As we know, in Gembox Spreadsheet, you can set a border (with C# language) for a cell like:
worksheet.Cells[row, 2].Style.Borders.SetBorders(MultipleBorders.All, Color.FromArgb(252, 1, 1), LineStyle.Thin);
It is a way to check if a cell contains border (bottom or top border) ?
Update
I found the solution with Gembox support:
var hasLeftBorder = cell.Style.Borders[IndividualBorder.Left].LineStyle != LineStyle.None;