Effects of grape seed extract on periodontal disease: an experimental study in rats

Abstract Natural compounds capable of modulating the host response have received considerable attention, and herbal products are suggested as adjunctive agents in periodontal disease treatment. Objective This study aimed to demonstrate the effect of grape seed extract (GSE) on periodontitis. Material and Methods Ligature induced periodontitis was created in 40 rats and they were assigned to four equal groups. One group was fed laboratory diet (group A) while three groups received GSE additionally. Silk ligatures were placed around the cervical area of the mandibular first molars for four weeks to induce periodontitis. The GSE groups were reallocated regarding GSE consumption as: for two weeks before ligation (group B; totally eight weeks), from ligation to two weeks after removal of the ligature (group C; totally six weeks), and for two weeks from ligature removal (group D; totally two weeks). Sections were assessed histologically and immunohistochemically. Inflammatory cell number (ICN), connective tissue attachment level (CAL), osteoclast density (OD), IL-10 and TGF-β stainings in gingival epithelium (GE), connective tissue (GC), and periodontal ligament (PL) were used as the study parameters. Results Lower ICN, higher CAL, and lower OD were observed in the GSE groups (p<0.05). IL-10 was more intensive in the GSE groups and in the GEs (p<0.05). Group B showed the highest IL-10 for PL (p<0.05). TGF-ß was higher in the GEs of all groups (p<0.017). Conclusions The results suggest anti-inflammatory activities of GSE, but further investigations are needed for clarification of these activities.

Grape seed extract (GSE) has been proposed as a promising immunomodulator agent, particularly due to its proanthocyanidin (PA) content, and is a naturally occuring polyphenolic compound obtained from seeds of Vitis vinifera, which possesses a wide range of biological activities such as antioxidant, 2,18,22,29 . GSE may strongly inhibit osteoclast differentiation, They were housed in an air-conditioned room at 23-25°C, exposed to a 24-h-light dark cycle of equal time, and fed standart laboratory diet and water ad libitum.

Groups
Animals were randomly divided into four groups (groups A, B, C, and D) with 10 rats in each one. Group A was used as a positive control group and the animals were fed only standard laboratory diet/water until two more weeks following ligature removal (totally six weeks). Group B included the rats that received GSE for two weeks before periodontitis induction and continued for six weeks (for a period of eight weeks).
Group C included the rats that received GSE from the day of periodontitis induction and continued for six weeks (for a period of six weeks). Group D included the rats that received GSE after ligature removal and continued for two weeks (for a period of two weeks). Regarding the experimental periods, rats were The mandibles were removed, separated from muscle and soft tissues, and the right mandibular sides were used for histological and immunohistological assessments. Designation of the experimental groups is shown in Figure 1.

Histological analysis
The

Results
Histomorphometrical assessments ICN, CAL, and OD were shown in Table 1. All the tissue destruction in different degrees ( Figure 2).
However, ICN was lower in groups B, C, and D than in group A; CAL was higher in groups B, C, and D than in group A; and OD was lower in groups B, C, and D than in group A (p<0.05).
Intergroup comparisons of IL-10 and TGF-ß stainings as HScores were given in  Figure 3). IL-10 stainings in GCs were similar for all the groups (p>0.05) (Table 2, Figure 3). Group B showed the most intensive IL-10 staining for PL comparisons as HScores were given in Table 3. There the stainings of all the groups for GE, GC, and PL ( Figure 4).

Intragroup comparisons of IL-10 and TGF-ß stainings
Intragroup comparisons were summarized in Table   4. IL-10 staining did not show any differences between GE-GC and GE-PL in group A (p>0.017), but it was higher in GC than that of PL in this group (p<0.017).   B (p<0.017), and it was similar in the GC and PL of this group (p>0.017). TGF-ß was higher in the GE of group B than that of the PL in this group (p<0.017).
IL-10 staining of GE was more intensive than GC and PL for groups C and D (p<0.017), but it was similar for the GCs and PLs of these groups (p>0.017). TGF-ß stainings of groups C and D were higher in GEs than those in PLs (p<0.017), and they were similar for the GEs-GCs and GCs-PLs of these groups (p>0.017).

Discussion
The      There is a growing interest in herbal remedies as adjunctive anti-inflammatory agents in the prevention of periodontal disease, particularly for the individuals prone to disease. This study evaluated the interaction between grape seed extract (GSE) and diseased periodontium in experimental peridontitis.
demonstrated more intensive IL-10 stainings in the Effects of grape seed extract on periodontal disease: an experimental study on rats TGF-ß levels.
Conclusion still needed to clarify possible mechanisms and details