My brother does nothing to his bike except ride it occasionally and generally punctures a lot. I've suggested we look at some of the options available on the market eg liners, slime etc that can be run with an inner tube.
any advice/ recommendations much appreciated

If thorn/small hole punctures, you can use Stans or other sealants in the tube.
If pinch flats, pump the tyres up or buy some puncture protection (like Panaracers with the ABS strip)

these guys'll sort your bro out.

Greentyre

either you ride near too many prickly things – solution ride somewhere else

or

lots of snake bites so either more pressure, thicker tubes, or thicker tyres a nice Maxxis Minion 2.35 single ply works quite well over lots of rocks in the lakes.

For a bit I used to ride the thick maxxis dh/fr tubes hell of a weight penalty but better than changing every 10 mins

Having babies is the most effective puncture prevention system I've encountered.

Come to think of it, since I had a kid, I've not broken anything on my bike at all.

But then I haven't been riding the bleedin thing.

Slime or Dr Sludge inner tubes, there well worth it. Only issue to be aware of is, when they do eventually go down due to a puncture they can't seal, you'll find you have actually 4/5 other punctres that were sealed by the slime while inflated.

DH tubes – the ones in my son's bike weigh 500g

vinnyeh have you tried these greentyres? I'm interested to hear if they are any good…

I take it you put some talc in the tyre before fitting the inner tube, helps the tube slip so in theory reduces chance of a pinch puncture or valve ripping off under braking…