Search #10: Murthy KN, Reddy VK, Veigas JM, Murthy UD. Study on wound healing activity of Punica granatum peel. J Med Food. 2004 Summer;7(2):256-9.
Punica granatum is pomegranate. For people who don’t know what pomegranates are (like me), they are plants. Fruit-bearing shrubs. The research, as said in the title, used the fruits’ peels.
Methods: Phenolic compounds were extracted from the peels via methanol. The extract was formulated as a water-soluble gel (so topical ito) in two concentrations, 2.5% (wt/wt) and 5%. Wound healing activity was assessed by measuring the percent contraction in skin and estimation of collagen content in terms of hydroxyproline content.
Results: rats treated with 2.5% gel moderate healing; complete healing after 12 days
treated with 5.0% good healing; complete healing after 10 days
positive control animals receiving blank gel took 16-18 days for complete healing
Anong connection sa research topic (ni AJ)? Punica granatum have polyphenols (which was the one extracted from the peels using methanol). And according to a book entitled Phenolics in Food and Nutraceuticals, there are 4.0 mg catechin per kg of pomegranate and 0.8 mg epicatechin per kg of pomegranate. In other words, MAY EPICATECHIN ANG PUNICA GRANATUM.
So anong kaibahan nito sa topic ni AJ? This research used Wistar rats. And the wound was not ischemic, excision lang sa skin. At ang ginamit na fruit was punica granatum (as opposed to AJ’s cocoa). It only contained small amounts of epicatechin, so epicatechin wasn’t the one really tested and it can’t be concluded that epicatechin was the one responsible for the wound healing.
Search # 13: Kapoor M, Howard R, Hall I, Appleton I. Effects of epicatechin gallate on wound healing and scar formation in a full thickness incisional wound healing model in rats.Am J Pathol. 2004 Jul;165(1):299-307.
Abstract Intro: “Catechins are naturally occurring polyphenolic compounds with putative anti-inflammatory, antioxidant and free radical scavenging effects in vitro. However, their potential effects in vivo have not been established.”
Result: Catechin epicatechin gallate (ECG)showed a significant improvement in the quality of scar formation both in terms of maturity and orientation of the collagen fibers. Also, an increase in the number of new blood vessels was observed in the ECG-treated group.
Comments: Binasa ko sa actual paper, Sprague dawley din ang gamit. But the mode of administration used was intradermal (as opposed to AJ’s proposal of topical administration). The wounds in this experiment were incision wounds (as opposed to the experiment in Search #13 which used excision wounds, and AJ’s proposal of using ischemic wounds). Also, the source of catechin epicatechin gallate wasn’t mentioned (or di ko lang nabasa). So I assume that the compound can be obtained in its pure form already (in the market or chem labs I guess?). So an advantage of AJ’s topic is the use of cocoa (ethnopharm?).
Search # 9: Kim H, Kawazoe T, Han DW, Matsumara K, Suzuki S, Tsutsumi S, Hyon SH. Enhanced wound healing by an epigallocatechin gallate-incorporated collagen sponge in diabetic mice. Wound Repair Regen. 2008 Sep-Oct;16(5):714-20.
Methods: Various concentrations (10, 100, and 1,000 ppm) of Epigallocatechin-3-O-gallate (EGCG) were incorporated into a collagen sponge (CS) in order to investigate its healing effects on full-thickness wounds created in type 2 diabetic mice.
Results: After 14 days, the residual wound size of the mice treated with 10 ppm EGCG-incorporated collagen sponge decreased significantly faster than that of the other mice.
Conclusion: These results suggest that a CS incorporated with EGCG at low concentrations can enhance wound healing in diabetic mice by accelerating reepithelialization and angiogenesis as well as improving the cellular reorganization of granulation tissue by triggering the activity of myofibroblasts.
Comments: Wounds here are specific for diabetic mice, which limits the scope.
Search #9: Madhan B, Subramanian V, Rao JR, Nair BU, Ramasami T. Stabilization of collagen using plant polyphenol: role of catechin. Int J Biol Macromol. 2005 Oct 30;37(1-2):47-53. Epub 2005 Sep 23.
