Targeting dyslipidemia by herbal medicines: A systematic review of meta-analyses

Abstract

Ethnopharmacological relevance

The worldwide increasing prevalence of dyslipidemia has become a global health concern. Various herbal remedies have been claimed to be effective for the treatment of dyslipidemia in traditional and folkloric medicine of different regions clinical trials have been conducted to investigate their efficacy. The aim of the current systematic review is to critically assess the meta-analyses of controlled trials (CT) evaluated herb medicines for dyslipidemia.

Materials and methods

Relevant studies from Web of Science, PubMed, Scopus, and Cochrane Library databases based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist until January 2021 have been searched. All meta-analyses which pooled studies on the effect of herbal medicines on lipid profile including total cholesterol (TC), triglyceride (TG), and low- or high-density lipoprotein cholesterol (LDL-C, HDL-C) were also included. Meta-analyses of in vitro, animal or observational studies were excluded.

Results

The overall of 141 meta-analyses were revealed. Vegetable oils, phytosterols, tea, soy protein, nuts, and curcumin have been studied frequently among the herbal medicines. Among 13 meta-analyses on vegetable oils, the greater reduce of TC (18.95 mg/dl), LDL-C (16.24 mg/dl) and TG (13.69 mg/dl) were exhibited from sunflower oil. Furthermore, rice bran oil (6.65 mg/dl) increased HDL-C significantly. Phytosterols in 12 meta-analyses demonstrated significant improvements in reducing TC, LDL-C and TG as 16.4, 23.7, and 8.85 mg/dl, respectively, and rise in HDL-C as 10.6 mg/dl. The highest reduction in serum level of TC, LDL-C and TG was reported while intake Green tea; 27.57, 24.75, and 31.87 mg/dl, accordingly within 9 meta-analyses. Average improvement of lipid profiles by 6 meta-analyses on plant proteins were 23.2, 21.7, 15.06, and 1.55 mg/dl for TC, LDL-C, TG, and HDL-C, respectively. Among 11 meta-analyses on nuts, almond showed better and significant alleviations in TC (10.69 mg/dl), walnut in LDL-C (9.23 mg/dl), pistachio in TG (22.14 mg/dl), and peanut in HDL-C (2.72 mg/dl). Overall, Curcumin, Curcuminoid, and Turmeric have resulted in the reduction of TC (25.13 mg/dl), LDL-C (39.83 mg/dl), TG (33.65 mg/dl), and an increase in the HDL-C (4.31 mg/dl).

Conclusion

The current systematic review shed light on the use of herbal medicines for the management of dyslipidemia. However, more well-conducted CTs are required to determine effective doses of herbal medicines.

Introduction

Dyslipidemia (DLP) is defined as an elevation in the level of total cholesterol (TC), triglyceride (TG), or low-density lipoprotein cholesterol (LDL-C) and decreased level of high-density lipoprotein cholesterol (HDL-C) (Heshmat-Ghahdarijani et al., 2020). Simultaneous increment of health problems led into the attraction of global attention. Atherosclerosis, cardiovascular complications, pancreas disorders, and fatty liver are avowed as the concurrent disease with DLP (Zhang et al., 2020). Likewise, DLP is associated with metabolic syndrome (Mets) and its components such as obesity and diabetes (Tabatabaei-Malazy et al., 2015). Cardiovascular disease (CVD) accounts for about 30% of the overall deaths in 2010 and an estimated annual deaths of 25 million by 2030; moreover, altered lipid profile plays a significant role in progression or regression of CVD (Khorshidi et al., 2020). As stated in previous studies, more than 60% patients with early coronary artery disease (CAD) symptoms struggle with DLP and 10% decline in TC reduces 15% of CAD, the importance of lipid profile supervise becomes prominent (Ding et al., 2020).

Diverse approaches are recommended to manage DLP; such as lifestyle modifications, diet intervention, and pharmacotherapy options (Shekarchizadeh-Esfahani et al., 2020). The more efforts do for the management of DLP, the less beneficial results the patients receive (Zhang et al., 2020). Despite the worldwide use of lipid-lowering agents, their long-term efficacy is still questionable (Shekarchizadeh-Esfahani et al., 2020). Lipid-lowering medications are associated with various adverse effects such as myopathy, impaired liver function, neuropathy and declined mental status (Teng et al., 2020); also increased risk of diabetes has been reported to be associated with the use of lipid-lowering medications (Yuan et al., 2019). Therefore, considering alternative therapies with lower adverse effects and cheaper choices is reasonable.

Herbal remedies used in traditional and folkloric medicine of different regions provide a worthwhile source for discovering and introducing new drugs (Bahramsoltani and Rahimi, 2020; Bahramsoltani et al., 2019; Ebrahimi et al., 2019). Recently, tremendous increase of the patients and physicians desire to manage lipid profile with natural extracts has been noticed (Sahebkar et al., 2016b; Tabatabaei-Malazy et al., 2016). A vast number of studies performed on the efficacy and safety of natural products, showed auspicious changes in the lipid profile and thus, reduction of the risk of CVD (Sahebkar et al., 2016b). Contrarily, a number of studies showed fewer positive effects on this matter or reported adverse effects of herbs, as containing active biologic components (Posadzki et al., 2016).

The aim of the present systematic review is to critically assess the meta-analysis studies conducted on the efficacy of herbal medicines trials in dyslipidemia.