Monitoring the use of novel psychoactive substances in Australia by wastewater-based epidemiology.

Users of novel psychoactive substances (NPS) are at risk, due to limited information about the toxicity and unpredictable effects of these compounds. Wastewater-based epidemiology (WBE) has been used as a tool to provide insight into NPS use at the population level. To understand the preferences and trends of NPS use in Australia, this study involved liquid chromatography mass spectrometry analysis of wastewater collected from Australian states and territories from February 2022 to February 2023. In total, 59 different NPS were included across two complementary analytical methods and covered up to 57 wastewater catchments over the study. The NPS detected in wastewater were 25-B-NBOMe, buphedrone, 1-benzylpiperazine (BZP), 3-chloromethcathinone, N,N-dimethylpentylone (N,N-DMP), N-ethylheptedrone, N-ethylpentylone, eutylone, 4F-phenibut, 2-fluoro deschloroketamine, hydroxetamine, mephedrone, methoxetamine, methylone, mitragynine, pentylone, phenibut, para-methoxyamphetamine (PMA), alpha-pyrrolidinovalerophenone (α-PVP) and valeryl fentanyl. The detection frequency for these NPS ranged from 3 % to 100 % of the sites analysed. A noticeable decreasing trend in eutylone detection frequency and mass loads was observed whilst simultaneously N,N-DMP and pentylone increased over the study period. The emergence of some NPS in wastewater pre-dates other sources of monitoring and provides further evidence that WBE can be used as an additional early warning system for alerting potential NPS use.

Antioxidant and Antiglycation Activities of Syzygium paniculatum Gaertn and Inhibition of Digestive Enzymes Relevant to Type 2 Diabetes Mellitus.

Advanced glycation end-products (AGEs) may be a contributing factor in the development of diabetes-specific vascular pathologies that affect the retina, glomerulus and peripheral nerves. In this study, Australian native food plant species Syzygium paniculatum was investigated for activities relevant to Type 2 diabetes mellitus including inhibition of α-amylase, α-glucosidase and protein glycation. A methanolic extract of the leaves showed the strongest α-amylase inhibition (IC50 = 14.29 ± 0.82 µg/mL, p < 0.05) when compared with other extracts. For inhibition of α-glucosidase, the strongest inhibition was shown for the water, methanolic and acetone extracts of leaves with IC50 values ranging from 4.73 ± 0.96 to 7.26 ± 0.92 µg/mL. In the BSA-glucose model, fruit and leaf extracts inhibited formation of protein-bound fluorescent AGEs with IC50 values ranging between 11.82 ± 0.71 and 96.80 ± 13.41 µg/mL. Pearson's correlation analysis showed that the AGE inhibition significantly correlated with DPPH (rp = -0.8964, p < 0.05) and ABTS (rp = -0.8326, p < 0.05). α-amylase inhibitory activities strongly correlated with DPPH (rp = -0.8964, p < 0.001). α-glucosidase inhibition strongly correlated with TPC (rp = -0.9243, p < 0.05), FRAP (rp = -0.9502, p < 0.01), DPPH (rp = -0.9317, p < 0.01) and ABTS (rp = -0.9486, p < 0.01). This study provides a strong rationale for further investigation aimed at isolating and identifying the active compounds responsible for the observed effects on targets relevant to diabetes.

Biological activity and LC-MS/MS profiling of extracts from the Australian medicinal plant Acacia ligulata (Fabaceae).

Acacia ligulata A.Cunn. ex Benth. (Fabaceae: Mimosoideae) is a native Australian plant used traditionally by Australian Aboriginal groups. This study was undertaken to investigate the bioactivity of A. ligulata extracts and to evaluate their chemical composition. Potential antibacterial, cytotoxic and enzyme inhibitory effects relevant to traditional medicinal and food uses of the species were examined and LC-MS/MS was performed to investigate the chemical composition. Antibacterial activity was observed for bark and leaf extracts with an MIC for the bark extract of 62.5 µg/mL against Streptococcus pyogenes. Pod extracts showed cytotoxic effects against cancer cells, with the highest activity against melanoma SK-MEL28 cells with IC50 values between 40.8 and 80.6 µg/mL. Further, the leaf and pod extracts also inhibited α-amylase EC-3.2.1.1 and α-glucosidase EC-3.2.1.20 with IC50 values between 9.7-34.8 and 12.6-64.3 µg/mL, respectively. The LC-MS/MS profiling indicated that several different saponins were present in the active extracts.

In vitro metabolism of the anti-inflammatory clerodane diterpenoid polyandric acid A and its hydrolysis product by human liver microsomes and recombinant cytochrome P450 and UDP-glucuronosyltransferase enzymes.

