Classical Active Ingredients and Extracts of Chinese Herbal Medicines: Pharmacokinetics, Pharmacodynamics, and Molecular Mechanisms for Ischemic Stroke

Stroke is a leading cause of death and disability worldwide, and approximately 87% of cases are attributed to ischemia. The main factors that cause ischemic stroke include excitotoxicity, energy metabolism disorder, Ca⁺ overload, oxidative damage, apoptosis, autophagy, and inflammation. However, no effective drug is currently available for the comprehensive treatment of ischemic stroke in clinical applications; thus, there is an urgent need to find and develop comprehensive and effective drugs to treat postischemic stroke. Traditional Chinese medicine (TCM) has unique advantages in treating ischemic stroke, with overall regulatory effects at multiple levels and on multiple targets. Many researchers have studied the effective components of TCMs and have achieved undeniable results. This paper reviews studies on the anticerebral ischemia effects of TCM monomers such as tetramethylpyrazine (TMP), dl-3-n-butylphthalide (NBP), ginsenoside Rg1 (Rg1), tanshinone IIA (TSA), gastrodin (Gas), and baicalin (BA) as well as effective extracts such as Ginkgo biloba extract (EGB). Research on the anticerebral ischemia effects of TCMs has focused mostly on their antioxidative stress, antiapoptotic, anti-inflammatory, proangiogenic, and proneurogenic effects. However, the research on the use of TCM to treat ischemic stroke remains incompletely characterized. Thus, we summarized and considered this topic from the perspective of pharmacokinetics, pharmacological effects, and mechanistic research, and we have provided a reference basis for future research and development on anticerebral ischemia TCM drugs.

Sanchi for acute ischaemic stroke

BACKGROUND

Currently very few drugs are supported for routine use for acute ischaemic stroke. Sanchi is one of the most widely used herbal medicines for ischaemic stroke in China.

OBJECTIVES

To assess the effectiveness and safety of sanchi in the treatment of acute ischaemic stroke.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register (last searched January 2008), the Chinese Stroke Trials Register (searched February 2007), the Cochrane Complementary Medicine Field trials register (searched February 2007), the Chinese Cochrane Centre Controlled Trials Register (last searched February 2007). We also searched the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 1, 2007), MEDLINE (1966 to February 2007), EMBASE (1980 to February 2007), CINAHL (1982 to February 2007), AMED (1985 to February 2007), CNKI (1979 to February 2007), CBM-disc (1979 to February 2007), Chinese scientific periodical database of VIP INFORMATION (1989 to February 2007), Wanfang Data (1982 to February 2007), CISCOM (1980 to February 2007), and TCMLARS (1984 to February 2007).

SELECTION CRITERIA

Randomised controlled trials comparing sanchi with placebo or no treatment for acute ischaemic stroke within 30 days of onset.

DATA COLLECTION AND ANALYSIS

Two review authors extracted data and assessed trial quality.

MAIN RESULTS

Eight trials involving 660 participants were included. Seven of the eight studies were of poor quality. Follow-up time was less than one month in six trials. Only two trials provided data for the number of participants who were dead or dependent at the end of 28 days of treatment, indicating a significantly lower rate of death and dependency in the sanchi group than in the control group (relative risk (RR) 0.63, 95% confidence interval (Cl) 0.45 to 0.88). One trial reported higher Barthel index scores in the sanchi group. Pooled analysis of seven trials indicated that sanchi might improve neurological deficit more than control with a significant difference (RR 0.29, 95%Cl 0.18 to 0.47). The total case fatality rate was lower than 1% indicating that participants probably had mild strokes. Few adverse events were reported. Data were limited in respect of stroke recurrence and quality of life.

AUTHORS' CONCLUSIONS

Sanchi appears to be beneficial and safe for acute ischaemic stroke in this review, but the small sample and inferior quality of studies prevented a definite conclusion. More well-designed randomised controlled trials are required.