Comparative analysis of cytotoxic effect of aqueous cinnamon extract from Cinnamomum zeylanicum bark with commercial cinnamaldehyde on various cell lines

Figures & data

Figure 1.  HPTLC chromatograms of (A) standard mixture of piperine, cinnamaldehyde and eugenol; (B) aqueous cinnamon extract (ACE). The amount of cinnamaldehyde present in ACE was determined from the calibration curve obtained by plotting the concentration of standard against the peak area of test sample (ACE). The quantity of cinnamaldehyde in ACE was found to be around 0.25% w/v. Thus, 50 mg/mL stock solution of ACE contained 400 μM cinnamaldehyde content. (B) Calibration curve for quantification of analytes from ACE.

Figure 2.  The amount of polyphenols present in ACE was determined from the calibration curve obtained by plotting the concentration of standard gallic acid equivalent against the test sample (ACE). The typical regression equation was y = 0.0056 x+ 0.2011 for polyphenols. The quantity of polyphenols in 50 mg/mL ACE was found to be 380.83 μg/mL or 0.76%. Standard plot obtained by plotting the concentration of gallic acid equivalent.

Table 1.  Effect of different concentrations of aqueous cinnamon extract (ACE) on cell viability.

Cell line	0.04 mg/mL (0.32 μM)^a	0.08 mg/mL (0.64 μM)^a	0.16 mg/mL (1.28 μM)^a	0.32 mg/mL (2.56 μM)^a	0.64 mg/mL (5.12 μM)^a	1.28 mg/mL (10.24 μM)^a
HT1080	100	100	100	100	85.74 ± 7.64	44.23 ± 9.93
A431	100	100	96.13 ± 5.33	89.48 ± 6.12	67.91 ± 11.46	23.28 ± 4.14
SK-N-MC	100	100	100	92.55 ± 3.502	67.86 ± 3.59	25.86 ± 2.178
MG63	100	100	87.06 ± 6.77	78.30 ± 1.12	80.15 ± 2.4	64.28 ± 3.5
Neuro2a	100	100	100	100	98.46 ± 3.15	62.93 ± 4.8
SiHa	100	100	100	100	81.83 ± 4.93	52.98 ± 1.07
L929	100	100	100	100	89.39 ± 4.3	81.81 ± 2.6
RAW264.7	100	100	100	100	100	100
Primary fibroblast	100	100	100	100	92.04 ± 4.84	63.38 ± 1.06
Mouse hepatocytes	100	100	98.72 ± 2.21	97.54 ± 4.26	85.67 ± 4.4	84.27 ± 3.4

^a Represents the concentration of cinnamaldehyde (μM) present in the aqueous cinnamon extract (ACE) as calculated from HPTLC analysis. Data is presented as mean ± SD of triplicates, with each experiment being repeated at least four times.

Table 2.  Effect of different concentrations of commercial cinnamaldehyde on cell viability.

Cell line	0.8 μM	1.6 μM	3.2 μM	5 μM	10 μM	20 μM	40 μM	80 μM	160 μM	320 μM
HT1080	100	100	100	100	100	100	72.3 ± 7.05	50.86 ± 1.2	21.30 ± 7.8	9.23 ± 0.2
A431	100	100	100	100	100	100	92.87 ± 1.34	47.1 ± 23	8.51 ± 3.09	3.24 ± 2.67
SK-N-MC	100	100	100	100	70.62 ± 5.58	58.66 ± 6.7	46.08 ± 3.84	19.52 ± 7.8	7.17 ± 3.86	3.19 ± 2.56
MG63	100	100	100	100	100	100	100	100	93.70 ± 8.4	33.44 ± 5.4
Neuro2a	100	100	100	100	100	100	82.3 ± 1.51	72.62 ± 1.2	30.24 ± 15	2.05 ± 0.3
SiHa	100	100	100	100	100	89.21 ± 8.4	66.07 ± 3.1	34.78 ± 22	15.84 ± 12	5.00 ± 6.58
L929	100	100	100	100	100	87.71 ± 4.5	85.29 ± 7.48	75.25 ± 12	8.60 ± 7.35	1.65 ± 0.2
RAW264.7	100	100	100	100	100	100	100	60.03 ± 3.5	44.70 ± 1.9	9.21 ± 5.77
Primary fibroblast	100	100	90.96 ± 5.4	90.06 ± 4.6	85.51 ± 1.4	83.65 ± 6.3	69.32 ± 1.5	31.69 ± 15	9.19 ± 4.6	2.23 ± 1.4
Mouse hepatocytes	100	98.85 ± 1.2	97.168 ± 0	94.41 ± 2.5	88.05 ± 13.6	86.63 ± 2.2	72.81 ± 12.1	35.35 ± 6.1	11.69 ± 3.1	4.09 ± 4.03

Data are presented as mean ± SD of triplicates, with each experiment being repeated at least four times.

Table 3.  Comparative analysis of cytotoxicity of ACE with that of commercial cinnamaldehyde.

Cell line	ACE (1.28 mg/mL) (10.24 μM)	Cinnamaldehyde (10 μM)	p-value
HT1080	44.23	100	p = 0.007
A431	23.28	100	p = 0.045
SK-N-MC	25.86	70.62	p = <0.001
MG63	64.28	100	p = <0.001
Neuro2a	62.93	100	p = 0.017
SiHa	52.98	100	p = <0.001
L929	81.81	100	p = 0.024
Primary fibroblast	63.38	85.51	p = 0.001

Student’s t-test was performed on data showing comparative effect of ACE with that of commercial cinnamaldehyde on percentage cell survival at 10 μM concentration, with respective p-values for each cell line.