NEW DELHI (AP) — It's an unlikely scene in deeply conservative India: A hugely popular Bollywood male star grinning widely as he holds up a sanitary pad and talks of menstrual hygiene.

But that's exactly what action hero Akshay Kumar did as he promoted his film "Padman," which opened in theaters Friday. Kumar plays the lead role of a man who starts manufacturing inexpensive sanitary pads after he discovers his wife's lack of access to them in a small town in southern India.

The subject of menstruation and menstrual hygiene is rarely, if ever, discussed openly in Indian homes.

At pharmacies and department stores, tampons and sanitary pads get the same treatment reserved for condoms — they are handed to customers discretely wrapped in black plastic bags kept on hand simply for the purpose of saving them any embarrassment.

In many homes women are barred from temples and religious rituals as well as cooking or entering the kitchen when they have their period.

So Kumar and his film are definitely breaking ground in cleaving through the layers of taboo.

"Yes, these are pads. Yes, they belong to these amazing women. Yes, they were happy to lend me one so I could stand with them in support of this much needed initiative," upcoming Bollywood actor Siddharth Malhotra tweeted Friday along with a photo of him surrounded by female fans as he held up a sanitary pad.

Malhotra isn't the only mainstream star to speak up about menstruation. Dozens of other Bollywood actors and actresses have tweeted photos of themselves holding up sanitary pads as they gave the film a shoutout. Radio talk shows have been discussing the film and the shame generally associated with the subject in India.

"This, I think is the biggest achievement of #PadMan...men and women breaking the taboo," Kumar, 50, tweeted of his film.

The film is loosely based on the life of Arunachalam Muruganantham, who invented a machine to make sanitary pads at a fraction of the cost of most commercially available products, when he found that his wife was forced to use rags and newspaper during her period.

Kumar's wife, the novelist and one-time actress Twinkle Khanna, wrote a book on Muruganantham's life, prompting her husband to make it into a film.