1. The metabolism of the anti-inflammatory diterpenoid polyandric acid A (PAA), a constituent of the Australian Aboriginal medicinal plant Dodonaea polyandra, and its de-esterified alcohol metabolite, hydrolysed polyandric acid A (PAAH) was studied in vitro using human liver microsomes (HLM) and recombinant UDP-glucuronosyltransferase (UGT) and cytochrome P450 (CYP) enzymes. 2. Hydrolysis of PAA to yield PAAH occurred upon incubation with HLM. Further incubations of PAAH with HLM in the presence of UGT and CYP cofactors resulted in significant depletion, with UGT-mediated depletion as the major pathway. 3. Reaction phenotyping utilising selective enzyme inhibitors and recombinant human UGT and CYP enzymes revealed UGT2B7 and UGT1A1, and CYP2C9 and CYP3A4 as the major enzymes involved in the metabolism of PAAH. 4. Analysis of incubations of PAAH with UDP-glucuronic acid-supplemented HLM and recombinant enzymes by UPLC/MS/MS identified three glucuronide metabolites. The metabolites were further characterised by ß-glucuronidase and mild alkaline hydrolysis. The acyl glucuronide of PAAH was shown to be the major metabolite. 5. This study demonstrates the in vitro metabolism of PAA and PAAH and represents the first systematic study of the metabolism of an active constituent of an Australian Aboriginal medicinal plant.

In vitro inhibitory activities of selected Australian medicinal plant extracts against protein glycation, angiotensin converting enzyme (ACE) and digestive enzymes linked to type II diabetes.

BACKGROUND: There is a need to develop potential new therapies for the management of diabetes and hypertension. Australian medicinal plants collected from the Kuuku I'yu (Northern Kaanju) homelands, Cape York Peninsula, Queensland, Australia were investigated to determine their therapeutic potential. Extracts were tested for inhibition of protein glycation and key enzymes relevant to the management of hyperglycaemia and hypertension. The inhibitory activities were further correlated with the antioxidant activities. METHODS: Extracts of five selected plant species were investigated: Petalostigma pubescens, Petalostigma banksii, Memecylon pauciflorum, Millettia pinnata and Grewia mesomischa. Enzyme inhibitory activity of the plant extracts was assessed against α-amylase, α-glucosidase and angiotensin converting enzyme (ACE). Antiglycation activity was determined using glucose-induced protein glycation models and formation of protein-bound fluorescent advanced glycation endproducts (AGEs). Antioxidant activity was determined by measuring the scavenging effect of plant extracts against 1, 1-diphenyl-2-picryl hydrazyl (DPPH) and using the ferric reducing anti-oxidant potential assay (FRAP). Total phenolic and flavonoid contents were also determined. RESULTS: Extracts of the leaves of Petalostigma banksii and P. pubescens showed the strongest inhibition of α-amylase with IC50 values of 166.50 ± 5.50 µg/mL and 160.20 ± 27.92 µg/mL, respectively. The P. pubescens leaf extract was also the strongest inhibitor of α-glucosidase with an IC50 of 167.83 ± 23.82 µg/mL. Testing for the antiglycation potential of the extracts, measured as inhibition of formation of protein-bound fluorescent AGEs, showed that P. banksii root and fruit extracts had IC50 values of 34.49 ± 4.31 µg/mL and 47.72 ± 1.65 µg/mL, respectively, which were significantly lower (p < 0.05) than other extracts. The inhibitory effect on α-amylase, α-glucosidase and the antiglycation potential of the extracts did not correlate with the total phenolic, total flavonoid, FRAP or DPPH. For ACE inhibition, IC50 values ranged between 266.27 ± 6.91 to 695.17 ± 15.38 µg/mL. CONCLUSIONS: The tested Australian medicinal plant extracts inhibit glucose-induced fluorescent AGEs, α-amylase, α-glucosidase and ACE with extracts of Petalostigma species showing the most promising activity. These medicinal plants could potentially be further developed as therapeutic agents in the treatment of hyperglycaemia and hypertension.

Development and Evaluation of a Topical Anti-Inflammatory Preparation Containing Dodonaea polyandra Extract.

PURPOSE: We have previously reported that the Australian Northern Kaanju (Kuuku I'yu) medicinal plant Dodonaea polyandra has anti-inflammatory activity. This is attributed largely to the presence of clerodane diterpenoids contained within the leaf resin. We envisaged developing a topical preparation to treat indications relating to skin inflammation. However, it was unknown whether the resin could be incorporated into a suitable dosage form while retaining the therapeutic value demonstrated in previous work. Therefore, the following study was undertaken to assess parameters of safety and efficacy for a prototype formulation containing the leaf resin extracted from D. polyandra. METHODS: Using the assessment criteria of optimum appearance, tactile feeling, spreadability and odour, 78 different formulations were developed. Formulation stability was assessed using a centrifugal test with preparations displaying phase separation further modified or re-formulated. A prototype formulation containing 5% w/w plant resin was selected and subjected to in vitro release studies. This was quantified through HPLC analysis using two major bioactive diterpenoids as reference. The prototype formulation was tested for efficacy in a TPA-induced acute murine skin inflammation model as well as a 3D human skin model for irritancy/toxicity (Epiderm™). RESULTS: The prototype resin cream was a chartreuse-coloured homogenous semisolid preparation that was readily spreadable upon contact with skin with no sensation of tackiness, residual greasiness, or irritation. The optimized cream showed no phase separation after 30 min centrifugation at 825 g. In the TPA-induced inflammation model, the resin formulation significantly reduced ear thickness and interleukin-1 beta levels in mouse ear tissue. The 5% w/w resin cream formulation showed no irritancy in a 3D human skin model. CONCLUSIONS: Our results demonstrate that bioactive resin from D. polyandra can be formulated into a stable and non-irritant semi-solid dosage form and reduce parameters of acute skin inflammation in vivo. This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.

