This Leaf Is So Rough It Was Used as Sandpaper to Polish Wood. Its Compounds Pull Sugar Into Your Muscles the Same Way Exercise Does.
Mempelas (Tetracera scandens) — the “stone leaf” the Orang Asli reached for to treat diabetes, long before anyone could name the pathway
For generations, Malaysians used this coarse jungle vine to sand carved wood and, separately, to treat blood sugar, gout, and high blood pressure. Modern laboratories have now isolated the compounds inside it — and found they switch on AMPK, the exact cellular fuel-gauge that exercise and the diabetes drug metformin both target. Here is what the science actually shows, and where it honestly stops.
“Mempelas leaves are so abrasive they were traditionally used as natural sandpaper to smooth carved wood. The same leaf was boiled and drunk to treat diabetes. Modern science found its compounds activate AMPK — the same metabolic switch flipped by exercise and by metformin.”
This is the kind of fact that should stop you. A jungle vine coarse enough to polish timber, that village healers and the Orang Asli also used for “kencing manis” (diabetes), aching joints, and high blood pressure — turns out to contain a family of compounds that do something genuinely remarkable inside muscle cells.
In the laboratory, isoflavones isolated from mempelas stimulate muscle cells to pull glucose out of the blood — and they do it by activating AMPK and increasing GLUT4 and GLUT1, the very glucose transporters that exercise recruits. In other words, at the cellular level, mempelas appears to partly mimic the effect of physical activity on blood sugar.
That is a striking finding. It is also where honesty has to enter: this is cell-culture and animal evidence, not human clinical trials. The traditional healers were observing something real. The lab has explained a plausible mechanism. But “promising mechanism” is not the same as “proven treatment” — and the gap between them is the whole point of this article.
This article is educational, not medical advice. Mempelas is not a replacement for diabetes medication, and nobody managing blood sugar should change their treatment based on it. If anything, its blood-sugar-lowering activity is a reason for caution — combined carelessly with diabetes drugs it could theoretically push blood sugar too low. This is the complete picture so you can ask better questions, not a prescription.
What Is Mempelas?
Mempelas (Tetracera scandens) is a woody climbing vine of the Dilleniaceae family, found across the forests and forest margins of Malaysia, Indonesia, Thailand, Vietnam, southern China, the Philippines, Myanmar, and India. It can climb 30 metres into the canopy. Its defining feature is its leaves: covered in tiny silica-hardened hairs that make them genuinely abrasive to the touch — rough enough that, before sandpaper was cheap and everywhere, they were used to sand and polish carved wood. That coarseness is why one of its English names is literally “stone leaf.”
It travels under several Malay names — Mempelas, Mempelas Kasar, Akar Mempelas, Akar Empelas — and a close cousin used almost interchangeably in traditional medicine, Tetracera indica, is known as Mempelas Paya (swamp mempelas). The names “kasar” (rough) and the comparison to a sanding tool tell you the first thing anyone ever noticed about this plant: its texture.
Mempelas Kasar / Akar Mempelas
Leaves, stems and roots all used in folk remedies. The rough leaf doubled as a household sanding tool — food, medicine, and workshop in one plant.
Tetracera scandens
Family Dilleniaceae. Synonyms include Delima sarmentosa and Tragia scandens. A liana climbing to 30m, with ovate rough leaves and small white-to-pink fragrant flowers.
“Stone Leaf”
Named for the abrasive, sandpaper-like leaf surface caused by silica-rich hairs — the same quality that made it a traditional wood-finishing tool.
Tetracera indica — Mempelas Paya
The swamp variety, used almost interchangeably for diabetes, fever, flu, skin complaints and more. Shares the rough leaf and the antidiabetic research interest.
What the Healers Used It For
What’s striking about mempelas in the ethnobotanical record is the breadth and consistency of its use across completely separate cultures — the same plant reached for to treat the same cluster of conditions by people who never met.
Darah Tinggi, Demam, Sakit Tekak
Used to lower high blood pressure, bring down fever, and soothe sore throat. The leaves boiled into a decoction (air rebusan) were the common preparation. Documented in Malaysian herb gardens and folk-medicine records.
Kencing Manis & Rheumatism
Reached for to manage diabetes (“sweet urine”), rheumatism, gout, and internal pains. Indigenous communities across the region independently used the leaves, stems and roots for these conditions — a convergence that earns scientific attention.
Hepatitis, Dysentery, Childbirth
Across Vietnam, Indonesia, Thailand and beyond: inflammatory diseases, hepatitis, urinary disorders, dysentery, and as a postpartum recovery aid. One of the most multi-purpose plants in the regional folk pharmacopoeia.
Natural Sandpaper
Entirely apart from medicine: the dried rough leaves were used to sand and finish carved wooden objects. A practical, non-medicinal use that is also the origin of the plant’s identity and name.
What the Laboratory Found Inside the Leaf
Here is where mempelas becomes genuinely interesting, because the modern research lands surprisingly close to what the traditional healers were using it for — diabetes above all.
