An effective solution to discover synergistic drugs for anti-cerebral ischemia from traditional Chinese medicinal formulae

Abstract

Recently, the pharmaceutical industry has shifted to pursuing combination therapies that comprise more than one active ingredient. Interestingly, combination therapies have been used for more than 2500 years in traditional Chinese medicine (TCM). Understanding optimal proportions and synergistic mechanisms of multi-component drugs are critical for developing novel strategies to combat complex diseases. A new multi-objective optimization algorithm based on least angle regression-partial least squares was proposed to construct the predictive model to evaluate the synergistic effect of the three components of a novel combination drug Yi-qi-jie-du formula (YJ), which came from clinical TCM prescription for the treatment of encephalopathy. Optimal proportion of the three components, ginsenosides (G), berberine (B) and jasminoidin (J) was determined via particle swarm optimum. Furthermore, the combination mechanisms were interpreted using PLS VIP and principal components analysis. The results showed that YJ had optimal proportion 3(G): 2(B): 0.5(J), and it yielded synergy in the treatment of rats impaired by middle cerebral artery occlusion induced focal cerebral ischemia. YJ with optimal proportion had good pharmacological effects on acute ischemic stroke. The mechanisms study demonstrated that the combination of G, B and J could exhibit the strongest synergistic effect. J might play an indispensable role in the formula, especially when combined with B for the acute stage of stroke. All these data in this study suggested that in the treatment of acute ischemic stroke, besides restoring blood supply and protecting easily damaged cells in the area of the ischemic penumbra as early as possible, we should pay more attention to the removal of the toxic metabolites at the same time. Mathematical system modeling may be an essential tool for the analysis of the complex pharmacological effects of multi-component drug. The powerful mathematical analysis method could greatly improve the efficiency in finding new combination drug from TCM.

Figure 1. The therapeutic effects of YJ with the optimal proportion.

(A)–(C) Effects of YJ on neurological deficits, cerebral infarct volume and content of cerebral water in rats induced by MCAO. EGb761 and YJ were both administered i.g. 15 min prior to MCAO and 6 h after MCAO. (D-1) Detection of cerebral blood flow. The cerebral blood flow perfusion color image [D-1. a (1–5) and c (1–5)], detected position image [D-1. b (1–5)], and blood flow time window [D-1. d (1–5)] are presented. [1, Vehicle control; 2, EGb761-treated group; 3–5, YJ-(1,5 and 25 mg·kg⁻¹) treated group]. (D-2) The reduced rate of rCBF. EGb761 and YJ were both administered i.g. 15 min prior to MCAO. Values were expressed as the mean ± SD (A, B and C, n = 10; D, n = 5), and the data were analyzed by one-way ANOVA. ^## P<0.01,^# P<0.05 versus the sham group; ^** P<0.01,^* P<0.05 versus the vehicle control.

Figure 2. The construction of the predictive model for YJ.

A. The values of R² for the five medical indices according to different calculation models; (A-a to d) The values of R² for the BPNN regression model, linear PLS regression model, multi-linear regression model and LARS-PLS regression model. B. Predicted values of the five medical indices for the different models. (B-a to e) Predicted values of resazurin, FP, PT, Rho and JC1 for different models.

Figure 3. Effects of the anti-apoptotic effect of YJ with the optimal proportion.

(A). Representative Western blots of Bcl-2, Bax, Cytochrome c, caspase-3 and β-actin. (B), (D), (E), The quantified densitometric analysis of Bcl-2, Bax, cytochrome c and caspase-3. (C). The ratio of Bax/Bcl-2 proteins. Values were expressed as the mean ± SD for the four independent experiments, and the data were analyzed by one-way ANOVA. ^## P<0.01,^# P<0.05 versus the sham group; ^** P<0.01,^* P<0.05 versus the vehicle control.

Figure 4. Morphological studies of mitochondria and brain tissue cells.

(A) The neurons picture (1000×). (B) The mitochondrial picture (3000×). a. The sham-treated group; b. The vehicle-treated group; c. The YJ-treated (25 mg·kg⁻¹) group.

Figure 5. The study of the combination mechanisms of YJ.

(A-1) VIP score on linear PLS regression model. (A-2) VIP score on LARS-PLS regression model. (B). The principal component of mitochondrial function. (D). Effects of YJ on neurological deficits induced by MCAO. Values were expressed as the mean ± SD (n = 10), and the data were analyzed by one-way ANOVA. ^## P<0.01,^# P<0.05 versus the sham group; ^** P<0.01,^* P<0.05 versus the vehicle control. (C). The analysis of synergy using principal components analysis (PCA) for mitochondrial function. (C-1) The principal components of group G, GB, GJ and GBJ. ^** P<0.01,^* P<0.05 versus the G-treated group. (C-2) The principal components of group B, GB, BJ and GBJ. ^** P<0.01,^* P<0.05 versus the B-treated group. (C-3) The principal components of group J, BJ, GJ and GBJ. ^** P<0.01,^* P<0.05 versus the J-treated group.