 0.032	0.325 ± 0.038	ND
M	0.008 ± 0.001	0.460 ± 0.056	0.094 ± 0.010	ND
Vaasa
V	0.028 ± 0.005	0.060 ± 0.005	0.045 ± 0.004	0.18 ± 0.035
A	0.021 ± 0.002	0.110 ± 0.001	0.152 ± 0.018	0.22 ± 0.032
J	0.024 ± 0.002	0.096 ± 0.008	0.086 ± 0.016	0.14 ± 0.021
M	ND	ND	ND	ND
Vaasa ristha*	0.008 ± 0.001	0.560 ± 0.042	0.125 ± 0.018	0.34 ± 0.041
Vrihat Vaasavaleh*	0.032 ± 0.004	0.390 ± 0.026	0.428 ± 0.062	0.23 ± 0.034
Bitter Neem
V	0.001 ± 0.000	0.380 ± 0.000	0.030 ± 0.006	0.23 ± 0.041
A	0.033 ± 0.004	0.440 ± 0.033	0.091 ± 0.006	0.08 ± 0.000
J	0.022 ± 0.003	0.098 ± 0.009	0.050 ± 0.003	0.27 ± 0.035
M	0.006 ± 0.001	0.752 ± 0.082	0.056 ± 0.008	0.31 ± 0.048
Neem tablet*	0.009 ± 0.000	0.438 ± 0.037	0.248 ± 0.032	0.09 ± 0.006
Mithi Neem
V	0.024 ± 0.003	0.390 ± 0.032	0.044 ± 0.002	ND
A	0.012 ± 0.002	0.540 ± 0.075	0.086 ± 0.003	ND
J	0.003 ± 0.000	0.350 ± 0.071	0.108 ± 0.009	ND
M	0.016 ± 0.002	0.429 ± 0.048	0.156 ± 0.012	ND
Vijaysar
V	0.010 ± 0.002	0.098 ± 0.008	0.562 ± 0.073	ND
A	0.010 ± 0.002	0.684 ± 0.058	0.538 ± 0.054	0.08 ± 0.012
J	<DL	0.536 ± 0.102	0.502 ± 0.036	0.02 ± 0.007
M	0.060 ± 0.012	0.087 ± 0.007	1.006 ± 0.206	ND

Values are mean ± SD for n = 3.

V, Varanasi; A, Ahmedabad; J, Jaipur; M, Mumbai; ND, not detected; DL, detection limit. *Commercial sample.

Table 5.  Comparison of dose converted concentration of Cd in parts per million (ppm) with the recommended daily intake limit.

Herbal medicine	Concentration of Cd (ppm)	Dose converted concentration of Cd (ppm)	Remarks on permissible limit (0.30 ppm)
Arjuna
V	0.049	0.294	Just equal
A	0.076	0.456	Above
J	0.046	0.276	Slightly below
M	0.012	0.072	Safe