Boerhaavia diffusa is a spreading plant with a thick perennial root found growing throughout India up to an altitude of 2,000 m. Both the whole plant and the root have been used in medicine for a variety of conditions; however, it is most widely used in Ayurveda for treating renal and urinary problems. Punarnava is a well known diuretic, anti-spasmodic and anti-inflammatory agent in urinary tract infections. The tender shoots are eaten as a vegetable. The plant has traditionally been used to reduce edema associated with kidney, heart, gastrointestinal tract disorders, and general debility. In addition, it is a cardiotonic, has laxative and diuretic activity, is useful in fever, and acts as a rejuvenative or rasayana. It pacifies vata and kapha. The roots have anti-convulsant, analgesic, laxative and expectorant properties. They also have hepatoprotective actions. It has both diuretic and anti-inflammatory properties and therefore is useful in inflammatory renal diseases. The antiedema action is beneficial for congestive heart failure, when it is often administered with arjuna bark. The plant has an official status in the Indian Herbal Pharmacopoeia, 2002, as a diuretic and hepato-protective agent. It has been used to treat edema and ascites resulting from early cirrhosis of the liver and in chronic peritonitis.
Boerhaavia diffusa Linn
Latin name: Boerhaavia repens
Sanskrit: Punarnava (what renews us)
English: Spreading hogweed
Parts Used: Whole plant, root
Tastes: Bitter, sweet, pungent
Dosha Effects: KV- P+
Tissues: Plasma, blood
Actions: Alterative, blood tonic, rejuvenative, diuretic
Boerhavia diffusa contains an antifibrinolytic glycoside-pun-amavoside, alkaloids, rotenoids (boeravinones A, B, C, D, E), lignans (Iiridoderdin, syringaresinol mono p-D-glucoside), flavones, ursolic acid, sterols (p-sitosterol), boeravine, p-ecdysone, hypoxanthine 9-L-arabinofuranoside, and potassium salts.
Pharmacological studies have shown that the plant has both diuretic and anti-inflammatory activities with maximum activity being seen in samples collected during the rainy season. When the various parts of the plant were tested, it was found that the extracts of leaves and roots showed significantly more anti-inflammatory and diuretic activities as compared to the whole plant. In addition, the alkaloidal fraction has been shown to have immunomodulatory activity. Punarnava has also been found useful in acute pyelonephritis in albino rats, and has been found to exhibit a diuretic effect equivalent to furosemide.
The initial trials were more exploratory in nature with very few patients, inadequate inclusion criteria, and lack of objective end points, which, however, served to give a clinical impression of the nature of the drug. The first trial included 5 cases of parenchymatous nephritis along with 19 cases of dropsy and jaundice, which were treated with Boerhaavia diffusa. It was found that the increase in urine output was accompanied by a decrease in the albumin content, and a decrease in specific gravity of the urine. Clinical trials to evaluate the diuretic effect of Boerhaavia diffusa were also conducted in 34 patients suffering from edema and dropsy because of varied causes using liquid extracts derived from both the dry and fresh plant and found that they were equally effective in the reduction of edema.
A total of 22 patients diagnosed with nephrotic syndrome were randomly allocated to one of two groups and treated with either punarnava crude drug-as powder or in the form of decoction- or steroids and diuretics in the control group. There were several drop-outs and only 15 patients completed the trial-12 in the drug group and 3 in the control group. Of the 12 patients who completed the trial 4 patients were relieved and 7 improved, whereas 1 patient showed deterioration. In the control group, two patients were relieved, whereas one improved. It was observed that the treatment with punarnava induced a slow and prolonged diuresis, and patients had relief in edema and a decrease in albuminuria with increase in protein levels.
In an open trial, 40 patients with nephrotic syndrome presenting edema, burning micturition, and albumin in urea were treated with three 500 mg capsules of fresh powder of Boerhaavia diffusa given thrice a day for 1 month. It was found that there was an increase in serum protein level and a reduction in urinary protein excretion in patients. Of the 27 patients who were severely anemic before the start of the trial 6 came into the normal range. There was a moderate decrease in blood urea and a significant reduction in serum creatinine concentration, whereas serum protein levels showed an increase. Levels of serum sodium and potassium showed only marginal changes and the final level depended on the initial values, the diet, and the primary condition of the patients. The level of immunoglobulin also tended to become normal.
The aerial parts of Boerhaavia diffusa are eaten as a vegetable and the plant is well tolerated, although it may show a laxative effect in some patients. The drug may cause vomiting in larger doses because of its emetic properties.