Cryptolepis sanguinolenta: an ethnobotanical approach to drug discovery and the isolation of a potentially useful new antihyperglycaemic agent

Abstract

Evidence has been published that a wide array of plant-derived active principles, representing numerous classes of chemical compounds, demonstrate activity consistent with their possible use in the treatment of patients with Type 2 diabetes mellitus (DM). Despite these interesting observations, to date, metformin is the only ethical drug approved for treatment of Type 2 DM derived from a medicinal plant. Why is this so, given the fact that higher plants are such a potential source of new drugs? The answer to this rhetorical question may lie in the reliance of most pharmaceutical companies on random, in vitro, mechanism-based, high throughput screening in the initial phases of plant drug research. In this article we describe an alternative pathway to discovery of drugs for the treatment of Type 2 DM: on based on an ethnomedical approach, involving ethnobotany and traditional medicine. In particular, we present evidence that cryptolepine, an indoloquinolone alkaloid isolated from Cryptolepis sanguinolenta, significantly lowers glucose when given orally to a mouse model of diabetes. The antihyperglycaemic effect of cryptolepine leads to a significant decline in plasma insulin concentration, associated with evidence of an enhancement in insulin-mediated glucose disposal. Finally, cryptolepine increases glucose uptake by 3T3-L1 cells. These data permit us to conclude that an ethnobotanical approach to drug discovery can identify a potentially useful drug for the treatment of Type 2 DM.

Clinical efficacy of a tea-bag formulation of <i>Cryptolepis sanguinolenta</i> root in the treatment of acute uncomplicated falciparum malaria

“…Crude extracts of C. sanguinolenta and their fractions, as well as indoquinoline alkaloids isolated from the plant, have been shown to have activity against Plasmodium falciparum both in vitro and in vivo. [9][10][11][12][13] In addition to studies indicating anti-plasmodial effect, extracts of C. sanguinolenta have been shown to have anti-microbial activity 3,6,[14][15][16][17][18][19][20][21] , to be anti-hyperglycaemic 22,23 and antiinflammatory. 24 A preliminary study of the clinical efficacy of an aqueous extract of C. sanguinolenta as an anti-malarial preparation had been carried out which indicated the efficacy of the extract against falciparum malaria.…”

Membrane Perturbations Induced by New Analogs of Neocryptolepine

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antihyperglycemic, 8,9) anti-inflammatory 10,11) and antimalarial activities.12-15) Phyto-Riker (Gihoc) Pharmaceuticals Ltd. (Accra, Ghana) has developed an herbal preparation (Phyto-laria ® ) from the dried root of C. sanguinolenta for the treatment of malaria. According to clinical studies, this tea-bag formulation of the root powder (2.5 g) has been shown to be highly effective in the treatment of acute uncomplicated malaria, with an overall cure rate of 93.5%.

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“…The extracts of the roots have been used in folk medicine as an antimalarial agent, in the treatment of rheumatism, and in urinary tract and upper respiratory tract infections for many generations. 2,3) Crude extracts from this plant and their fractions, as well as isolated indoloquinoline alkaloids, have been shown to have antibacterial, [4][5][6][7] antihyperglycemic, 8,9) anti-inflammatory 10,11) and antimalarial activities. [12][13][14][15] Phyto-Riker (Gihoc) Pharmaceuticals Ltd. (Accra, Ghana) has developed an herbal preparation (Phyto-laria ® ) from the dried root of C. sanguinolenta for the treatment of malaria.…”

Antidiabetic effects of Cycas edentata aqueous leaf extract on the blood glucose levels of alloxan-induced diabetic imprinting control regions mice (Mus musculus L.)

“…[22] In a study on Cryptolepis sanguinolenta, alkaloids have been shown to have antihyperglycemic effect in diabetic mouse models, which leads to a decline in blood glucose concentration. [23] A study on Catharanthus roseus (L.) G. Don yielded four alkaloids that were found to be able to ameliorate type 2 diabetes through protein tyrosine phosphatase-1B inhibition. [24] On the other hand, alkaloids isolated from the roots and stems of Berberis L. have antihyperglycemic activity due to its alphaglucosidase inhibition and to decrease glucose transport in the intestinal epithelium.…”