Astragalus (Astragalus membranaceus) and Kidney support: evidence and sources

Background Astragalus (Radix Astragali, huang qi) is the dried root of Astragalus membranaceus (Fisch.) Bge. var. mongholicus (Bge.) Hsiao or Astragalus membranaceus (Fisch.) Bge. (Family Leguminosae). It is one of the most widely used herbs in traditional Chinese medicine for treating kidney diseases. Evidence is needed to help clinicians and patients make judgments about its use for managing chronic kidney disease (CKD). Objectives This review evaluated the benefits and potential harms of Astragalus for the treatment of people with CKD. Search methods We searched the Cochrane Renal Group's Specialised Register to 10 July 2014 through contact with the Trials' Search Co-ordinator using search terms relevant to this review. We also searched CINAHL, AMED, Current Controlled Trials, OpenSIGLE, and Chinese databases including CBM, CMCC, TCMLARS, Chinese Dissertation Database, CMAC and Index to Chinese Periodical Literature. Selection criteria Randomised controlled trials (RCTs) and quasi-RCTs comparing Astragalus, used alone as a crude herb or an extract, with placebo, no treatment, or conventional interventions were eligible for inclusion. Data collection and analysis Two authors independently extracted data and assessed risk of bias in the included studies. Meta-analyses were performed using relative risk (RR) for dichotomous outcomes and mean differences (MD) for continuous outcomes, with 95% confidence intervals (CI). Main results We included 22 studies that involved 1323 participants, of whom 241 were receiving dialysis treatment. Risk of bias was assessed as high in six studies, and unclear in the remaining 16 studies. Study quality was low overall.Our nominated primary outcomes of time to requirement for renal replacement therapy (RRT) or initiation of dialysis and all-cause mortality were not reported in any of the included studies.Results concerning the effects of Astragalus on kidney function were inconsistent. Astragalus significantly increased CrCl at end of treatment (4 studies, 306 participants: MD 5.75 mL/min, 95% CI 3.16 to 8.34; I² = 0%), decreased SCr (13 studies, 775 participants: MD -21.39 µmol/L, 95% CI -34.78 to -8; I² = 70%) and especially in those whose baseline SCr was Authors' conclusions Although Astragalus as an adjunctive treatment to conventional therapies was found to offer some promising effects in reducing proteinuria and increasing haemoglobin and serum albumin, suboptimal methodological quality and poor reporting meant that definitive conclusions could not be made based on available evidence.

Decoctions prepared from the roots of Astragali Radix are known as "Huangqi" and are widely used in traditional Chinese medicine for treatment of viral and bacterial infections, inflammation, as well as cancer. Astragaloside IV (AS-IV), one of the major compounds from the aqueous extract of Astragalus membranaceus, is a cycloartane-type triterpene glycoside chemical. To date, many studies in cellular and animal models have demonstrated that AS-IV possesses potent protective effects in cardiovascular, lung, kidney and brain. Based on studies over the past several decades, this review systematically summarizes the pharmacological effects, pharmacokinetics and the toxicity of AS-IV. We analyze in detail the pharmacological effects of AS-IV on neuroprotection, liver protection, anti-cancer and anti-diabetes, attributable to its antioxidant, anti-inflammatory, anti-apoptotic properties, and the roles in enhancement of immunity, attenuation of the migration and invasion of cancer cells and improvement of chemosensitivity of chemotherapy drugs. In addition, the latest developments in the combination of AS-IV and other active ingredients of traditional Chinese medicine or chemical drugs are detailed. These pharmacological effects are associated with multiple signaling pathways, including the Raf-MEK-ERK pathway, EGFR-Nrf2 signaling pathway, Akt/PDE3B signaling pathway, AMPK signaling pathway, NF-κB signaling pathway, Nrf2 antioxidant signaling pathways, PI3K/Akt/mTOR signaling pathway, PKC-α-ERK1/2-NF-κB pathway, IL-11/STAT3 signaling pathway, Akt/GSK-3β/β-catenin pathway, JNK/c-Jun/AP-1 signaling pathway, PI3K/Akt/NF-κB pathway, miRNA-34a/LDHA pathway, Nox4/Smad2 pathway, JNK pathway and NF-kB/PPARγ pathway. This review will provide an overall understanding of the pharmacological functions of astragaloside IV on neuroprotection, liver protection, anti-cancer and anti-diabetes. In light of this, AS-IV will be a potent alternative therapeutic agent for treatment of the above mentioned diseases.