Low concentrations of grape seed extract maintain osteoblast morphology, cell adhesion, and mineralization

Abstract The increase in life expectancy has led to a higher incidence of osteoporosis, characterized by an imbalance in bone remodeling. Several drugs are used for its treatment, but most promote undesirable side effects. The present investigation evaluated the effects of two low concentrations of grape seed extract (GSE) rich in proanthocyanidins on MC3T3-E1 osteoblastic cells. The cells were cultured in an osteogenic medium and divided into control (C), 0.1 µg/mL GSE (GSE0.1), and 1.0 µg/mL GSE (GSE1.0) groups to evaluate cell morphology, adhesion, and proliferation, in situ alkaline phosphatase (ALP) detection, mineralization and immunolocalization of osteopontin (OPN). The data obtained were analyzed by statistical tests for a significance of 5%. Cell morphology was maintained with both GSE concentrations, whereas cell adhesion significantly increased within three days in all groups. Cell proliferation increased significantly at seven days of culture, followed by a significant decrease in all experimental periods, with no statistical difference among them. In situ detection of ALP and mineralization increased with time, but within each period, no statistical differences among groups were observed. The expression of osteopontin was distributed regularly with more intensity after 24 hours in the GSE0.1 group. After three days, OPN expression was more intense in the control group, followed by GSE0.1 and GSE1.0 groups. Data obtained suggest that low concentrations of GSE do not affect the morphology and may stimulate the functional activity of osteoblastic cells.

Resumo O aumento da expectativa de vida tem levado a uma maior incidência de osteoporose, caracterizada por um desequilíbrio na remodelação óssea. Vários medicamentos são utilizados para o seu tratamento, contudo, a maioria promove efeitos colaterais indesejáveis. A presente investigação avaliou os efeitos de duas baixas concentrações de extrato de semente de uva (GSE) rico em proantocianidinas em células osteoblásticas MC3T3-E1. As células foram cultivadas em meio osteogênico e divididas em grupos controle (C), 0,1 µg/mL de GSE (GSE0.1) e 1,0 µg/mL de GSE (GSE1.0) para avaliar morfologia, adesão e proliferação celular, detecção in situ de fosfatase alcalina (ALP), mineralização e imunolocalização da proteína osteopontina (OPN). Os dados obtidos foram analisados por testes estatísticos para um nível de significância de 5%. A proliferação celular aumentou significativamente aos sete dias de cultura, seguido de uma diminuição significativa em todos os períodos experimentais, sem diferença estatística entre eles. A detecção in situ de ALP e mineralização aumentou com o tempo, mas dentro de cada período não foram observadas diferenças estatísticas entre os grupos. A morfologia celular foi mantida com ambas as concentrações de GSE, enquanto a adesão celular aumentou significativamente aos três dias em todos os grupos. A expressão de osteopontina distribuiu-se regularmente com maior intensidade após 24 horas no grupo GSE0.1. Após três dias, a expressão de OPN foi mais intensa no grupo controle, seguida pelos grupos GSE0.1 e GSE1.0. Os dados obtidos sugerem que baixas concentrações de GSE não afetam a morfologia e podem estimular a atividade funcional das células osteoblásticas.

Effect of grape seed extract (GSE) on functional activity and mineralization of OD-21 and MDPC-23 cell lines

Abstract Recent studies on functional tissue regeneration have focused on substances that favor cell proliferation and differentiation, including the bioactive phenolic compounds present in grape seed extract (GSE). The aim of this investigation was to evaluate the stimulatory potential of GSE in the functional activity of undifferentiated pulp cells and odontoblast-like cells. OD-21 and MDPC-23 cell lines were cultivated in odontogenic medium until subconfluence, seeded in 24-well culture plates in a concentration of 2x104/well and divided into: 1) OD-21 without GSE; 2) OD-21+10 µg/mL of GSE; 3) MDPC-23 without GSE; 4) MDPC-23+10 µg/mL of GSE. Cell proliferation, in situ detection of alkaline phosphatase (ALP) and total protein content were assessed after 3, 7 and 10 days, and mineralization was evaluated after 14 days. The data were analyzed by ANOVA statistical tests set at a 5% level of significance. Results revealed that cell proliferation increased after 10 days, and protein content, after 7 days of culture in MDPC-23 cells. In situ ALP staining intensity was higher in undifferentiated pulp cells and odontoblast-like cells after 7 and 10 days, respectively. A discrete increase in MDPC-23 mineralization after GSE treatment was observed despite OD-21 cells presenting a decrease in mineralized nodule deposits. Data suggest that GSE favors functional activity of differentiated cells more broadly than undifferentiated cells (OD-21). More studies with different concentrations of GSE must be conducted to confirm its benefits to cells regarding dentin regeneration.

Gastric and renal effects of COX-2 selective and non-selective NSAIDs in rats receiving low-dose aspirin therapy

Abstract The consumption of low-dose aspirin (LDA) to prevent cardiovascular disease continues to increase worldwide. Consequently, the number of chronic LDA users seeking dental procedures that require complementary acute anti-inflammatory medication has also grown. Considering the lack of literature evaluating this interaction, we analyzed the gastric and renal effects caused by a selective COX-2 inhibitor (etoricoxib) and a non-selective COX-2 inhibitor (ibuprofen) nonsteroidal anti-inflammatory drug (NSAID) in rats receiving chronic LDA therapy. Male Wistar rats were divided into six experimental groups (carboxymethylcellulose (CMC) - vehicle; LDA; LDA + ibuprofen; ibuprofen; LDA + etoricoxib; and etoricoxib) and submitted to long-term LDA therapy with a subsequent NSAID administration for three days by gavage. After the experimental period, we analyzed gastric and renal tissues and quantified serum creatinine levels. The concomitant use of LDA with either NSAID induced the highest levels of gastric damage when compared to the CMC group (F = 20.26, p < 0.05). Treatment with either LDA or etoricoxib alone was not associated with gastric damage. No significant damage was observed on kidney morphology and function (F = 0.5418, p > 0.05). These results suggest that even the acute use of an NSAID (regardless of COX-2 selectivity) can induce gastric damage when combined with the long-term use of low-dose aspirin in an animal model. Additional studies, including clinical assessments, are thus needed to clarify this interaction, and clinicians should be careful of prescribing NSAIDs to patients using LDA.