TCM astragalus found to protect against drug induced liver injury

The liver is a very important organ that is, unfortunately, vulnerable to various toxic agents and harmful elements. Among these are drugs like paracetamol that, when taken in doses that exceed what’s recommended, can stress out or even damage the liver. Fortunately, an investigative team comprising of researchers from Saudi Arabia, Cairo, and Turkey have found a possible solution in the Astragalus genus. Also known as milkvetch or locoweed, these herbs and small shrubs have long been utilized in medicinal applications for all types of disorders. The researchers behind this particular study have uncovered another one.

For their study, the team focused on two specific members of Astragalus: Astragalus echinops and Astragalus logopodioides. The roots of these plants were dried, ground, then turned into ethanolic extracts. As part of the experiment portion, 42 male rats were obtained and fed a standard diet one week prior. The researchers then randomly divided the animals into seven groups:

The first group served as the normal control group.

The second group was designated as the paracetamol-hepatotoxic control group.

The third group was given 100 milligrams per kilogram (mg/kg) doses of silymarin or milk thistle.

The fourth and fifth groups of rats received ethanolic extract at doses of A. echinops at 250 and 500 mg/kg, respectively.

The sixth and seventh groups were administered A. logopodioides ethanolic extract doses at 250 and 500 mg/kg, respectively.

This occurred daily over a period of seven days. On the fifth day, all of the rats save those from the first group were subjected to induced hepatotoxicity by way of oral administration of paracetamol. On the seventh and last day of the experiment, blood samples were taken from all of the rats two years after treatment. The rats were then euthanized immediately after, their livers collected and halved into two for analysis.

Animals from the second group exhibited significantly elevated levels of alanine transaminase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and gamma-glutamyltransferase (GGT). All of these are considered biomarkers of liver disease. According to HopkinsGuides.com, high levels of ALT and AST are indicative of severe acute liver cell injury and liver inflammation, while increase dALP and GGT are signs of bile duct obstruction or primary biliary cirrhosis or liver scarring.

By contrast, the rats who’d been given silymarin, A. echinops ethanolic extract, or A. logopodioides ethanolic extract had lower levels of ALT, AST, ALP, and GGT. Based on these results, the researchers stated that the hepatoprotective effect of the ethanolic plant extracts was namely due to them lowering oxidative stress on the liver while simultaneously promoting antioxidant activity.

"The capability of A. echinops and A. logopodioides extracts to protect against [paracetamol]-induced hepatic damage in rats could be related to their phyto-components. The genus Astragalus is well documented…as a source of biologically active compounds such as phenolics, triterpenoid saponins, flavonoids, and polysaccharides. The flavonoid mixture and polysaccharides of some Astragalus plants are known to have a strong antioxidant effect ," wrote the researchers. 

The histopathological study confirmed their belief. Liver sections taken from the rats of the second group appeared to show cellular inflammation, congestion, and severe necrotic changes. On the other hand, all of the rats who’d been treated with Astragalus ethanolic extracts had markedly different liver sections, although A. echinops ethanolic extracts appeared to have had the greatest protective effect. "It can be referred to the antioxidant effect of the tested extracts that markedly decreased the oxidative stress and thereby reduced the histopathological alterations of the liver," said the researchers.

Thus, the researchers concluded that both taking A. echinops and A. logopodioides extracts prior to overdosing on paracetamol could encourage the restoration and production of liver antioxidants among rats. Moreover, they could defend the liver against paracetamol-induced liver injuries as well, again thanks to their abundance of antioxidants.

The researchers then added: "Together, the absence of toxicity and supportive evidence of their antioxidant properties may suggest the potential application of A. echinops and A. logopodioides as alternative antidotes against the ailments where liver antioxidants stored is compromised and/or hepatic damage is manifested."