In veterinary medicine, we are often faced with chronic diseases like cancer, skin diseases, immune-mediated diseases and more. Treating chronic diseases with conventional medicine often is frustrating, unrewarding and the outcome is seldom positive long term. Alternative medicine is able to offer another view on a case and another possibility for treatment after conventional medicine and its specialists have lost hope. The goal of this review is to evaluate some literature about Astragalus membranaceus, sometimes used in Western herbal medicine formulas, for the treatment of protein-losing nephropathy (PLN) and briefly touching on its potential usage in the treatment of inflammatory bowel disease (IBD).
Astragalus membranaceus is also known as Huang Qi in Chinese herbal medicine. The root is usually harvested from 4 year old plants and is the part most often used for medicinal purposes (Ehrlich 2008). Astragalus is part of the Fabaceae family (Leguminoseae or legume family). In TCM, it is believed to enter the lung, spleen and heart meridians and is considered to be a sweet and warming herb.
It has been around for centuries and is often used with other herbs to help amongst other things: to stimulate the immune system, reduce side-effects of chemotherapy, act as a restorative tonic and also has an adaptogen (Abrams et Al. 2011). In Western Herbal Veterinary Medicine, according to Dr Barbara Fougere (2007), it may be used for geriatric support, congestive heart failure, early heart failure, chronic infection, immune deficiency, renal disease and cancer. Yu et al. (2007) establish the safety dosage range at 5.85-19.95g/kg for beagle dogs. No obvious toxicities nor side-effects were noted. Finally, it is interesting to note that standard operating procedures have established astragalus, so this may help us find suppliers we can trust (Yang 2006).
We know that IBD and PLN are suspected to be caused by multiple factors like underlying food allergies, immune mediated issues or underlying genetic predisposition (AKC 2011). So, one wonders if astragalus could be used in a Western Herbal formula for its combined effects on the bowels and its effects on the kidney. This brings us to research done on astragalus membranaceous in regards to its effects on the kidneys.
An article talks about a meta-analysis of randomized and semi-randomized clinical trials to evaluate Astragalus in diabetic nephropathies in 1804 people (Li et al 2011). They concluded that the role of this herb is profound in diabetic nephropathy. In another study, two independent assessors, basically came to the conclusion that astragalus is able to reduce albuminuria, reduce fasting blood glucose, reverse hyperfiltration of the glomeruli and also managed to ameliorate pathological changes in rats that had early diabetic nephropathy (Zhang et al. 2009). Another study performed, using benazepril as the control group, showed that animals receiving astragalus improved more in comparison to the controlled groups (Zhang et al. 2007). A research study done on rats using astragalus and angelica sinensis assessed their combined impact on nephrotic syndrome (Wojcikowski et al. 2006). It seems that both enalapril and this combination of herbs was able to decrease proteinuria, decrease triglycerides, lower expression of collagen type III and IV, lower laminin, lower fibronectin, and blood urea nitrogen levels. In rabbits this time, a study was done to evaluate the injury done to renal tubules by high energy shock waves. It showed that astragalus has a strong protective effects on free radical-mediated renal tubular damage. Also, it showed that these effects were superior to verapamil (Li et al. 2006). Denzler et al. (2010) recently published a study where they used botanogenomics (or herbogenomics) to evaluate astragalus and other herbs. They confirmed its impact on cytokines and also its renoprotective effects. But, more interestingly, they also identified the presence of lipopolysaccharides in astragalus. It seems that these lipopolysaccharides are naturally present in medicinally prepared extracts of astragalus. Their conclusion was that astragalus induced genes involved in a strong, generalized proinflammatory response. They stipulate that this response may be responsible for the antimicrobial activity associated with astragalus.
In regards to using astragalus for IBD, there are some research about Astragalus and its potential in the treatment of diarrhea related to colitis through its action on cytokines (immunomodulary effects) in rats (Ko et al. 2009). They concluded that Astragalus given orally or locally injected seemed to have a protective effect against experimental colitis. It has immunomodulary effects on the colon which in turn help alleviate signs of diarrhea in colitis. Also, another study supported the fact that astragalus has activity on the bowels and mostly on the jejunum of dogs. It seems to be able to strengthen movement and muscle tonus gastro-intestinal tract (Yang 1993).
Another study showed that, in combination with angelica sinensis, it has a role of prophylaxis on the infection of cryptosporidium infection in immunosuppressed mice by improving their immune status (Zhang et al. 2008). A study performed on colitis in rats demonstrated that this herb seems to have anti-inflammatory actions by its anti-oxidative effect on the colon, so their conclusion was that this herb seems to have a therapeutic potential and also may be beneficial as a preventive measure (Ko et al. 2005).
In conclusion, the main goal of this review was to evaluate the possibility of using astragalus for concurrent PLN and IBD disease in regards to its multi-systemic effects and its impact on the immune system. Astragalus seems to be able to decrease proteinuria, increase serum albumin, decrease weight loss by sparing muscle protein, improve overall renal function, may slow down the progression of renal disease and may help prevent damage to the kidneys.
In regards to IBD, astragalus may help reduce inflammation in the colon, acts as an adaptogen, have immunomodulatory effect and anti-oxidant effects on the bowels. It is definitely an interesting herb to study and to consider incorporating in a Western Herbal formula for the treatment of concurrent IBD and PLN. With our conventional medicine minds, we often don’t think outside the box, instead we set limits on what we want to learn and we forget that there is a lot of stuff about medicine that we don’t know. There are yet many diseases to be cured, many treatments to be found, so why limit our medicine by the constraints imposed on us by our previous learning or previous studies?
Written by Dr Cindy Lizotte, DVM, MBA, CVFT (CHI institute), CVA (IVAS), Grad Dip Vet Western Herb Med (CIVT) Cert CVHM (IVAS)