“Collagen, a unique connective tissue protein finds extensive application as biocompatible biomaterial in wound healing, as drug carriers, cosmetics, etc.”
Catechin treated collagen fibres showed a shrinkage temperature around 70 degrees C implying that catechin is able to impart thermal stability to collagen.
Results: Catechin treated collagen fibres has been found to be stable even after treatment with high concentration of the secondary structural destabilizer, urea. Circular dichroism studies revealed that there is no major alteration in the structure of collagen on treatment with catechin.
Search #3: Yamazaki KG, Romero-Perez D, Barraza-Hidalgo M, Cruz M, Rivas M, Cortez-Gomez B, Ceballos G, Villarreal F. Short- and long-term effects of (-)-epicatechin on myocardial ischemia-reperfusion injury. Am J Physiol Heart Circ Physiol. 2008 Aug;295(2):H761-7. Epub 2008 Jun 20.
“Cocoa contains large amounts of flavonoids, in particular flavanols (mostly catechins and epicatechins). Flavonoids possess pleiotropic properties that may confer protective effects to tissues during injury.”
Methods: Epicatechin was administered to Sprague dawley rats via oral gavage. Ischemia was induced via a 45-min coronary occlusion. Reperfusion was allowed until 48 h or 3 wk while Tx continued. Infarct (MI) size (%), hemodynamics, myeloperoxidase activity, tissue oxidative stress, and matrix metalloproteinase-9 (MMP-9) activity in 48-h groups were measured.
Results: After 10 days, a significant approximately 50% reduction in MI size occurred. Epicatechin rats demonstrated no significant changes in hemodynamics. Tissue oxidative stress was reduced significantly in the epicatechin group vs. controls. MMP-9 activity demonstrated limited increases in the infarct region with epicatechin. By 3 wk, a significant 32% reduction in infarct size was observed with Tx, accompanied with sustained hemodynamics and preserved chamber morphometry.
Comment: Basically, it was found out through the experiment that epicatechin treatment confers cardioprotection in the setting of I/R injury. But, as opposed to AJ’s topic which tests for wound healing, this experiment focused on lessening the damage (not healing) by an ischemic injury.
Search # 1: Lee KW, Kang NJ, Oak MH, Hwang MK, Kim JH, Schini-Kerth VB, Lee HJ. Cocoa procyanidins inhibit expression and activation of MMP-2 in vascular smooth muscle cells by direct inhibition of MEK and MT1-MMP activities. Cardiovasc Res. 2008 Jul 1;79(1):34-41. Epub 2008 Mar 1.
“Expression and activation of matrix metalloproteinase (MMP)-2 play pivotal roles in the migration and invasion of human aortic vascular smooth muscle cells (VSMC) originating from normal human tissue, which is strongly linked to atherosclerosis.”
Results: Cocoa procyanidin fraction (CPF) and procyanidin B2, one of major procyanidins in cocoa (3 microg/mL and 5 microM, respectively), strongly inhibited thrombin-induced activation and expression of pro-MMP-2 in VSMC, as determined by zymography. The thrombin-induced invasion and migration of VSMC were inhibited by CPF or procyanidin B2 (P < 0.05), as assessed by a modified Boyden chamber and wound healing assays, respectively.
Conclusion: Cocoa procyanidins are potent inhibitors of MEK and MT1-MMP, and subsequently inhibit the expression and activation of pro-MMP-2, and also the invasion and migration of VSMC, which may in part explain the molecular action of antiatherosclerotic effects of cocoa.
Comment: Anong connection sa topic ni AJ? Procyanidins are polymer chains of catechins. At sa cocoa rin sila kumuha ng extract. The ONLY difference was the object of experiment. In AJ’s proposal, ischemic wounds would be induced in Sprague dawley rats. In this research, they used human cells. Yes, they cultured actual human vascular smooth muscle cells. On one of the assays, the cells were damaged using a 2-mm-wide tip.