What is Hyperuricemia?
Hyperuricemia refers to elevated levels of uric acid in the blood. This is often caused by a disorder in the metabolism of purine in the body, when excretion of uric acid is hindered.
Hyperuricemia is a known cause of gout as well as kidney damage.
How does Hyperuricemia cause Gout?
Hyperuricemia will mostly results in gouty arthritis, which is the what we commonly call a gout flare or attack.
How this happens: Excess uric acid will show up as uric acid crystals called Monosodium Urate (MSU). Monosodium Urate builds up in the joints and soft tissue, resulting in the painful symptoms of gout.
How does TCM treat Gout?
There are two ways by which TCM treats Gout.
One of the ways is by reducing pain and inflammation. When used during an acute flare, Chinese herbs are able to reduce pain and inflammation of arthritis.
TCM is also able to treat gout by bringing down levels of uric acid in the blood in an efficacious manner. This reduces the severity and duration of pain during the acute phase; this is also very useful during remission because it ensures that there is no build up of excessive uric acid.
TCM treats gout by reducing uric acid production through the Xanthine Oxidase pathway and increasing uric acid excretion through the OAT pathway.
TCM treats Gout by inhibiting the Xanthine Oxidase pathway
The first pathway for reducing uric acid levels is the Xanthine Oxidase pathway. The Xanthine Oxidase pathway is required in the production of uric acid in the body. When this pathway is inhibited, less uric acid is produced. Reduced hyperuricemia means reduced frequency of gout attacks.
One herbal combination that is known to reduce Xanthine Oxidase is Yi Yi Ren Tang. This herbal combination is best suited to someone who presents with joint pain but without red, hot, swollen joints. Yi Yi Ren Tang is made up of the following Chinese herbs:
- Yiyiren, Cangzhu
- Mahuang, Guizhi
- Danggui, Baishao
- Shengjiang, Gancao
TCM treats Gout by increasing Uric Acid Uptake
The second pathway for reducing uric acid levels is the OAT pathway. When OAT is elevated, uric acid uptake is increased. This means uric acid is cleared from the body, reducing the likelihood of gouty arthritis.
Two formulas that are able to reduce OAT levels are Yi Yi Ren Tang and Si Wu Jia Er Miao Tang.
In animal studies, Si Wu Jia Er Miao Tang is shown to upregulate OAT1 and OAT3 expression, hence reducing uric acid levels by intervening in the OAT pathway.
What is Si Wu Jia Er Miao Tang?
This is a formulation made up of two well-known herbal formulations.
One is Si Wu Tang, which was originally a formula to facilitate healing from physical trauma. Much research on Si Wu Tang shows it to have broad anti-inflammatory effects in animals and humans alike.
It is also evident that usage of formulas like Si Wu Tang are very important because formulas are these are able to help circulation and alter blood rheology. Think of Si Wu Tang as a circulatory herb combination.
The other herbal combination is called Er Miao San, which is made up of only two herbs, Cangzhu and Huangbai. Research by Kong et al (2004) showed how this herb pair was able to reduce xanthine oxidase levels, hence reducing blood uric acid levels in mice. This of Er Miao San as an anti-inflammatory herb combination.
This combination of Si Wu Tang and Er Miao San is able to facilitate whole body circulation and reduce systemic inflammation. It evidently is also able to treat gout by reducing uric acid levels.
2 Formulas that treat Gout are modifications of Er Miao San
From the herbal combination Er Miao San we see other herbal formulas being created to treat pain and also gout.
Dan Xi Tong Feng Tang is a classical herb combination based on Er Miao San tha treats pain and gout. This 800 year-old herbal formulation is more effective than Celebrex in reducing ESR levels, according to research by Shen et al (2018). Elevated ESR levels indicate acute inflammation; reduced ESR levels attest to efficacy in reducing systemic inflammation in the body. More importantly, this herbal formula is able to reduce uric acid levels, which then reduces the frequency of gout attacks.
Another herbal combination created from Er Miao San is called Si Miao San. According to Huang et al (2017), Si Miao San is able to reduce CRP, ESR and IL-8 levels – these are 3 blood indicators of acute inflammation in gout arthritis.
Yi Yi Ren Tang reduces Uric Acid Levels and prevents Kidney Damage
Yi Yi Ren Tang has been used in the treatment of Osteoarthritis, Rheumatoid Arthritis and Gout. Lee et al (2019) explored how this formula is specifically able to reduce uric acid levels through the following actions:
- Decreasing uric acid production by increasing xanthine oxidase (XO) inhibition. Xanthine oxidase facilitates uric acid production; by inhibiting XO, we reduce uric acid production.
- Increasing uric acid excretion by increasing OAT3 levels and reducing GLUT9 levels. OAT3 helps in uric acid excretion in the kidneys, while GLUT9 reabsorb uric acid.
In addition, Yi Yi Ren Tang is able to suppress inflammation and protect against kidney damage caused by hyperuricemia. This was done by blocking the action of pro-inflammatory cytokine IL-1α, which then resulted in:
- Reduction in neutrophil gelatinase-associated lipocalin (NGAL), which is a early biomarker for acute kidney injury
- Decrease in kidney injury molecule-1 (KIM-1), another biomarker indicating renal inflammation
Other Herbal Formulations which reduce Uric Acid Levels and prevent Kidney Damage
We also know from research that there are two other herbal combinations that are able to treat hyperuricemia. They are Ba Wei Di Huang Wan and Wu Ji San.
Similar to Yi Yi Ren Tang, these two herbal formulations are able to reduce uric acid levels by inhibiting XO levels, increasing OAT3 levels and reducing GLUT9 levels. They also have kidney protective function, evidenced by a reduction in renal inflammatory biomarkers NGAL and KIM-1.
Similar to Yi Yi Ren Tang, they are considered warming formulations most suitable for treating arthritis or pain that do not present with redness, heat and significant swelling.