Pentacyclic triterpenoids including the oleanane, ursane and lupane groups are widely distributed in many medicinal plants, such as Glycyrrhiza species, Gymnema species, Centella asiatica, Camellia sinensis, Crataegus species and Olea europaea, which are commonly used in traditional medicine for the treatment of diabetes and diabetic complications. A large number of bioactive pentacyclic triterpenoids, such as oleanolic acid, glycyrrhizin, glycyrrhetinic acid, ursolic acid, betulin, betulinic acid and lupeol have shown multiple biological activities with apparent effects on glucose absorption, glucose uptake, insulin secretion, diabetic vascular dysfunction, retinopathy and nephropathy. The versatility of the pentacyclic triterpenes provides a promising approach for diabetes management.

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Many spices have been shown to impart an antioxidative effect in foods. This study summarized the literature on the antioxidative effects of spices. The term spice is defined as dry plant material that is normally added to food to impart flavor. The methanolic crude extracts of Allium sativum, Coriandrum sativum, Cuminum cyminum, Zingiber officinale, Cinnamomum verum, Elettaria cardamomum and Cinnamomum tamala were screened for their free radical scavenging properties using ascorbic acid as standard antioxidant. Free radical scavenging activity was evaluated using 1,1-diphenyl-2-picryl hydrazyl (DPPH) free radical. The overall antioxidant activity of Cuminum cyminum was found to be the strongest, followed in descending order by Z. officinale, C. sativum, A. sativum, C. tamala, C. verum, E. cardamomum. The IC50 values of the extracts ranged between 15.48 and 217.431 (microg mL(-1)). The ascorbic acid levels was 22.78 (microg mL(-1)) the present study revealed that the selected plants would exert several beneficial effects by virtue of their antioxidant activity and could be harnessed as drug formulation.

Propolis samples from Kangaroo Island, South Australia, were investigated for chemical constituents using high-field nuclear magnetic resonance spectral profiling. A type of propolis was found containing a high proportion of prenylated hydroxystilbenes. Subsequently, the botanical origin of this type of propolis was identified using a beehive propolis depletion method and analysis of flora. Ligurian honey bees, Apis mellifera ligustica Spinola, were found to produce propolis from resin exuded by the Australian native sedge plant Lepidosperma sp. Montebello (Cyperaceae). The plants, commonly known as sword sedge, were found to have resin that matched with the propolis samples identified as the most abundant propolis type on the island containing C- and O-prenylated tetrahydroxystilbenes (pTHOS) in addition to a small amount of prenylated p-coumarate. The isolation of five pTHOS not previously characterized are reported: (E)-4-(3-methyl-2-buten-1-yl)-3,4',5-trihydroxy-3'-methoxystilbene, (E)-2,4-bis(3-methyl-2-buten-1-yl)-3,3',4',5-tetrahydroxystilbene, (E)-2-(3-methyl-2-buten-1-yl)-3-(3-methyl-2-butenyloxy)-3',4',5-trihydroxystilbene, (E)-2,6-bis(3-methyl-2-buten-1-yl)-3,3',5,5'-tetrahydroxystilbene and (E)-2,6-bis(3-methyl-2-buten-1-yl)-3,4',5-trihydroxy-3'-methoxystilbene. A National Cancer Institute 60 human cell line anticancer screen of three of these compounds showed growth inhibitory activity. The large Australasian genus Lepidosperma is identified as a valuable resource for the isolation of substances with medicinal potential.

The present study was undertaken to explore the free radical scavenging, antimicrobial and cytotoxic activity of the methanolic extract of Glycyrrhiza glabra (Fabaceae) using DPPH, disc diffusion and brine shrimp lethality bioassay methods respectively. Different degrees of effect was noticed incase of different methods of study. In antimicrobial screening, G. glabra showed potent antimicrobial activity against almost all the test organisms except Pseudomonas aeruginosa. It exhibited highest sensitivity against Staphylococcus aureus with the zone of inhibition 22 mm. The extract possessed potent cytotoxic activity having LC 50 value of 0.771µg/ml. On the other hand, the free radical scavenging activity was found moderate having IC 50 value of 87.152 µg/ml.