Absorption mechanism of oxymatrine in cultured Madin–Darby canine kidney cell monolayers

Figures & data

Table 1. Stability of OMT (1 μg/mL) in different pH Hanks (mean ± SD, n = 5).

	Concentration (μg/mL)
pH	30 min	60 min	90 min	120 min	Accuracy (%)
1.5	0.932 ± 0.067	0.895 ± 0.071	0.861 ± 0.061	0.843 ± 0.057	84.3
3.0	0.957 ± 0.055	0.922 ± 0.038	0.907 ± 0.085	0.885 ± 0.073	88.5
5.0	0.977 ± 0.084	0.975 ± 0.073	0.975 ± 0.042	0.968 ± 0.065	96.8
6.5	0.982 ± 0.049	0.973 ± 0.028	0.998 ± 0.073	0.989 ± 0.049	98.9
8.0	0.988 ± 0.082	0.991 ± 0.068	1.013 ± 0.033	0.997 ± 0.074	99.7

The accuracy was determined at 2 h.

Accuracy (%): measured concentration/nominal concentration × 100%.

Figure 1. Time effects on the transport of OMT (10⁻⁴ M) across MDCK cell monolayers on AP side at 37 °C. Each point represents the mean ± SD of three different cell monolayers.

Figure 2. Concentration effects on the transport of OMT across MDCK cell monolayers. OMT transport amount was measured at 37 °C after 120 min incubation. Data are presented as mean ± SD of three different cell monolayers.

Figure 3. Concentration effects on the transport of OMT across MDCK cell monolayers. Cells were incubated with OMT 10⁻⁴ M from AP to BL compartment for 2 h at 37 °C. Each point represents the mean ± SD of three different cell monolayers.

Table 2. P_app of OMT at different concentration across MDCK monolayers (Mean ± SD, n = 3).

	Papp (×10^−6cm/s)
OMT (mol/L)	AP-BL	BL-AP	Efflux ratio PBL-AP/PAP-BL
1.0 × 10^−5	3.507 ± 0.61	3.421 ± 0.04	0.97
3.0 × 10^−5	3.624 ± 1.58	3.551 ± 0.94	0.98
1.0 × 10^−4	3.402 ± 0.82	3.371 ± 0.12	0.99
3.0 × 10^−4	3.040 ± 0.23	3.011 ± 0.06	0.99
1.0 × 10^−3	3.697 ± 0.19	3.623 ± 0.23	0.98

P_app: the apparent permeability coefficient; MDCK: Madin–Darby canine kidney cell line; AP-BL: apical to basolateral; BL-AP: basolateral to apical.

Figure 4. Effects of temperature on OMT (10⁻⁴ M) transport across MDCK cell monolayers. Data are represented as mean ± SD of three different cell monolayers.

Figure 5. Effect of pH on OMT (10⁻⁴ M) transport across MDCK cell monolayers. Transport of OMT was measured at 37 °C for 30 min. Asterisks signs denote significant differences; **p < 0.01 versus control (pH 5).

Figure 6. Effect of transport enhancers on P_app of OMT (10⁻⁴ M) across MDCK cells. Transport of OMT was measured at 37 °C for 15 min. Results are expressed as mean ± SD of three different cell monolayers. Asterisks signs denote significant differences; *p < 0.05 versus control; **p<0.01 versus control.