D-limonene: A multifunctional compound with potent therapeutic effects.

D-limonene or 4-isopropenyl-1-methylcyclohexene (C10 H16 ) is a monocyclic monoterpene abundant in citrus plants like lemon, orange, and grape. The application of D-limonene in the form of flavor and fragrance additive in perfumes, soaps, foods, and beverages is consistently increased due to its high-quality fragrance property. This review is intended to analyze and delineate every possible available evidence and details about D-limonene with the special focus on its therapeutic efficacy. Many studies have reported that D-limonene effectively plays a valuable role in the prevention of several chronic and degenerative diseases. This review provides worthy information about the beneficial effects of D-limonene such as antioxidant, antidiabetic, anticancer, anti-inflammatory, cardioprotective, gastroprotective, hepatoprotective, immune modulatory, anti-fibrotic, anti-genotoxic etc. This could in turn help in the application of D-limonene for clinical studies. PRACTICAL IMPLICATIONS: Various plant families contain Terpenes as their secondary metabolites. Monoterpenes constitute an important part of these secondary metabolites. D-limonene is a well-identified monoterpene that is commonly applied as a fragrance ingredient in essential oils. D-limonene is known to possess remarkable biological activities. It can be effectively used for treating various ailments and diseases. Due to its diverse functions, it can be efficiently utilized for human health.

Hesperidin attenuates mitochondrial dysfunction during benzo(a)pyrene-induced lung carcinogenesis in mice.

The present study is designed to assess the mitochondrial status during benzo(a)pyrene (B(a)P)-induced lung carcinogenesis in Swiss albino mice and to reveal the modulatory effect of hesperidin over it. B(a)P (50 mg/kg body weight)-induced mitochondrial abnormalities was evident from alterations in mitochondrial lipid peroxides, antioxidant status (superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione-S-transferase, reduced glutathione, vitamin E, and vitamin C), major tricarboxylic acid (TCA) cycle enzyme activities (isocitrate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, alpha-ketoglutarate dehydrogenase), electron transport chain (ETC) complexes activities and ATP levels. Ultrastructural changes in lung mitochondria were also in accord with the above aberrations. Hesperidin (25 mg/kg body weight) supplementation effectively counteracted all the above changes and restored cellular normalcy, indicating its protective role during B(a)P-induced lung cancer.

Modulatory effect of hesperidin on benzo(a)pyrene induced experimental lung carcinogenesis with reference to COX-2, MMP-2 and MMP-9.

Hesperidin is a naturally occurring flavonoid that has been reported to possess anticancer effects. The purpose of this study is to evaluate the effect of hesperidin in modulating the expressions of cyclooxygenase-2 (COX-2), mast cells (MCs) and matrix metalloproteinases (MMPs) during benzo(a)pyrene (B(a)P) induced lung carcinogenesis in mice. B(a)P (50 mg/kg body weight) induced animals showed increased mast cell density (MCD) as revealed by toluidine blue staining and severe expression of COX-2 along with upregulated expression of MMP-2 and MMP-9 as revealed by Western blotting and immunohistochemistry. Supplementation of hesperidin (25 mg/kg body weight) to lung cancer bearing mice attenuated MCD and downregulated the expressions of COX-2, MMP-2 and MMP-9. These observations show that hesperidin exerts its anti-carcinogenic activity against lung cancer by altering the expressions of COX-2, MMP-2 and MMP-9.

Chemopreventive task of capsaicin against benzo(a)pyrene-induced lung cancer in Swiss albino mice.

A voluminous number of evidence suggests that an increased consumption of fruits and vegetables is a relatively easy and practical strategy to reduce significantly the incidence of cancer. The present study is an effort to identify the chemopreventive role of alkaloid capsaicin against benzo(a)pyrene-induced lung cancer in Swiss albino mice. Benzo(a)pyrene-induced lung cancer-bearing animals showed abnormal changes in body weight, lung weight, tumour incidence and alterations in the activities of marker enzymes adenosine deaminase, aryl hydrocarbon hydroxylase, gamma-glutamyl transpeptidase, 5'-nucleotidase and lactate dehydrogenase. On capsaicin pre-co-treatment, all the above alterations were returned to near normal. Immunohistochemical analysis of proliferating cell nuclear antigen together with lung histological examination further supported our biochemical findings that demonstrated the chemoprotective role of capsaicin against benzo(a)pyrene-induced experimental lung cancer.

