Molecular mechanisms associated with the chemoprotective role of protocatechuic acid and its potential benefits in the amelioration of doxorubicin-induced cardiotoxicity: A review.

Since its discovery in the 1960 s, doxorubicin (DOX) has constantly elicited the broadest spectrum of cancerocidal activity against human cancers. However, cardiotoxicity caused by DOX directly as well as its metabolites is a great source of concern over the continuous use of DOX in chemotherapy. While the exact mechanism of DOX-induced cardiotoxicity is yet to be completely understood, recent studies indicate oxidative stress, inflammation, and several forms of cell death as key pathogenic mechanisms that underpin the etiology of doxorubicin-induced cardiotoxicity (DIC). Notably, these key mechanistic events are believed to be negatively regulated by 3,4-dihydroxybenzoic acid or protocatechuic acid (PCA)-a plant-based phytochemical with proven anti-oxidant, anti-inflammatory, and anti-apoptotic properties. Here, we review the experimental findings detailing the potential ameliorative effects of PCA under exposure to DOX. We also discuss molecular insights into the pathophysiology of DIC, highlighting the potential intervention points where the use of PCA as a veritable chemoprotective agent may ameliorate DOX-induced cardiotoxicities as well as toxicities due to other anticancer drugs like cisplatin. While we acknowledge that controlled oral administration of PCA during chemotherapy may be insufficient to eliminate all toxicities due to DOX treatment, we propose that the ability of PCA to block oxidative stress, attenuate inflammation, and abrogate several forms of cardiomyocyte cell death underlines its great promise in the amelioration of DIC.

Dietary protocatechuic acid abrogates male reproductive dysfunction in streptozotocin-induced diabetic rats via suppression of oxidative damage, inflammation and caspase-3 activity.

Clinical and experimental studies demonstrated that reproductive dysfunction is a non-lethal complication of diabetes. Protocatechuic acid (PCA) reportedly elicited several pharmacological effects in diabetic animals. However, there is paucity of information on the role of PCA in reproductive dysfunction associated with diabetes. The present study investigated the influence of PCA on the functional changes along the hypothalamic-pituitary-testicular axis in male diabetic rats. Streptozotocin (STZ)-induced diabetic rats were orally treated with PCA at 25 and 50 mg/kg body weight for 45 consecutive days. Results showed that PCA treatment significantly dwindled blood glucose level as well as prevented diabetes mediated decrease in body weight gain and organo-somatic indices of the testes and epididymis in the treated rats. Moreover, PCA increased the reproductive hormone levels, marker enzymes of testicular function and sperm functional characteristics in the treated rats. Further, PCA augmented the antioxidant status, inhibited lipid peroxidation and suppressed pro-inflammatory biomarkers including myeloperoxidase (MPO) activity, nitric oxide (NO) and tumor necrosis factor alpha (TNF-α) levels as well as caspase-3 activity inhypothalamus, testes and epididymis of diabetic rats. Collectively, PCA effectively abrogated reproductive deficits in diabetic rats via mechanisms involving suppression of oxidative stress, inflammation and caspase-3 activity along with enhancement of sperm functional parameters. Thus, PCA may preserve reproductive health in humans suffering from diabetes.

Impact of prepubertal exposure to dietary protocatechuic acid on the hypothalamic-pituitary-testicular axis in rats.

Protocatechuic acid (PCA; 3, 4-dihydroxybenzoic acid) is a phenolic compound widely found in many edible fruits, vegetables, grape wine and plant-derived beverages. The present study investigated the impact of PCA on the hypothalamic-pituitary-testicular axis of rats orally treated with PCA during the period of prepubertal development to adulthood. Protocatechuic acid was administered to prepubertal male rats at doses of 0, 5, 10, 50 and 100 mg/kg body for 45 consecutive days. The results revealed no treatment-related changes in the body weight gain and organo-somatic indices of the hypothalamus, testes, epididymis, prostate gland and seminal vesicle in rats administered with PCA when compared with control. However, prepubertal exposure to PCA significantly enhanced antioxidant enzyme activities and glutathione level whereas it markedly decreased biomarkers of inflammation and oxidative stress in the hypothalamus, testes and epididymis of the treated rats. Protocatechuic acid significantly increased circulatory concentrations of luteinizing hormone and follicle-stimulating hormone with concomitant increase in serum and intra-testicular testosterone levels. Moreover, PCA-treated rats exhibited significant increase in marker enzymes of testicular function namely acid phosphatase, alkaline phosphatase, lactate dehydrogenase and glucose-6-phosphate dehydrogenase without statistically significant increase in spermatogenesis and sperm functional characteristics including sperm count, motility and viability. Light microscopic examination of the hypothalamus, testes and epididymis of rats treated with PCA showed histo-architectures similar to control. In conclusion, prepubertal exposure to PCA is safe and positively impacted reproductive function at sexual maturity in male rats. The observed beneficial effects of PCA is related to its anti-inflammatory and redox regulatory mechanisms.