Mohammad Rafi Reshi
Drug-induced hepatotoxicity is an injury to the liver caused by drugs or herbal medicines ultimately leading to liver dysfunction. As theliver plays an important role in the metabolism and elimination of drugs, it is very susceptible to the toxicity induced by them. Drug-induced liver injury is a leading health problem globally. Approximately, more than 1000 drugs have been reported to induce liver disease. Currently, used first-line antitubercular drugs such as isoniazid, rifampicin, and pyrazinamide induce hepatotoxicity have a serious adverse effect. They individually have been associated with hepatotoxicity and the risk is enhanced when these drugs are used in combination. Antitubercular drug-induced hepatotoxicity is a common serious adverse drug reaction. It is one of the most challenging clinical problems. It is a main cause of treatment interruption during tuberculosis treatment course that may even cause hospitalization and life-threatening events.
Manuka honey is a monofloral honey produced in New Zealand and Australia. It is produced from nectar collected from Leptospermum scoparium, which grows wild on undeveloped and un-spoilt land. Manuka honey is rich in carbohydrates, fatty acids, proteins, and a high amount of phenolic compounds such as flavonoids. It consists of a high amount of phenolic compounds such as flavonoids, methyl syringate, and a methoxylated benzoic acid, a structural isomer of syringic acid. The phenolic compounds are more potent antioxidants than the non-phenolic antioxidants in honey. In addition, it also contains a bioactive fraction called methylglyoxal that exhibits non-peroxide antibacterial activity. Furthermore, manuka honey has demonstrated broad-spectrum antibacterial activity with an inhibitory effect on around 60 species of bacteria.
In vitro studies have indicated methylglyoxal is an effective antimicrobial agent against forms of methicillin-resistant Staphylococcus aureus. Hence, manuka honey is considered as a superior form of honey. As manuka honey is rich in phenolic antioxidants, it is suggested that it may possess hepatoprotective activity. Furthermore, due to its broad-spectrum antibacterial activity, it may be beneficial in resolving the tubercular infection also. Various studies have shown hepatoprotective property of honey. An earlier study has reported the beneficial effects of honey in antitubercular drug-induced hepatotoxicity also. However, the hepatoprotective activity of manuka honey in antitubercular drug-induced hepatotoxicity has not been investigated yet. Hence, this study was carried out to compare the effect of manuka honey with honey in hepatotoxicity induced by antitubercular drugs in rats.
Hepatotoxicity is a serious adverse effect of anti-tubercular drugs such as isoniazid, rifampicin, and pyrazinamide. They alone are hepatotoxic, and when given in combination, their toxic effect is enhanced. The antitubercular drug-induced hepatotoxicity is mediated through oxidative stress and free radical damage to hepatocytes. Hepatic damage is characterized by an increase in serum AST and ALT levels. Free radicals cause lipid peroxidation and subsequently increase serum MDA concentration. Therefore, lipid peroxidation represents tissue injury due to inflammation and serves as an indicator of severe liver damage. Liver biopsy is the most reliable index of liver damage. Liver damage is indicated by degeneration, necrosis, and fibrosis while the reduction in these parameters and evidence of regeneration are suggestive of hepatoprotection. Administration of anti-tubercular drugs also resulted in inflammation, degeneration, and necrotic changes in rat liver.
In this study, concurrent administration of manuka honey along with anti-tubercular drugs significantly prevented the rise in the level of serum ALT, AST, and tissue MDA. Similarly, manuka honey significantly prevented fall in serum total protein and SOD as compared to the group receiving anti-tubercular drugs alone. Administration of manuka honey reduced inflammation, degeneration, and necrotic changes. These results showed that manuka honey is effective as hepatoprotective agent and prevented the antitubercular drugs induced hepatotoxicity. Since manuka honey is considered as a superior form of honey and silymarin is a standard hepatoprotective agent in hepatotoxicity, the effect of manuka honey was compared with them also. However, the effects produced by manuka honey were not statistically different from these two interventions. The results showed that the effects produced by manuka honey were on par with these two, and it was equally effective.
Manuka honey is effective as a hepatoprotective agent as it significantly prevented the hepatotoxic damage induced by antitubercular drugs in rats. However, the comparison between the effects produced by manuka honey and honey or silymarin showed that the difference was not statistically significant. Hence, contrary to the popular belief, it is only as good and effective as honey.
—The author is from Watlab , Sopore. He can be reached at: email@example.com