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Our interest in Macaranga originated in the observation that an organic extract of
Macaranga schweinfurthii Muell.Arg. (Euphorbiaceae) leaves possessed potent
(mean 50 % growth inhibition of 2.2 µg/mL) and differential (>2000-fold) activity
in the NCI 60 human tumour-cell assay (Figure 1). The most sensitive cell lines
included several brain tumour cell lines, especially the glioblastoma lines SF-295
and SF-539, and a number of lines in other organ panels.

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using similar drugs together sometimes boosts effectiveness because they're similar, not identical, they may use different metabolites, etc, so that may get you through a natural bottleneck to a higher dosage. It's not much of a chance, but it's a chance.

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Originally posted by DREAMTROVE:
gotta catch 'em all.

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Originally posted by DREAMTROVE:
Any thoughts on how one might get leaves from cameroon?

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Originally posted by DREAMTROVE:
Related species but do they carry the schweinfurthin a? if so, why did everyone trek back to cameroon?
I think there are other schweinfurthins. I'm not sure, more data is needed, brain empty again.

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However, none of the extracts originating from the other Macaranga species demonstrated a cytotoxicity profile consistent with the schweinfurthins. While schweinfurthin-like compounds have not
to this date been found in NCI Macaranga collections, other reports show that the ability to biosynthesize schweinfurthins is not unique to the single species M. schweinfurthii. Indeed, the compound vedelianin was isolated from M. vedeliana from the Loyalty Islands, New Caledonia prior to our work, although no bioactivity was attributed to it at the time (Thoison et al. 1992). Mappain, an analog of schweinfurthin C in which neither side chain is cyclized, was isolated from a Philippine species, M. mappa, growing in Hawaii (Van der Kaaden et al. 2001). Most recently, the Kingston group has reported isolation of cytotoxic schweinfurthin analogues from a Madagascan species of Macaranga (Yoder et al. 2004).

One potential reason for the inconsistent occurrence of schweinfurthins might be that production could be a response to herbivory, or to another type of threat to the plant’s well-being. Indeed, the voucher specimen for the initial collection of M. schweinfurthii is a large leaf full of holes (Figure 3; see colour pages elsewhere in this book), presumably due to insect damage. Another independent photo of this species on the worldwide web at ...(see below) shows similarly perforated leaves.

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