Invivo hepatoprotective potential of extracts obtained from floral spikes of Prunella vulgaris L

Abstract

Background: Prunella vulgaris, commonly known as self-heal, has been extensively used in the traditional system of medicines. The plant has been found to contain a number of bioactive molecules including those having radical scavenging property which indicates its potential for the treatment of those diseases which are induced by free radical damage like drug-induced hepatotoxicity.

Objective: The current study was undertaken to investigate the flavonoid and total phenolic content and evaluate the hepatoprotective potential of various extracts obtained from floral spikes of P. vulgaris.

Material and methods: Flavonoid and otal phenolic contents were obtained from the standard curves of Gallic acid as per the reported methods. The extent of hepatotoxicity induced by paracetamol (500 mg/kg b.w, p.o daily for 14 days), hepatoprotective potential of extracts (200 mg/kg b.w/day, orally) and standard drug silymarin (50 mg/kg b.w/day, orally) were evaluated by analyzing various biochemical parameters like Serum Glutamic Oxaloacetic Transaminase, Serum Glutamic Pyruvic Transaminase, Alkaline Phosphatase, Total Proteins, Total and Direct Bilirubin and detailed histopathology of rat livers.

Results: Methanolic extract showed higher quantity of flavonoids and total phenolic content followed by ethanolic, hydroalcoholic and aqueous extracts. Treatment of rats with extracts showed a highly significant reduction in the enzyme activities of Serum Glutamic Oxaloacetic Transaminase, Serum Glutamic Pyruvic Transaminase, Alkaline Phosphatase, and serum levels of Total, Direct Bilirubin (P < 0.01) and highly significant elevation in Total Proteins (P < 0.01) when compared with the toxic control group. This was further confirmed by histopathological evaluation, where almost normal hepatic architecture or very less hepatic damage was observed in groups treated with extracts and silymarin compared to paracetamol treated group. Results from biochemical and histopathological evaluation indicated that among the extracts methanolic extract was most effective.

Conclusion: From the results, it can be concluded that the extracts obtained from floral spikes of P. vulgaris possess highly significant hepatoprotective activity which could be attributed to its radical scavenging potential and hepatic regeneration. This is further authenticated by the presence of phenolic and flavonoids which are known to possess radical scavenging properties.

Keywords: Extracts; Hepatoprotective potential; Paracetamol; Prunella vulgaris; Silymarin.

Fig. 1

Calibration curve for the estimation of Flavonoids Using Gallic acid as Standard.

Fig. 2

Flavonoids (mg/g) in terms of Gallic Acid equivalents (GAE) in different extracts of floral spikes of P. vulgaris.

Fig. 3

Calibration curve for the estimation of Total Phenols Gallic acid as standard.

Fig. 4

Total Phenolic Content (mg/g) in terms of Gallic Acid equivalents (GAE) in different extracts of floral spikes of P. vulgaris.

Fig. 5

Histopathology of liver of rats from different groups (H&E $\times$ 100). A: Liver of normal rat showing normal hepatic architecture. B: Liver of rat administered paracetamol showing severe degeneration, nuclear pyknosis, necrotic cells, congestion and infiltration throughout the liver. C: Silymarin treated rat liver showing normal hepatocytes with mild infiltration and very mild congestion in portal areas. D: Ethanolic extract treated rat liver showing mild areas of congestion with normal hepatocytes and intact hepatic cords. E: Aqueous extract treated rat liver showing congestion and areas of degeneration. F: Hydroalcoholic extract treated rat liver showing mild infiltration and congestion in portal areas. G: Methanolic extract treated rat liver showing mild infiltration and congestion without any degeneration. Hepatocytes are normal and hepatic cords are intact.