Geranium intoxication induces detoxification enzymes in the Japanese beetle, Popillia japonica Newman.

Popillia japonica is a generalist herbivore that feeds on >300 host plant species in at least 72 plant families. It is unknown why P. japonica, despite possessing active detoxification enzymes in its gut, is paralyzed when feeding on the petals of one of its preferred host plant, Pelargonium×hortorum, or on artificial diet containing quisqualic acid (QA), the active compound in zonal geranium. We hypothesized that Pelargonium×hortorum or QA do not induce activity of the cytochrome P450, glutathione S transferase (GST), and carboxylesterase (CoE) detoxification enzymes in P. japonica. In this study, P. japonica were fed petals of zonal geranium or agar plugs containing QA, or rose petals, another preferred but non-toxic host. Midgut enzyme activities of P450, GST, and CoE were then assayed after 6, 12, or 24h of feeding. In most cases, P450, GST, and CoE activities were significantly induced in P. japonica midguts by geranium petals and QA, though the induction was slower than with rose petals. Induced enzyme activity reached a peak at 24h after consumption, which coincides with the period of highest recovery from geranium and QA paralysis. This study shows that toxic geranium and QA induce detoxification enzyme activity, but the induced enzymes do not effectively protect P. japonica from paralysis by QA. Further investigation is required through in vitro studies to know if the enzymes induced by geranium are capable of metabolizing QA. This study highlights a rare physiological mismatch between the detoxification tool kit of a generalist and its preferred host.

A historical, scientific and commercial perspective on the medicinal use of Pelargonium sidoides (Geraniaceae).

UNLABELLED: ETHNOPHARMACOLOGICAL CONTEXT: A detailed review of the ethnobotany and commercial history of Pelargonium sidoides is presented, together with a brief summary of pre-clinical and clinical scientific results that support the use of the plant in modern, evidence-based phytomedicines. The aim is to identify the main factors responsible for the success in product development. MATERIALS AND METHODS: The literature studied includes all modern scientific papers and also old documents and books that are no longer readily accessible. RESULTS: Available ethnobotanical information shows that several tuberous Pelargonium species (including Pelargonium sidoides) are important traditional medicines with a rich ethnobotanical history. A summary of the interesting history of the commercial development of Stevens' Cure or Umckaloabo in Europe is presented. Scientific evidence for the efficacy of the product, mainly as a treatment for acute bronchitis, is reviewed. These include numerous in vitro studies as well as 18 clinical studies. The botanical identity of the plant and its complex mixture of coumarins and other chemical constituents are summarised. CONCLUSIONS: The use of Pelargonium stems or tubers for a variety of ailments (including the complications of dysentery) is an important but hitherto under-estimated part of traditional medicine in southern Africa. Key elements in the successful development of Pelargonium sidoides from a profound traditional remedy to a highly successful phytomedicine include the choice of species, a favourable cost-benefit ratio, innovative marketing over many years, good scientific evidence of the botanical and chemical identity of the product and convincing proof of concept.

Protective efficacy of an aerosol preparation, obtained from Geranium sanguineum L., in experimental influenza infection.

A polyphenol-rich extract from the aerial roots of the medicinal plant Geranium sanguineum L. (PC) protected mice from mortality in the experimental influenza A/Aichi/2/68 (H3N2) virus infection. To provide evidence how a maximum therapeutic benefit can be derived of this preparation, it was inoculated by 6 different routes. It was found that the aerosol application of PC was highly effective. In the dose 5.4 mg/ml, applied according to a prophylactic-therapeutic schedule, the extract exhibited a marked protective effect. The protective index reached the value of 70.1% and the mean survival time was prolonged with 2.9-4.9 days. The lung infectious virus titres and the lung consolidation of virus-infected and PC-treated animals were all reduced in comparison with control. The application of PC according to schedules, excluding the pretreatment of mice, proved that this condition was essential for protection.

Estimation of antinociceptive and anti-inflammatory activity on Geranium pratense subsp. finitimum and its phenolic compounds.

To obtain experimental evidence on the therapeutic efficacy of Geranium species and its phenolic compounds for inflammatory diseases, we examined the effects of the aqueous extract of the aerial parts of Geranium pratense subsp. finitimum (Woronow) Knuth, its fractions and isolated compounds, the mixture of quercetin 3-O-alpha-arabinopyranoside, kaempferol 3-O-beta-galactopyranoside (1), the mixture of quercetin 3-O-beta-glucopyranoside, quercetin 3-O-beta-galactopyranoside (2), kaempferol 3-O-beta-glucopyranoside (3), (-)-6-chloroepicatechin (4), the mixture of quercetin 3-O-(2''-O-galloyl)-beta-glucopyranoside, quercetin 3-O-(2''-O-galloyl)-beta-galactopyranoside (5) and myricetin 3-O-(2''-O-galloyl)-beta-glucopyranoside (6), on carrageenan-, PGE(2)- and TPA-induced inflammation in mice and p-benzoquinone-induced writhing reflex to assess anti-inflammatory and antinociceptive activities. The effective dose of materials for the inhibition of carragenan-induced hind paw edema assay was determined to be 100 mg/kg, which was also used in the assays with the extract, its fractions and isolated compounds in all other experiments. The aqueous extract, 1, 2 (100 mg/kg), as well as indomethacin (10 mg/kg) inhibited significantly the formation of the carrageenan-induced hind paw edema. There was also a significant reduction in PGE(2)-induced hind paw edema and TPA-induced ear edema models with 5, in addition to the aqueous extract and the other active components 1 and 2. In the antinociceptive assay, the aqueous extract and its fractions, as well as 1, 2, and 5 diminished significantly the number of writhings. Based on the results obtained it is suggested that the aqueous extract of Geranium pratense subsp. finitimum and its phenolic compounds display anti-inflammatory activity, supporting the folkloric use.