Spectroscopic examination of purified extracts of the rumen content of sheep intoxicated by Brachiaria decumbens revealed the presence of two spirostanes, identified as epi-sarsasapogenin and epi-smilagenin. Sarsasapogenone was obtained by the oxidation of sarsasapogenin. The reduction of sarsasapogenone using lithium aluminum hydride yielded isomeric products, sarsasapogenin (20%) and epi-sarsasapogenin (80%).
Phytochemical studies on rhizome of Etlingera elatior have resulted in the isolation of 1,7-bis(4-hydroxyphenyl)-2,4,6-heptatrienone (1), demethoxycurcumin (2), 1,7-bis(4-hydroxyphenyl)-1,4,6-heptatrien-3-one (3), 16-hydroxylabda-8(17),11,13-trien-16,15-olide (4), stigmast-4-en-3-one (5), stigmast-4-ene-3,6-dione (6), stigmast-4-en-6b-ol-3-one (7), 5α,8α-epidioxyergosta-6,22-dien-3β-ol (8). 1 and 4 were new compounds. Compounds 5 and 7 displayed high antitumour-promoting activity. Ethyl acetate extract showed a very significant cytotoxic activity against CEM-SS and MCF-7 cell lines (4 μg/ml and 6.25 μg/ml respectively). The antitumour-promoting activity was determined by EBV-EA assay and cytotoxic activity was determined by MTT assay.
The methanol extracts of three Macaranga species (M. denticulata, M. pruinosa, and M. gigantea) were screened to evaluate their total phenolic contents and activities as cholinesterase inhibitors, nitric oxide (NO) production inhibitors, tyrosinase inhibitors, and antioxidants. The bark of M. denticulata showed the highest total phenolic content (2682 mg gallic acid equivalent (GAE)/100 g) and free radical scavenging activity (IC50 = 0.063 mg/mL). All of the samples inhibited linoleic acid peroxidation by greater than 80%, with the leaves of M. gigantea exhibiting the highest inhibition of 92.21%. Most of the samples exhibited significant antioxidant potential. The bark of M. denticulata and the leaves of both M. pruinosa and M. gigantea exhibited greater than 50% tyrosinase inhibition, with the bark of M. denticulata having the highest percentage of inhibition (68.7%). The bark and leaves of M. denticulata exhibited greater than 50% inhibition (73.82% and 54.50%, resp.) of the acetylcholinesterase enzyme (AChE), while none of the samples showed any significant inhibition of butyrylcholinesterase (BChE). Only the bark of M. denticulata and M. gigantea displayed greater than 50% inhibition of nitric oxide production in cells (81.79% and 56.51%, resp.). These bioactivities indicate that some Macaranga spp. have therapeutic potential in medicinal research.
Andrographolide (AGP) and 14-deoxy-11,12-didehydroandrographolide (DDAG), two main diterpenoid constituents of Andrographis paniculata were previously shown to ameliorate asthmatic symptoms in a mouse model. However, due to inadequacies of both compounds in terms of drug-likeness, DDAG analogues were semisynthesised for assessment of their anti-asthma activity. A selected analogue, 3,19-diacetyl-14-deoxy-11,12-didehydroandrographolide (SRS27), was tested for inhibitory activity of NF-κB activation in TNF-α-induced A549 cells and was subsequently evaluated in a mouse model of ovalbumin (OVA)-induced asthma. Female BALB/c mice, 6-8weeks old were sensitized on days 0 and 14, and challenged on days 22, 23 and 24 with OVA. Compound or vehicle (3% dimethyl sulfoxide) was administered intraperitoneally 1h before and 11h after each OVA aerosol challenge. On day 25, pulmonary eosinophilia, airway hyperresponsiveness, mucus hypersecretion, inflammatory cytokines such as IL-4, -5 and -13 in BAL fluid, gene expression of inflammatory mediators such as 5-LOX, E-selectin, VCAM-1, CCL5, TNF-α, AMCase, Ym2, YKL-40, Muc5ac, CCL2 and iNOS in animal lung tissues, and serum IgE were determined. SRS27 at 30μM was found to suppress NF-κB nuclear translocation in A549 cells. In the ovalbumin-induced mouse asthma model, SRS27 at 3mg/kg displayed a substantial decrease in pulmonary eosinophilia, BAL fluid inflammatory cytokines level, serum IgE production, mucus hypersecretion and gene expression of inflammatory mediators in lung tissues. SRS27 is the first known DDAG analogue effective in ameliorating inflammation and airway hyperresponsiveness in the ovalbumin-induced mouse asthma model.
Spectroscopic examinations of purified extracts of the rumen content of sheep intoxicated by Brachiaria decumbens revealed the presence of a mixture of sapogenins, identified as 3-spirostanols. These isomeric steroid sapogenins (C27H44O3) are believed the toxic principles in causing toxicity in sheep after feeding on B. decumbens.