The effect of cultivation and plant age on the pharmacological activity of Merwilla natalensis bulbs

Merwilla natalensis bulbs were cultivated at two different sites under different treatments. Bulbs were harvested every six months for a period of two years and were tested for antibacterial, anti-inflammatory and anthelmintic activity. The cultivation treatments had no significant effect (P ≤ 0.05) on neither the antibacterial activity, nor the anti-inflammatory activity. However, the age of the bulbs had a significant effect against the test bacteria and on the inhibition of prostaglandin synthesis by COX-1, with activity decreasing as the bulbs matured. The cultivation treatments had a significant effect on the antihelmintic activity of bulbs cultivated at the Fort Hare site. Results suggest that irrigation might increase the antihelmintic activity of the bulbs if cultivated in areas of low rainfall. The age of the bulbs at both sites had a significant effect on the antihelmintic activity, with activity increasing with plant maturity.