Mempelas compounds activate AMPK — the same switch as exercise and metformin
This is the headline finding. Researchers isolated five isoflavones from mempelas — genistein and its derivatives (3′,5′-diprenylgenistein, 6,8-diprenylgenistein, derrone, and alpinumisoflavone). When tested on muscle cells (L6 myotubes), several of these compounds significantly stimulated glucose uptake — making the muscle pull sugar out of its surroundings.
The mechanism is the remarkable part. They worked by activating AMPK (AMP-activated protein kinase) and increasing the expression of GLUT4 and GLUT1 — the glucose transporter proteins that move sugar into cells. AMPK is the cell’s master fuel gauge. It is the same pathway switched on by physical exercise, and the same pathway targeted by metformin, the most prescribed diabetes drug in the world. At the cellular level, mempelas’s compounds partly imitate what a workout does to your blood sugar.
The same compounds also inhibited PTP1B — an enzyme that acts as a brake on insulin signalling. Inhibiting it is a recognised strategy for improving insulin sensitivity. So mempelas appears to push glucose metabolism in the right direction through more than one mechanism at once.
Source: Myung SL et al. (2009), Genistein-Derivatives from Tetracera scandens Stimulate Glucose-Uptake in L6 Myotubes, Biological & Pharmaceutical Bulletin 32(3):504-508.
The blood-sugar effect held up in diabetic rats — not just cell cultures
Cell-culture findings are promising but limited — a compound that works on cells in a dish doesn’t always work in a living body. So it matters that mempelas was also tested in vivo. In a study on alloxan-induced diabetic rats, aqueous and methanol extracts of the leaves showed significant anti-hyperglycaemic (blood-sugar-lowering) activity, supporting the traditional use and the cell-based mechanism.
A further study used GC-MS metabolite profiling to confirm that mempelas leaf extracts potently inhibit alpha-glucosidase — the gut enzyme that breaks complex carbohydrates into absorbable sugar. Slowing that enzyme blunts the post-meal blood sugar spike, which is exactly how the diabetes drug class acarbose works. So mempelas appears to act on blood sugar at two ends: less sugar absorbed from the gut, and more sugar pulled into muscle.
Sources: Anti-hyperglycemic activity of Tetracera scandens in alloxan-induced diabetic rats, J. Ethnopharmacology (2010) · Investigation of α-Glucosidase Inhibitory Metabolites from Tetracera scandens, GC-MS metabolomics study (2020).
Xanthine oxidase inhibition — the same target as gout medication
Mempelas was traditionally used for gout and rheumatism, and the chemistry offers an explanation. Polar extracts of Tetracera scandens have been shown to inhibit xanthine oxidase in a concentration-dependent way. Xanthine oxidase is the enzyme that produces uric acid — the substance that crystallises in joints to cause gout. It is the same enzyme targeted by allopurinol, the standard gout drug.
This is a recurring theme in well-chosen traditional remedies: the plant used for joint pain turns out to act on the exact enzyme modern medicine targets for the same condition. It does not make mempelas a gout cure — but it makes the traditional use look a great deal less like coincidence.
Source: Nguyen MT et al. (2004), Xanthine oxidase inhibitory activity of Vietnamese medicinal plants, Biological & Pharmaceutical Bulletin 27:1414-1421.
Flavonoids, antioxidants and anti-inflammatory activity
Beyond the headline isoflavones, mempelas is rich in flavonoids and phenolic compounds with documented antioxidant and anti-inflammatory activity. This fits the broad traditional use for inflammatory diseases and internal pains, and it connects to the same underlying logic as the cholesterol and kaduk stories: many of these conditions share oxidation and chronic inflammation as a common root, and a plant that calms that environment can plausibly help across several of them at once.
The close cousin Tetracera indica (Mempelas Paya) has shown insulin-like and insulin-sensitising activity in fat-cell studies, reinforcing that the antidiabetic potential runs through the whole genus, not one species alone.
Sources: Phytochemicals and biological activity of Tetracera scandens: a short review (2020) · Flavonoids from Tetracera indica induce glucose uptake activities in 3T3-L1 adipocytes (2017).
What the Evidence Shows
Genistein and four derivatives isolated from mempelas, several with significant glucose-uptake activity.
The cellular fuel switch mempelas activates — the same one targeted by exercise and metformin.
AMPK/GLUT (metformin & exercise), alpha-glucosidase (acarbose), xanthine oxidase (allopurinol).
The honest gap. All evidence to date is cell-culture and animal. No completed human trials yet.
“The healers could not have known what AMPK was. They only knew that the bitter decoction of a rough jungle leaf helped with kencing manis. Three centuries later, the laboratory found the pathway. The knowledge was right; the explanation simply arrived late.”
The Claims, Honestly
“Mempelas is a natural cure for diabetes.”
The mechanism is genuinely exciting — AMPK activation, glucose uptake, alpha-glucosidase inhibition, all documented. But every study to date is in cells or animals. There are no completed human clinical trials, no established dose, and no proof it controls diabetes safely in people. “Promising traditional antidiabetic plant with a plausible mechanism” is true. “Cure” is false and dangerous — nobody should drop their medication for it.
