If plants could speak they will boast about being part of remedies such as the common aspirin to a leukaemia drug derived from the rosy periwinkle. Over a quarter of western medicines contain plant toxins some deriving from tropical forest species.

There is no strong evidence either way for several herbal remedies commonly taken to relieve troublesome menopausal symptoms, concludes the January issue of the Drug and Therapeutics Bulletin (DTB). And for some, there is hardly any evidence at all.

As winter approaches many of us reach for over-the-counter vitamins and herbal remedies, such as Vitamin C and Echinacea, in a bid to ward off illnesses and improve health. But the vast array of supplements available and lack of industry regulation make it difficult for the average person to make an informed choice about taking supplements.

Aspirin didn't pan out. Neither did two other potential anti-aging agents. But a synthetic derivative of a pungent desert shrub is now a front- runner in ongoing animal experiments to find out if certain chemicals, known to inhibit inflammation, cancer and other destructive processes, can boost the odds of living longer.

A common herbal extract available in health food stores can greatly reduce urinary tract infections and could potentially enhance the ability of antibiotics to kill the bacteria that cause 90 percent of infections in the bladder.