Sugar Ray Leonard understands the art of self-defense and carries it over into his private life. The jeep in which the former world welterweight boxing champ was riding was hit by a pickup truck in Beltsville, Md., last month. Since he was wearing a seat belt, he was not seriously injured. Because of his defensive-driving behavior, Leonard was honored by the American Seat Belt Council yesterday in the office of Transportation Secretary Elizabeth Dole, who described the former boxer as a "master in the art of self-defense" . . .

As was expected, Cathy Evelyn Smith, charged with murder and drug violations in the death of comedian John Belushi, stood silent in a Los Angeles court yesterday while her attorney entered an innocent plea on her behalf . . .

A federal judge has thrown out a $100,000 jury award to actress Vanessa Redgrave, ruling that the Boston Symphony Orchestra should not be liable for damages to her career that might have occurred because her performance in a 1982 concert series was canceled. The orchestra, however, must pay Redgrave $27,500 for breach of contract. She contended that she was fired because of her strong support of the Palestine Liberation Organization . . .

American University President Richard Berendzen announced yesterday that Saudi Arabia has given the university $1 million to endow a chair in Islamic studies. Meanwhile, Prince Abdul Aziz, the 11-year-old son of Saudi King Fahd, is also giving away money. Tuesday he gave $100,000 to Children's Hospital and today he will tour the Capital Children's Museum and make a donation of $100,000 . . .

The Valentine's story at the Kennedy Center: Taryn Grimes and Stephen McDonough, currently starring in the musical "Take Me Along," were married while playing in the same production at the Shubert Theater in New Haven, Conn., last December. At the end of one of the New Haven shows, the announcement was made: "This play is about love. Unfortunately, two of our members got carried away" . . .