“It’s just a leaf, so it’s completely safe to take as much as you want.”
A plant active enough to lower blood sugar is active enough to interact. Taken alongside diabetes medication, mempelas could in theory push blood sugar dangerously low (hypoglycaemia). Its safety profile, correct dose, and long-term effects in humans simply haven’t been established. “Natural” does not mean “consequence-free” — especially for something with real pharmacological activity.
“Old folk remedies are just superstition with no real basis.”
Mempelas is the counter-example. Healers across separate cultures independently used it for diabetes — and the lab later found compounds that activate the same metabolic pathway as the leading diabetes drug. That is not superstition; it is empirical observation that arrived before the explanation. The honest position respects the traditional knowledge and demands modern proof — not one at the expense of the other.
“If the lab confirmed the mechanism, the science is settled.”
Confirming a mechanism in a cell or a rat is a crucial step, but it is not the finish line. Many compounds that work beautifully in a dish fail in human trials — wrong dose, poor absorption, unexpected side effects. Mempelas has cleared the early hurdles impressively. It has not yet faced the one that matters most: a proper human clinical trial. Genuinely promising; not yet proven.
How It Was Traditionally Used
These reflect documented traditional practice and are presented for completeness, not as dosing instructions.
The most common form: leaves (and sometimes stems or roots) boiled in water, the liquid cooled and drunk. The aqueous extract is also the form that showed anti-hyperglycaemic activity in the animal research — the traditional method and the studied method align.
Different parts — leaves, stems, roots — were used for different complaints across the region. Leaves featured most in the diabetes and blood-pressure preparations.
Dried rough leaves as natural sandpaper for finishing carved wood — the everyday workshop role that gave the plant its name and identity.
Questions Worth Asking Your Doctor
Mempelas is a conversation to have with a professional — not a decision to make alone
- “I’ve read that Tetracera scandens has documented blood-sugar-lowering activity in lab and animal studies. Given my current diabetes medication, is there any interaction or hypoglycaemia risk I should be aware of?”
- “If I want to include traditional herbs, how should we monitor my blood sugar so we’d catch any additive effect early?”
- “Are there reasons in my specific health profile — kidney function, other medications — that I should avoid bioactive herbs altogether?”
- “What’s the safest way to explore this without ever replacing my proven medication?”
The traditional knowledge was real. Healers across the region used mempelas for diabetes, gout, and high blood pressure for centuries — and modern chemistry has now found mechanisms that plausibly explain all three: AMPK activation for blood sugar, xanthine oxidase inhibition for gout, supporting cardiovascular and anti-inflammatory activity for the rest.
The mechanism is genuinely impressive. A jungle leaf whose compounds switch on the same metabolic pathway as exercise and metformin is not a small finding. The convergence between folk use and laboratory mechanism is exactly what makes mempelas worth knowing about.
But the evidence stops at the cell and the rat. There are no completed human clinical trials, no established safe dose, no proof of long-term safety. Everything beyond the mechanism is still an open question — and the blood-sugar activity that makes it interesting is the same activity that makes carelessly combining it with medication risky.
So hold both truths at once. Mempelas is a remarkable example of traditional knowledge the science is catching up to — and it is not a proven, dose-defined, human-tested treatment you should substitute for medicine. Respect the leaf. Respect the gap. Ask the better questions. That is the whole of what AJHerbs is here to give you.
References & Sources ↓
- Myung SL, Chung HK, Duc MH et al. (2009). Genistein-Derivatives from Tetracera scandens Stimulate Glucose-Uptake in L6 Myotubes. Biological & Pharmaceutical Bulletin 32(3):504-508.
- Anti-hyperglycemic activity of the leaves of Tetracera scandens Linn. Merr. in alloxan-induced diabetic rats. Journal of Ethnopharmacology (2010).
- Investigation of α-Glucosidase Inhibitory Metabolites from Tetracera scandens Leaves by GC-MS Metabolite Profiling and Docking Studies. PMC7072363 (2020).
- Nguyen MT et al. (2004). Xanthine oxidase inhibitory activity of Vietnamese medicinal plants. Biological & Pharmaceutical Bulletin 27:1414-1421.
- Phytochemical Investigation of the Leaves of Tetracera scandens Linn. and In Vitro Antidiabetic Activity of Hypoletin. Springer (IIUM).
- Phytochemicals and biological activity of Tetracera scandens Linn. Merr. (Dilleniaceae): A short review (2020).
- Flavonoids from Tetracera indica Merr. induce adipogenesis and exert glucose uptake activities in 3T3-L1 adipocyte cells. PMC5577826 (2017).
- Plant Resources of South-East Asia No. 12: Medicinal and Poisonous Plants; MyBIS (Malaysia Biodiversity Information System).
- Note: this article reports a promising but preliminary body of evidence. Where findings are from cell-culture or animal studies, that is stated. No human clinical trial evidence currently exists.