Antioxidant and anticancer efficacy of hesperidin in benzo(a)pyrene induced lung carcinogenesis in mice.

Chemoprevention is regarded as one of the most promising and realistic approaches in the prevention of cancer. Several bioactive compounds present in fruits and vegetables have revealed their cancer curative potential on lung cancer. Hesperidin is one such naturally occurring flavonoid widely found in citrus fruits. The aim of the present study is to divulge the chemopreventive nature of hesperidin during benzo(a)pyrene (B(a)P) induced lung cancer in Swiss albino mice. Administration of B(a)P (50 mg/kg body weight) to mice resulted in increased lipid peroxides (LPO), lung specific tumor marker carcinoembryonic antigen (CEA) and serum marker enzymes aryl hydrocarbon hydroxylase (AHH), gamma glutamyl transpeptidase (GGT), 5'nucleotidase (5'ND) and lactate dehydrogenase (LDH) with concomitant decrease in the levels of tissue antioxidants like superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), reduced glutathione (GSH), vitamin E and vitamin C. Hesperidin supplementation (25 mg/kg body weight) significantly attenuated these alterations thereby showing potent anticancer effect in lung cancer. Further the antiproliferative effect of hesperidin was confirmed by histopathological analysis and proliferating cell nuclear antigen (PCNA) immunostaining. Overall, these findings substantiate the chemopreventive potential of hesperidin against chemically induced lung cancer in mice.

Silymarin downregulates COX-2 expression and attenuates hyperlipidemia during NDEA-induced rat hepatocellular carcinoma.

Silymarin is a naturally available bioflavonoid and is a strong antioxidant with a capacity to inhibit the formation of tumors in several cancer models. In the present study, we investigated whether dietary supplementation of silymarin has any role in lipid components, lipid-metabolizing enzymes, free fatty acid profile, and expression of cyclooxygenase-2 (COX-2) in N-nitrosodiethylamine (NDEA)-induced hepatocellular carcinoma in rats. NDEA-induced rats showed severe hyperlipidemia along with upregulated expression of COX-2 as revealed by western blotting and immunohistochemistry. Dietary silymarin supplementation attenuated this hyperlipidemia and downregulated the expression of COX-2. Thus we conclude that compounds like silymarin with potent hypolipidemic effect are strong candidates as chemopreventive agents for the treatment of liver cancer.

The effects of quercetin on antioxidant status and tumor markers in the lung and serum of mice treated with benzo(a)pyrene.

Chemoprevention has emerged as a very effective preventive measure against carcinogenesis. Several bioactive compounds present in fruits and vegetables have revealed their cancer curative potential on benzo(a)pyrene (B(a)P) induced carcinogenesis. In the present study, the efficacy of quercetin on the level of lipid peroxides, activities of antioxidant enzymes and tumor marker enzymes in B(a)P induced experimental lung carcinogenesis in Swiss albino mice was assessed. In lung cancer bearing animals there was an increase in lung weight, lipid peroxidation and marker enzymes such as aryl hydrocarbon hydroxylase, gamma glutamyl transpeptidase, 5'-nucleotidase, lactate dehydrogenase and adenosine deaminase with subsequent decrease in body weight and antioxidant enzymes-superoxide dismutase, catalase, glutathione peroxidase, glutathione-S-transferase, glutathione reductase, reduced glutathione, vitamin E and vitamin C. Quercetin supplementation (25 mg/kg body weight) attenuated all these alterations, which indicates the anticancer effect that was further confirmed by histopathological analysis. Overall, the above data shows that the anticancer effect of quercetin is more pronounced when used as an chemopreventive agent rather than as a chemotherapeutic agent against B(a)P induced lung carcinogenesis.