Critical pharmacokinetic and pharmacodynamic drug-herb interactions in rats between warfarin and pomegranate peel or guava leaves extracts.

BACKGROUND: In-depth information of potential drug-herb interactions between warfarin and herbal compounds with suspected anticoagulant blood thinning effects is needed to raise caution of concomitant administration. The current study aimed to investigate the impact of co-administration of pomegranate peel and guava leaves extracts, including their quality markers namely; ellagic acid and quercetin, respectively, on warfarin's in vivo dynamic activity and pharmacokinetic actions, in addition to potential in vitro cytochrome P450 enzymes (CYP) inhibition. METHODS: Influence of mentioned extracts and their key constituents on warfarin pharmacodynamic and kinetic actions and CYP activity were evaluated. The pharmacodynamic interactions were studied in Sprague Dawley rats through prothrombin time (PT) and International Normalized Ratio (INR) measurements, while pharmacokinetic interactions were detected in vivo using a validated HPLC method. Furthermore, potential involvement in CYP inhibition was also investigated in vitro on isolated primary rat hepatocytes. RESULTS: Preparations of pomegranate peel guava leaf extract, ellagic acid and quercetin in combination with warfarin were found to exert further significant increase on PT and INR values (p < 0.01) than when used alone (p < 0.05). Pomegranate peel extract showed insignificant effects on warfarin pharmacokinetics (p > 0.05), however, its constituent, namely, ellagic acid significantly increased warfarin Cmax (p < 0.05). Guava leaves extract and quercetin resulted in significant increase in warfarin Cmax when compared to control (p < 0.01). Furthermore, guava leaves extract showed a significant effect on changing the AUC, CL and Vz. Significant reduction in CYP2C8, 2C9, and 3A4 was seen upon concomitant use of warfarin with ellagic acid, guava leaves and quercetin, unlike pomegranate that insignificantly affected CYP activities. CONCLUSION: All combinations enhanced the anticoagulant activity of warfarin as the results of in vivo and in vitro studies were consistent. The current investigation confirmed serious drug herb interactions between warfarin and pomegranate peel or guava leaf extracts. Such results might conclude a high risk of bleeding from the co-administration of the investigated herbal drugs with warfarin therapy. In addition, the results raise attention to the blood-thinning effects of pomegranate peel and guava leaves when used alone.

Anti-inflammatory aminoacetylenic isoindoline-1,3-dione derivatives modulate cytokines production from different spleen cell populations.

We recently designed a series of N-[4-(t-amino-yl)-but-2-yn-1-yl] isoindoline-1,3-diones as anti-inflammatory compounds, called ZM compounds. These ZM compounds were categorized according to the nature of the cyclic amino groups into ZM2, ZM3, ZM4, and ZM5 and were shown to reduce carrageenan-induced inflammation, inhibit cyclooxygenase (1 and 2) and have less adverse effects than the common non-steroidal anti-inflammatory drugs. In the present study, we are examining the potential effects of ZM compounds in modulating cytokines production in vivo and in vitro from stimulated spleen cells, CD4+ CD25+ve T regulatory cells and CD4+CD25-ve T helper cells. Six hours following oral administration of 20mg/kg of ZM4 and ZM5 compounds reversed LPS-induced TGF-ß suppression whereas ZM2, ZM3, ZM4, and ZM5 reversed LPS-induced TNF-α and IL-12 increase in mice spleen. In addition, increasing concentrations of ZM2, ZM4 and ZM5 increased significantly TGF-ß1 production, whereas ZM3, ZM4 and ZM5 suppressed only TNF-α production in LPS and LPS+PMA stimulated spleen cells. Furthermore, only ZM5, enhanced significantly TGF-ß1 production from LPS and LPS+PMA stimulated CD4+CD25+ve cells (p<0.001), whereas none of the ZM compounds modulated TNF-α from CD4+CD25-ve T helper cells. These results indicate that ZM5 (N-{4-(2-Azepan-1-yl)-but-2-yn-1-yl}isoindoline-1,3-dione) enhances TGF-ß production from CD4+CD25+ve cells independent of protein kinase C activation and suggest that all ZM compounds suppress TNF-α from monocytes/macrophage cells. In conclusion, these ZM compounds have potential to be used use as anti-inflammatory agents and further studies to show the possibility of utilizing these basic aminoacetylenic isoindolines in autoimmune mediated inflammatory diseases are warranted.

Plasma concentrations of 25-hydroxyvitamin D among Jordanians: Effect of biological and habitual factors on vitamin D status.

BACKGROUND: Vitamin D is cutaneously synthesized following sun exposure (vitamin D3) as well as it is derived from dietary intake (vitamin D3 and D2). Vitamin D2 and D3 are metabolized in the liver to 25-hydroxyvitamin D (25(OH)D). This metabolite is considered the functional indicator of vitamin D stores in humans. Since Jordan latitude is 31°N, cutaneous synthesis of vitamin D3 should be sufficient all year round. However, many indications reveal that it is not the case. Thus, this study was conducted to determine the 25(OH)D status among Jordanians. METHODS: Three hundred healthy volunteers were enrolled in a cross sectional study; 201 females and 99 males. 25(OH)D and calcium concentrations were measured by enzyme linked immunosorbent assay and spectroscopy techniques, respectively. All participants filled a study questionnaire that covered age, sex, height, weight, diet, and dress style for females. Females were divided according to their dress style: Western style, Hijab (all body parts are covered except the face and hands), and Niqab (all body parts are covered including face and hands). RESULTS: The average plasma 25(OH)D levels in males and females were 44.5 ± 10.0 nmol/l and 31.1 ± 12.0 nmol/l, respectively. However, when female 25(OH)D levels were categorized according to dress styles, the averages became 40.3, 31.3 and 28.5 nmol/l for the Western style, Hijab and Niqab groups, respectively. These 25(OH)D levels were significantly less than those of males (p < 0.05, 0.001, 0.001, respectively). In addition, the plasma 25(OH)D levels of the Western style group was significantly higher than those of Hijab and Niqab groups (p < 0.001). Furthermore, dairy consumption in males was a positive significant factor in vitamin D status. Even though calcium concentrations were within the reference range, the Hijab and Niqab-dressed females have significantly less plasma calcium levels than males (p < 0.01). CONCLUSIONS: Very low plasma 25(OH)D levels in females wearing Hijab or Niqab are highly attributed to low sunlight or UVB exposure. In addition, most of males (76%) and Western style dressed females (90%) have 25(OH)D concentrations below the international recommended values (50 nmol/l), suggesting that although sun exposure should be enough, other factors do play a role in these low concentrations. These findings emphasize the importance of vitamin D supplementation especially among conservatively dressed females, and determining if single nucleotide polymorphisms of the genes involved in vitamin D metabolism do exist among Jordanians.