Polyandric acid A, a clerodane diterpenoid from the Australian medicinal plant Dodonaea polyandra, attenuates pro-inflammatory cytokine secretion in vitro and in vivo.

Dodonaea polyandra is a medicinal plant used traditionally by the Kuuku I'yu (Northern Kaanju) indigenous people of Cape York Peninsula, Australia. The most potent of the diterpenoids previously identified from this plant, polyandric acid A (1), has been examined for inhibition of pro-inflammatory cytokine production and other inflammatory mediators using well-established acute and chronic mouse ear edema models and in vitro cellular models. Topical application of 1 significantly inhibited interleukin-1ß production in mouse ear tissue in an acute model. In a chronic skin inflammation model, a marked reduction in ear thickness, associated with significant reduction in myeloperoxidase accumulation, was observed. Treatment of primary neonatal human keratinocytes with 1 followed by activation with phorbol ester/ionomycin showed a significant reduction in IL-6 secretion. The present study provides evidence that the anti-inflammatory properties of 1 are due to inhibition of pro-inflammatory cytokines associated with skin inflammation and may be useful in applications for skin inflammatory conditions including psoriasis and dermatitis.

Learning from both sides: Experiences and opportunities in the investigation of Australian aboriginal medicinal plants.

With one of the oldest surviving cultures in the world, Australian Aboriginal people have developed immense knowledge about the diverse Australian flora. Western scientific investigation of some Australian Aboriginal medicinal plants has demonstrated interesting pharmacological activities and chemistry, however the majority of these species have not yet been extensively examined. We argue that research that is locally initiated and driven by Indigenous traditional owners in collaboration with Western scientists has significant potential to develop new plant-based products. Locally driven medicinal plants research in which traditional owners work as researchers in collaboration with University-based colleagues in the investigation of medicines rather than "stakeholders" or "informants" is one model that may be used in characterising plants with the potential to be developed into sustainable plant-based medicinal products with commercial value. Our team has taken this approach in research located both on traditional homelands and in the laboratory. Research being conducted by the University of South Australia and Chuulangun Aboriginal Corporation has led to patent filing for protection of intellectual property associated with novel compounds and extracts with the potential for development through cosmetic, complementary medicine and pharmaceutical routes. Ongoing research is examining the commercial developmental pathways and requirements for product development in these spaces. This review will address the opportunities that might exist for working in partnership with Australian Indigenous communities, some of the scientific knowledge which has been generated so far from our work together and the lessons learnt since the inception of the collaboration between the Chuulangun Aboriginal Corporation and scientists from the University of South Australia.

Dioecy in plants--is it an important factor for phytochemists to consider?

Plants with separate male and female flowers are termed dioecious. Dioecy is not rare, yet is a characteristic that could potentially impact the phytochemical and subsequent pharmacological properties of a species. This is a brief insight which highlights why the sex of the plant might be an important factor to consider for researchers within phytochemistry related fields.

Flavonoids from the leaves and stems of Dodonaea polyandra: a Northern Kaanju medicinal plant.

Three prenylated flavonoids 5,7,4'-trihydroxy-3'(3-methylbut-2-enyl)-3-methoxy flavone, 5,7-dihydroxy-3'(3-methylbut-2-enyl)-3,4'-dimethoxy flavone and 5,7,4'-trihydroxy-3',5'(3-methylbuyt-2-enyl)-3-methoxy flavone together with three other known flavonoids were isolated from the medicinal plant Dodonaea polyandra. The plant is used in the traditional medicine system of Northern Kaanju people of Cape York Peninsula, Queensland, Australia. The extracts studied have previously been found to possess anti-inflammatory activity. Successive fractionation of leaf and stem extracts by column and high performance liquid chromatography led to the isolation of these compounds. Their structures were determined using a number of spectroscopic techniques including 1D and 2D NMR and high resolution mass spectroscopy. The structural elucidation is reported herein accompanied by full ¹H and ¹³C NMR spectroscopic data. Spectroscopic data of known compounds was in agreement with that previously reported in literature.