Pharmacological Properties and Therapeutic Potential of Naringenin: A Citrus Flavonoid of Pharmaceutical Promise.

Naringenin chemically known as 5,7-dihydroxy-2-(4-hydroxyphenyl)chroman-4-one is a common dietary polyphenolic constituent of the citrus fruits. It has received considerable attention for pharmaceutical and nutritional development due to potent pharmacological activities and therapeutic potential. Accruing evidence from both in vitro and in vivo studies have unraveled numerous biological targets along with complex underlying mechanisms suggesting possible therapeutic applications of naringenin in various neurological, cardiovascular, gastrointestinal, rheumatological, metabolic and malignant disorders. Functionally, this ameliorative effect of naringenin is primarily attributed to its antiinflammatory (via inhibiting recruitment of cytokines and inflammatory transcription factors) and anti-oxidant (via scavenging of free radicals, bolstering of endogenous antioxidant defense system and metal ion chelation) effects. The present article provides a comprehensive review of the various studies that have evaluated the therapeutic potential of naringenin and its actions at the molecular level. It also summarizes the pharmacokinetic data and issues and challenges involved in pharmaceutical development and suggest that it may be a potential agent for further exploration as well as may be useful as a dietary adjunct in treatment of various human ailments.

Preclinical evidence for the pharmacological actions of naringin: a review.

Naringin, chemically 4',5,7- trihydroxyflavanone-7-rhamnoglucoside, is a major flavanone glycoside obtained from tomatoes, grapefruits, and many other citrus fruits. It has been experimentally documented to possess numerous biological properties such as antioxidant, anti-inflammatory, and antiapoptotic activities. In vitro and in vivo studies have further established the usefulness of naringin in various preclinical models of atherosclerosis, cardiovascular disorders, diabetes mellitus, neurodegenerative disorders, osteoporosis, and rheumatological disorders. Apart from this, naringin has also exerted chemopreventive and anticancer attributes in various models of oral, breast, colon, liver, lung, and ovarian cancer. This wide spectrum of biological expediency has been documented to be a result of either the upregulation of various cell survival proteins or the inhibition of inflammatory processes, or a combination of both. Due to the scarcity of human studies on naringin, this review focuses on the various established activities of naringin in in vitro and in vivo preclinical models, and its potential therapeutic applications using the available knowledge in the literature. Additionally, it also encompasses the pharmacokinetic properties of naringin and its inhibition of CYP isoenzymes, and the subsequent drug interactions. Moreover, further clinical research is evidently needed to provide significant insights into the mechanisms underlying the effects of naringin in humans.

Andrographis paniculata extract protect against isoproterenol-induced myocardial injury by mitigating cardiac dysfunction and oxidative injury in rats.

Present study evaluated the cardioprotective effect of Andrographis paniculata (100, 200 or 400 mg/kg) against isoproterenol (85 mg/kg, b.w.)-induced cardiotoxicity referred as myocardial infarction in rats. Isoproterenol significantly (p < 0.05) decreased mean arterial pressure, heart rate, contractility and relaxation and increased left ventricular end diastolic pressure. Isoproterenol also significantly (p < 0.05) decreased antioxidants, superoxide dismutase, catalase, glutathione peroxidase, glutathione and increased leakage of cardiac injury markers; creatine phosphokinase-MB isoenzyme, lactate dehydrogenase concomitant to increased lipid peroxidation and histopathological perturbations. However, pretreatment with A. paniculata favorably restored hemodynamic parameters and left ventricular function and significantly (p < 0.05) prevented the depletion of endogenous antioxidants and myocyte marker enzymes as well as inhibited lipid peroxidation. Significant (p < 0.05) reversal of almost all the hemodynamic, biochemical and histopathological parameters by A. paniculata pretreatment in isoproterenol-induced cardiotoxicity depicted the cardioprotective effect of A. paniculata. Results showed that A. paniculata protected heart against cardiotoxic effects of isoproterenol by boosting endogenous antioxidant network, restoring ventricular function and maintaining structural integrity of heart.

Effect of Inula racemosa root extract on cardiac function and oxidative stress against isoproterenol-induced myocardial infarction.

The cardioprotective potential of Inula racemosa root hydroalcoholic extract against isoproterenol-induced myocardial infarction was investigated in rats. The rats treated with isoproterenol (85 mg/kg, s.c.) exhibited myocardial infarction, as evidenced by significant (P < 0.05) decrease in mean arterial pressure, heart rate, contractility, relaxation along with increased left ventricular end diastolic pressure, as well as decreased endogenous myocardial enzymatic and non-enzymatic antioxidants. Isoproterenol also significantly (P < 0.05) induced lipid peroxidation and increased leakage of myocyte injury marker enzymes. Pretreatment with I. racemosa extract (50, 100 or 200 mg/kg per day, p.o.) for 21 consecutive days, followed by isoproterenol injections on days 19th and 20th significantly (P < 0.05) improved cardiac function by increasing the heart rate, mean arterial pressure, contractility and relaxation along with decreasing left ventricular end diastolic pressure. Pretreatment with I. racemosa also significantly (P < 0.05) restored the reduced form of glutathione and endogenous antioxidant enzymes superoxide dismutase, catalase, glutathione peroxidase from the heart, which were depleted after isoproterenol administration. In addition to restoration of antioxidants, I. racemosa significantly (P < 0.05) inhibited lipid peroxidation and prevented the leakage of myocytes specific marker enzymes creatine phosphokinase-MB and lactate dehydrogenase from the heart. Thus, it is concluded that I. racemosa protects heart from isoproterenol-induced myocardial injury by reducing oxidative stress and modulating hemodynamic and ventricular functions of the heart. Present study findings demonstrate the cardioprotective effect of I. racemosa and support the pharmacological relevance of its use and cardioprotection mechanism in ischemic heart disease as well as substantiate its traditional claim.